Antioxidant and Antimicrobial Investigations of Methanol Extract of Garcinia Cowa Stem

Abstract

Garcinia cowa have been used in traditional folk medicine in Malaysia, Thailand and Myanmar. It is an abundant source of bioactive phytochemicals. Phytochemical investigations of the plant parts indicated that the fruit, twig and stem are the best source of secondary metabolites, providing flavonoids, phloroglucinols and xanthones respectively. Garcinia cowa has been used as a medicinal plant for the treatment of various diseases like dysentery, Stomach ache, Cramps, Headache. It is effective as an astringent, used in spasm. Many reports are available on the antiviral, antibacterial, antifungal, and anti-inflammatory, antimalarial properties of plants. The aim of the present study was to evaluate the antioxidant and antimicrobial activity of methanol extract of Garcinia cowa stem. The antioxidant activity was measured by DPPH scavenging assay and total Phenol content test. The IC50 values of DPPH test was 52.358μg/ml for methanol extract of G. cowa stem. The Total Phenol content was 149.6±10.57mg/g equivalent to Gallic Acid for methanol extract of Garcinia cowa stem. By determining antioxidant property, the present result suggests that the tested plant extracts have potent antioxidant activity. The antimicrobial activities of methanol extract of Garcinia cowa stem were tested against ten microorganisms by observing the zone of inhibition. The antimicrobial test was performed by disc diffusion method. The methanol extract of Garcinia cowa stem showed good (7mm11mm) antimicrobial activities against themicroorganisms. Methanol extract of Garcinia cowa stem showed highest activity against Salmonella typhi and moderate activity against Bacillus megaterium, Pseudomonas aureus, Bacillus subtilis, and E.Coli. No activity was found against Bacillus sereus, Salmonella paratyphi and Staphylococcus aureus. In conclusion, further investigations are needed to identify the active constituents and the exact mechanisms of action responsible for the reported antioxidant and antimicrobial properties of Garcinia cowa stem.