Samanea tubulosa Benth. (Fabaceae): Antinociceptive effect on acute pain in mice: K+ATP channel and opioid activity.

Samanea tubulosa Benth. it has been widely used in traditional medicine to treat inflammatory processes. The present study aimed to investigate the antinociceptive effect and mechanism of action of the fractions obtained from the Samanea tubulosa pods in mice. The antinociceptive activity was evaluated in formalin, capsaicin and glutamate tests and the. The possible mechanisms of action involved in the antinociceptive effect of the hexane and ethyl acetate fraction in the opioid system, also the the K + ATP channels and the L-arigine pathways of nitric oxide were evaluated. The chemical characterization analysis revealed in the hexane fraction the presence of triterpenes such as lupenone and lupeol. In the glutamate test, the hexane and ethyl acetate fractions showed antinociceptive activity at the dose of 12.5 and 25 mg kg-1. The antinociception produced by the hexane and ethyl acetate fractions was significantly reversed by naloxone, indicating that the fractions act through the opioid pathway. Antinociceptive response of the ethyl acetate fraction was blocked by glibenclamide, indicating that this fraction acts via the K + ATP channels activation. It is concluded that the fractions under study exert antinociceptive activity possibly related to the opioid route and through K+ ATP channels activation.

Systemic and reproductive toxicity induced by Parkia platycephala ethanolic extract in female Wistar rats

The present study was conducted to evaluate the toxicity of the ethanolic extract of leaves of Parkia platycephala Benth., Fabaceae, on systemic and reproductive parameters. In toxicity on the estrous cycle, four groups of not-pregnant Wistar rats received distilled water and the doses 250, 500 and 1000 mg.kg-1 of plant extract for thirty days, at the end of which they were examined as to the frequency of their phases. The systemic toxicity was assessed through the consumption of water and food and by measuring body mass. After the extract was administered, serum AST, ALT, ALP, bilirubin (total, direct and indirect), urea and creatinine were dosed. The evaluation of the organs (brain, heart, hypophysis, adrenal glands, liver, spleen, uterus and ovaries) in their macroscopic aspects, relative and absolute masses and histological structure showed that the plant extract induced a decrease of water and food consumption and of body mass. It caused an increase in the luteal phase and a decrease in the follicular phase of the estrous cycle and rose serum alkaline phosphatase levels.The data exhibit systemic and reproductive toxicity induced by plant extract in female Wistar rats.

Angiotensin-(1-7): a novel peptide in the ovary.

The present study was undertaken to investigate the presence of angiotensin-(1-7) [Ang-(1-7)] in the ovary and a possible role for it. Cycling female rats were killed in each phase of the estrous cycle, and ovarian Ang II and Ang-(1-7) were separated by HPLC and measured by RIA. The mean levels of Ang-(1-7) in proestrus and estrus were significantly higher than those in metestrus and diestrus (P < 0.05). Ang-(1-7) was also significantly higher in equine chorionic gonadotropin (eCG)-treated immature rats. Ang-(1-7) induced a significant increase in estradiol and progesterone production (P < 0.05) in the ovary of immature rats (24-25 d old) pretreated with eCG and perfused in a closed circuit system. This effect was blocked by A-779, a specific Ang-(1-7) antagonist (P < 0.05). The present data demonstrate the presence and physiological role of a novel renin-Ang system peptide in the ovary. The higher level of Ang-(1-7) in proestrus and estrus as well as in eCG-treated rats suggests the involvement of this renin-Ang system peptide in pre- and postovulatory events.