ANTIBACTERIAL ACTIVITIES OF THE EXTRACTS AND CONESSINE FROM HOLARRHENA FLORIBUNDA G. DON. (APOCYNACEAE)

The methanolic extract and conessine isolated from the stem bark of Holarrhena floribunda (Hf) were tested for their antibacterial activities on Bacillus: Bacillus cereus, Bacillus subtilis, Bacillus megaterium and Bacillus stearothermophilus using the disc diffusion method. Phytochemical analysis of the crude extract and fractions was also conducted. The inhibition parameters of the crude methanol extract and the total alkaloid fraction were determined using the macrodilution method. The results showed that the crude extract, the total alkaloid fraction and conessine exhibited a significant antibacterial effect against all the strains studied. The antibacterial effect of conessine is almost similar to that of chloramphenicol used as reference. The ratio of the minimal bactericidal concentration (MBC) over the minimal inhibitive concentration (MIC) indicates the bactericidal effect of the plant. These results support common use of stem bark of Hf and conessine isolated from Hf in the treatment of some infectious diseases

Evaluation of antimicrobial activity of the fruitrind of Picralima nitida (Aapocynaceae) and the stem bark of Cylicodscus gabunensis (Mimosaceae)

Ethyl acetate(EA) extract of the stem bark of Cylicodiscus gabunensis (CG) and methanol(M) extract of the fruit-rinds of Picralima nitida (PN) were analysed phytochemically and evaluated for their antimicrobial activity against 17 pathogenic species isolated from patient: Escherichia coli, Klebsiella pneumoniae, Shigella dysenteriae, Shigella flexneri, Morganella morganii, Proteus vulgaris, Proteus mirabilis, Salmonella thyphi, Citrobacter freundii, Enterobacter cloacae, Enterobacter agglomerans, Staphylococcus aureus, Streptococcus feacalis, Pseudomonas aeruginosa, Bacillus cereus T, Candida albicans and Candida glabrata. Alkaloids, flavonoids, saponins, polyphenols, cardiac glycoside and glycoside were detected in the (M) extract of PN whereas flavonoids, saponins, tannins, polyphenols, coumarins, triterpenes and/or sterols and reducing sugars were detected in the (EA) extract of CG. The best MIC and MBC values for the microorganisms sensitive to the (EA) extract of CG were 0.00078 and 0.00315mg/ml respectively whereas its were 0.00078 and 0.001525mg/ml respectively to the methanol extract of PN. The greater and remarkable antimicrobial activities of the (EA) extract of CG were recorded with Staphylococcus aureus, Proteus vulgaris and Bacillus cereus T whereas it was recorded with Proteus mirabilis for the (M) extract of PN. These results provide a rationalization for the traditional use of both plants for the treatment of infections diseases. Keywords: Antimicrobial activity, Cylicodiscus gabunensis, Picralima nitida West African Journal of Pharmacology and Drug Research Vol. 21 (1&2) 2005: pp. 6-1

EVALUATION OF ANTIDIARRHOEAL ACTIVITY OF THE FRUIT-RIND OF PICRALIMA NITIDA (APOCYNACEAE)

The methanol (M) extract of the fruit-rind of Picralima nitida (PN) (Apocynaceae) was tested for its anti-diarrhoeal activity. Like loperamide (3 mg/kg body weight), a single oral dose of PN-M (375, 750 mg/kg body weight) produced a significant decrease in the frequency of defecation and severity of diarrhoea. To understand the mechanism of its anti-diarrhoeal activity, its effect was further evaluated on intestinal transit; castor oil-induced intestinal fluid accumulation (enteropooling) and electrolyte concentration in the small intestinal fluid. PN-M produced a decrease in intestinal transit (18.81-21.86%) as compared to castor oil treated animals. Unlike atropine, PN-M significantly inhibited castor oil-induced enteropooling. However it did not alter the electrolyte concentration in intestinal fluid as compared to castor oil treated rats

Evaluation of Antimicrobial Activity of the Stem Bark of Cylicodiscus Gabunensis (Mimosaceae)

Ethyl acetate(EA) extract of the stem bark of Cylicodiscus gabunensis (CG) was analysed phytochemically and evaluated for its antimicrobial activity against 17 pathogenic species isolated from patient: Escherichia coli, Klebsiella pneumoniae, Shigella dysenteriae, Shigella flexneri, Morganella morganii, Proteus vulgaris, Proteus mirabilis, Salmonella typhi, Citrobacter freundii, Enterobacter cloacae, Enterobacter agglomerans, Staphylococcus aureus, Streptococcus feacalis, Pseudomonas aeruginosa, Bacillus cereus T, Candida albicans and Candida glabrata. Flavonoids, saponins, tannins, polyphenols, coumarins, triterpenes and/or sterols and reducing sugars were detected in the (EA) extract of CG. The best MIC and MBC values for the microorganisms sensitive to the extract were 0.00078 and 0.00315 mg/ml respectively. The greater and remarkable antimicrobial activity of the (EA) extract of CG was recorded with Staphylococcus aureus, Proteus vulgaris and Bacillus cereus T. These results provide a rationalization for the traditional use of this plant for the treatment of infections diseases