• capsaicin;
  • lipid peroxidation;
  • liposome


Ultraviolet-radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8-methyl-n-vanillyl-6-nonenamide), the pungent principle of red hot pepper, was shown to modify UV-induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV-induced lipid peroxidation, while high doses (0.1–0.5 μg/mL of PC liposome) caused a significant decrease of UV-induced peroxidation. These pro-oxidant and antioxidant activities of capsaicin over UV-induced liposomal lipid peroxidation were also comparable to experiments modulated with standard pro-oxidant ferrous sulphate and antioxidant sodium azide. The observed dual nature of capsaisin's action on the UV-induced lipid peroxidation of the liposomal membrane may be attributed to the previously reported “activation” followed by “desensitization” action of capsaicin on other membrane lipid systems.