Effects of Ginkgo biloba extract on brain oxidative condition after cisplatin exposure Abstract Purpose: The purpose of this study was to evaluate the efficacy of Ginkgo biloba extract (EGb 761) on oxidative events of brain in cisplatin-administrated rats.Methods: Rats were divided into four experimental groups: 1) control (n=6); 2) cisplatin (8 mg/kg, intraperitoneally one dose, n=6); 3) EGb 761 (100 mg/kg intraperitoneally for 15 days, n=6); and 4) cisplatin + EGb 761 (n=6). After drug administration, rats were sacrificed and brain tissues were removed. Nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) levels were evaluated in brain tissues.Results: Single dose cisplatin administration significantly increased NO and GSH levels, but decreased MDA levels in brain tissue samples. EGb 761 treatment reversed the effects of cisplatin on NO and GSH levels, but did not affect the decreased MDA levels.Conclusion: Results of the study indicate that oxidative stress can be an important pathogenetic mechanism of cisplatin-induced neurotoxicity. EGb 761, an standardized extract of G. biloba leaves that has antioxidant properties, may improve the oxidative stress-related neurological side effects of cisplatin. SUPPLEMENT

Wound healing is a highly orchestrated process including complex and coordinated interactions involving peptide growth factors of which transforming growth factor-beta (TGF-beta) is one of the most important modulators. Exogenous TGF-beta treatment has been shown to accelerate wound healing in normal and impaired animal models. Nitric oxide (NO) also plays a key role in wound healing. The objective of this study is to examine the effects of exogenous TGF-beta 1 treatment on NO and lipid peroxidation levels in the process of oral wound healing on different days. In this study, we used 5-month-old New Zealand albino male rabbits. After a standard surgical incision in the diestema region, the rabbits were divided into controls and TGF-beta 1 implanted groups. NO levels and malondialdeyhde (MDA) levels which are indicators of lipid peroxidation were determined by spectrophotometry. In the TGF-beta 1 implanted groups, both NO and MDA levels significantly increased only on the third day after wounding when compared to control groups. We found decreased MDA levels parallel to NO levels on the fifth day after wounding. These findings suggest that TGF-beta 1 affects mucosal wound healing by altering NO production on different days of wounding. TGF-beta 1 may regulate NO production by its dual effect in as both an activator and inhibitor an in oral mucosal healing.

Macrophages are leukocytes that play a strategic role in immune response and can be associated with various diseases due to their effects on the inflammation process and oxidative events. The current study was evaluated the anti‐inflammatory and antioxidant properties of cinnamaldehyde and eugenol, which are phyto‐compounds with numerous bioactive properties, on lipopolysaccharide (LPS)‐induced macrophage cells. For this purpose, Raw 264.7 cells were incubated with cinnamaldehyde or eugenol (15, 25, and 50 μM) then stimulated with LPS. After 24 hr, tumor necrosis factor‐alpha (TNF‐α), interleukin‐1β (IL‐1β), and IL‐6 levels (as inflammatory mediators), and malondialdehyde (MDA) and nitric oxide (NOx) levels as well as superoxide dismutase (SOD) and catalase (CAT) activities (as oxidative status markers) were determined in cell cultures. Cinnamaldehyde and eugenol pre‐treatments decreased TNF‐α, IL‐1β, and IL‐6 levels as compared to LPS group at all concentrations. Furthermore, these pre‐treatments increased SOD activity while decreased MDA and NOx levels as well as CAT activity at different concentrations. Our results demonstrated that these phyto‐compounds have potential for the treatment of various diseases as protective agents against chronic inflammation and oxidative stress. Practical applications Chronic inflammation and oxidative stress are complications that play a detrimental role in the pathophysiology of many diseases. Alternative treatment methods have been investigated to prevent them. Cinnamaldehyde and eugenol are phyto‐compounds with high bioactivity that can be obtained from foods and spices. In this study, the protective effects of cinnamaldehyde and eugenol on lipopolysaccharide‐induced oxidative stress and inflammation in macrophage cells were investigated. According to the obtained results, cinnamaldehyde and eugenol pre‐treatments decreased inflammation and also reduced oxidative stress. Cinnamaldehyde and eugenol may be a better natural alternative protective agent for the chronic inflammation‐ and oxidative stress‐related diseases.

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