Background: Ethnobotanical pharmacopoeia is confidently used in disease intervention and there is need for documentation and preservation of traditional medical knowledge to bolster the discovery of novel drugs. The objective of the present study was to document the indigenous medicinal plant utilization, management and their extinction threats in Samburu District, Kenya.

Cardiovascular activities of nitidine chloride from Zunthoxylum chulybeum have been compared with those of 9-methoxycbelerytbrine. Wbereas nitidine chloride was found to show significant hypotensive activity in rabbits, 9-methoxychelerythe chloride showed no bypotensive activity. The effect of nitidine chloride on isolated rabbit heart was also compared with those of adrenaline and acetylcholine. 9-Methoxychelerythrine7 which bas hitherto been regarded as an artefact formed by recrystallization of chelerythrine base from methanol, bas been shown in this work to be a true natural constituent of Zunthoxylum chlybeum.

Ageratum conyzoides root and aerial part extracts induced relaxation on isolated trachea. There was no significant difference between the activities of root and aerial part extracts. When Histamine (hist) and the plant extract were introduced into the tissue bath simultaneously, 14% of the activity of the plant extract was inhibited. When the same procedure was used, 5hydroxytryptamine (5-HT) inhibited 21% of the plant extract activity. Conversely, 86% and 79% activities of hist and 5-HT, respectively, were inhibited by the plant extract. This could be the mechanism of its activity as a tracheal relaxant. Acetylcholine (ACh) and 5-HT induced contractions on isolated rat uterus. The treatment of isolated rat uterus with the plant extract inhibited uterine contractions induced by 5-HT, suggesting that the plant extract exhibited specific antiserotonergic activity on isolated uterus. However, the uterine contraction caused by ACh was unaffected by the plant extract.

Zinc phosphide, a commonly used rat poison in Kenya was mixed with maize flour in a concentration of 0.15 %, wlw and fed to a group of 60 experimental mice for 3 hours. The mice were tlien randomly divided into 5 equal groups, A, B, C, D and E. To group A, B, C and D was administered 1 ml of activated charcoal (3 % wlv), sodium bicarbonate (10 % wlv), hydrogen peroxide (0.5 % vlv) and potassium permanganate (1:5000), respectively. Group E was given 1 ml distilled water and used as control. A11 five groups were observed for symptoms of toxicity, often culminating in death. The observations were continued over a period of 36 hours. Results of the experiment showed that all 4 test substances minimized the lethal effect of zinc phosphide. Although no attempt was made to quantify the antidotal effect of the 4 substa~ces, activated charcoal appeared to have a higher effect than the others, while potassium permanganate had a low rating.

A methanol extract of L. trifolia produced bronchodilation of isolated guinea pig trachea comparable to that of salbutamol. The plant extract reduced bronchoconstriction induced by histamine, 5-HT and acetylcholine on isolated guinea pig trachea. Physostigmine failed to inhibit neuromuscular blocking activity of the extract on rat phrenic nerve diaphragm.