The anthelmintic effect of aqueous methanol extract of Combretum molle (R. Br. x. G. Don) (Combretaceae) in lambs experimentally infected with Haemonchus contortus.

The aqueous methanol extract from the stem-bark of Combretum molle was evaluated for anthelmintic activity in lambs infected with Haemonchus contortus using faecal egg count (FEC) reduction assay. The extract showed a dose-dependent reduction in FEC in infected animals. At doses of 500, 1000 and 2000 mg kg(-1), the extract caused FEC reduction of 63%, 69.25% and 96.23%, respectively. Similarly, the standard anthelmintic (albendazole) at a dose of 200 mg kg(-1) produced FEC reduction of 99.24%. FEC reduction produced by the extract at doses of 500 and 1000 mg kg(-1) is below the minimum standard of 90% FEC recommended by the World Association for the Advancement of Veterinary Parasitology (WAAVP). However, there was no significant (P>0.05) difference between the means of groups treated with 1000 mg kg(-1) and 2000 mg kg(-1) compared to that of albendazole. In this study, C. molle has shown a promising anthelmintic activity against experimental haemonchosis. Nonetheless, further studies to evaluate its detailed toxicity are required for the plant extract to be developed into a useful anthelmintic drug. There is also the need to evaluate other parts of the plant (root, leaves, fruits, etc.) for the same effect.

Anti-inflammatory activity of crude saponin extracts from five Nigerian medicinal plants.

Crude saponin extracts of five medicinal plants used in the treatment of inflammatory diseases like rheumatoid arthritis, gout and haemorrhoids were screened for anti-inflammatory activity using carrageenan-induced rat paw oedema test. These plants were the whole plant of Schwenkia americana Linn (WSA), the rhizomes of Asparagus africanus Lam (RAA), the leaves of Dichrostachys cinerea Linn (LDC), the stem bark of Ficus iteophylla Miq (BFI) and the leaves of Indigofera pulchra Willd (LIP). A modify traditional method of crude saponins extraction was used to give the following percentage yields: WSA-2.74%, RAA-3.59%, LDC-1.62%, BFI-0.81% and LIP-1.57% respectively. Thin-layer chromatography was used to identify the type of saponins present in the extracts. The acute toxicity study of the crude saponin extracts in mice gave the following intraperitoneal LD50: WSA-471.2mg/kg, RAA- 1264.9mg/kg, LDC-1264.9 mg/kg, BFI-118.3mg/kg and LIP-1264.9 mg/kg respectively. The anti-inflammatory study of the extracts showed statistically significant (P<0.05) decreases in the rat paw-oedema as compared to the control. The percentage inhibitions of the extracts after four hours were as follow: WSA-61%, RAA-55%, LDC-72%, BFI-66% and LIP-40% respectively. These values were found to be comparable to that of ketoprofen-63%. The study showed that the anti-inflammatory properties attributable to these plants may be due to their saponins contents.

Toxicological screening of lyophilized extract of some Nigerian wild mushrooms in mice.

Mushrooms are macrofungi widely consumed as food. However, many mushrooms rot away in the wild because of fear of toxicity. Therefore, lyophilized aqueous extracts of 6 mushroom species collected from Zaria, Nigeria and taxonomically identified as Chlorophyllum molybdites, Panaeolus subalteatus, Macrolepiota procera, Leucopaxillus albissmus, Hygrophoropsis aurantiacus and Pholiota aurea were screened for toxicity in mice. Lyophilized aqueous extract of each of these mushrooms was administered to three groups of 3 mice intraperitoneally (i.p.) at doses of 100, 1000 and 10, 000 mg kg(-1), respectively. Another group of three mice given distilled water served as control. The mice were examined for clinical signs of toxicity over a period of 72 h and pathological examinations conducted on dead animals. The severity of clinical signs, onset of death and pathological lesions were dose dependent. Death occurred within 10 min in all the mice dosed at 10,000 mg kg(-1) with the lyophilized extracts of all the mushrooms screened, with the exception of that of H. aurantiacus, which produced death 21-23 h post administration. This result showed that all the screened mushrooms, including the popular edible M. procera were found toxic. Therefore, since all the mushrooms screened were found toxic, it is recommended that extreme caution should be exercised in their consumption. Furthermore, in view of the regional differences in the toxicity of mushrooms, there is the need to screen more wild mushrooms found in Nigeria for toxicity. This will boost mushroom mycophagy, reduce poisoning incidence and reduce wastage of edible mushrooms in the wild.

Anticonvulsant activity of Carissa edulis (Vahl) (Apocynaceae) root bark extract.

AIM OF THE STUDY: To investigate the anticonvulsant activity of root bark extract of Carissa edulis. MATERIALS AND METHODS: The median lethal dose (LD(50)) of Carissa edulis extract was determined using Lork's method (1983). The anticonvulsant activity of the extract was assessed in pentylenetetrazole (PTZ)-induced convulsion in mice and maximal electroshock test (MEST) in chicks, with benzodiazepine and phenytoin as standard drugs, respectively. While mechanistic studies were conducted using both flumazenil, a GABA(A)-benzodiazepine receptor complex site antagonist and naloxone a non-specific opioid receptor antagonist. RESULTS: The median lethal dose (LD(50)) of Carissa edulis was 282.8mg/kg and over 5000mg/kg following intraperitoneal and oral administration, respectively. Carissa edulis produced 40% and 20% protection against convulsion at 5 and 20mg/kg, respectively, compared with 100% protection with benzodiazepine. The mean onset and percentage protection against convulsion in Carissa edulis extract-treated mice were reduced by flumazenil and naloxone. Carissa edulis exhibited dose-dependent inhibition of the convulsion induced by MEST with 20mg/kg providing 90% protection while phenytoin (20mg/kg) produced 100% protection. CONCLUSION: These results suggest that Carissa edulis possesses biologically active constituent(s) that have anticonvulsant activity which supports the ethnomedicinal claims of the use of the plant in the management of epilepsy.

The perception and practice of traditional medicine in the treatment of cancers and inflammations by the Hausa and Fulani tribes of Northern Nigeria.

A survey was conducted among Hausa and Fulani, two major tribes of Northern Nigeria to identify plants and methods used traditionally in the treatment of cancers and inflammatory diseases. The ecological zones that were considered include Zaria, Kaduna and Kano in the Northern part of Nigeria. The survey involves traditional healers, hunters, farmers and Fulani nomads. This survey has identified plants useful in the treatment of cancers. The plants were identified via taxonomic means and classified according to their habitats, families, genera. Evidently the plants span families and genera, the knowledge and values of the plants was evaluated with the aim of understanding the scientific basis for the use of the plants. The inventory provides the unique opportunity of capturing plants of common uses across the communities.

Effect of Annona senegalensis rootbark extracts on Naja nigricotlis nigricotlis venom in rats.

Annona senegalensis Pers (family: Annonaceae) is used traditionally in Nigeria to treat victims of snakebite. The potency of the methanol extract of the root bark of the plant was tested against cobra (Naja nigricotlis nigricotlis Wetch) venom in rats. The extract was also tested on brine shrimp (Artemia saline Leach). The activity of the extract against the venom induced mortality, occurrence of toxic signs, activity on liver enzymes as well as its ability to reverse experimentally induced increase in body temperature were evaluated. Results indicated that the extract caused reduction in the induced hyperthermia and directly detoxified the snake venom used by 16-33%. It, however, failed to restore the biochemical functions (sGOT and sGPT) of the liver. The extract exhibited an LC(50) of 232.7 microg/ml in the brine shrimp test.

Purification and activity of two phospholipase enzymes from Naja nigricolis nigricolis Reinhardt venom.

Two phospholipase enzymes NN1 and NN2 were purified from the venom of Naja nigricolis nigricolis Reinhardt to apparent homogeneity. NN1 was purified by a two-step anion-exchange chromatography on DEAE-cellulose column while NN2 was purified by a combination of anion-exchange chromatography and gel filtration on Sephadex G-150. The enzyme NN1 moved homogenously on acrylamide gel as a monomer with a molecular weight of 65 kDa while NN2 was a dimer of 71 kDa. Both enzymes were clearly separated. Both enzymes hydrolyzed L-alpha-phosphatidyl choline with activities of 345.5 for NN1 and 727.8 micromol min(-1) x mg(-1) for NN2. The dimeric 71-kDa enzyme has a higher haemolytic and anticoagulant activity than the monomeric 65-kDa enzyme. It is apparent that the dimeric enzyme has a more pronounced activity than the monomer has, thus toxic activity may be related to the hydrolysis of phospholipids.

Aryl sulfatase from Naja nigricolis venom: characterization and possible contribution in the pathology of snake poisoning.

The venom of Naja nigricolis was found to contain a high level of the enzyme aryl sulfatase. The enzyme was isolated from the venom of N. nigriclois and purified to electrophoretic homogeneity by gel chromatography on Sephadex G-100, DEAE-cellulose, and phenyl-sepharose columns. The enzyme was optimally active at pH 5 and 40 degrees C. Arrhenius plot for the determination of the activation energy (E(a)) gave the value 25 kJ/mol with a half-life (t(1/2)) of 5 min at 50 degrees C. It was highly activated by Fe(2+) and Ca(2+) and inhibited by Co(2+) and Mn(2+). The enzyme catalyzed the hydrolysis of the fluorescent compound methylumbelliferyl-sulfate (MU-SO(4)). Double reciprocal plots of initial velocity data, using MU-SO(4) as substrate, gave a K(M) value of 110 microM and V(max) of 225 micromol min(-1) x mg(-1). N. nigricolis Aryl sulphatase also hydrolyzed chondroitin-4-sulphate. It was inhibited competitively by N-acetyl glucosamine sulfate (GlcNAc-SO(4)), glucose-6-sulfate (Glc-6-SO(4)), and glucose 1-sulfate (Glc-1-SO(4)). Extrapolated inhibition binding constants (K(i)) gave the values of 3, 25, and 315 microM for GlcNAc-SO(4), Glc-6-SO(4), and Glc-1-SO(4) respectively.

Inhibition of Naja nigricolis venom acidic phospholipase A2 catalysed hydrolysis of ghost red blood cells by columbin.

The inhibitory effects of a naturally occurring diterpenoid furanolactone, columbin, on partially purified acidic phospholipase A2 (PLA2) from Naja nigricolis was investigated. Columbin inhibited the N. nigricolis PLA2 in a dose related pattern with an IC50 value of 2.5 microM. Double reciprocal plots of initial velocity data of inhibition by columbin revealed a non-competitive pattern. The KM remained constant at 19 microM, while the Vmax changed from 54 micromoles/min/mg to 32 micromoles/min/mg and 20 micromoles/min/mg in the presence of 2 and 10 microM of columbin, respectively. Extrapolated Ki values were 3 and 6.28 microM at 2 and 10 microM inhibitor, respectively. Columbin also inhibited PLA2 hydrolysis of ghost RBC in a dose-dependent fashion. At least 70% suppression of PLA2-catalysed haemolysis of RBC was observed in the presence of 2 microM columbin.

The repellant and antifeedant properties of Cyperus articulatus against Tribolium casteneum Hbst.

Cyperus articulatus is an insect repellant plant commonly found in Northern Nigeria and used traditionally in pest control. The light petroleum and methanol extracts of the plant's rhizome were evaluated against Tribolium casteneum Hbst (the red flour beetle) using standard techniques. The methanol extract showed more antifeedant property than the light petroleum extract, while both the extracts were observed to have similar repellant actions.

In vitro snake venom detoxifying action of the leaf extract of Guiera senegalensis.

The extract of the leaves of Guiera senegalensis was found to detoxify (in vitro) venom from two common northern Nigerian snake species, Echis carinatus and Naja nigricollis, in separate experiments. There was a remarkable reduction in the mortality of albino mice after intra-peritoneal (i.p.) administration of reconstituted venom incubated with the extract, when compared to those challenged with the venom only. The survival of the animals exposed to the venom incubated with the different concentrations of the extract was used as the in vitro detoxification parameter.