Evaluation of Antimicrobial Activity of Casuarina equisetifolia Frost (Casuarinaceae)

The crude methanolic extracts of bark, wood, leaf and fruits of Casuarina equisetifolia and chromatographically isolated compounds were studied for antibacterial and antifungal activity by Cup and Plate method. Various parts of plant were collected from near by Nashik region identified as Casuarina equisetifolia Linn Family Casuarinaceae by P. S. N. Rao, Joint Director, Botanical Survey of India, Pune (M.S.). The plant materials were dried in oven at 40°C. The structures of isolated compounds were confirmed by spectroscopic techniques. The compounds ANA 01, ANA 02 and ANA 04 were confirmed as Catechin, Ellagic acid and Gallic acid from bark; Quercetin (ANA 03) and (ANA 05) Lupeol were characterized from leaf and fruit respectively. The screenings of antibacterial and antifungal activities of isolated compounds were compared with Ampicillin (10units/disc) and Ketokonazole (10units/disc).

The isolated compounds ANA01-05 have shown activity against Gram negative bacteria and less activity against Gram positive bacteria. Among these, ANA04 (Gallic acid) and ANA05 (Lupeol) have shown good activity against Gram-negative (E. coli and Pseudomonas aeuroginosa) bacteria.

Methanolic extracts of wood, bark and fruit has shown good activity (10.0, 12.0 and 10.0 mm respectively) against Gram positive microorganisms (Staph. aureous) while the extracts were without any effect against Gram negative microorganism. Fruit extract has resulted in good antifungal activity against Candida albicans. Lupeol was isolated from fruit which has shown similar (8.0 mm) antifungal activity.