Methanolic leaf extract of Punica granatum attenuates ischemia-reperfusion brain injury in Wistar rats: Potential antioxidant and anti-inflammatory mechanisms

Objective(s): This study was conducted to evaluate the cerebroprotective effect of methanolic leaf extract of Punica granatum (MePG) in Wistar rats.Materials and Methods: The MePG was initially assessed for in vitro antioxidant activity, and later evaluated on LPS-induced RAW 264.7 cell line assay. Finally, the MePG was evaluated against ischemia-reperfusion (I/R) induced brain injury in Wistar rats.Results: In DPPH, FRAP and ORAC assays, the MePG has exhibited potent antioxidant activity. Further, the MePG has significantly inhibited the generation of nitrite, ROS and TNF-α in LPS-induced RAW 264.7 cell lines. Besides, global ischemia followed by reperfusion caused significant changes in the neurological and behavioral functions in I/R control animals compared to sham control. Additionally, in the I/R control group there was a substantial decrease in the catalase and superoxide dismutase activities; Likewise, reduced glutathione levels reduced and lipid peroxidation levels enhanced significantly. Also, pro-inflammatory cytokines such as TNF-α, IL-6, and ICAM-I were increased and the levels of IL-10 was decreased significantly. Furthermore, the I/R insult caused increase in brain volume and cerebral infarct formation. Similarly, histopathology of the brain tissue revealed hallmarks like necrosis, leukocyte infiltration, cerebral edema and vascular congestion in I/R control. Notably, MePG (200 and 400 mg/kg) pretreatment for 7 days, has attenuated all the I/R-persuaded pathological changes compared to I/R control. In addition, the LC-MS/MS analysis showed presence of acteoside, apigenin, gallic acid, gossypin, pentagalloyl glucose, quercetin, and rutin as major ingredients in the MePG.Conclusion: These findings suggest that the MePG possesses significant cerebroprotective activity.