LAUSR

Abstract Purpose Bevacizumab is a recombinant humanized monoclonal antibody that specifically binds to vascular endothelial growth factor (VEGF). Cutaneous side effects of bevacizumab are seen with substantial frequency and may require the interruption of the treatment. The aim of the study was to conduct a biochemical and histopathological investigation of the effects of carvacrol against the possible oxidative skin damage caused by bevacizumab in rats. Materials and methods A total of 18 adult male Wistar albino rats were randomly assigned to three groups as healthy (H group; n = 6), bevacizumab alone (B group; n = 6), and carvacrol + bevacizumab (CB group; n = 6). Carvacrol was injected intraperitoneally (IP) at a dose of 50 mg/kg in the CB group. Sterile salt solution (0.9% NaCl) was used as a solvent for the H and B groups. One hour after the administration of carvacrol and solvent, bevacizumab at a dose of 10 mg/kg IP was administered to the CB and B groups. Bevacizumab was given once daily for a total of two doses, 15 days apart. Carvacrol was administered once daily for one month. After that period, all animals were sacrificed and their skin tissues removed. Malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPO), catalase (CAT), superoxide dismutase (SOD), total oxidant status (TOS), and total antioxidant status (TAS) levels in rats’ skin tissues were biochemically evaluated. The parameters were measured with spectrophotometric method by using a microplate reader (BioTek, Winooski, VT, USA). The skin tissues were also examined histopathologically by the pathologist (blind) for the study groups. Results The MDA and TOS levels of the H and CB groups were significantly lower than the B group (p < 0.05). The mean scores of the other biochemical levels (GSH, GPO, CAT, SOD, TAS) in the H group were significantly higher than in the B and CB groups. Pathological examination of H group was normal. In B group epidermal atrophy, abnormal keratin accumulation, degenerated hair follicles, edoema and inflammatory cells accumulation in the dermis were observed. In the CB group, these findings were significantly improved. Conclusion The positive effect of carvacrol against possible local oxidative skin damage due to bevacizumab in rats was demonstrated. In addition, more detailed studies are required to clarify the mechanism of the protective effect of carvacrol against bevacizumab-induced skin toxicity. The effect should be evaluated through further human studies, as well as studies using different doses of carvacrol.