Protective effect of thymoquinone on D-galactose-induced aging in mice

Abstract

Background: Aging is considered as a gradual biological process, which induces alteration in biochemistry and morphology of a biological system. Thymoquinone (TQ), is the major ingredient of volatile oil from Nigella sativa L. seeds. Because of the various pharmacological effects of TQ, this constituent was used for the current study. Objectives: Anti-aging property of TQ in D-galactose-induced model of aging was investigated in mice. Methods: Aging was induced in Razi mice with D-galactose injection (500 mg/kg, SC, daily) for 42 consecutive days. Animal treatment conducted with D-galactose alone or with different doses of TQ (2.5, 5 and 10 mg/kg). Malondialdehyde (MDA) and glutathione (GSH) concentrations were determined in liver and brain tissues at the end of treatment. Serum concentration of interleukin 6 (IL-6) and tumor necrosis factor-? (TNF-?), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as well as dehydroepiandrosterone- sulfate (DHEA-S) and testosterone were determined. Results: Administration of D-galactose (500 mg/kg, SC, daily) for 42 consecutive days increased the level of MDA in brain and liver tissues while diminished the GSH content. Additionally, the serum levels of TNF-?, IL-6, ALT and AST were significantly elevated following induction of aging phenomena while the level of male sex hormones were markedly reduced. Treatment with TQ (5 and 10 mg/kg) elevated level of GSH while decreased MDA production. In addition, the serum level of TNF-?, IL-6, ALT and AST decreased while the level of male sex hormones improved following treatment with TQ. Conclusions: TQ showed anti-aging effect in this model. These effects in part can be mediated through antioxidant effects of TQ.