Photo-protective Effect of Murraya koenigii (Curry Leaf) Against Photodamage Induced in Swiss Albino Mice Under Acute Exposure to UVB Radiation

Exposure of the skin to UVB radiation causes skin damage. UVB is considered lethal as it spontaneously causes sunburn, is genotoxic, and responsible for significant depletion of dermal antioxidants (enzymic and non-enzymic). It initiates photochemical reactions resulting in extensive free radical generation and in turn oxidative stress. The harmful effects of chemical based commercial sunscreens has led to the exploration of “safe” and “economical” alternatives. One approach is to use plant antioxidants as potential photoprotectives. Recent years have witnessed the application of antioxidative phytochemical compounds such as phenolic acids, flavonoids and high molecular weight polyphenols, as beneficial photoprotective agents. However, the photoprotective role of commonly available antioxidant rich aromatic plants such as Murraya koenigii (Curry Leaf) is still less understood. In the present study, antioxidant activity of Murraya koenigii extracts was studied qualitatively and quantitatively. Hot and Cold chloroform extracts of M.koenigii showed maximum antioxidant activity with IC50 values of 17.46 μg/μL and 16.06 μg/μL respectively. Dermal antioxidant enzymatic response to a single UVB exposure was studied in Swiss albino mice by determining the change in catalase and superoxide dismutase enzyme activities in the presence and absence of the plant extract. In the absence of the plant extract, the antioxidant activity of enzymes SOD and CAT decreased significantly (p<0.05) indicative of the stress induced. SOD enzyme showed a significant (p<0.05) improvement in its activity in the presence of the plant extract. The study thus indicates the photo-protective effect of cold chloroform extract of M.koenigii, against acute UVB damage induced in Swiss albino mice.