ANTIRADICAL, ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY OF HARPULLIA ARBOREA (BLANCO) RADLK. (SAPINDACEAE)

Objective: The present study was conducted to investigate antiradical and antimicrobial potential of extract of Harpullia arborea (Blanco) Radlk. (Sapindaceae) leaves obtained by maceration process.Methods: Antiradical activity of leaf extract was performed by DPPH and ABTS radical scavenging assays. Antibacterial activity of leaf extract was carried out by Agar well diffusion assay. Antifungal activity of leaf extract was carried out by Poisoned food technique.Results: Leaf extract displayed concentration dependent scavenging of radicals with potent scavenging activity against ABTS radicals (IC50 value 4.26µg/ml) when compared to DPPH radicals (IC50 value 27.26µg/ml). Extract exhibited inhibitory activity against all test bacteria. Marked and least activity was observed against Staphylococcus epidermidis and Escherichia coli respectively. Considerable reduction in the mycelial growth of test fungi was observed in poisoned plates. Curvularia sp. and Alternaria sp. were inhibited to highest and least extent respectively. Conclusion: In suitable form, the plant can be used to treat oxidative damage, infectious diseases caused by pathogenic bacteria and to manage seed-borne fungi

ANTIBACTERIAL AND ANTIFUNGAL ACTIVITY OF THREE RAMALINA SPECIES

Lichens are an association of a photobiont (an alga or a cyanobacterium) and a mycobiont (a fungus). The lichen genus Ramalina is one of the cosmopolitan lichen genera and is characterized by fruticose thallus. In the present study, an antibacterial and antifungal activity of an extract of three Ramalina species (Ramalinaceae) viz. R. hossei Vain, R. conduplicans Vain and R. pacifica Asahina obtained by maceration process were investigated. The lichens were collected from different places of Shivamogga district, Karnataka, India and identified on the basis of morphological, anatomical and chemical tests. The antibacterial and antifungal activity of lichen extracts was carried out by Agar well diffusion and Poisoned food technique respectively. Overall, B. cereus and E. coli were inhibited to higher extent and least extent respectively by extracts of Ramalina species. R. pacifica and R. hossei inhibited bacteria to highest and least extent respectively. In the case of antifungal activity, marked and least inhibitory activity was shown by an extract of R. hossei and R. pacifica respectively. Among fungi, Alternaria sp. and Fusarium sp. were inhibited to highest and least extent respectively. The observed antimicrobial potential could be ascribed to the presence of secondary metabolites such as usnic acid, salazinic acid and sekikaic acid present in the Ramalina species.Key words: Lichens, Ramalina, Antimicrobial, Agar well diffusion, Poisoned food techniqueÂ