ASSESSMENT OF ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF CAPSAICIN EXTRACTED FROM CHILI SAMPLES OF NEPAL

Chilies are widely used as vegetables, spices, and external medicines throughout the world. Capsaicin, the potent alkaloid responsible for the pungent flavor of chilies, has been shown to have antioxidant and antimicrobial properties. In this study, the capsaicin content and antioxidant and antimicrobial activity of five different types of chilies were evaluated, namely Green chilies, Habanero chilies, Jalapeno chilies, Chile chilies, and Green capsicum. Fresh chilies were obtained from the market and divided into two halves. The dried chilies were prepared by sun drying the fresh chilies. Capsaicin was extracted from the samples using methanol and a Soxhlet extraction apparatus, and the presence of capsaicin was confirmed using TLC and chemical tests. The amount of capsaicin present in the samples was quantified using a UV spectrophotometer. The antioxidant activity of the capsaicin extracts was determined using the DPPH scavenging assay, and the IC50 values were calculated using Graph Pad Prism software. Capsaicin antibacterial effectiveness was tested against bacterial strains: Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 43888), Pseudomonas aeruginosa (ATCC 9027), Salmonella Typhi (ATCC 14028), and Listeria monocytogenes (ATCC 19115). The results showed that fresh chilies had lower capsaicin content than dried chilies, with the capsaicin content ranging from 94.41% to 98.03% for fresh chilies and from 99.59% to 111.12% for dried chilies. Fresh chilies also exhibited higher antioxidant activity than dried chilies, with the IC50 values ranging from 18.02 to 94.47 mg/ml for fresh chilies and from 20.86 to 121.40 mg/ml for dried chilies. Capsaicin also showed some level of inhibitory effect on bacterial strains, with the ZOI ranging from 10 to 28 mm depending on chili extracts. Compared to commercial antibiotics, capsaicin was more effective against the tested microorganisms. The rise of antibiotic resistance and the use of artificial food preservatives are both major concerns. Therefore, capsaicin is very useful in the food industry as a preservative but also in the pharmaceutical sector as a replacement for many synthetic antibiotics.