Phytochemical analysis, antimicrobial and antioxidant efficacy of Neolamarckia cadamba (Roxb.) fruit

Abstract

Neolamarckia cadamba also known as Kadamb, an important traditional medicinal plant belonging to the Rubiaceae family was utilised for treating several diseases. The present study was carried out to quantify secondary metabolites and antimicrobial and antioxidant activities of an aqueous extract (AE) of Neolamarckia cadamba fruits. Different concentrations of plant extracts (1.25, 2.5, 5.0 and 10 mg/disc) have been screened against Gram positive (Staphylococcus aureus and Bacillus subtilis) and gram negative (Escherichia coli and Pseudomonas aureginosa) bacterial strains to detect antimicrobial activity by disc diffusion and minimum inhibitory concentration (MIC) by serial dilution method. AE of N. cadamba fruits with concentrations of 5 and 10 mg/disc showed significant antibacterial activity. The MIC of fruit extract was 3.75 mg/ml for Escherichia coli, Pseudomonas aureginosa and Staphylococcus aureus and 1.875 mg/ml for Bacillus subtilis. FTIR analysis confirmed the presence of alcoholic groups, N-H bending, C-O stretching and aromatic compounds in the extract. The fruit extract was found to exhibit significant antioxidant activity with IC50 = 1.5 mg/ml. Quantitative phytochemical investigation showed the presence of alkaloids (52.00±1.00 mg/g equivalent of atropine), flavonoids (110.33±0.577 mg/g equivalent of rutin), phenols (50.33±0.577 mg/g equivalent of gallic acid) and saponin (22.33±0.333 mg/g equivalent of diosgenin) contents in the extract which might be the reason for its promising antimicrobial and antioxidant potential.