Potential protective effects of quercetin and curcumin on paracetamol-induced histological changes, oxidative stress, impaired liver and kidney functions and haematotoxicity in rat.

The present study was carried out to evaluate the potential protective role of quercetin and curcumin against paracetamol-induced oxidative injury, liver damage and impairment of kidney function, as well as haematotoxicity in rats. Also, N-acetylcysteine was used to evaluate the potency of quercetin and curcumin. Paracetamol caused an elevation in thiobarbituric acid-reactive substances (TBARS) paralleled with significant decline in glutathione peroxidase, glutathione S-transferase, superoxide dismutase and catalase activities (in plasma, brain, lung, heart, liver, kidney and testes) and glutathione content (in lung, liver and kidney). The apparent oxidative injury was associated with evident hepatic necrosis confirmed in histological examination, elevated plasma transmainases, alkaline phosphatase and lactate dehydrogenase. Paracetamol reduced plasma total protein, albumin and globulin, while increased bilirubin, urea and creatinine, and induced haematotoxicity. The presence of quercetin or curcumin with paracetamol successfully mitigated the rise in TBARS and restored the activities of antioxidant enzymes compared to the group treated with both paracetamol and N-acetylcysteine. They also protected liver histology, normalized liver and kidney functions, which was more pronounced with curcumin. Therefore, it can be concluded that concomitant administration of quercetin or curcumin with paracetamol may be useful in reversing the toxicity of the drug compared to N-acetylcysteine.

An in vitro study on reproductive toxicity of aluminium chloride on rabbit sperm: the protective role of some antioxidants.

An in vitro study using rabbit sperm was designed to evaluate the cytotoxic effects of different concentrations of aluminium chloride (AlCl(3)) at 0, 2 and 4h of incubation on sperm motility and viability, oxidative status and the activities of some antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)), transaminases and acid phosphatase. The role of vitamin C (1 mM) or vitamin E (2 mM) was also investigated in counteracting deterioration caused by AlCl(3) on the tested parameters. Rabbit sperm was incubated with different concentrations of AlCl(3) (0, 1, 5, 10, 15 and 20 mM) with or without vitamin C or vitamin E for 2 and 4 h. Results revealed that the percentage of motile and viable sperm decreased significantly after AlCl(3) treatment at 10, 15 and 20 mM and the response was both concentration and time dependent. Aluminium chloride at concentrations of 10, 15 and 20 mM caused significant induction of oxidative stress as evidenced by increased thiobarbituric acid reactive substances (TBARS) levels and inhibition in the activities of SOD and CAT. Increase in the activities of aspartate transaminase (AST) and alanine transaminase (ALT) and decline in the activity of acid phosphatase (ACP) were also observed at AlCl(3) concentrations of 15 and 20 mM. Co-incubation with either vitamin C or vitamin E resulted in marked degrees of protection against AlCl(3)-induced cytotoxic effects, represented in decreased TBARS levels and restoration of enzymes activities near control. On the other hand, no significant effect was exerted from vitamin C or vitamin E on motility and viability. The present study demonstrated that AlCl(3) caused deterioration in sperm motility and viability, enhancement of free radicals and alterations in enzymes activities. The antioxidants revealed protective effects against the cytotoxicity of AlCl(3).