Articles

Characterization and Comparison of Interaction of Capsaicin with Hemoglobin and Bovine Serum Albumin Using Circular Dichroism

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Capsaicin, the primary pungent compound in chili peppers (Capsicum species), exhibits a wide range of pharmacological and biological activities. Investigating its interaction with proteins is crucial for understanding its behaviour in biological systems and potential physiological effects. This study explores the binding of capsaicin with two model proteins, hemoglobin (Hb) and bovine serum albumin (BSA), using circular dichroism (CD) spectroscopy to evaluate structural changes induced by ligand interaction. Far-UV CD spectra of Hb and BSA reveals characteristic negative bands around 208 nm and 222 nm, consistent with their predominantly α-helical secondary structures. Upon titration with capsaicin, significant changes in the intensity of these bands were observed, indicating partial alterations in α-helical content and conformational adjustments in both proteins. These structural modifications suggest that capsaicin binds to Hb and BSA, likely through hydrophobic interactions and potential hydrogen bonding with specific amino acid residues. Comparative analysis showed differences in the extent of conformational change between Hb and BSA, reflecting variations in their binding affinity and interaction modes with capsaicin. The results highlight the impact of capsaicin on protein stability and secondary structure and demonstrate the utility of CD spectroscopy as an effective tool for probing protein–ligand interactions. This study provides valuable insights into the molecular mechanisms of capsaicin–protein binding, which may inform its physiological and therapeutic relevance.

The Efficiency of Capsaicin in Chilli on Antibacterial Activity of Salmonella

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This research aimed to study the extraction of capsaicin from Capsicum annuum and Capsicum frutescens fruits by the reflux extraction method and its ability to inhibit the growth of salmonella bacteria. 

Material and method: Capsaicin from Capsicum annuum and Capsicum frutescens fruits were extracted by reflux method using acetone as a solvent. Then, the acetone was separated from the extracts by a rotary evaporator, taken the extracts for measure the absorbance and tested for inhibiting the growth of Salmonella bacteria. Each group of 3 samples were prepared. The control group is a 100µL solution containing Salmonella at a concentration of 1:1000, mixed with 900 µL of saline. Experimental groups were the plates mixed with Salmonella and the extracts. All plates were incubated for 24 hours at 35.5 °C. and counted bacterial colonies as the number of bacteria colonies forming units (CFUs).  

Results: Revealed the light absorbance of the extracts from the Capsicum annuum and Capsicum frutescens was in the same range as the absorbance of pure capsaicin. To test the ability to inhibit the growth of Salmonella bacteria, the average number of Salmonella colonies was 134 CFUs in the control group, and the experimental groups with the capsaicin from both chilli peppers did not find the number of Salmonella colonies. 

Conclusion: The extracts of Capsicum annuum and Capsicum frutescens fruits had capsaicin. The substances obtained from the extracts of both peppers were able to inhibit the growth of Salmonella with no difference in effectiveness.