Investigation of tissue protective, antiapoptotic and antioxidant effects of ellagic acid and silibinin in ultraviolet a and b induced skin damage in rats by molecular and stereological methods

Keskin S. Investigation of Tissue Protective, Antiapoptotic and Antioxidant Effects of Ellajic Acid and Silibinin in Ultraviolet A and B - Induced Skin Damage in Sharp S. Rats by Molecular and Stereological Methods. Van, Yuzuncu Yil University Institute of Health Sciences, Department of Medical Histology and Embryology, M.Sc. Thesis, Van, 2018. Studies indicate that ultraviolet A and B (UVAB) radiation causes oxidative stress and DNA damage, whereas ellagic acid (EA) and silibinin antioxidant properties. In this study, the therapeutic efficacy of EA and SB was investigated by biochemical, immunohistochemical (TUNEL) and stereological methods against UVAB damage generated experimentally in rat dorsal ridge. For this purpose, changes in oxidative stress and apoptosis were evaluated together with stereological examination. Six groups of 7 Wistar albino female rats were formed each. Groups; The control group (K), Ultraviolet A and B group (UVAB), Ellagic acid (EA) group, Silibinin (SB) group, UVAB + EA (Ultraviolet AB + Ellagic acid) group and UVAB + SB (Ultraviolet AB+ Silibinin) group. The animals in the UVAB, UVAB + EA and UVB + SB groups were exposed to UVAB radiation for 2 hours daily for 30 days. 50 mg/kg/day EA and 50 mg/kg/day SB were given orally 30 minutes prior to each UVAB application to the UVAB + EA and UVAB + SB groups. EA and SB without UVAB were given 50 mg/kg/day EA and SB by the same doses. All animals were sacrificed on the 30th day. Ridge skin tissues were taken for analysis. According to the results of the research; UVAB group compared with the control group, the decrease in total antioxidant status (TAS) and the increase in TAS level compared with the UVAB group were not significant (p> 0.05). There was a significant increase in total oxidant status (TOS) and oxidative stress index (OSI) levels compared to the UVAB group control group (p <0.05). However, these increases in TOS and OSI levels decreased significantly in treatment groups (p <0.05). When the stereological findings obtained in the study were evaluated, it was observed that the volume ratio of epidermis in the UVAB group was significantly increased compared to the control group (p <0.05). There was a statistically significant decrease in the dorsal skin epidermis thickness of the treatment group rats compared to the UVAB group (p <0.05). When EA and SB were administered together with UVAB, the number of dermal mast cells decreased significantly, compared statistically to the UVAB group (p <0.05). The number of TUNEL positive cells in the UVAB + EA and UVAB + SB treatment groups significantly decreased when compared with the UVAB group (p <0.05). This study found that ellagic acid and silibinin could be useful in the treatment of UVAB damage. In order to support the findings obtained here, there is a need for further in vitro and in vivo studies to be carried out by oral or topical administration of different doses of ellagic acid and silibinin. Key words: Skin, Ellagic acid, Apoptosis, Oxidative stress, Silibinin, Stereology, UVAB.