Antimicrobial activity of some essential oils and extracts from natural sources on skin and soft tissue infection causing microbes: An In-vitro study

Skin and soft tissue infections (SSTIs) constitute the diverse group of infections with varied clinical presentation and severity. SSTI's are the most common infections treated in hospital today posing diagnostic and therapeutic challenges. Natural herbs have been widely used as a potential source of therapeutic substances all over the world. A study was conducted to determine the antimicrobial effect of some natural extracts on important SSTI causing pathogens.

In this study the antimicrobial potential of essential oil of Cinnamomum zeylanicum, Eugenia caryophyllata, oil of Cymbopogon citratus, Melaleuca alternifolia, Mentha piperita, Ocimum sanctum and extracts of Curcuma longa, Azadirachta indica and Cassia fistula were analysed against common skin and soft tissue infections (SSTIs) causing microorganisms. The organisms include methicillin resistant Staphylococcus aureus (MRSA), methicillin sensitive Staphylococcus aureus (MSSA), Streptococcus pyogenes, Streptococcus agalactiae, Cutibacterium acnes, E.coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Bacteroides fragilis. The antimicrobial assay was performed by agar punch well method with different concentrations of essential oil and extracts. High performance liquid chromatography (HPLC) was performed in order to identify the active constituents present in the extracts. Further a formulation was made, with the powdered extract (neem, turmeric, bark of golden shower) and cinnamon oil as the chief component to look for any probable synergetic activity.

In this study all the essential oils showed good antimicrobial activity than the crude extracts. Significant activity against the Gram negative organisms was exhibited by all the products used in the study. Cinnamon and Clove oil had an excellent activity against all the organism whereas tea tree, mint and Tulsi oil showed better results against the Gram positive organisms including acne vulgaris causing organisms. HPLC results emphasised the presence of eugenol and cinnamaldehyde in clove and cinnamon oil respectively. A significant zone of inhibition was observed from the formulation prepared. Hence we indicate that the natural products used in this study have therapeutic properties and therefore could be considered as an alternative medication in treatment of SSTIs.