The anti-ulcer properties of the leaf extracts of Borreria ocymoides Burm. F. (Rubiaceae) was investigated. Sixty (60) albino rats of either sex weighing 160-216g and fifteen (15) albino mice weighing 25-36 g were used for the study. Standard pharmacological methods were used to carry out acute toxicity (LD 50 ) and phytochemical screening of the plant extract. Gastrointestinal and anti-ulcer studies were performed using standard methods. The extract had an oral LD 50 of > 8000mg/kg in mice. Phytochemical screening revealed the presence of abundant amounts of carbohydrates, reducing sugars, alkaloids, tannins, proteins, and moderate amounts of flavonoids, terpenoids, saponins and glycosides. There were also trace amounts of resins and steroids. The aqueous and methanolic extracts of Borreria ocymoides (AEBO and MEBO) at dose level of 800mg/kg orally, increased gastro-intestinal motility by 6.1% and 22.5% respectively. This increase was not significant when compared with the negative control (p > 0.05). The laxative drug, bisacodyl (5mg/kg), increased motility by 17.4%. However, when bisacodyl (5mg/kg) was administered concomitantly either with AEBO (800mg/kg) or MEBO (800mg/kg), gastrointestinal motility was increased significantly by 67.8% or 70.1% respectively (p < 0.001). Furthermore, the AEBO and MEBO (800mg/kg b.w, p.o) produced significant ulcer protective potency against indomethacin and histamine induced gastric ulceration when compared with the negative control (p < 0.001). The MEBO had comparable ulcer protective potency with cimetidine. Both extracts possess gastric ulcer protective potency and justifies the use of this plant for ulcer treatment.

The effects of phenobarbital on the histology of the liver and the brain and on selected biochemical parameters of the liver of wistar rats were studied. Histological examination showed prominent lesions in the liver and brain of the tested groups of rats. Biochemical analysis revealed significant (P < 0.05) increase in the activities of alkaline phosphatase, alanine transaminase and in the level of cholesterol, with increased drug dosage. These correlated with the pathological changes observed in the liver and the brain of the wistar rats. The effects of phenobarbital on the liver and brain cells were found to be dose-dependent. Half the LD 50 of the drug (8mg/160g) administered on the rats caused reasonable injuries to the tissues of the liver and the brain of the wistar rats.

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Ethnomedically, the root, stem bark, seed or leaves of Picralima nitida are relevant in local preparations as antimalaria, antipyretic, antihypertensive and gastrointestinal agents. This study was therefore designed to determine the antimalarial and antioxidant effects of the methanol extract of the root bark of Picralima nitida using standard procedures. The antioxidant activity of the methanol root bark extract was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method and ferric reducing antioxidant power (FRAP) assay. The antimalarial activity of the methanol root bark extract was investigated using the 4-day suppressive test in mice infected with Plasmodium berghei. The extract showed a concentration-dependent antioxidant activity with 50% inhibitory concentration (IC50) for free radical scavenging activity of 10.19 µg/mL, while the FRAP value was 0.17 ± 0.00 mM FSE/g Extract. The extract demonstrated significant antimalarial activity with 68.33% and 67.27% parasitaemia suppression at doses of 400 mg/kg and 800 mg/kg, respectively. The present study has shown that the root bark extract of P. nitida has antioxidant and antimalarial activities. This study does not only validate the claimed ethnomedicinal use of the plant as antimalaria but also has shown the plant as a potential source of active antimalarial agent.