Research Articles (Paraclinical Sciences)

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South African medicinal plants as natural defences against bovine mastitis
Masuku, Nelisiwe P.; Erhabor, Chinelo Rosemary; Mokoka, Tsholofelo Abednego; Ramagoma, Rolivhuwa B.; Maqolo, Kholosa; McGaw, Lyndy Joy (Elsevier, 2025-09)
Bovine mastitis is an inflammation of the mammary parenchyma that affects dairy cattle. It is a worldwide disease commonly caused by Staphylococcus aureus, Streptococcus spp., Escherichia coli, and other microorganisms. Antibiotics are used to treat and manage bovine mastitis; however, this is complicated by the emergence of multiple drug-resistant strains. Currently, medicinal plant extracts and phytochemicals are promising possibilities in the quest for effective treatment strategies to mitigate the effects of antibiotic resistance and drug residues contaminating dairy products and the environment. This review aims to synthesize the current understanding of the potential of South African medicinal plants against bovine mastitis-causing pathogens in an effort to guide future research. The objectives were to identify South African plant species with antimicrobial efficacy against pathogens implicated in causing bovine mastitis, as well as relevant biological activities. The literature was collected from various online research databases, books, dissertations and theses. We identified 28 plant species from 12 families with good to exceptional antibacterial activities. The most studied plants were Searsia lancea, Erythrina caffra, Indigofera frutescens, Antidesma venosum and Elaeodendron croceum. Various plant species had a range of pharmacological activities such as antibiofilm formation, anti-quorum sensing, and anti-inflammatory efficacy. Few studies reported the isolation of compounds responsible for activity. Owing to the complex nature of the pathogens responsible for mastitis and the corresponding host response, plant-based formulations with multiple beneficial effects may yield promising agents in reducing the incidence of persistent mastitis infections. Further targeted investigation is warranted on selected plant species with potential to prevent and treat bovine mastitis.
Efficacy of three weed species against bovine mastitis-causing bacteria, and their anti-inflammatory, antioxidant and cytotoxic activities
Erhabor, Rosemary Chinelo; Dzoyem, Jean Paul; Petzer, Inge-Marie; McGaw, Lyndy Joy (Elsevier, 2025-11)
Bovine mastitis is a significant infectious disease in the dairy industry, and it tends to re-occur owing to antibiotic resistance. Management of the condition using complementary treatments could reduce the economic burden caused by the disease. Different extracts (methanol, ethanol, acetone, dichloromethane: methanol, hot and cold water) of three species commonly growing as weeds in South Africa (Leonotis leonurus, L. nepetifolia and Tithonia rotundifolia) were investigated. The plants are reported to be used traditionally to treat breast swelling, inflammation, abscesses, wounds, pains, fever, and muscular cramps. The antibacterial, antibiofilm, quorum quenching, anti-inflammatory, antioxidant activity and cytotoxicity of the different extracts were investigated. The antibacterial activity against six Staphylococcus aureus species isolated from clinical cases of bovine mastitis, and two Staphylococcus reference strains (S. aureus ATCC 29213 and S. epidermidis ATCC 35984) was tested. Quorum quenching activity using Chromobacterium violaceum as a model was conducted. At the same time, antibiofilm assays were carried out using crystal violet and 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium (INT) assays to determine the antiadhesion and biofilm inhibitory activity, as well as the viability of bacterial cells after treatment with the plant extracts. The antioxidant activity was investigated using in vitro chemical assays. Inhibition of the 15-lipoxygenase enzyme (15-LOX) and nitric oxide (NO) release from activated macrophages was used to determine the anti-inflammatory potential of the extracts. The cytotoxicity of the extracts was assessed via a tetrazolium-based colorimetric reduction assay against Vero African green monkey kidney and bovine dermis cell lines. The extracts showed moderate to good inhibition of bacterial growth with minimum inhibitory concentration (MIC) values ranging between 0.02 and 2.5 mg/mL. The extracts of Leonotis leonurus had the best anti-adhesion and biofilm inhibitory activity against the pathogens. They inhibited the metabolic activity of the bacterial cells at different times, with the most active resulting in 100 % inhibition. Eight extracts had excellent anti-quorum sensing ability with violacein inhibition ≥50 % at all concentrations (IC50 = 0.08 to 2.5 mg/mL). Most of the extracts had excellent activity against the 15-LOX enzyme compared with the positive controls, as well as good to moderate NO inhibition. The extracts were less toxic to the bovine dermis cells than to the Vero cells. The antibacterial effects, little to no cytotoxicity at low concentrations and the promising antibiofilm and quorum quenching results in this study provide motivation for further investigation of the extracts as potential candidates for development of a novel therapy for the management of pathogenic traits in organisms implicated in causing mastitis.
In vitro biological activities of selected plant species used in traditional livestock medicine in Zimbabwe : a useful step in the quest for novel therapeutic options against some bacterial infections of economic importance in goats
Munengwa, Anderson; Nyahangare , Emmanuel T.; Jambwa, Prosper; Mugoti , Alban; Mandara, Steven; Dzviti, Melody (Elsevier, 2025-12)
The search for novel antibacterial agents in livestock is prompted by the scourge of antibiotic resistance and costly nature of conventional drugs. Potential antibacterial alternatives should be cheap, safe and therapeutically active. Biological activities of five selected ethnobotanical plant species (Euclea divinorum Hiern., Kigelia africana (Lam.) Benth., Senna singueana (Delile) Lock, Cassia abbreviata Oliv. and Erythrina abyssinica Lam.) were investigated. The serial microdilution assay was used to evaluate antibacterial activities of extracts against six bacterial strains (Salmonella Typhimurium, Clostridium perfringens, Corynebacterium pseudotuberculosis, Salmonella Enteritidis, Escherichia coli and Staphylococcus aureus). Antioxidant and anti-lipoxygenase activities were evaluated using the free radical scavenging and ferrous oxidation-xylenol orange assays, respectively. The tetrazolium-based colorimetric (MTT) reduction assay was used to assess cytotoxicity of extracts. Acetone extracts of S. singueana and E. abyssinica had broad spectrum antibacterial activity (MIC < 100 µg/ml; total activity > 1000 mg/g). All acetone extracts had substantial antibiofilm activity against at least one of the tested bacterial strains (≥ 50 % inhibition). Acetone and DCM/methanol extracts of S. singueana and the DCM/methanol extract of E. abyssinica had the best antioxidant capacity. The LC50 values were similar to those of the positive controls (P > 0.05). The best anti-lipoxygenase activity was shown by acetone extracts of E. divinorum (LC50 = 4.67 ± 0.08 µg/ml). All extracts tested were less toxic than the control anticancer agent, doxorubicin (P < 0.05). In conclusion, acetone extracts of S. singueana, E. abyssinica and E. divinorum had a cocktail of therapeutic activity and could be leads in the development of useful livestock antibacterial drugs.
Ethnomedicinal use and cytotoxicity of medicinal plants used in soft porridge for infant health issues in Vhembe District, South Africa
Shikwambana, Zanele Geraldin; Ramashia, Shonisani Euginia; Tshisikhawe, Milingoni Peter; Naidoo, Vinny; Nethathe, Bono (Elsevier, 2027-01)
ETHNOPHARMACOLOGICAL RELEVANCE : In South Africa, the Vhavenda tribe traditionally feed infants Tshiunza/Khongoḓoli, a very light, warm, and soft porridge prepared with medicinal plant concoctions. This practice is believed to prevent, manage, or treat various diseases and provide nutritional support. AIM OF THE STUDY : The aim of the study was to document the medicinal plants administered through soft porridge, including preparation methods and dosages for infant illnesses, among the Vhavenda tribe of Vhembe District, South Africa, and to determine the cytotoxicity of selected medicinal plants. MATERIALS AND METHODS : Semi-structured interviews were conducted with caregivers, elderly women, and traditional healers. Cytotoxicity assay of five selected medicinal plants was conducted using the MTT assay on African monkey kidney cells (Vero cells). RESULTS : Seventy-two medicinal plants were documented, of which 38 were used in the preparation of Tshiunza/Khongoḓoli. Roots were the most frequently used plant part, and the dominant preparation method involved soaking plant material in water and using the extract to make the soft porridge. These plants were commonly used to treat fontanelle-related illnesses and stomach problems. Combretum molle R.Br. ex G.Don. and Gymnosporia buxifolia (L.) exhibited low cytotoxicity with IC50 of 476.7559 and 276.4863 μg/mL, respectively. CONCLUSION : This study provides novel ethnomedicinal evidence on medicinal plants administered through soft porridge, a culturally important infant-feeding practice among the Vhavenda people. However, the cytotoxicity of Combretum molle R.Br. ex G.Don. and Gymnosporia buxifolia (L.) underscores the need for further toxicological evaluation of medicinal plants used in infant foods, especially for infants under 3 months old, whose physiological and metabolic systems are still developing. HIGHLIGHTS • In the Vhembe District (South Africa), Vhavenda communities rely heavily on traditional medicine for infant illnesses. • Thirty-eight (38) medicinal plant species were administered with soft porridge. • Plants were commonly used for stomach problems, fontanelle-related illnesses, and to improve the immune and digestive system. • The plants were administered to infants as young as 0-3 months old. • Combretum molle R.Br. ex G.Don. Gymnosporia buxifolia (L.) showed low cytotoxicity.
Mechanisms of anti-inflammatory and antioxidant activity of extracts of selected South African Celastraceae and Crassulaceae plant species with known efficacy against bovine mastitis bacterial pathogens
Ogbuadike, Eucharia Chika; Nkadimeng, Sanah Malomile; Khunoana, Edward Thato; Igwe, Chima C.; Qekwana, Daniel Nenene; Petzer, Inge-Marie; McGaw, Lyndy Joy (Wiley, 2026-02-23)
Inflammation, a complicated reaction to microbial infection or injury, promotes healing under normal circumstances. However, when it becomes uncontrolled, it can result in cell damage or even death. Inflammation is a major feature of infectious mastitis in cattle as well as in humans, with substantial health, welfare and financial challenges. Uncontrolled inflammation is commonly accompanied by excess reactive oxygen species (ROS), which may be harmful. Ethanol and acetone leaf extracts of Bryophyllum pinnatum (Lam.) Oken (synonym: Kalanchoe pinnata (Lam.) Pers.), Kalanchoe gunniae Gideon F. Sm. and Figueiredo, Maytenus undata (Thunb.) Blakelock and Maurocenia frangula Mill. were investigated for their antioxidant and anti-inflammatory activities. In previous work, these plant species had promising antimicrobial activity against mastitis-causing bacteria. In this study, anti-inflammatory activity of the extracts was investigated in terms of their ability to inhibit the action of the enzymes implicated in inflammation, namely 15-lipoxygenase (15-LOX) and cyclooxygenase (COX). Their ability to inhibit the production of nitric oxide (NO) by lipopolysaccharide (LPS)-activated RAW 264.7 macrophages was also tested. Using ELISA kits, the effect of the plant extracts on the regulation of cytokine production was determined. Evaluation of antioxidant activity was done using electron reducing 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and radical scavenging 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. The best 15-LOX inhibitory activity with IC50 values of 1.25 and 2.03 μg/mL for acetone and ethanol extracts, respectively, was observed with K. gunniae extracts. The best NO inhibition of 80.48% and cell viability of 96.75% was produced by the acetone extract of B. pinnatum at the highest concentration (100 μg/mL). Significant inhibition of COX-2 was observed with both extracts of K. gunniae and B. pinnatum. In this study, the highest inhibitory activity against proinflammatory cytokines and enhanced production of anti-inflammatory cytokines were observed with extracts of B. pinnatum. Kalanchoe gunniae extracts had the best antioxidant activity with IC50 values ranging from 0.06 to 0.42 μg/mL. This research highlights the therapeutic potential of the selected plant species in managing inflammation and oxidative stress associated with bacterial mastitis.
The ethnobotanical use and potential of southern African Menispermaceae species in combating concurrent tuberculosis and helminth infections
Akande, Rebecca Temitope; Kayoka-Kabongo, Prudence Ngalula; McGaw, Lyndy Joy (Elsevier, 2026-06)
Species of the Menispermaceae family have a variety of medicinal uses globally, especially in African traditional medicine. In southern Africa, many Menispermaceae species are widely used for therapeutic purposes. This review is an assessment of the traditional uses, biological, phytochemistry and toxicological effects of the southern African Menispermaceae species investigated from 1980 to 2022 with particular emphasis on the concomitant use of some species for treating helminth infections and tuberculosis. A broad electronic search was conducted using databases such as Web of Science, Google Scholar, Scopus, WorldCat Discovery, MSc and Ph.D. theses, Scifindern, Science Direct and Research gate to compile the relevant information used in this study. Cissampelos mucronata and Cocculus hirsutus are the most studied South African species. The Menispermaceae family is a rich source of bisbenzylisoquinoline alkaloids, this contributes to its extensive therapeutic efficacy in ethnomedicine. Comprehensive biological, chemical and toxicological as well as pharmacological studies needs to be conducted on the South African Menispermaceae species to verify their traditional uses and the data obtained on species of this family in other regions. In particular, the ability of some species of the family to modulate the immune system with potential effect against immune-related ailments such as parasitic helminth infection, tuberculosis or coinfections with tuberculosis require further research, as this may potentially have an effect on the pathogenesis of tuberculosis in vulnerable populations. HIGHLIGHTS • The southern African Menispermaceae species have diverse uses in ethnomedicine. • Some pharmacological effects were reported from this family. • The extensive use of Menispermaceae species in ethnomedicine is due to its alkaloidal constituents.
In vitro bioactivity of leaf extract fractions and Quercetin-3-O-rhamnoside from Combretum elaeagnoides against Staphylococcus species implicated in causing bovine mastitis
Erhabor, Rosemary Chinelo; Dzoyem, Jean Paul; Petzer, Inge-Marie; Abdalla, Muna A.; McGaw, Lyndy Joy (MDPI, 2026-02)
Globally, antibiotic resistance is a growing concern, motivating the search for alternatives. Bovine mastitis is an inflammatory disease of the udder caused by various microorganisms, many of which are resistant to various antibiotics, impacting the quality of dairy products and farmer income. In this study, the in vitro bioactivity of the methanol leaf extract, fractions (ethyl acetate (CeEtOAc), butanol (CeBuOH), hexane (CeHx), dichloromethane CeDCM), and water (CeAq), and a purified compound, quercetin-3-O-rhamnoside isolated from the CeEtOAc fraction of Combretum elaeagnoides Klotzsch, were investigated against six Staphylococcus aureus (S. aureus) strains isolated from clinical cases of bovine mastitis and two reference ATCC strains (S. aureus ATCC 29213 and S. epidermidis ATCC 35984). Methods used for assessing bioactivity included serial microdilution for antibacterial efficacy, crystal violet staining and p-iodonitrotetrazolium (INT) metabolic assays for anti-biofilm activity, and a microdilution assay for anti-quorum-sensing potential. The anti-inflammatory assays included 15-lipoxygenase enzyme inhibition and nitric oxide assays. Cytotoxicity screening was conducted using a tetrazolium-based colorimetric assay against bovine dermis cells. The extracts and fractions exhibited moderate to good antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.07 to 1.04 mg/mL, with the ethyl acetate fraction being the most effective. The anti-biofilm activity of the extract, fractions, and isolated compound (quercetin-3-O-rhamnoside) varied at time zero (T0), with inhibition ranging from 3% to 100%. The CeDCM and CeEtOAc fractions exhibited the most potent anti-biofilm effects after 24 h, with inhibition ranging from 24% to 91%. The extracts and fractions exhibited significant inhibition (>50%) of biofilm within the incubation times (T0–T48), and quercetin-3-O-rhamnoside alone had >60% inhibition at 48 h. The CeEtOAc fraction had the most significant anti-quorum-sensing activity (IC50 < 0.08 mg/mL). The methanol extract and fractions exhibited significant anti-inflammatory activity, inhibiting nitric oxide production (IC50: 7–26 µg/mL). In contrast, the CeAq, CeHx, and CeDCM fractions showed the best inhibitory activity against the 15-lipoxygenase enzyme (IC50 = 3–4 µg/mL). The extracts and fractions were non-cytotoxic to bovine dermis cells (LC50 = 0.88–1 mg/mL). Combretum elaeagnoides extract and its fractions are recommended for further investigation as potential herbal treatments for the management of mastitis and its symptoms.
In vitro evaluation of antiproliferative and cytotoxic effects of Annona stenophylla (Engl. & Diels), Strophanthus petersianus (Klotzsch), and Synadenium glaucescens (Pax) extracts against MCF-7 breast cancer and Vero cell lines
Nhamussua, Roberto; Ibrahim, Mohammed Auwal; Mwakalesi, Alinanuswe; Mabiki, Faith; McGaw, Lyndy Joy (Elsevier, 2026-09)
Please read abstract in the article.
Lymphoplasmacytic gastritis in cheetahs under human care : a bile acid-driven gastroenteropathy arising from disrupted feeding ecology
Tordiffe, Adrian Stephen Wolferstan (MDPI, 2026-05-13)
Lymphoplasmacytic gastritis (LPG) is one of the most prevalent chronic diseases affecting cheetahs (Acinonyx jubatus) under human care, yet its underlying cause remains unresolved. Gastric inflammation occurs in the majority of adult captive cheetahs but is uncommon in free-ranging populations, suggesting that management-related factors contribute to disease pathogenesis. This review proposes that LPG represents a bile acid-driven gastroenteropathy arising from disruption of the natural feeding ecology of the cheetah. In free-ranging systems, cheetahs consume large episodic meals separated by prolonged fasting intervals and ingest whole-prey containing substantial connective tissue and collagen. In captivity, feeding patterns are typically characterized by smaller, more frequent meals and diets dominated by lean skeletal muscle with reduced structural complexity. I hypothesize that this mismatch alters gastric emptying kinetics, disrupts coordinated pancreatic and biliary secretion, and destabilizes fat digestion. Inefficient lipolysis may impair micelle formation and promote bile acid mislocalization within the gastrointestinal tract, increasing mucosal exposure to hydrophobic bile acids capable of inducing chemical epithelial injury. Within this framework, lymphoplasmacytic gastritis is interpreted as a secondary inflammatory reaction to chronic bile acid-mediated mucosal stress rather than a primary immune-mediated disorder. The model also provides a mechanistic explanation for the frequent coexistence of gastritis with fat and protein maldigestion in captive cheetahs. Differential responses to antimicrobial therapy, glucocorticoids, sulfasalazine, pancreatic enzyme supplementation, and bile acid-modifying agents are broadly consistent with this proposed mechanism. Recognition of LPG as a physiologically driven gastroenteropathy has important implications for management, emphasizing restoration of feast–fast feeding patterns, inclusion of collagen-rich carcass components, and targeted modulation of bile acid composition and signaling. SIMPLE SUMMARY : Chronic stomach inflammation is one of the most common diseases affecting cheetahs living under human care, yet the underlying cause remains poorly understood. This article proposes that the disease may develop because captive feeding practices differ substantially from the natural feeding behavior of wild cheetahs. Wild cheetahs consume large whole-prey meals separated by prolonged fasting periods, whereas captive cheetahs are often fed smaller meals more frequently and may receive diets low in connective tissue and collagen. The article suggests that these differences may disrupt normal digestion and bile acid movement within the gastrointestinal tract, leading to chemical irritation of the stomach lining and chronic inflammation. This framework may help explain why digestive problems frequently occur alongside gastritis in captive cheetahs and why many current treatments provide inconsistent results. If correct, the hypothesis could improve long-term management by encouraging feeding practices and diet structures that more closely resemble the natural biology of the species.
Immobilisation and clinical effects of four drug combinations used to chemically capture white rhinoceros (Ceratotherium simum)
Ndunda, Matt M.; Buss, Peter Erik; Gleed, Robin D.; Donaldson, Ashleigh Claire; Leiberich, Marion; Hooijberg, Emma Henriette; Snelling, Edward P.; Boesch, Jordyn Marie; Meyer, Leith Carl Rodney (Medpharm Publications, 2026-03)
Etorphine is an ultra-potent opioid used to immobilise white rhinoceros (Ceratotherium simum) in the field, but it can also cause extensive metabolic and cardiorespiratory derangements. To potentially reduce the severity of these derangements, etorphine is combined with synergistic drugs including medetomidine (an alpha-2 adrenoreceptor agonist), midazolam (a benzodiazepine agonist), or azaperone (a butyrophenone drug). The potentiation effects of these synergistic drugs are believed to reduce induction times and excitement, induce muscle relaxation, and improve immobilisation quality and safety. To test the benefits of these synergistic drugs, eight healthy, wild-caught boma-housed white rhinoceros (sub-adult males) were used in a repeated-measures randomised cross-over study. Each rhinoceros was immobilised with four treatments: etorphine only (control), etorphine + azaperone (azaperone), etorphine + medetomidine (medetomidine), and etorphine + midazolam (midazolam). Butorphanol was administered intravenously after 12 min of immobilisation in all treatments. First signs of drug effects, immobilisation induction times, immobilisation quality, tremor scores, rectal temperature, heart and respiratory rates, and peripheral arterial oxygen-haemoglobin saturation, were compared between and within treatments. All four treatments effectively immobilised rhinoceros, however the addition of azaperone, medetomidine and midazolam were associated with significantly shorter induction times compared to the etorphine-only. All treatments initially caused severe muscle tremors, hypopnea, hypoxaemia, and tachycardia (except for medetomidine). The administration of butorphanol partly corrected most of these derangements. Our study shows that the synergistic drugs effectively speed up induction into immobilisation. However, they provide little other physiological or clinical benefit over etorphine-only. Butorphanol remains an important ancillary treatment when administering these drug combinations in rhinoceros.
Pathological findings in 61 free-ranging leopards (Panthera pardus) from the Greater Kruger National Park, South Africa. Part Two : non-parasitic conditions
Mitchell, Emily P.; De Klerk-Lorist, Lin-Mari; Buss, Peter Erik; Reininghaus, Bjorn; Bengis, Roy (Elsevier, 2026-07)
Few reports on diseases in free-ranging leopards (Panthera pardus) are available. A retrospective review of tissues from free-ranging leopards from the Greater Kruger National Park, South Africa, that were submitted for histological examination was conducted. Non-parasitic lesions were recorded in 61 free-ranging juvenile to elderly leopards. They had died or been euthanized between 1998 and 2023. Parasitic conditions in these leopards have been reported separately. Traumatic injury was common (41%). Respiratory tract conditions included pneumoconiosis (36%) and tuberculosis (23%), presumed to be due to Mycobacterium bovis infection in this endemic area. Classic granulomata were not present in the paucibacillary histiocytic lung lesions. Coronary arteriosclerosis, present in 36% of leopards, may be age-related, together with glomerulopathy (26%), adrenal gland corticomedullary fibrosis (8%), thyroid gland epithelial lipofuscinosis (n = 3), inactive ovaries (n = 2), obsolescent glomeruli (n = 1), pancreatic nodular hyperplasia (n = 1), bile duct carcinoma (n = 1) and cutaneous fibroma (n = 1). Mild tissue inflammation including interstitial nephritis (34%) and periportal hepatitis (28%) was often recorded. Tuberculosis and rabies were the only diagnosed infectious diseases recorded in this series of leopards, 85% of which were euthanized due mainly to the perceived risk they posed to humans rather than clinical illness. Apart from these diseases and trauma, most of the lesions noted in these animals were likely incidental in free-ranging animals. Lack of information on population dynamics and disease status in the free-ranging leopard population means that the true prevalence of these conditions is not known.
Uterine squamous cell carcinoma in a 10-year-old Vietnamese pot-bellied pig (Sus scrofa domesticus)
Janse van Rensburg, Le-lani; Tagwireyi, Whatmore Munetsi; Magadu, Rungano; Grobler, Miemie; Avenant, Lida; Brown, Geoffrey James; Hoepner, Nicolene (BioMed Central, 2026-05)
A 10-year-old intact female Vietnamese Pot-bellied pet pig (Sus scrofa domesticus) presented to the Production Animal Clinic at the Onderstepoort Veterinary Academic Hospital in South Africa (OVAH) with recurrent vaginal bleeding as the primary complaint. Clinical examination, vaginoscopy with vaginal cytology and abdominal ultrasound localised the haemorrhage to the reproductive tract and initially revealed a pyometra. After the failure of medical treatment with a luteolytic agent, anti-inflammatory and antibiotics, an exploratory laparotomy was performed, during which two macroscopical uterine lesions were observed. Histopathology identified the lesions as a squamous cell carcinoma infiltrating the endo- and myometrium and a focal endometrial polyp. An ovariohysterectomy resulted in a full recovery. No evidence of pulmonary metastases was found.
Epidemiology of a Salmonella outbreak at a South African equine veterinary academic hospital between October and December 2016
Shaik, Tahiyya; Annandale, Henry; Qekwana, Daniel Nenene (MDPI, 2026-04)
Salmonellosis in equine medicine is of clinical and public health significance. There are no published studies on nosocomial Salmonella outbreaks in South Africa. Electronic medical records of patients admitted to the equine veterinary academic hospital between October and December 2016 were reviewed. The SOPs for hospital infection, prevention and control measures pre-, during, and post-outbreak, and possible zoonotic transmission were collected using structured questionnaires. Salmonella was isolated from 25% of patients, including a white rhinoceros. Salmonella Typhimurium was the most common serotype isolated from patients (42%), stables (72.2%), and clinic areas (84%). Hospitalisation duration (p = 0.017) and repeated faecal samples (p = 0.011) were significantly associated with Salmonella infection, but there was no association between syndromic clinical presentation of salmonellosis and Salmonella infection. Four students reported symptoms of salmonellosis, and one was hospitalised with a positive faecal culture. The importance of heightened biosecurity around high-risk patients cannot be over-emphasised. A continuous surveillance programme of both patients and the environment is essential to identify early lapses in infection prevention and control measures, and patient care should be optimised to reduce the length of hospitalisation. Syndromic clinical signs of salmonellosis cannot always be used to identify Salmonella-positive patients as previously suggested, emphasising the importance of a surveillance programme. SIMPLE SUMMARY : In this study, we investigated a Salmonella outbreak at a South African equine veterinary academic hospital between October and December 2016, addressing the lack of local data on the epidemiology of Salmonella in equine referral hospitals. The aim was to identify animal-, environmental-, and management-related risk factors associated with infection and to evaluate infection prevention and control practices. Hospital records and laboratory results of admitted patients were reviewed, and environmental sampling and questionnaires were analysed. Salmonella was isolated from a quarter of hospitalised patients, including a white rhinoceros, with Salmonella Typhimurium the predominant serotype. The number of faecal samples collected, and the duration of hospitalisation were significantly associated with infection, whereas syndromic presentation alone was not a reliable predictor of infection. Salmonella was frequently recovered from stables and other hospital areas, with Salmonella Typhimurium again predominating, indicating environmental contamination. Four students reported clinical signs consistent with salmonellosis, one of whom had a positive faecal culture, providing evidence of zoonotic transmission. The findings emphasise the need for continuous surveillance, strict biosecurity protocols, optimisation of patient management to reduce hospitalisation duration, and ongoing staff and student education to mitigate equine and zoonotic Salmonella transmission, thereby improving both animal and public health outcomes.
Anti-inflammatory and antioxidant activities and nitric oxide inhibition of acetone extracts of three Algerian Saharan medicinal plants in LPS-stimulated RAW 264.7 cells
Lakas, Manal; Sifi, Ibrahim; Eloff, Jacobus Nicolaas (Elsevier, 2026-06)
INTRODUCTION : This study investigates the anti-inflammatory and antioxidant activities of acetone extracts from Anvillea radiata, Marrubium deserti, and Asphodelus tenuifolius using a multidisciplinary approach that integrates phytochemical screening, biochemical assays, LC-MS/MS metabolite profiling, and in silico analysis. METHODS : The anti-inflammatory activity was examined by 15-lipoxygenase (15-LOX) inhibition and nitric oxide (NO) reduction and viability in LPS-stimulated RAW 264.7 cells. The metabolite profiles of the extracts were determined using advanced LC-MS/MS techniques, followed by molecular docking analysis. RESULTS : Quantitative analysis of phenolic and flavonoid compounds in the extracts indicated that M. deserti had the highest content. This correlated well with its strong antioxidant performance in DPPH, ABTS, and FRAP assays. All extracts had significant 15-LOX inhibition, with A. radiata being the most potent (IC50 = 4.15 ± 0.03 µg/mL). A. tenuifolius extracts had the highest NO inhibition (77.02 % at 100 µg/mL). Cell viability remained above 75 % at this concentration for all extracts, indicating low cytotoxicity. LC-MS/MS analysis identified several key metabolites, including coumaric acid, caffeic acid, and chrysin, which are known for their anti-inflammatory activities. Molecular docking studies showed strong binding affinities of selected metabolites to the human lipoxygenase (hydroxycoumarin (-7.1 kcal/mol), caffeic acid (-6.9 kcal/mol) lawsone (-6.8 kcal/mol) and coumaric acid (-6.6 kcal/mol)), outperforming standard inhibitors quercetin (-4.8 kcal/mol) and zileuton (-6.0 kcal/mol). CONCLUSION : ADMET predictions further confirmed the potential safety and drug-likeness of these compounds. Together, these results point to the therapeutic potential of these Algerian Saharan species as promising sources of natural compounds with anti-inflammatory properties. HIGHIGHTS • Highlights the therapeutic potential of three Algerian Saharan medicinal plants. • Investigates the anti-inflammatory and antioxidant activities of acetone extracts. • All plant extracts inhibit 15-lipoxygenase. • Highest inhibition of nitric oxide (NO) with cell viability indicating a lack of cytotoxicity.
β-Lactam antibiotics and β-lactamases : historical perspectives and a review of β-lactamase inhibitors derived from natural products
Moyo, Phanankosi; Albert, Ikhane O.; Hlungwani, Neo; Sibanda, Thulani; Lumu, Perfoy; Khorommbi, Ndivhuwo Kevin; Kaur, Gurleen; Calvopina Tapia, Karina; Siegwart, George; Buabeng, Nana Kwaku; Danquah, Cynthia A.; McGaw, Lyndy Joy; Cosa, Sekelwa; Schofield, Christopher J.; Maharaj, Vinesh J. (Royal Society of Chemistry, 2026)
The history of β-lactam antibiotics and, subsequently, β-lactamase inhibitors highlight the indispensable role of natural products in modern medicine. The isolation and testing of β-lactam bearing natural products led to world-changing therapeutic breakthroughs, yielding efficacious, safe, and cost-effective medicines that are still widely used today. The scientific triumph of β-lactams was, however, followed by a period of reduced research into new antibiotics, during which time bacterial pathogens acquired multiple mechanisms of resistance. The available evidence suggests that this situation is not irretrievable – whereas insufficient medicinal chemistry is currently being carried out to enable a renaissance in antibiotic development, our molecular understanding of antimicrobial modes of action and resistance mechanisms has improved dramatically. The history of β-lactams and many other drug classes suggests that natural product-based approaches will be critical in the future. Here, we summarise the history of β-lactams, focusing on natural product science. We then examine historical and recent efforts to identify new types of β-lactamase inhibitors using natural product-based screening approaches. We conclude by providing a perspective on how we can most efficiently discover β-lactamase inhibitors from microbial and plant-derived natural products.
A critical insight of African ethnoveterinary research : a multi-database bibliometric review on trends and patterns from 2001 to 2024
Aremu, Adeyemi Oladapo; Omogbene, Temitope Olorunyomi; McGaw, Lyndy Joy; Masondo, Nqobile Andile (Elsevier, 2026-08)
ETHNOPHARMACOLOGICAL RELEVANCE : In Africa, ethnoveterinary medicine (including the use of botanicals) often serves as the dominant source of affordable and accessible means for managing animal health and well-being, particularly among resource-poor households in local communities. An understanding of the historical versus prevailing trends and patterns remain essential to drive the maturation of African ethnoveterinary research and to bridge the gap between Indigenous knowledge and scientific inquiry. AIM OF THE STUDY : This study entails a comprehensive scientometric review to map the research landscape of ethnoveterinary practices in Africa, focusing on the use of medicinal plants for animal health management. The analysis aims to identify historical trends, thematic evolution, influential contributors, and geographic patterns in the field from 2001 to 2024. METHODS : A bibliometric approach was applied, leveraging data from Scopus, Web of Science, and Dimensions (n = 190 articles). Literature retrieval was based on structured search strings targeting plant-based remedies in African ethnoveterinary context. Data consolidation, cleaning, and analysis were performed via R/Bibliometrix, encompassing citation dynamics, authorship productivity, institutional contributions, keyword co-occurrence, and thematic evolution. RESULTS : The research field demonstrated steady growth (5.92% annual rate), with Nigeria (87 citations/article), Kenya (67.3), and South Africa (48.8) emerging as leading contributors. Dominant themes included phytotherapy, medicinal plants, and livestock parasitology (e.g., Haemonchus contortus). Seminal works underscored the integration of traditional knowledge with pharmacological assessment. Despite the growth, international collaboration remains sparse (5.79% of works). Thematic shifts revealed a transition from broad ethnobotanical documentation (2001–2009) to targeted studies on plant efficacy and parasitic challenges (2018–2024). Citation peaks occurred in the early 2000s, followed by a post-2014 decline, predictably attributed to field saturation and absorption into broader veterinary domains. The need for enhanced global partnerships to amplify research impact, rigorous validation of traditional remedies, and equitable capacity-building in underrepresented regions cannot be overemphasised. Sources such as the Journal of Ethnopharmacology and Veterinary Parasitology were pivotal in disseminating research, while institutions such as the University of Pretoria drove productivity in Africa. CONCLUSION : This review underscores the maturation of African ethnoveterinary research, bridging Indigenous knowledge with scientific inquiry. Future efforts should prioritise interdisciplinary collaboration, conservation of medicinal plant resources, and policy frameworks to optimise animal healthcare in resource-limited settings. This review provides a foundational roadmap for researchers, policymakers, and funding bodies to advance the sustainability of African ethnoveterinary and the potential global relevance. HIGHLIGHTS • African ethnoveterinary research increased at 5.92% annually dominated by plant-based remedies. • Thematic evolution integrates Indigenous knowledge with modern scientific methods. • South Africa, Ethiopia, Nigeria were the leading countries in African ethnoveterinary. • More global collaboration and novel paradigms needed for future impact.
Use of essential oils in foods from animal origin to improve their safety, a systematic review
Garcia-Diez, Juan; Moura, Dina; Cenci-Goga, Beniamino Terzo; Saraiva, Sonia; Saraiva, Cristina (Elsevier, 2026-10)
Essential oils (EOs) are increasingly being investigated as "clean label" antimicrobials to control foodborne pathogens and spoilage microbiota in foods of animal origin. This systematic review synthesizes the evidence on the application of EOs and EO-derived compounds to improve the microbiological safety and shelf life of meat and meat products, fish and shellfish, dairy products, and other animal-derived foods. Across all matrices, the most frequently studied EOs include oregano (Origanum vulgare), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), clove (Syzygium aromaticum), and cinnamon (Cinnamomum spp.), as well as key components such as carvacrol, thymol, cinnamaldehyde, linalool, and allyl isothiocyanate. The reported targets encompass major foodborne pathogens (particularly Listeria monocytogenes, Salmonella spp., pathogenic Escherichia coli, including O157:H7, and Staphylococcus aureus) and dominant groups of spoilage or hygiene indicators (e.g., Pseudomonas spp., Shewanella putrefaciens, lactic acid bacteria, Enterobacteriaceae, and yeasts/molds), with results commonly expressed as delayed growth, significant logarithmic reductions, and longer refrigerated shelf life relative to untreated controls. A consistent finding across the literature is that EO performance is more reliable when delivery is designed for the product interface. Incorporation into active packaging, edible films/coatings (particularly chitosan- or protein/polysaccharide-based systems), and encapsulation or nanoemulsion strategies improve dispersion, stabilize volatile compounds, moderate sensory impact, and enable controlled release, often enhancing antimicrobial effects with lower EO loadings. In fish and seafood, combinations with modified atmosphere packaging or vacuum packaging typically extend shelf life considerably through the synergistic suppression of specific spoilage consortia and pathogens. In dairy products, films/coatings with EOs exhibit consistent antimicrobial activity against Gram-positive bacteria and remarkable antifungal efficacy against spoilage molds. Overall, EOs represent a promising natural preservation tool for foods of animal origin, and the strongest evidence supports barrier approaches that combine EOs with packaging and post-processing technologies tailored to the food matrix.
Alternative approaches and plant-based remedies for livestock health management among the Batswana of southern Africa : a review
Mpolokeng, Tswelelopele G.; Shikwambana, Ndzalama; Chakale, Mompati V.; Asong, John A.; McGaw, Lyndy Joy; Amoo, Stephen O.; Masondo, Nqobile A.; Aremu, Adeyemi O. (Wiley, 2026-04)
Due to limited access to, and the high cost of conventional veterinary services, Batswana communities often rely on ethnoveterinary practices for livestock health management. This review provides an in-depth analysis on the ethnoveterinary uses, biological properties and safety assessment of plants utilised in livestock husbandry. A systematic literature search was conducted using scientific databases, focusing on articles published from 1997 to 2024. After generating the inventory of plants with ethnoveterinary data, further search was conducted to assess the documented biological activities, safety, and phytochemicals for the recorded plants. A total of 116 plants were documented as remedies for managing nine livestock conditions. The most cited health conditions were retained placenta (81 citations), diarrhoea (65), and wounds (44). The most prominent plants were Senna italica (10 citations), Terminalia sericea (8 citations), and Ziziphus mucronata (8 citations). Approximately 52% of the 116 plants with ethnoveterinary records have empirical data on their biological effect, safety, and phytochemicals. Antimicrobial screening was the most common assay conducted (36%), which dominantly used microbial strains such as Staphylococcus spp., Pseudomonas aeruginosa, and Escherichia coli. We established the vital role of ethnoveterinary practices in Batswana livestock management and the potential of plants in sustainable veterinary care.
Antibacterial, antibiofilm and anti-quorum sensing activities of 1,2,3,5-tetrazine derivatives linked to a benzothiazole moiety
Dzoyem, Jean Paul; Tsemeugne, Joseph; Kamdem, Boniface Pone; Meupiap, Rostand Foyou; Kuate, Boris Arnaud; Mkounga, Pierre; Boyom, Fabrice Fekam; McGaw, Lyndy Joy (Public Library of Science, 2025-06-03)
A series of known tetrazine derivatives, containing benzothiazole scaffold, were prepared during the coupling reactions of selected diazotized 2-aminobenzo[d]thiazole derivatives with p-acetaminophen. The as-prepared compounds were characterized based on NMR and MS spectrometry. The antibacterial and anti-biofilm activities of the synthesized compounds were evaluated by microdilution method, whereas the anti-quorum sensing effect was carried out using assay for the inhibition of violacein formation. As a result, compounds 4a, 4b and 4c revealed minimum inhibitory concentrations and minimum bactericidal concentrations ranging from 8 to 128 µg/mL and from 32 to 256 µg/mL, respectively. Compounds 4a (52-86.5%), 4b (57.7-79.4%) and 4c (59.9-80.3%) prevented biofilm formation in all the four bacteria tested with percentages of inhibition more than 50%. The concentrations of 4a, 4b and 4c that inhibited 50% of violacein production were found to be 62.71, 28.56 and 107.45 µg/mL, respectively, thus attesting that these compounds possess anti-quorum sensing activity. Noteworthy, our previous investigation attested that these compounds are non-cytotoxic on the human mammalian cells Vero. This novel contribution demonstrates the antibacterial, antibiofilm and anti-quorum sensing activities of tetrazine-based benzothiazoles, which might be prospected as scaffolds for the discovery of efficient antibiotics with decreased risk of microbial drug resistance.
Cytotoxic activity of chemical constituents of Clerodendrum glabrum and Combretum nelsonii root extracts against selected cancer cell lines
Mabunda , Kopelo V.; Kemboi, Douglas; Famuyide, Ibukun Michael; McGaw, Lyndy Joy; Mokgalaka-Fleischmann, Ntebogeng S.; Tembu, Vuyelwa Jacqueline (MDPI, 2025-09-11)
Breast and colon cancers are leading causes of death worldwide. There is a need for improved treatment strategies. South African medicinal plants, including Clerodendrum glabrum (C. glabrum) and Combretum nelsonii (C. nelsonii), are known for their cytotoxic properties. This study aimed to isolate and characterize terpenoids and stilbenes from the roots of C. glabrum and C. nelsonii and evaluate their anticancer potential against colorectal adenocarcinoma (Caco-2) and hormone receptor-positive breast cancer (MCF-7) cell lines. Spectroscopic techniques including nuclear magnetic resonance spectroscopy (NMR) were used to characterize the isolated compounds. Repeated column chromatography of C. glabrum extract led to the isolation of ferruginol (1), royleanone (2), and β-amyrin palmitate (3). C. nelsonii extract afforded combretastatin A-1 (4), a mixture of combretastatin A-1-2′-O-β-D-glucopyranoside (5a) and combretastatin B-1-2′-O-β-D-glucopyranoside (5b). Compounds 1, 2, 4, 5a, and 5b were isolated for the first time from the plant species. C. glabrum extract showed good anticancer properties with LC50 of 1.30 × 103 µg/mL (CaCo-2) and 2790 µg/mL (MCF-7). Compound (1) exhibited high toxicity against the Caco-2 at LC50 of 24.3 µg/mL and moderate activity against MCF-7 at 48.4 µg/mL. Compound (4) and the mixture (5a and 5b) showed moderate activity against the MCF-7 at LC50 72.0 and 44.1 µg/mL, respectively. These findings highlight C. glabrum and C. nelsonii as promising sources of anticancer lead compounds.

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