Determination of Antioxidant and Antimicrobial Activity of Dichloromethane Extract of Garcinia cowa stem

This thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Pharmacy (B.Pharm) in East West University, Dhaka, Bangladesh.Many pharmaceutical drug discoveries originated from traditional folk medicine and it’s associated plant materials and bioactive secondary metabolites. The genus Garcinia, belonging to the Family Clusiaceae which comprises of about 300 species, have been widely investigated in terms of their bioactive ingredients. Garcinia is a rich source of secondary metabolites. 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. Many of the isolated compounds have a wide range of pharmacological activities including anticancer, anti-inflammatory, antibacterial, antiviral, anti-fungal, anti-HIV, antidepressant and antioxidant. The aim of the present study was to evaluate the antioxidant and antimicrobial activity of dichloromethane extract of Garcinia cowa. The antioxidant activity was measured by DPPH and total Phenol test. The IC50 values of DPPH test was 53.404 μg/ml for dichloromethane extract of Garcinia cowa stems. The Total Phenol content was 173.93 ± 5.87 mg/g equivalent to Gallic Acid for methanol extract of Garcinia cowa stem. By determining antioxidant property, the result suggests that the plant extract which have been tested possesses antioxidant property. The antimicrobial activities of dichloromethane 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 dichloromethane extract of Garcinia cowa stem showed good antimicrobial activities (6 mm-16mm) against the microorganisms. Dichloromethane extract of Garcinia cowa stem showed highest activity against Sarcina lutea and Pseudomonas aureus.Moderate activity against Vibrio parahemolyticus, E.coli, Bacillus megaterium, Staphylococcus aureus, Shigella dysenteriae. In conclusion, further investigations are needed to identify the active constituents and the exact mechanisms of action responsible for the reported antioxidant an antimicrobial properties of Garcinia cowa