The genus Bridelia: a phytochemical and ethnopharmacological review.

Approximately 60 species of Bridelia, (Phyllanthaceae) are found throughout tropical and subtropical regions of the world, mainly in Africa and Asia. Several Bridelia species are used in popular medicines as antiamebic, antianemic, antibacterial, anticonvulsant, anti-diabetic, antidiarrhoeal, antihelmintic, anti-inflammatory, antimalarial, antinociceptive, antiviral, hypoglycemic and for abdominal pain, cardiovascular, gynecological and sexual diseases. The present paper reviews the traditional usage, the biological activities and the correlated chemical compounds of Bridelia species with emphasis on the validation of the ethnopharmacological uses. The findings in some Bridelia species of, for example, gallocatechin-(4'-O-7)-epigallocatechin (1), quercetin (2), myricetin glycosides (5-6), bridelone (11), bridelonine (12), isoflavone may justify the uses of these species against pains in African and Asian traditional medicines.

Validation of use of a traditional remedy from Bridelia grandis (Pierre ex Hutch) stem bark against oral Streptococci.

AIM OF THE STUDY: Bridelia grandis (Pierre ex Hutch) (Euphorbiaceae) is a medicinal plant traditionally used in Cameroon by pygmies Baka as a remedy for oral cavity affection. Bioassay-guided stem bark extracts were investigated for their in vitro antimicrobial properties as well as their phytochemical constituents. MATERIALS AND METHODS: The first extraction was carried out according to the traditional use. Further extractions were carried out with solvents of different polarity such as methanol (MeOH), ethyl acetate (EtOAc) and mixtures of MeOH-H2O. The antimicrobial activity of the extracts against oral Streptococci was evaluated on the basis of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) by the macrodilution method; the bacterial surface hydrophobicity was also evaluated. RESULTS: Water, methanol and mixtures methanol-water extracts, exhibited antibacterial activity with MIC between 0.5 and 2mg/ml justifying the traditional use of Bridelia grandis stem bark for oral cavity affection. Preliminary phytochemical analysis was performed on the most active extract (methanol) using appropriate tests and well established analytical screening methods, such as TLC and RP-HPLC/DAD. CONCLUSIONS: The data obtained indicate that tannins constitute the chemical family responsible for the biological activity.