International Journal of Current Microbiology and Applied Sciences
ISSN: 2319-7706 Volume 2 Number 10 (2013) pp. 238-248
Phytochemical screening , Invitro Anti-bacterial and Antioxidant activity of the Psidium guajava root bark
B.Ramya Kuber*, M.Rajya Lakshmi, E.Deepika, and P.Yamini
Department of Pharmacognosy,Institute of Pharmaceutical Technology, Sri Padmavathi Mahila Visvavidyalayam, Tirupati, 51072, India.
Aim of the present work was to evaluate potential in-vitro antioxidant and antibacterial activity of alcoholic extract of root bark of Psidium guajava (PG) of family Myrtaceae. The antioxidant activity of alcoholic extract of PG root bark was evaluated by DPPH, Lipid Peroxidation and Nitric oxide Scavenging activity. The concentration of alcoholic extract were (3-800 ug/ml). The PG extract showed maximum scavenging activity at a concentration of 800 µg/ml. The percentage inhibition of the scavenging of the DPPH was found to be 75.6% where as Lipid Peroxidation was 82.4% and nitric oxide scavenging activity was found to be 85.6%. The antibacterial activity of the alcoholic extract of Psidium guajava root bark was carried out and it was determined by the cup plate method against Staphylococcus aureus, Escherichia coli, Proteu vulgaries and Bacillus subtilis. Streptomycin was used as a positive control. The zone of inhibition of alcoholic extract of PG against various microorganisms was measured and compared with standard control, PG showed antibacterial activity at the concentration of 240 mg/ml against all the bacterial strains however, maximum activity with zone of inhibition (3 cm and 2.8 cm) againist Staphylococcus aureus and Bacillus subtilis. Escherichia coli and Proteus vulgaries exhibited moderate antibacterial activity. The preliminary phytochemical screening of alcoholic extract of PG showed the presence of pharmacological important constituents like tannins, flavonoids, alkaloids, saponin glycosides. Hence on the basis of the results obtained in the phytochemical study, the antioxidant activity of PG may be due to flavonoids and antimicrobial activity could be due to tannins. Phytochemical analysis intended to serve as a major resource for information on analytical and instrumental methodology in the plant sciences.
Antioxidants; Psidium guajava; Free radicals; Antibacterial activity; Cup plate method; Phyto- chemicals.