Mohammad Zarei

Effects of the hydroalcoholic extract of Rosa damascena on learning and memory in male rats consuming a high-fat diet

Abstract Context: High-fat diet (HFD) can cause deficits in learning and memory through oxidative stress and increase Alzheimer disease risk. Rosa damascena Mill. (Rosaceae) extract possesses potent antioxidant properties. Objective: This study investigated the effects of the hydroalcoholic extracts of petals of R. damascena on learning and memory in male rats consuming an HFD. Materials and methods: Forty male Wistar rats (200–250 g) were randomly assigned to four groups: control, R. damascena extract, HFD and HFD + extract. The extract (1 g/kg bw daily) was administered by oral gavage for 1 month. Animals were allowed free access to high-fat chow for 3 months. The Morris water maze and the passive avoidance learning tests were used to assess learning and memory. Results: In the passive avoidance learning test, the step-through latencies in the retention test (STLr) of the extract (147.4 ± 23.3) and HFD (150.3 ± 25.2) groups were significantly lower than those of the control group (270.4 ± 10.5) (respectively, p < 0.001 and p < 0.01). STLr was significantly higher in the HFD + extract group (265.3 ± 10.6) than in the HFD group (150.3 ± 25.2) (p < 0.01). Time spent in the dark compartment (TDC) in the HFD + extract group (5.3 ± 2.6) was significantly lower than that in the HFD group (85.8 ± 19.1) (p < 0.05). Discussion and conclusion: Our results indicate that, while HFD or R. damascena extract alone leads to memory deficits, R. damascena extract exerted a positive effect on HFD-induced memory deficits. We hypothesize that the observed effects of R. damascena extract are likely due to its strong antioxidant properties.

Effect of Hydroalcoholic Leaves Extract of Rhus Coriaria on Pain in Male Rats

Background: The drive toward the use of medicinal plants has been increasing in recent years. They have few side effects and a large variety of efficient components. Objectives: This study was designed to investigate the analgesic effects of hydroalcoholic Rhus coriaria leaf extract (HRCLE) in a rat model. Materials and Methods: A total of 42 adult male rats were divided into seven groups: a control group (the animals did not receive any drug), three HRCLE groups, (receiving 80, 100, and 300 mg/kg, intraperitoneally [ip]), a morphine group (1 mg/kg, ip) an aspirin group (1 mg/kg, ip), and a group that received 300 mg/kg of HRCLE plus naloxone (1 mg/kg, ip). The analgesic effects of HRCLE were assessed via writhing, tail flick, and formalin tests, and the data obtained were compared with the control group using one-way analysis of variance and Tukey post hoc tests. Results: HRCLE significantly inhibited the number of contractions induced by acetic acid in the writhing test at all doses, while anti-nociceptive activity was only shown at the 100 mg/kg dose (in the chronic phase) and at the 300 mg/kg dose (in the chronic-acute phase) in the formalin test. Interestingly, the greatest effect was observed at the 300 mg/kg HRCLE dose in the tail flick test. Simultaneous utilization of naloxone and HRCLE inhibited the anti-nociceptive effect of the extract in all tests. It is worth mentioning that aspirin and morphine revealed anti-nociceptive effects in all tests. Conclusions: Our findings suggest that the analgesic effect of HRCLE may be mediated via both peripheral and central mechanisms. The presence of flavonoids might be responsible for the anti-nociceptive activity of this plant.

Antinociceptive activity of Inula britannica L. and patuletin: In vivo and possible mechanisms studies

ETHNOPHARMACOLOGICAL RELEVANCE Inula britannica L. is a predominant medicinal plant traditionally utilized in the treatments of arthritis and back pain in Iranian folk medicine. AIM OF THE STUDY The purpose of this research was to evaluate the antinociceptive effects of Inula britannica L. flower essential oil (IBLEO) and one of its major constituents, Patuletin (Pn), in male mice. MATERIALS AND METHODS In this study, we used pain assessment tests including acetic acid-induced writhing, tail-flick (TF), formalin induced paw licking (FIPL) model, and glutamate-induced paw licking (GPL). For understanding the supposed antinociceptive mechanisms of IBLEO, opioid and L-arginine/NO/cGMP/ KATP pathways were examined. RESULTS In the TF, writhing, GPL, and FIPL tests, a dosage of 100 mg/kg of IBLEO showed noteworthy antinociceptive effects in comparison with control (p < 0.05). In writhing test, administration of selective opioid antagonists (naltrindole, nor-binaltorphimine, and naloxonazine) attenuated the antinociceptive effect of IBLEO in comparison with control (p < 0.001). Both methylene blue and glibenclamide blocked the antinociceptive effect of IBLEO (p < 0.05), but the administration of L-arginine or sodium nitroprusside fundamentally potentiated the antinociception induced by IBLEO in phase II of the FIPL (p < 0.05). Additionally, patuletin showed significant antinociceptive effects in writhing, FIPL, and GPL tests (p < 0.01). CONCLUSION The results of this examination showed that IBLEO and Pn have antinociceptive effects. The modulation of glutamatergic systems by opioid receptors could be involved, at least in part, in these effects. Our data also suggest the activation of the L-arginine/NO/cGMP/KATP pathway in IBLEO antinociceptive effects.