Microbicidal and anti-inflammatory effects of Actinomadura spadix (EHA-2) active metabolites from Himalayan soils, India

Abstract

Actinomycetes play an essential role in producing several bioactive compounds. In the present study, microbicidal and anti-inflammatory effects of metabolites from actinomycetes were investigated. Actinomycetes were isolated from north eastern Himalayan soil samples, India. The actinomycetes were investigated for their microbicidal property by conventional method and the active actinomycetes were identified by 16s rDNA sequence analyses. Further the metabolites were extracted and fractionated to evaluate the antimicrobial potency; they were subjected to GC-MS analysis. The active fraction was evaluated for selective toxicity and anti-inflammatory potential. Among isolated actinomycetes, EHA-2 showed potent antimicrobial activity and was identified as Actinomadura spadix. Fraction-8 from ethyl acetate extract of EHA-2 showed 100% inhibition against Candida sp. (MIC-80 μg/mL) and Enterococcus faecalis (MIC-80 μg/mL). The expression of GAPDH in primary cells and 16s rRNA levels on E. faecalis treated with fraction-8 revealed no toxicity to the primary cells. Fraction-8 also suppressed the paw thickness on carrageenan induced animals and also controlled the release of NO, TNFα and IL-1β levels on LPS induced RAW 264.7 cell lines. GC-MS profile of fraction-8 showed the presence of an antimicrobial agent 3,6 di-isobutyl 2,5 piperazinedione, which is the first report in A. spadix. The actinomycetes isolate EHA-2 can be proceed further to produce antibiotics.