Peripheral antinociceptive action of mangiferin in mouse models of experimental pain: Role of endogenous opioids, KATP-channels and adenosine

AbstractThis study aimed to assess the possible systemic antinociceptive activity of mangiferin and to clarify the underlying mechanism, using the acute models of chemical (acetic acid, formalin, and capsaicin) and thermal (hot-plate and tail-flick) nociception in mice. Mangiferin at oral doses of 10 to 100mg/kg evidenced significant antinociception against chemogenic pain in the test models of acetic acid-induced visceral pain and in formalin- and capsaicin-induced neuro-inflammatory pain, in a naloxone-sensitive manner, suggesting the participation of endogenous opiates in its mechanism. In capsaicin test, the antinociceptive effect of mangiferin (30mg/kg) was not modified by respective competitive and non-competitive transient receptor potential vanilloid 1 (TRPV1) antagonists, capsazepine and ruthenium red, or by pretreatment with l-NAME, a non-selective nitric oxide synthase inhibitor, or by ODQ, an inhibitor of soluble guanylyl cyclase. However, mangiferin effect was significantly reversed by glibenclamide, a blocker of KATP channels and in animals pretreated with 8-phenyltheophylline, an adenosine receptor antagonist. Mangiferin failed to modify the thermal nociception in hot-plate and tail-flick test models, suggesting that its analgesic effect is only peripheral but not central. The orally administered mangiferin (10–100mg/kg) was well tolerated and did not impair the ambulation or the motor coordination of mice in respective open-field and rota-rod tests, indicating that the observed antinociception was unrelated to sedation or motor abnormality. The findings of this study suggest that mangiferin has a peripheral antinociceptive action through mechanisms that involve endogenous opioids, KATP-channels and adenosine receptors

Morphological characterization of fruits and seeds of Jatropha mollissima (Pohl) Baill. (Magnoliopsida: Euphorbiaceae)

Abstract. Jatropha mollissima (Pohl) Baill. is a native plant of the Brazilian semiarid that belongs to the Euphorbiaceae family. It is a widely distributed monoecious occurring in all states of Northeast Brazil, except Maranhão, and inhabiting areas of caatinga and restinga. In order to add information about this species as well as to facilitate their identification, this study aimed to determine the biometrics, to describe and illustrate the internal and external structures of the seed and the fruit, and to determine the chemical composition of J. mollissima seed. It was observed that the fruit is dry, smooth, and capsular, with average length of 2.31 cm, width of 2.06 cm, and thickness of 2.01 cm, respectively. The seed is eurispermic, oval, dorsum convex, flat wrap, with caruncle, and its average length, width, and tickeness are 1.27 cm, 0.84 cm, and 0.66 cm, respectively. The cytochemical and chemical analyses revelead marked lipid (35%) and protein (19.87%) contents in the seeds of this species