Ultraviolet radiation (UVR) from sunlight is an environmental human carcinogen. Skin exposure to UVR would increase the oxidative stress, deoxyribonucleic acid (DNA) damage, melanogenesis and photocarcinogenesis. Therefore, development of photoprotective agent is necessary in order to reduce the cutaneous toxicity. The use natural active compounds like stilbenes and its derivatives have gained attention as photoprotection to skin due to its broad biological activities such as antioxidant, anti-inflammatory, anti melanogenesis and chemoprevention. This review article aims to analyse the existing literature on the photoprotective effect of stilbenes and its derivatives which include the resveratrol, pterostilbene, piceatannol and oxyresveratrol on in vitro and in vivo studies. This article describes the stilbenes and its derivatives protect and prevent UVR induced skin disorders via the reduction of oxidative stress, alleviation of DNA damage, inhibition of melanogenesis and anti photocarcinogenic effect.

Dietary antioxidant supplements such as L-glutathione have gained considerable attention in dermatology and cosmeceutical fields. L-glutathione possesses antiaging, antimelanogenic, antioxidant, and anticancer properties. This study aimed to investigate the inhibitory effects of L-glutathione on melanogenesis activity and oxidative stress in ultraviolet B (UVB)-irradiated BALB/c mice. Eighteen female BALB/c mice were randomly divided into 3 groups: a control group (n=6), a group without UVB irradiation and L-glutathione administration; a UVB irradiated group (n=6), a group irradiated with a UVB dose of 250 mJ/cm2 for 3 min; and a treatment group (n=6), a group irradiated with UVB and treated with 100 mg/kg of L-glutathione by oral gavage. Treatment was given for 14 days, and UVB irradiation was given on days 9, 11, and 13. Oral L-glutathione significantly (P<0.05) reduced lipid peroxidation and elevated superoxide dismutase activity the and glutathione level. L-glutathione also inhibited melanin content and tyrosinase activity significantly (P<0.05) as compared with the UVB-irradiated group. Histopathological examination also showed that L-glutathione reduced the deposition of melanin pigment in the basal layer of the epidermis as compared with that in UVB-irradiated mice. All in all, the present study demonstrated that L-glutathione has the potential to be developed as a photoprotection agent against UVB-induced oxidative stress and melanogenesis.

Extended dermal exposure of ultraviolet B (UVB) can induce erythema, hyperpigmentation, epidermal hyperplasia and cancer. Natural active compound such as pterostilbene (PS) is a potential UV-protecting agent as it has broad biological activities. This study aimed to evaluate the photoprotective effect of pterostilbene on ultraviolet-B-induced BALB/c mice. Twenty-four female mice were randomised into four groups (n=6/group): vehicle control (VC); UVB irradiated only (UVB only); UVB irradiation treated with pterostilbene 10 mg/kg (PS10+UVB); (iv) UVB irradiation treated with pterostilbene 20 mg/kg (PS20+UVB). The PS treatments were given for 14 days, and UVB was given at dose 250 mJ/cm2 on days 9, 11, and 13 of the treatment periods. The results showed that PS lessened redness and scaling on the skin of UVB-irradiated mice. The skinfold thickness and epidermal thickness in the PS-treated group were significantly reduced (p<0.05) in comparison with those in the UVB only group. The PS10 and PS20 groups (5.927 ± 0.354 and 5.660 ± 0.765 nmol/g, respectively) demonstrated significantly decreased MDA levels (P<0.05) relative to the UVB only group (13.343 ± 1.350 nmol/g). The GSH level in both PS10 (0.555 ± 0.020 µmol/mg) and PS20 (0.568 ± 0.055 µmol/mg) groups increased significantly (p<0.05) compared with that in the UVB only group (0.376 ± 0.025 µmol/mg). SOD activity in the PS20 group (1.388 ± 0.172 U/min/mg) increased significantly (p<0.05) compared with that in the UVB only group (0.561 ± 0.034 U/min/mg). Histological observation showed that PS reduced leukocyte infiltration and epidermal hyperplasia. Hence, oral PS may exert a photoprotective effect by acting as an anti-inflammatory and antioxidant agent on UVB-irradiated mice skin.

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