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This study aimed to determine in vitro anthelmintic activity of plant extracts of eleven plant species used traditionally in South Africa to treat various disorders including symptoms related to nematode infections, and to isolate bioactive compounds from the most active plant extract. Crude plant extracts were tested on different life-cycle stages of Haemonchus contortus. The cytotoxicity of the most active extracts, fractions and compounds was evaluated on Vero cells and the most potent extract, fractions and compounds were tested for their ability to kill the parasitic H. contortus and the free-living nematode Caenorhabditis elegans. Typha capensis acetone extract had the strongest egg hatching inhibitory effect with an EC50 of 184.94 μg/mL, and this extract also halted larval development of H. contortus with an EC50 of 83.30 μg/mL compared to the positive control (albendazole) with an EC50 of 2.66 μg/mL. Typha capensis crude extract and its butanol fraction had promising anthelmintic activity against both parasitic H. contortus and free-living C. elegans. Two compounds isolated from T. capensis, namely, isorhamnetin-3-O-β-d-glucoside and isorhamnetin 3-O-rutinoside, had antioxidant activity with IC50 values of 3.16 μg/mL and 0.96 μg/mL respectively, and good anthelmintic activity against H. contortus with IC50 values of 55.61 μg/mL and 145.17 μg/mL respectively. Identification of bioactive compounds from the T. capensis crude extract supports development of this extract as a complementary or alternative treatment against haemonchosis. However, further research is necessary to confirm the anthelmintic efficacy of the plant, including in vivo studies. [ABSTRACT FROM AUTHOR]

Background: Urinary tract infections (UTIs) caused by opportunistic pathogens are among the leading health challenges globally. Most available treatment options are failing as a result of antibiotic resistance and adverse effects. Natural sources such as plants may serve as promising alternatives. Methods: Compounds were isolated from the South African weed Chromolaena odorata through column chromatography. Purified compounds were tested for antimicrobial activity using the p-iodonitrotetrazolium chloride (INT) colorimetric method, against uropathogenic Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Aspergillus fumigatus and Cryptococcus neoformans. Anti-biofilm, anti-adhesion and metabolic inhibition activities were investigated against selected strains. Safety of the compounds was determined against Vero monkey kidney, C3A human liver and colon (Caco2) cells. Results: Four compounds identified as pectolinaringenin (1), (±)-4′,5,7-trimethoxy flavanone (2), 5-hydroxy-3,7,4′-trimethoxyflavone (3) and 3,5,7-trihydroxy-4′-methoxyflavone) (4) were isolated. Minimum inhibitory concentration (MIC) varied between 0.016 and 0.25 mg/mL. Compounds 2 and 3 showed promising antimicrobial activity against E. coli, S. aureus, K. pneumoniae, A. fumigatus and C. neoformans with MIC between 0.016 and 0.125 mg/mL, comparable to gentamicin, ciprofloxacin and amphotericin B used as positive controls. Compounds 2 and 3 showed good anti-biofilm and metabolic inhibition activities against E. coli and S. aureus but weak anti-adhesion activity against the organisms. Low toxicity with selectivity indexes between 1 and 12.625 were recorded with the compounds, indicating that the compounds were rather toxic to the microbial strains and not to the human and animal cells. Conclusion: Pharmacological activities displayed by compounds 2 and 3 isolated from C. odorata and low toxicity recorded credits it as a potential lead for the development of useful prophylactic treatments and anti-infective drugs against UTIs. Although known compounds, this is the first time these compounds have been isolated from the South African weed C. odorata and tested for antimicrobial, anti-biofilm, metabolic inhibition and anti-adhesion activities. [ABSTRACT FROM AUTHOR]

Background: The rise in antimicrobial resistance in a plethora of nosocomial and opportunistic bacterial pathogens often isolated from commercial eggs, poses a serious public health concern. The existence of these contaminants may also serve as a drawback in the current efforts of improving the well-being of immunocompromised patients. The aim of this study was to determine the efficacy of plant extracts that had good activity on Escherichia coli in previous word on pathogens isolated from eggs for possible use in combating pathogens from eggs. Methods: Acetone leaf extracts of nine trees with good activities against Escherichia coli were tested for their in vitro antibacterial activity against six opportunistic bacterial isolates from commercial eggs (Stenotrophomonas maltophilia, Klebsiella pneumoniae, Salmonella serotype Typhimurium, Proteus mirabilis, Enterobacter cloacae and Escherichia coli) using a serial microdilution method with tetrazolium violet as indicator of growth. Cytotoxicity was determined using a tetrazolium-based colorimetric assay against Vero kidney cells, and selectivity index calculated. Results: The MIC values range of the different extracts against Stenotrophomonas maltophilia was 0.08-0.31 mg/ml, Klebsiella pneumonia 0.08-0.63 mg/ml, Salmonella ser. Typhimurium 0.08-0.63 mg/ml, Proteus mirabilis 0.02-1.25 mg/ml, Enterobacter cloacae 0.08-0.31 mg/ml and Escherichia coli 0.08-0.16 mg/ml respectively. Escherichia coli was the most sensitive while Proteus mirabilis was most resistant pathogen to the different test extracts, with mean MIC values of 0.08 mg/ml and 0.46 mg/ml respectively. Cremaspora triflora extracts had good activity against all the pathogenic egg isolates, with the exception of Proteus mirabilis. Maesa lanceolata and Elaeodendron croceum had the best total antibacterial activity (TAA), while generally the selectivity index of the extract was low (SI < 1). Conclusion: The exceptional activity of C. triflora extracts suggests that the plant has potential as a therapeutic agent against some members of the Enterobacteriaceae. Further pharmacological investigations may be interesting in the search for new antimicrobial leads. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance This paper presents results of an ethnobotanical survey of medicinal plants used for the management of candidiasis and related fungal infections in the Venda area, South Africa. Materials and methods Ethnobotanical data about the uses of plants were gathered from eleven rural traditional healers using semi-structured interviews. Results A total of 45 species belonging to 24 different families were identified, of which the dominant family was the Fabaceae with 13 species (28.9%) followed by the Asteraceae and Solanaceae with 3 species each (6.7 %). A total of 28 of these plant species (62.2%) have been shown to have anticandidal activity and 14 species (31%) have been recorded for antifungal uses in the literature. Amongst the 45 species recorded, 51% were trees, 33% were shrubs, and 16% were herbs. The most widely used plant species were Acacia caffra , Clerodendrum glabrum, Croton gratissimus, Elaeodendron transvaalense, Faurea saligna, Hippocratea longipetiolata, Osyris lanceolata, Richardia brasiliensis, Schkuhria pinnata, Schotia brachypetala, Spilanthes acmella, Strychnos potatorum, Vangueria infausta subsp. infausta and Withania somnifera . The plant parts mostly used in the therapeutic preparations were roots (27.7%), bark (23.2%), and a combination of roots, bark (18.7%) and leaves (14.3%). Decoctions (44.4%), infusions (20%), macerations (17.7%), burning (11.4%) and paste (6.5%) were used. Most of the herbal remedies were administered orally. The main factors threatening the conservation status of these plants are unsustainable methods of harvesting, logging for firewood, building materials and crafts. Conclusion The Venda area is rich in plant diversity and local indigenous knowledge of medicinal plants can play an important role as a model for low cost primary health care. Further studies are in progress to validate the indigenous plants recorded as traditional remedies in this area [ABSTRACT FROM AUTHOR]

The safety and effectiveness of many of the medicinal plants used in traditional medicine by rural people with little or no access to allopathic drugs is yet to be evaluated. With this in mind, Ozoroa and Searsia (previously known as Rhus ) species traditionally used in South Africa to treat microbial infections and gastrointestinal disorders were selected for in vitro evaluation of biological activities and cytotoxicity. Phenolic-enriched leaf extracts were prepared using mixture of 1% HCl acidified 70% acetone and n-hexane. The crude extract was further fractionated with solvent of different polarities. Crude extracts and fractions were tested against Staphylococcus aureus , Pseudomonas aeruginosa , Escherichia coli , Enterococcus faecalis , Aspergillus fumigatus , Candida albicans and Cryptococcus neoformans . In addition, the antioxidant potentials were determined by DPPH, ABTS, hydroxyl radical scavenging and linoleic acid peroxidation inhibition. The cytotoxic activity of the crude extracts was assayed against Vero cells. The crude extract and the various fractions had good biological activities. The most noteworthy activity is the growth inhibition of the hexane and dichloromethane fractions with MIC values as low as 19 μg/ml. The ethyl acetate and butanol fractions had moderate to low antimicrobial activities with MICs ranging from 39 to 2500 μg/ml. The polar fractions were more active against the fungal pathogens compared with the non-polar fraction. In the DPPH antioxidant assays, the active compounds were concentrated in the polar fractions (IC 50 of the crude extract ranged between 0.90 and 15.82 μg/ml). The ethyl acetate fraction was the most active (IC 50 ranging between 0.84 and 7.92 μg/ml). Although the water fraction was the most polar, the antioxidant activities were low due to the transfer of the active components into the ethyl acetate and butanol fractions. The crude extracts also had good linoleic acid peroxidation inhibition (LC 50 ranging between 13.99 and 40.45 μg/ml). Crude extracts and fractions of the Ozoroa mucronata , O. paniculosa , Searsia leptodictya , S. pendulina , and S. pentheri species tested in this study had good activities relating to diarrhoea mechanisms of pharmacological relevance. However, use of phenolic-enriched crude extracts from these plants for diarrhoeal treatment or any other diseases need to be applied with caution as most of the plant extracts were reasonably toxic against Vero cell line. A next step in the possible application of these extracts to treat diarrhoea would be to identify the bioactive and toxic compounds. [ABSTRACT FROM AUTHOR]

Background: Microbial infections and resulting inflammation and oxidative stress are common pathogenesis of gastrointestinal tract (GIT) disorders. In South Africa, several species of the genus Maytenus are used in traditional medicine to treat various infectious diseases. Most of the previous work on this genus was focused on nonpolar extracts from the root and bark. In this study, leaf extracts of polar extracts of Maytenus peduncularis, Maytenus procumbens, Maytenus senegalensis and Maytenus undata were evaluated for antimicrobial, anti-inflammatory and antioxidant activities to determine their efficacy as therapeutic agents in GIT disorders. Methods: Phenolic-enriched leaf extracts and fractions were prepared by extracting with acidified 70% methanol and solvent-solvent fractionation. The activities of the fractions against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis as well as clinical isolates of Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans were determined using a serial microplate dilution method. Antioxidant activities were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH) radical scavenging and linoleic acid peroxidation inhibitory assays. The phenolic composition as well as the cytotoxicity against Vero cell lines of the crude extracts was evaluated using various standard protocols. Results: The antimicrobial activities were concentrated in the non-polar fractions of hexane, dichloromethane and ethyl acetate (MICs 19-312 µg/ml). The crude extracts and polar fractions (butanol and water) had moderate to poor antimicrobial activity (MICs 312 to above 2500 µg/ml). The crude extracts and polar fractions had good antioxidant activity (EC50 values varied from 1.22 to 607 µg/ml, 1.71 to 312 µg/ml and 23 to 284 µg/ml for DPPH, ABTS and OH respectively. Linoleic acid peroxidation inhibition EC50 values of the crude extracts ranged between 27 and 39 µg/ml with relatively low toxicity against Vero cell lines (IC50 values 87 to 187 µg/ml). Fractionation of a crude extract with low activity could lead to fractions with more potent activity. Conclusion: This study justifies the traditional use of leaf crude extracts and fractions from these four plants to remedy gastrointestinal disorders resulting from infection, inflammation and oxidative stress complications. The study also provides rationale for the use of leaf extracts with same beneficial effects in place of unsustainable root and bark harvest. [ABSTRACT FROM AUTHOR]

Abstract: Viral infections remain a major threat to humans and animals and there is a crucial need for new antiviral agents especially with the development of resistant viruses. The hexane, dichloromethane, acetone and methanol extracts of six plant species selected for their traditional use against infections were tested for in vitro antiviral activity against canine distemper virus (CDV), canine parainfluenza virus-2 (CPIV-2), feline herpesvirus-1 (FHV-1) and lumpy skin disease virus (LSDV). All extracts were tested for their cytotoxicity using a colorimetric tetrazolium-based (MTT) assay and were tested for antiviral efficacy at concentrations below CC50 values on the various cell types used in this study. The antiviral activity of extracts was tested using virucidal and attachment assays. In the virucidal assay, extracts were incubated with virus prior to infection. The most potent inhibition was observed with the acetone and methanol extracts of Podocarpus henkelii against CDV and LSDV, which inhibited replication of the viruses by >75% at 3μg/ml with selectivity index (SI) values ranging between 12 and 45. Excellent activity was also found with the hexane extracts of Plumbago zeylanica and Carissa edulis against CDV, with the extracts reducing viral-induced CPE by 50% and 75% respectively. The hexane extract of C. edulis had moderate activity against FHV-1 with EC50 <70μg/ml and SI value <2. Only the acetone extract of P. henkelii moderately inhibited replication of LSD virus in the attachment assay, with low activity in other extracts. Of the four extracts with significant antiviral activity, two were prepared from P. henkelii. Therefore, future work will focus on isolating and characterizing the substance(s) responsible for bioactivity in extracts of this species. [Copyright &y& Elsevier]

Ethnoveterinary medicine (EVM) practices remain a common feature of South African animal husbandry, particularly in rural livestock healthcare. This review provides an update of research undertaken on South African EVM from 2009 until 2019. This review collates information and investigates trends in the increasing field of EVM research in South Africa over the last decade. A literature search was conducted using available databases including ScienceDirect, PubMed, Scopus and Google Scholar. Dissertations, theses, books and technical reports were also searched. In the past decade, ethnoveterinary surveys conducted in South Africa report the use of 139 plants from 50 families used against 21 animal diseases and conditions. Leaves, roots and bark have remained popular plant parts used for EVM. In terms of livestock species reported, the major focus was on cattle, goats and poultry. Only four of the nine provinces in the country have been surveyed. Relatively few publications reporting on ethnoveterinary surveys have originated from South Africa. These papers refer to many plants used for a variety of commonly encountered animal diseases and afflictions. With reference to recently published guidelines on conducting ethnobotanical surveys, several recommendations can be made to improve the robustness of surveys documenting the use of plants for EVM in South Africa. Image 1 [ABSTRACT FROM AUTHOR]

Background: Influenza A virus (IAV) is still a major health threat. The clinical manifestations of this infection are related to immune dysregulation, which causes morbidity and mortality. The usage of traditional medication with immunomodulatory properties against influenza infection has been increased recently. Our previous study showed antiviral activity of quercetin-3-O-α-L-rhamnopyranoside (Q3R) isolated from Rapanea melanophloeos (RM) (L.) Mez (family Myrsinaceae) against H1N1 (A/PR/8/34) infection. This study aimed to confirm the wider range of immunomodulatory effect of Q3R on selective pro- and anti-inflammatory cytokines against IAV in vitro, to evaluate the effect of Q3R on apoptosis pathway in combination with H1N1, also to assess the physical interaction of Q3R with virus glycoproteins and RhoA protein using computational docking. Methods: MDCK cells were exposed to Q3R and 100CCID50/100 μl of H1N1 in combined treatments (co-, pre- and post-penetration treatments). The treatments were tested for the cytokines evaluation at RNA and protein levels by qPCR and ELISA, respectively. In another set of treatment, apoptosis was examined by detecting RhoA GTPase protein and caspase-3 activity. Molecular docking was used as a tool for evaluation of the potential anti-influenza activity of Q3R. Results: The expressions of cytokines in both genome and protein levels were significantly affected by Q3R treatment. It was shown that Q3R was much more effective against influenza when it was applied in co-penetration treatment. Q3R in combination with H1N1 increased caspase-3 activity while decreasing RhoA activation. The molecular docking results showed strong binding ability of Q3R with M2 transmembrane, Neuraminidase of 2009 pandemic H1N1, N1 and H1 of PR/8/1934 and Human RhoA proteins, with docking energy of − 10.81, − 10.47, − 9.52, − 9.24 and − 8.78 Kcal/mol, respectively. Conclusions: Quercetin-3-O-α-L-rhamnopyranoside from RM was significantly effective against influenza infection by immunomodulatory properties, affecting the apoptosis pathway and binding ability to viral receptors M2 transmembrane and Neuraminidase of 2009 pandemic H1N1 and human RhoA cellular protein. Further research will focus on detecting the detailed specific mechanism of Q3R in virus-host interactions. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial resistance (AMR) remains an important global health issue but the gap between AMR and development of new antimicrobials is increasing. Plant extracts may have good activity per se or may be sources of effective antimicrobial compounds which can act against planktonic and/or biofilms of pathogens. We determined the antimicrobial efficacy and cytotoxicity of some under-investigated plants from the Myrtaceae family endemic to South Africa. The ability of the plant extracts to inhibit or destroy pre-formed bacterial biofilms was also determined. Methods: Based on previous preliminary in vitro screening and on chemotaxonomy, nine species from the Myrtaceae family were selected. The antimicrobial activity of the crude acetone leaf extracts was determined against six common nosocomial pathogens, namely: Gram-positive bacteria (Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) using a two-fold serial microdilution assay with p-iodonitrotetrazolium violet as growth indicator. The number of antimicrobial compounds present in extracts was determined by bioautography. Cytotoxicity of extracts was determined against Vero kidney cells using a colorimetric tetrazolium-based assay. The total antibacterial activity (TAA) in ml/g and selectivity index (LC50/MIC) of the plant extracts were calculated. A modified crystal violet assay was used to determine the antibiofilm activity of the extracts. Results: Syzygium legatii, Syzygium masukuense, and Syzygium species A had the best activities against Gram-negative and Gram-positive bacteria (MIC) values ranging from 0.04–0.08 mg/ml. Eugenia erythrophylla had the best MIC (0.02 mg/ml) against Bacillus cereus. Many extracts had relatively low cytotoxicity (LC50 > 20 μg/ml) leading to reasonable selectivity indices. Three leaf extracts (Syzygium masukuense, Syzygium species A, and Eugenia natalitia) were moderately cytotoxic (20 μg/ml < LC50 < 100 μg/ml). The plant extracts had a good capacity to reduce biofilm formation and good to poor potential to destroy pre-formed biofilms. Conclusions: The plant species examined in this study had varying degrees of antibacterial activity against bacterial planktonic and biofilm forms with some having good activity against both forms. Several of these selected species may be potential candidates for further investigation to isolate antimicrobial compounds and to determine the mechanism of activity. [ABSTRACT FROM AUTHOR]

• Six species of endophytic fungi were identified from six South African medicinal plants. • Endophytes extracts had low levels of antibacterial and antifungal activity. • Some endophytes produced useful extracellular enzymes and ability to solubilize phosphate. • Three isolates had polyketide synthase 1 gene, with potential to produce interesting polyketides. Endophytes are bacteria or fungi which live inside the host plant and participate in many biological processes without causing disease or other adverse effects. Endophytes are recognised as a rich source of secondary metabolites with potentially useful pharmacological properties. Many South African medicinal plants are highly under-investigated sources of potentially useful endophytic microbes. In this report six endophytic fungi were obtained from the leaves, stems and roots of South African medicinal plants which are known for their traditional uses and pharmacological properties. The endophytic fungi were isolated from Cotyledon orbiculata L., Psychotria zombamontana (Kuntze) Petit, Tecomaria capensis (Thunb.) Lindl., Catha edulis (Vahl) Endl. and Melianthus comosus Vahl. The crude extracts of the isolated endophytic fungi were investigated for their antimicrobial potential, extracellular enzymatic activity and phosphate solubilization. Additionally, the present study used genetic screening to assess the ability of the endophytic fungi to synthesize bioactive compounds, indicated by the presence of the polyketide synthase type 1 (PKS 1) gene. In preliminary microbial inhibition screening the fungal extracts had promising antifungal activity against Cryptococcus neoformans and Candida albicans. Furthermore, the endophytic fungus Talaromyces funiculosus displayed extracellular enzymatic activity, namely xylanase and cellulase. Five fungal strains demonstrated ability to solubilize phosphate and three strains demonstrated the presence of polyketide synthase type 1 (PKS 1) gene. It is worth considering further investigation of their bioactive secondary metabolites. [ABSTRACT FROM AUTHOR]

Abstract Ethnopharmacological relevance Inflammation is a complex mechanism employed by the body to promote healing and restoration to normal function in the event of injury. Eleven plant species were selected in this study based on their use in traditional medicine against inflammation in South Africa. Methods Hexane, acetone, ethanol, methanol and water extracts of the powdered plants were prepared and a total of fifty-five extracts were tested for their anti-inflammatory and antioxidant activities. The anti-inflammatory activity of extracts was evaluated via the 15-lipoxygenase (15-LOX) inhibitory and the nitric oxide (NO) inhibition assays using lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophages. Total flavonoid and total phenolic contents were determined. The antioxidant activity of the extracts was performed using radical scavenging DPPH (2, 2-diphenyl-1-picrylhydrazyl) and electron reducing ABTS (2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assays. Results The hexane extract of Typha capensis (TC) had good lipoxygenase inhibitory activity with IC 50 of 4.65 µg/mL, significantly (p < 0.05) higher than that of the positive control quercetin (IC 50 = 24.60). The same extract also had good nitric oxide inhibitory activity with 86% NO inhibition and cell viability of 97% at 50 µg/mL. The TC acetone extract had the best antioxidant activity with IC 50 of 7.11 and 1.91 µg/mL respectively in the DPPH and ABTS assays. Following fractionation of the TC plant material, the ethyl acetate fraction had interesting antioxidant activity and the methanol/water (35%) and hexane fractions had good 15-LOX inhibitory activity. The antioxidant and anti-inflammatory activities therefore resided in both polar and more non-polar fractions. Conclusion The acetone extract of Typha capensis and its fractions had good anti-inflammatory and antioxidant activities, supporting the medicinal use of this species against inflammation. Other species including Ficus elastica, Carpobrotus edulis, Cotyledon orbiculata and Senna italica also had good activity worthy of further investigation. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological importance: Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation. Aims: Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated. Materials and Methods: The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2''-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS+) radical scavenging and ferric reducing antioxidant power (FRAP) methods. In vitro antimicrobial activities of the extracts were determined against bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) and clinical isolates of the opportunistic fungal strains (Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans) using a serial dilution microplate method. The polyphenolic contents were quantified using standard methods, and anti-inflammatory activities of the crude extracts were determined using the cyclooxygenase and soybean 15-lipoxygenase enzyme inhibitory assays. The safety of the extracts was evaluated by determining the cytotoxicity against Vero cell lines. Results: The acidified 70% acetone crude extract and their fractions had good antiradical potency against the DPPH and ABTS radicals. The methanol soluble portions of the butanol fractions were more potent (EC50 ranges from 0.64±0.05 to 1.51±0.07 and 0.88±0.18 to 1.49±0.09μg/ml against DPPH and ABTS radical respectively) compared to the standard, trolox and ascorbic acid (EC50 ranges from 1.47±0.24 to 1.70±0.27μg/ml) for both DPPH and ABTS. The crude extracts contained variable quantities of phenolic content. The crude extracts and their fractions had weak to good antimicrobial activities, inhibiting the growth of the organisms at concentrations ranging from 39 to 2500μg/ml. The BAG crude extract and its fractions were the most active against the fungi (MICs ranging from 39 to 625μg/ml) while the BAB extract and its fractions were the least active with the MICs ranging between 39 and 2500μg/ml. Aspergillus fumigatus was the least susceptible fungus while Cryptococcus neoformans was the most susceptible. The phenolic-rich crude extracts of BAB, BAG, and BAP had moderate to good dose-dependent cyclooxygenase-1 enzyme inhibitory activity with inhibitions between 22.8% and 71.4%. The extracts were however, inactive against cyclooxygenase-2. The extracts had some level of cytotoxicity towards Vero cell lines, reducing cell viability to less than 10% at concentrations more than 50μg/ml. Conclusion: The biological activities observed in Bauhinia species provide a scientific basis for the use of the plants in traditional medicines to treat diseases with multi-factorial pathogenesis such as diarrhoea, with each aspect of activity contributing to the ultimate therapeutic benefit of the plants. However, the use of the phenolic-rich extracts of these plants to treat diarrhoea or any other ailments in traditional medicine needs to be monitored closely because of potential toxic effects and selective inhibition of COX-1 with the associated GIT injury. [Copyright &y& Elsevier]

The emergence of drug-resistant Mycobacterium tuberculosis strains is a threat to global health necessitating the discovery of novel chemotherapeutic agents. Natural products drug discovery, which previously led to the discovery of rifamycins, is a valuable approach in this endeavor. Against this backdrop, we set out to investigate the in vitro antimycobacterial properties of medicinal plants from Ghana and South Africa, evaluating 36 extracts and their 252 corresponding solid phase extraction (SPE) generated fractions primarily against the non-pathogenic Mycobacterium smegmatis and Mycobacterium aurum species. The most potent fraction was further evaluated in vitro against infectious M. tuberculosis strain. Crinum asiaticum (bulb) (Amaryllidaceae) emerged as the most potent plant species with specific fractions showing exceptional, near equipotent activity against the non-pathogenic Mycobacterium species (0.39 µg/ml ≤ MIC ≤ 25 µg/ml) with one fraction being moderately active (MIC = 32.6 µg/ml) against M. tuberculosis. Metabolomic analysis led to the identification of eight compounds predicted to be active against M. smegmatis and M. aurum. In conclusion, from our comprehensive study, we generated data which provided an insight into the antimycobacterial properties of Ghanaian and South African plants. Future work will be focused on the isolation and evaluation of the compounds predicted to be active., (© 2024. The Author(s).)

Background: Diarrhoea is a major health issue in both humans and animals and may be caused by bacterial, viral and fungal infections. Previous studies highlighted excellent activity of Newtonia buchananii and N. hildebrandtii leaf extracts against bacterial and fungal organisms related to diarrhoea-causing pathogens. The aim of this study was to isolate the compound(s) responsible for antimicrobial activity and to investigate efficacy of the extracts and purified compound against bacterial biofilms., Methods: The acetone extract of N. buchananii leaf powder was separated by solvent-solvent partitioning into eight fractions, followed by bioassay-guided fractionation for isolation of antimicrobial compounds. Antibacterial activity testing was performed using a broth microdilution assay. The cytotoxicity was evaluated against Vero cells using a colorimetric MTT assay. A crystal violet method was employed to test the inhibitory effect of acetone, methanol: dichloromethane and water (cold and hot) extracts of N. buchananii and N. hildebrandtii leaves and the purified compound on biofilm formation of Pseudomonas aeruginosa, Escherichia coli, Salmonella Typhimurium, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus., Results: Myricetin-3-o-rhamnoside (myricitrin) was isolated for the first time from N. buchananii. Myricitrin was active against B. cereus, E. coli and S. aureus (MIC = 62.5 μg/ml in all cases). Additionally, myricitrin had relatively low cytotoxicity with IC 50  = 104 μg/ml. Extracts of both plant species had stronger biofilm inhibitory activity against Gram-positive than Gram-negative bacteria. The most sensitive bacterial strains were E. faecalis and S. aureus. The cold and hot water leaf extracts of N. buchananii had antibacterial activity and were relatively non-cytotoxic with selectivity index values of 1.98-11.44., Conclusions: The purified compound, myricitrin, contributed to the activity of N. buchananii but it is likely that synergistic effects play a role in the antibacterial and antibiofilm efficacy of the plant extract. The cold and hot water leaf extracts of N. buchananii may be developed as potential antibacterial and antibiofilm agents in the natural treatment of gastrointestinal disorders including diarrhoea in both human and veterinary medicine.

Background: Tuberculosis is a world-wide problem affecting humans and animals. There is increasing development of resistance of the pathogens to current antimycobacterial agents. Many authors have investigated activities of extracts and isolated compounds from plants. The traditional uses of plants have frequently been the criterion to select plants investigated. In this contribution, we investigate whether plant extracts with very good activity against Escherichia coli may also be active against mycobacteria., Methods: The antimycobacterial activity of eight South African tree leaf extracts with high activity against Escherichia coli were determined in vitro against Mycobacterium smegmatis, M. fortuitum and M. aurum, using a serial microdilution method. The cellular cytotoxicity was also determined by the MTT assay using Vero monkey kidney cells. The selectivity index was determined by dividing the cytotoxicity of extracts by MIC., Results: The antimycobacterial activity of the extracts ranged from 0.02 to 2.5 mg/ml. Mycobacterium smegmatis was more sensitive to the extracts (Average MIC = 0.96 mg/ml) and Mycobacterium aurum was comparatively resistant (Average MIC = 2.04 mg/ml). The extracts of Cremaspora triflora had strong antimycobacterial activity with a MIC of 0.05 mg/ml that compared reasonably well with that of streptomycin (0.01 mg/ml) and rifampicin (0.03 mg/ml), p > 0.05. Cremaspora triflora had the best selectivity index of 2.87 against Mycobacterium fortuitum., Conclusion: The high activity of C. triflora extracts against the fast-growing mycobacteria and good cellular safety is promising. It may be interesting to investigate extracts against pathogenic M. tuberculosis, M. bovis and M. avium cultures and to isolate active antimycobacterial compounds.