Antibacterial activity of plants used in Indian herbal medicine

Abstract

Delonix elata, Enicostemma axillare, Merremia tridentata, Mollugo cerviana and Solanum incanum are medicinal plants used in traditional Indian medicine for the treatment of various ailments. These plants were selected to evaluate their potential antibacterial activity. To determine antibacterial activity and phytochemicals in the crude extracts of five medicinal plants used in traditional Indian medicine for the treatment of various ailments like rheumatism, piles fever, skin diseases and snake bite. The antibacterial activity of organic solvent extracts of these plants were determined by disc diffusion and broth dilution techniques against grampositive bacterial strains (Bacillus subtilis, Staphylococcus aureus) and gram-negative bacterial strains (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa). Results revealed that the chloroform and methanol extracts of D. elata and methanol extracts of M. cerviana exhibited significant antibacterial activity against gram-positive and gram-negative strains with minimum bactericidal concentration (MBC) ranging from 1.5 to 100 mg/ml. Methanol extracts of M. tridentata exhibited activity only against gram-positive bacterial strains with MBC ranging from 12.5 to 100 mg/ml. Extracts of E. axillare and S. incanum showed activity only against B. subtilis and were not bactericidal at 100 mg/ml. The most susceptible organism to the organic extracts from all the studied plants was B. subtilis and the most resistant organism was P. aeruginosa. The presence of phytochemicals such as alkaloids, tannins, triterpenoids, steroids and glycosides in the extracts of these plants supports their traditional uses as medicinal plants for the treatment of various ailments. The present study reveals potential use of these plants for developing new antibacterial compounds against pathogenic microorganisms.

Antimicrobial and antioxidant properties of methanol extract, fractions and compounds from the stem bark of Entada abyssinica Stend ex A. Satabie

“…The observed wide range of antimicrobial properties for the methanol extract and fractions can be explained by the presence of various groups of potentially active classes of secondary metabolites (Table 1). Indeed flavonoids [21], saponins [22], polyphenols [23], cardiac glycosides [24], coumarines [25], tannins [26], triterpenes and alkaloids [27,28] have been reported to possess antimicrobial activities. It was noted that the bacterial agents were more susceptible to the tested samples than yeasts.…”

Antibacterial and antioxidant properties of crude extract, fractions and compounds from the stem bark of Polyscias fulva Hiern (Araliaceae)

“…Indeed saponins [16], phenols [17], tannins [18] and alkaloids [19], identified in thesetested materials [9] have been reported to possess antimicrobial activities. The relative wide range of antimicrobial properties may results from the individual or from the combined modes of action of compounds belonging to the identified groups of constituents.…”

Phytochemical Profile and Antimicrobial Potential of Extracts Obtained from Thymus marschallianus Willd

“…The MIC index was also calculated for each extract based on the ratio MBC/MIC to evaluate whether the extract exhibits bactericidal (MBC/MIC < 4) or bacteriostatic (MBC/MIC > 4) effect against the tested bacterial strains [54].…”