Analgesic activity of the roots and leaves extracts of Calliandra portoricensis.

The analgesic activity of the methanolic extracts of the roots and leaves of Calliandra portoricensis was investigated in mice and rats using acetic acid-induced writhing and formalin tests. The extracts given orally at the doses of 200, 400, 600 mg/kg showed a dose-dependent activity in the tests used.

Diuretic activity of the stem-bark extracts of Steganotaenia araliacea hochst [Apiaceae].

The diuretic activity of the stem-bark extracts of Steganotaenia araliacea (SbESa) and effects on urine electrolytes in rats was studied. Furthermore, a toxicological effect of the SbESa on several tissues was investigated. Groups of male Wister albino rats (170 +/- 0.77 g) were employed. Four doses of 20mg/kg body weight (b.w.), of SbESa (water, methanol, ethanol) and furosemide were administered intraperitoneally (IP). The control group received normal saline alone by oral administration. The 24-h urine outputs per day (in ml) were: normal saline (1.57 +/- 0.11); water extract (3.18 +/- 0.24); methanol extract (3.22 +/- 0.29); ethanol extract (3.62 +/- 0.27) and furosemide (4.22 +/- 0.23). The urine output among the extracts (water, methanol, ethanol) and the furosemide against the control was statistically significant, (P < 0.05), (P < 0.05), (P < 0.02), and (P < 0.01), respectively. The ethanol preparation gave the highest diuretic activity among the extracts. There was marked increase in K(+) ion excretion (122 +/- 7.3 mMol/l) in the ethanol extract as compared to control (95.8 +/- 1.2 mMol/l) and furosemide (standard) (90.05 +/- 0.1 mMol/l). The LD(50) of 1.75 g/kg body weight was observed and the histopathological examination reveals damage to vital organs. The authors conclude that though there are compelling evidence of diuretic potentials in the use of the stem-bark of Steganotaenia araliacea, the toxic effects on vital organs is a drawback to its recommendation for use as a diuretic agent.

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.

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.

Euphorbia hirta leaf extracts increase urine output and electrolytes in rats.

Euphorbia hirta is locally used in Africa and Australia to treat numerous diseases, including hypertension and edema. The diuretic effect of the E. hirta leaf extracts were assessed in rats using acetazolamide and furosemide as standard diuretic drugs. The water and ethanol extracts (50 and 100 mg/kg) of the plant produced time-dependent increase in urine output. Electrolyte excretion was also significantly affected by the plant extracts. The water extract increased the urine excretion of Na+, K+ and HCO3-. In contrast, the ethanol extract increased the excretion of HCO3- decreased the loss of K+ and had little effect on renal removal of Na+. Acetazolamide, like the water extract, increased urine output and enhanced the excretion of Na+, K+ and HCO3-. The high-ceiling diuretic, furosemide, increased the renal excretion of Na+ and Cl-; but had no effect on K+ and HCO3- loss. This study suggests that the active component(s) in the water extract of E. hirta leaf had similar diuretic spectrum to that of acetazolamide. These results validate the traditional use of E. hirta as a diuretic agent by the Swahilis and Sukumas.

Analgesic effect of Irvingia gabonensis stem bark extract.

Irvingia gabonensis is used medicinally in most parts of tropical Africa for the treatment of a number of ailments. In West Africa the Mende tribe of Sierra Leone uses the stem bark to relieve pain. In order to establish a pharmacological rationale for the traditional use of this plant as a remedy for pain, the water and ethanol extracts of the powdered stem bark were screened for analgesic activity and compared with standard analgesic drugs. The water extract and morphine protected the mice from heat-induced pain. In contrast, the ethanol extract and metamizole sodium showed very low level of analgesic activity in this test. However, using tail pressure as a source of pain, the water and ethanol extracts, metamizole sodium and morphine offered protection to the mice against pain stimuli. Morphine and the water extract were more potent as analgesic agents in heat than non-heat pain test. The analgesic effects of the water extract and morphine were blocked by a non-selective opioid receptor antagonist, naloxone in both tests, whereas the analgesic effects of the ethanol extract and metamizole sodium were not antagonized by the same dose of the opioid antagonist. The data presented in this study suggest that the active principle(s) in the water extract has analgesic profile similar to that of the narcotic analgesic and the ethanol extract might contain compound(s) that behave like non-narcotic analgesic agent. These findings provide for the first time the pharmacological basis for the folkloric use of Irvingia gabonensis in the relief of pain.