In vitro antimicrobial efficacy of Rhynchostegium vagans A. Jaeger (moss) against commonly occurring pathogenic microbes of Indian sub-tropics

ObjectiveTo study the antimicrobial effect of organic extracts with a standard dose of Rhynchostegium vagans (R. vagans) on pathogenic bacteria and fungi.MethodsR. vagans was extracted in solvents (ethanol and acetone) and the extracts were evaluated for antimicrobial activity by using disc diffusion assay. Minimum inhibitory concentration and minimum bactericidal/fungicidal concentration was observed by employing micro broth dilution method. Mode of inhibition of ethanolic extract against Aspergillus flavus var. columnaris (A. flavus var. columnaris) was assessed by scanning electron microscopy.ResultsIt was found that the ethanolic extract of R. vagans was the most potent with lowest minimum inhibitory concentration (3.91 to 61.25 μg/mL) and minimum bactericidal/fungicidal concentration (3.91 to 500 μg/mL), respectively. Significant morphological and ultrastructural alterations were seen in A. flavus var. columnaris. Among microorganisms, Gram negative bacteria (Escherichia coli, Erwinia chrysanthemi and Salmonella enterica) and fungi (A. flavus var. columnaris and Aspergillus parasiticus var. globosus) were found more sensitive. Ethanolic extract was found superior over the antibiotics (chloramphenicol and fluconazole).ConclusionsR. vagans exhibited effective antimicrobial activity against all the microorganisms. The moss can be used as a broad spectrum herbal antimicrobial agent in pharmaceutics.