Study of antibacterial and antioxidant activities of four common Nepalese kitchen spices

Given the alarming incidence of antibiotic resistance in bacteria of medical importance and multiple side effects associated with the modern day chemotherapeutics, there is a constant need for new and effective therapeutic agents that could be easily extracted from our daily used Nepalese culinary. To study the antibacterial and antioxidant activity of common spices, locally available  Clove (Eugenia caryophyllus), Cinnamon (Cinnamomum zylancium), Cumin (Cumin cyminum) and Timur (Zanthoxylum alatum) were subjected to cold extraction using ethanol and was assayed through agar well diffusion method and DPPH radical scavenging activity for different concentration gradient(100 to 500 µg). Zanthoxylum and Eugenia have showed potent antimicrobial activity against Proteus vulgaris and Pseudomonas aeruginosa followed by Cinnamomum and Cumin against Pseudomonas aeruginosa. All the extracts showed effective antimicrobial activity against gram positive and gram negative bacteria, however Escherichia coli remains ineffective towards any of the concentration of spices. DPPH radical scavenging activity showed effective antioxidant activity of the spices in the following order: Eugenia (93.84%) > Cumin (90.4%), Zanthoxylum (88.73%) > Cinnamomum (87.23%). Hence, our present study demonstrated that the ethanolic extract of different spices, Eugenia being the most effective, possess potent antibacterial and antioxidant activity and can be further analyzed for antimicrobial therapeutics and pharmacological evaluation.   Key words: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, Eugenia, Zanthoxylum, Cinnamon, Cumin.