In vitro antibacterial and antifungal potential of methanolic crude extracts of some Heliotropium spp.

Abstract

Natural products obtained from plants are best source of remedies for many infectious diseases. The active ingredients are found in each part of the plant. In the present study the methanolic crude extracts of three plants, that is, Heliotropium europeaum L., Heliotropium curassavicum L. and Heliotropium crispum Desf. of family Boraginaceae were tested against five pathogenic bacterial and two fungal strains using agar well diffusion and tube dilution methods respectively. Different concentrations (5.0, 7.5, 10.0, 12.5 and 15.0 mg/ml) against bacterial strains and only one concentration of 15 mg/10 ml for fungal strains were tested. The activity of Heliotropium spp. was compared with the broad spectrum commercially available antibiotic doxycyclin (DOX). The results indicate that the different concentrations of extract of the three plants have a wide range of antibacterial and antifungal activity. Among the different concentration used, 15 mg/ml was found best against bacterial strains. Staphylococcus aureus was the most sensitive strain and Bacillus subtilis was the most resistant strain towards all the extracts of three plants. In the present study, methanolic extract of these plants showed good growth inhibition at 15 mg/10 ml concentration against the two fungal species used. By analyzing the overall data it could be concluded that the sensitivity of the microbes increase with increase in the crude extract concentration in the well. All the concentration has high efficiency and broad spectrum activity but lower than that of standard antibiotic.

Keywords: Heliotropium europeaum L., Heliotropium curassavicum L., Heliotropium crispum, antibacterial activity, antifungal activity.

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