Anthelmintic efficacy of cashew (Anarcadium occidentale L.) on in vitro susceptibility of the ova and larvae of Haemonchus contortus

The use of plants for the treatment of human and animal diseases continues to rise although there are few studies providing proof of these effects. Among them is the Anacardium occidentale L., popularly known as cashew. In vitro egg hatch and larval development and viability assays was conducted to determine possible direct anthelmintic effect of acetone extract and fractions of A. occidentale against nematode of sheep, predominantly, Haemonchus contortus. The effect of the extracts on hatching of eggs and development and survival of infective larvae (L3) was assessed. The best-fit LC50 values were computed by global model of non-linear regression curve fitting (95% confidence interval). The presence of A. occidentale extracts in the cultures decreased the hatchability of eggs and survival of L3 larvae in a concentration dependent manner. The LC50 values of acetone extract was 0.311 and 1.72 mg/ml for egg hatch and larval viability test, respectively. The fractions of A. occidentale were more active, demonstrating a lower LC50 compare with the acetone extract. The activities of the fractions were not significantly different against the eggs and larvae of H. contortus (p > 0.05). Further studies are required to identify the compound(s) responsible for activity and more clearly comprehend the anthelmintic mechanism detected in this study.Key words: Anacardium occidentale, anthelmintic, Haemonchus contortus, in vitro detection, larvae, ova

IN VITRO ANTHELMINTIC EFFECT OF ANOGEISSUS LEIOCARPUS (DC.) GUILL. & PERR. LEAF EXTRACTS AND FRACTIONS ON DEVELOPMENTAL STAGES OF HAEMONCHUS CONTORTUS

The anthelmintic effect of acetone leaf extract and fractions of Anogeissus leiocarpus was investigated to determine the relative efficacy of the components as anthelmintic against Haemonchus contortus (Rudolphi). The fractions were obtained by solvent-solvent group separation of the leaf extract. The fractions were evaluated for ovicidal and larvicidal activity by egg hatch inhibition assay and larval development viability assay. Best-fit LC50  values for egg hatch test were 0.360, 0.316, 0.093, 0.219 and 0.196 mg/ml for the crude acetone extract, hexane, chloroform, butanol, and 35% water in methanol fractions, respectively. While the best-fit LC50 values for larval development and viability test were 0.509, 0.162, 0.186, 0.288 and 0.130 mg/ml for the crude acetone extract, hexane, chloroform, butanol, and 35% water in methanol fractions, respectively. The 35% water in methanol fractions was the more active on larvae, although differences in activity between fractions were not significant (p>0.05). A. leiocarpus  leaf extracts could find application in anthelmintic therapy in veterinary practice.Keywords: Anogeissus leiocarpus; anthelmintic; Haemonchus contortus; eggs; larvaeAfr J Tradit Complement Altern Med. (2011) 8(2):134-13

The diversity of antifungal compounds of six South African Terminalia species (Combretaceae) determined by bioautography

A bioautography method was developed to determine the number of antifungal compounds in Terminalia species extracts. Acetone, hexane, dichloromethane and methanol leaf extracts of six Terminalia species (T. prunioides, T. brachystemma, T. sericea, T. gazensis, T. mollis and T.sambesiaca) were tested against five fungal animal pathogens (Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Microsporum canis and Sporothrix schenkii). The Rf values and relative activities of separated compounds were determined. Hexane and dichloromethane extracts had at least three times more antifungal compounds than the other extracts indicating the nonpolar character of the antifungal compounds. From the Rf values, the non-polar character of the antifungal compounds was confirmed indicating that the antifungal activity is not due to tannins. M. canis had the highest number, up to ten, of antifungal compounds. All Terminalia species contained a compound (Rf =0.46 in benzene/ethanol/ammonium hydroxide (90/10/1) active against all tested pathogens. T. sericea and T. brachystemma were the most promising candidates for isolating antifungal compounds. The results demonstrate the value of bioautography in examining plant extracts with antifungal activity,selecting species for further study and dereplicating the isolation of compounds

Bioautography indicates the multiplicity of antifungal compounds from twenty-four southern African Combretum species (Combretaceae)

Dried ground leaves of 24 Combretum spp were extracted with hexane, dichloromethane, acetone and methanol and analysed by bioautography to determine the number of antifungal compounds againstfive animal fungal pathogens (Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Microsporum canis and Sporothrix schenckii). There was some similarity in the chemical compositionof the non-polar components of extracts using extractants of varying polarity. Acetone extracted the most antifungal compounds from Combretum spp. Combretum spp. in the section Hypocrateropsis, C.celastroides ssp. celastroides and C. clelastroides ssp. orientale had 62 different antifungal zones of inhibition compared to the 7 to 8 of C. microphyllum and C. paniculatum in the Connivetaia section. C.collinum subspecies were not active against all the tested pathogens. C. neoformans was the most sensitive organism against all Combretum species, with 367 zones of inhibition using different TLCsolvent systems and extracts. A. fumigatus was the most resistant (192 zones of inhibition). The antifungal activity and number of active antifungal compounds were high enough to consider the use ofextracts for clinical application and to isolate antifungal compounds from the extracts. Based on the Rf values of the antifungal compounds determined using solvents of varying polarity, activity is not onlybe attributable to tannins found in Combretum extracts as was previously postulated

Combretum woodii (Combretaceae) leaf extracts have high activity against Gram-negative and Gram-positive bacteria

Dried ground leaves of Combretum woodii were extracted with 10 different solvents (hexane, diisopropyl ether, diethyl ether, methylene dichloride, ethyl acetate, tetrahydrofuran, acetone, ethanol, methanol and water) to determine the best extractant for subsequent isolation and characterization of antibacterial compounds. With the exception of the water extract, which had no antibacterial activity, the other extracts were bioactive with at least one of them exhibiting minimum inhibitory concentration values of 0.04 mg/ml against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli or Enterococcus faecalis. Intermediate polarity solvents extracted c. 10% of the dry mass compared to c. 3% with the more polar or non-polar solvents. These solvents also had higher antibacterial activity than more polar or non-polar extractants. Ethyl acetate was the best extractant with an average minimum inhibitory concentration (MIC) value of 0.08 mg/ml for the four pathogens followed by acetone and methylene dichloride with values of 0.14 mg/ml. The average MIC values for the positive controls were 0.13 (ampicillin) and 0.12 mg/ml (chloramphenicol). By taking the quantity extracted from the leaf powder into consideration, the total activity, a measure of potency, was highest for methylenedichloride (1309 ml/g) followed by acetone (1279 ml/g) extracts. The antibacterial activity was high enough to consider the use of extracts for  clinical application and to isolate and characterise antibacterial compounds from the extracts. Based on the Rf values of the antibacterial compoundsdetermined by bioautography, the antibacterial compound was not a polyphenol or a tannin

Aloe arborescens aqueous gel extract alters the activities of key hepatic enzymes and blood concentration of triglycerides, glucose and insulin in alloxan-induced diabetic rats

The present study investigated the antidiabetic activity and the possible mechanisms of action of aqueous extract of Aloe arborescens leaf gel (AALGEt) on normal and alloxan-induced diabetic rats. Diabetes was induced in 12 h fasted rats by intraperitoneal injection of 140 mg/kg body weight of alloxan. Blood glucose levels, body weight and water intake were determined on day 7, 14 and 21 of AALGEt treatment. Plasma insulin and triglycerides levels, as well as activities of hepatic glucokinase and glucose 6-phosphatase (G6Pase) were determined at the end of the study. Blood glucose levels, plasma triglyceride and insulin levels, as well as the activity of hepatic G6Pase were significantly increased in diabetic rats. With the exception of hepatic glucokinase activity, daily oral administration of AALGEt to diabetic rats significantly reversed the effects induced by alloxan. The activities of glucokinase and glucose-6-phosphatase as well as plasma insulin levels in AALGEt-treated normal rats were comparable with those observed in untreated normal rats. The results suggest that AALGEt ameliorates physiological parameters altered by the diabetic state. These effects may be mediated in part, through the protection of pancreatic beta cells from further damage by alloxan.Keywords: Aloe arborescens, alloxan, diabetic rats, antidiabetic activity, hepatic enzymes

Inflammation: the foundation of diseases and disorders. A review of phytomedicines of South African origin used to treat pain and inflammatory conditions.

Great interest in herbal medicine as a potential source of phytopharmaceuticals has created the need to review common factors responsible for major diseases and body disorders. This review shows one such common factor in inflammation and the role herbal medicine can play. Traditional medicinal herbal remedies in the southern African region have long been used to treat various pain- or inflammation-related symptoms. Although the precise mechanisms of action of many herbal drugs have yet to be determined, some of them have been shown to exert anti-inflammatory and/or antioxidant effects in a variety of cells in the human and animal bodies. There is increasing evidence toindicate that both peripheral and central nervous system cells play a prominent role in the chronic inflammatory responses in the body system and anti-inflammatory herbal medicine and its constituents are being proved to be a potent protector against various pro-inflammatory mediators in diseases and disorders. These mediators have therefore been suspected of being the functional basis of diseases and disorders. The structural diversity of these medicinal herbs makes them a valuable source of novel lead compounds against the therapeutic molecular targets, cytokines and mediators, that have been newly discovered by the platforms of genomics, proteomics, metabolomics and highthroughput technologies. This article reviews the basic mechanisms of inflammation and the potential of 123 southern African plant species to be effective as chronic inflammatory disease preventive agents. With one third of these species there are no indications of the chemical composition, indicating possible subjects for further research

A critical scientific review on South African governance of genetically modified organisms (GMOs)

Credible governance of genetically modified organisms (GMOs) is essential because of public concerns in South Africa (SA) and internationally. In this preliminary study, the opinions of a number of scientists with experience and/or interest in GMO governance were determined by means of two questionnaires to determine their perceptions on the credibility of risk governance of GMOs in SA. The respondents felt ‘some improvement’ was required in criteria related to good governance. Excellence (quality of risk assessment) and effectiveness, such as protracted regulatory processes needed ‘some to much improvement’. The responses were evaluated against an analysis of the South African GMO Act, regulations, policy guidelines and available information. The Act provides a pro-active basis for good governance comparable to internationally described risk governance models, but implementation seemed to follow the less advanced technocratic model. A number of reasons were identified such as unclear roles of decision makers. Some of the causes for protracted decision-making identified by respondents were: a) excessive precaution in decision making, and b) different mandates resulting in no unanimity among government departments. Proposals for improvement in credibility included communication as a critical component of risk governance and continued training of reviewers and decision makers.Keywords: Genetically modified organisms, risk assessment, risk governance, South AfricaAfrican Journal of Biotechnology Vol. 12(32), pp. 5010-502

NITRIC OXIDE INHIBITORY ACTIVITY OF STRYCHNOS SPINOSA (LOGANIACEAE) LEAF EXTRACTS AND FRACTIONS

Background: The study was aimed at determining the anti-inflammatory activity of fractions and extracts obtained from Strychnos spinosa leaves on a mediator of inflammation nitric oxide (NO). Materials and Methods: Leaves were extracted with acetone and separated into fractions with different polarities by solventsolvent fractionation. The Griess assay was used to determine the nitric oxide (NO) inhibitory activity. Cellular toxicity was determined by "using the MTT reduction assay". Results: With the exception of the ethyl acetate fraction which had an IC50 >750 μg/mL, all extracts and fractions had significant nitric oxide-inhibitory activity. The most active being the water fraction, chloroform fraction and the dichloromethane/methanol extracts with IC50 values of 88.43 μg/mL, 96.72 μg/mL and 115.62 μg/mL, respectively. The extracts and fractions had low cytotoxicity on macrophage U937 cell lines. Conclusion: Extracts and fractions of Strychnos spinosa leaves may be promising sources of natural anti-inflammatory agents. Findings obtained from this study showed that Strychnos spinosa leaves possess promising anti-inflammatory action and could be used in the treatment of inflammation-related conditions

Antibacterial, Anti-HIV-1 Protease and Cytotoxic Activities of Aqueous Ethanolic Extracts from Combretum Adenogonium Steud. Ex A. Rich (Combretaceae).

\ud \ud Records have shown that Combretum adenogonium Steud. Ex A. Rich (Combretaceae) is used in traditional medicine systems of several tribes in Tanzania. This study focused on the investigation of antibacterial activity, anti-HIV-1 protease activity, toxicity properties and classes of phytochemicals in extracts from C. adenogonium Steud. Ex A. Rich (Combretaceae) to evaluate potential of these extracts for development as herbal remedies. Dried plant material were ground to fine powder and extracted using 80% aqueous ethanol to afford root, leaf and stem bark extracts. The extracts were assayed for anti-HIV-1 protease activities, antibacterial activities using microdilution methods and cytotoxicity using brine shrimps lethality assay. Screening for major phytochemical classes was carried out using standard chemical tests. All extracts exhibited antibacterial activity to at least one of the test bacteria with MIC-values ranging from 0.31-5.0 mg/ml. Two extracts, namely, root and stem bark exhibited anti-HIV-1 PR activity with IC50 values of 24.7 and 26.5 μg/ml, respectively. Stem bark and leaf extracts showed mild toxicity with LC50 values of 65.768 μg/ml and 76.965 μg/ml, respectively, whereas roots were relatively non-toxic (LC50 = 110.042 μg/ml). Phytochemical screening of the extracts indicated presence of flavonoids, terpenoids, alkaloids, tannins, glycosides and saponins. These results provide promising baseline information for the potential development of C. adenogonium extracts in treatment of bacterial and HIV/AIDS-related opportunistic infections