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Background & Objective: Black pepper is frequently used in Iranian traditional medicine as an analgesic (E.g, for toothache). This investigation was conducted to evaluate the response of mice to pain induced by hot-plate and Formalin test either with or without Piperine (One of the active substances of the pepper). Materials & Methods: This randomized experimental study was performed on mice. Hot-plate and Formalin tests were planned to pain measurement. The mice were divided into 2 groups in each arm of study (Hot-plate and Formalin test group). The data of control (Saline) and drug (Piperine) groups were separately compared in each arm of study with student t-test and ANOVA. The difference between each point of data was considered significant at P-value under 0.05. Results: There was not a significant difference in tolerance time of subjects between hot-plate and saline groups. Piperine (25, 50 and 75 mg/kg) along with Morphine (10 mg/kg) causes significant increase to saline group in tolerance time and also significant increase to Morphine group, but in Formalin test Piperine could have significant effect in decreasing the pain induced by of Formalin on mice. These effects are comparable with Morphine. In Formalin test, pain has 2 phases. The first phase is acute and the 2nd one is chronic that begins from 15-20 minutes. Acute pain has central effect and chronic pain has peripheral pathway and Piperine causes decreasing response to Formalin test at the first phase of pain. Naloxone can prevent these effects in all groups. In Formalin test and hot-plate, the effect of Piperine were dose dependent. Conclusion: Piperine can centrally act on the nociception pathway and its effect on Opioid system exhibits as an enhancement Opioid effect. The effects are dose dependent and will be inhibited by Opioid antagonist.

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Background & Objective: Hinosan is an organophosphate that inhibit acetylcolinesterase activity, which could be resulted in damages of genital organs. This compound has been used extensively in the agriculture, for pest control. Therefore, in the present study we investigated the effect of Hinosan on spermatogenesis in mice.

Materials & Methods: For this experimental study, the male mice were divided into three groups. In the cases group, mice were injected with Hinosan consecutive doses (20mg/kg i.p, five consecutive days per week for one month), sham (normal saline) and control (no injection). Animals were scarified 7 days after the latest Hinosan injection. Therefore, the mice testis sections were prepared and morphologic aspects of testis and spermatogenesis processes were examined. Data were analyzed using of one-way ANOVA. Significance was set at P<0.05.

Results: The Hinosan showed a significant decrease in number of germ cells, spermatocyt, spermatids, Leydig cells, blood vessels and also diameter of seminiferous on testes of the mice decreased, compared with control groups (P<0.05).

Conclusion: This study demenstrated that Hinosan is effective on spermatogenesis and seminiferous tubule structure, also can decrease germinal cells.