Phytochemical Screening, Anti-radical and Antibacterial Activities of Leaves from Combretum glutinosum, a Plant Used in Treatment of Urinary Infections in Benin Republic

Abstract

Infectious diseases are a major global health problem. Bacterial infections represent about 70% of mortality cases. This work aims to evaluate Combretum glutinosum through identification of secondary metabolites and evaluation of anti-radical and antibacterial activities of its leaves. Secondary leaf metabolites of Combretum glutinosum were identified by specific staining and precipitation reactions for each metabolite before phenolic compounds were determined by spectrophotometer. Antibacterial activity was assessed by macrodilution method in microplates and Petri dishes. Based on results obtained, Combretum glutinosum leaves contain a diversity of secondary metabolites with a total flavonoid content of 16.78 mgEQ/gEx, total phenols of  93.291 mgEAG/gEx and total tannins of 0.583 mgEL/g Ex. Hydroethanolic extract of C. glutinosum leaves showed bactericidal activity against strains of Staphylococcus aureus and Streptococcus D, Klebsiella pneumoniae and Escherichia coli. There is a gradual increase in the rate of DPPH radical capture with increasing concentration of Combretum glutinosum  hydroethanolic extract. Thus the lowest IC50 (3.5mg/mL) was obtained with hydroethanolic extract of Combretum glutinosum. These findings support the traditional use of Combretum glutinosum in treating urinary infections and suggest its potential as a source of antibacterial and antioxidant agents.