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BACKGROUND AND OBJECTIVE: Acetaminophen overdose is the most frequent cause of liver injuries. N-acetyl-p-benzoquinone imine (NAPQI) has been proposed as the toxic metabolite of acetaminophen induced by cytochrome P-450. Piperine has antioxidant activities and has been introduced as an inhibitor of CYP3A and P4502E1 activities. This study was done to evaluate pretreatment effect of piperine in acetaminophen induced hepatotoxicity in rat.
METHODS: In this study, the rats (weighing 150-250g) were divided into 5 groups: saline, piperine (10 mg/kg), acetaminophen (sequential doses of 500 and 1000 mg/kg within 18 hours), piperine with acetaminophen and silymarin (25 mg/kg) with acetaminophen. Activity of alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase in serum were evaluated and the total antioxidant activity was measured by FRAP method.
FINDINGS: Piperine as pretreatment prevented increasing in AST and ALT after acute acetaminophen poisoning (respectively, 1711.25±1108.65 and 496±463.55, compared to acetaminophen, 3956.29±5934.73 and 1914.57±3413.47). Total antioxidant level in acetaminophen group was higher than the saline and piperine groups (respectively, p<0.009 and p<0.003) but no statistical significant differences in results were seen between piperine- acetaminophen and silymarin-acetaminophen groups.
CONCLUSION: Piperine may partially prevent increasing level of the enzymes after acetaminophen poisoning. It may be concluded that in presence of piperine the level of antioxidants trends to be decreased. In other word, piperine can decrease the need of high antioxidant capacity to deal NAPQI produced following acetaminophen induced hepatotoxicity.

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BACKGROUND AND OBJECTIVE: Several factors have influence on sperm fertilization, between them semen hyperviscosity is one of the idiopathic factors involved in sperm viability and function deficiency. Probably, decrease in human seminal antioxidants is one of the negative effects of hyperviscosity on sperm function. The aim of this study was to compare the total antioxidant activity (TAC) in seminal plasma of infertile patients with hyperviscosity and non- hyperviscosity.
METHODS: In this cross sectional study, 47 semen samples were provided from infertile patients with hyperviscosity (n=22) and without hyperviscosity (n=25) at Fatemeh Zahra Infertility and Health Reproductive Research Center. After determine the semen hyperviscosity by measuring the length of the thread on withdrawal of the rod, sperm parameters (volume, sperm counts, motility and normal morphology) were evaluated on microscopic examination. TAC was measured in all samples by FRAP method and compared.
FINDINGS: The mean of sperm parameters including: counts (29.32 ± 25.35), motility (30.95 ± 19.11) and normal morphology (4.23 ± 2.5) in patients with hyperviscosity were significantly lower than those in non-hyperviscosity patients (counts 46.80 ± 26.29, motility (52.8 ± 15.41) and normal morphology (7.56 ± 3.16)) (p<0.02, p<0.001 and p<0.001, respectively). The mean of TAC in seminal plasma of non- hyperviscosity patients (1710.31 ± 458.67µmol/l) was significantly higher than that of hyperviscosity group (1230.25 ± 352 µmol/l) (p<0.01).
CONCLUSION: Our results showed that there is a positive significant correlation between TAC and sperm parameters quality. Decrease in TAC concentration in seminal plasma of patients with hyperviscosity is one of the probability mechanisms for sperm parameters abnormality.