RESUMO
Background: Juglans (J.) nigra leaf is obtained from a plant that is used in traditional medicine in some countries to alleviate inflammatory diseases. Aim: The aim of this study was to compare the effects of J. nigra extract on acute nociceptive and inflammatory pain in rats. Methods: Antinociceptive activity was examined in Wistar rats by the tail-immersion and formalin tests. Motor function was assessed using the rotarod test. Plant extract was administered intraperitoneally. Results: In the tail-immersion test, the maximal antinociceptive effect of the plant extract (100-330 mg/kg) was about 24-30% and is the result of the effect of a high concentration of ethanol. In the formalin test, the plant extract (41.3-330 mg/kg) significantly and dose-dependently inhibited nociception in both phases of the test with similar maximal effects of about 76% and 85%. Only the plant extract at the dose of 330 mg/kg caused a significant time-dependent reduction in time spent on the rotarod. Conclusions: In rats, the preventive systemic administration of the hydroethanolic extract of J. nigra leaf reduced chemically but not thermally induced pain. Higher efficacy was obtained in pain associated with inflammation and tissue injury. The antinociceptive effect is dose-dependent and may be limited by motor impairment.
RESUMO
The current study was aimed to analyze the therapeutic effect of selected medicinal plants, that is, Curcuma longa, Zingiber officinale, Trigonella graceum-foenum, Nigella sativa, and Syzygium aromaticum against carrageenan-induced oxidative stress and inflammation in rats. Phytochemical analysis revealed the presence of diverse range of bioactives. IC50 values for antioxidant assays including DPPH (2,2-diphenyl-1-picrylhydrazyl), metal chelating, ABTS scavenging (2, 2'-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid), ß-carotene bleaching, and H2O2 (hydrogen peroxide) scavenging ranged from 37-294, 71-243.4, 69.66-191.8, 98.92-228.5, and 82-234.9 µg/mL, respectively. All tested plants extract were found active against tested pathogenic microorganisms with lowest minimum inhibitory concentrations. Oral administration of tested plants extracts in different doses (250, 500, and 1000 mg/kg b. w) did not exhibit any toxicological effects on hemato-biochemical profile of treated rats in comparison to control group rats. Further, plants extract exhibited considerable anti-inflammatory activity in rats paw inflammation and decreased cellular infiltration to inflammatory site in dose dependent manner. Pretreatment of animals with tested plants extract (100, 200, and 400 mg/kg b. w.) caused significant alteration in total antioxidants, oxidants, and enzymes activities in paw tissue homogenate and the effect was more pronounced at higher concentration (400 mg/kg b. w.). Results showed that tested plants extract are rich source of diverse classes of phenolics and have therapeutic potential against oxidative stress and inflammation.