In vitro and in vivo evaluation of inhibition activity of lotus (Nelumbo nucifera Gaertn.) leaves against ultraviolet B-induced phototoxicity

Lotus (Nelumbo nucifera Gaertn.), an aquatic vegetable, is extensively cultivated in eastern Asia, particularly in China. Our previous study showed that lotus leaf extracts (LLEs) have strong antioxidant effects in vitro and in vivo. The main antioxidants in lotus leaf have been identified via liquid chromatography–mass spectrometry. Ultraviolet B (UVB) protective effects have been associated with plant extracts rich in antioxidants. The current study focuses on the mitochondria model to evaluate the potent inhibition activity of LLE against UVB-induced phototoxicity. The level of thiobarbituric acid reactive substances, glutathione, lipid hydroperoxide, conjugated diene, and 4-hydroxynonenal were measured. The in vivo activity of LLE was also investigated in mice model. The results showed that all concentrations of LLE (10, 100, and 1000 μg/ml) possessed strong protective effect against UVB-induced phototoxicity in the mitochondria model. The in vivo test showed that LLE have significant protective effects on the level of superoxide dismutase, catalase, and glutathione peroxidase, as well as the contents of hydroxyproline and malondialdehyde in the skin samples. This study would provide a foundation for broadening the applications of lotus leaf in both the medical and food industries.