Phytochemical analysis, antimicrobial and antioxidant activity of Lophopetalum wightianum Arn. (Celastraceae)

Abstract

Objectives: Lophopetalum wightianum Arn. (Celastraceae) is a lofty evergreen tree reaching around 40m in height. The present study was carried out to investigate antimicrobial and antioxidant activity of leaf and bark extract of L. wightianum. Methods: The shade dried and powdered leaf and bark were extracted by maceration process using methanol. Extracts were screened for phytoconstituents present by standard protocols. Antibacterial and antifungal activity of extracts was evaluated by agar well diffusion and poisoned food technique respectively. Antioxidant activity was determined by DPPH radical scavenging and ferric reducing assays. Results: Phytochemicals viz. alkaloids, flavonoids, sterols, saponins and triterpenoids were detected in both leaf and bark extracts. Inhibitory activity against test bacteria of bark extract was marked than leaf extract. Bark extract displayed more or less similar activity against test bacteria while leaf extract was more effective against Escherichia coli. In antifungal activity, leaf extract showed highest inhibitory against Bipolaris sp. than A. niger. Bark extract showed more or less similar antifungal activity against A. niger and Bipolaris sp. Bark extract scavenged DPPH radicals more efficiently with IC50 value 7.03µg/ml than leaf extract which scavenged radicals with IC50 value of 24.64µg/ml. Reducing potential exhibited by bark extract was higher when compared to leaf extract. Conclusion: Overall, bark extract displayed marked antimicrobial and antioxidant potential. The plant is shown to contain bioactive principles with activity against pathogenic microorganisms and free radicals that cause oxidative damage. Keywords: Lophopetalum wightianum, Maceration, Phytochemical, Antimicrobial, Antioxidant