Lycium Barbarum Polysaccharides Decrease Hyperglycemia-Aggravated Ischemic Brain Injury through Maintaining Mitochondrial Fission and Fusion Balance

Abstract

Although it has been reported that polysaccharides found in Lycium barbarum possess neuroprotective effects, little is known of their ability to ameliorate hyperglycemia-aggravated ischemia/reperfusion brain injury. In this study, normoglycemic (NG) and hyperglycemic (HG) rats were compared after 30 minutes of middle cerebral artery occlusion (MCAO), followed by 24 or 27 hours of reperfusion, with HG rats pretreated with lyceum barbarum polysaccharides (LBP) or insulin. In each group, the neurological deficit, infarct volume, pathohistology, and expression of proteins, Opa1 and Drp1, were assessed to determine the efficacy of LBP in alleviating hyperglycemia-aggravated ischemia/reperfusion brain injury. Our results show that, compared to the NG group, the HG group had increases in neurological deficits, infarct volume, and evidence of neuronal pyknosis at 24- and/or 72-h of reperfusion (P<0.05) and that pre-treatment with LBP decreased these effects (P<0.05). In addition, immunohistochemistry revealed an increase of Drp1 and a decrease of Opa1 positive neurons in the HG group after 24 and 72 hours of reperfusion when compared to the NG group. LBP treatment prevented the HG-induced alterations in Drp-1 and Opa1 expression. Western blots further confirmed these findings showing that HG caused an increase in phospho-Drp1 and a decrease in Opa1 which were subsequently reversed by LBP addition. These results suggest that hyperglycemia-aggravated ischemic brain damage is associated with an alteration of mitochondrial dynamics and that pre-treatment with LBP ameliorates the hyperglycemia-enhanced ischemic brain damage through maintaining mitochondrial dynamic balance.

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“…Several investigations have shown that mitochondrial fission is critical for the mitochondrial homeostasis. Mitochondrial fission factor (MFF) or fission 1 (FIS1)-mediated excessive mitochondrial fission could lead to ROS burst and activation of the mitochondrial apoptosis pathway [39]. In the present study, we also found that MPS promoted MFF and FIS1 protein expressions while VO-OHpic attenuated these changes (Fig.…”

Lycium�barbarum polysaccharides protect human trophoblast HTR8/SVneo cells from hydrogen peroxide‑induced oxidative stress and apoptosis

“…LBP is the main active component of the Chinese wolfberry ( 21 ). LBP was purchased from Qinghai General Health Bio-science Co., LLC (Xining, China) and the purity of LBP was >50%.…”

Beneficial Effect of Intestinal Fermentation of Natural Polysaccharides

“…Another study showed that Lycium barbarum derived from polysaccharides ameliorated hyperglycemia-aggravated ischemic/reperfusion brain injury through equilibrating mitochondrial fission and fusion. An increase in phospho-Drp1 and a decrease in Opa1 that negatively correlated with LBP dosage were observed [ 186 ]. In addition, according to Shi et al [ 187 ], Lycium barbarum polysaccharides protected against ischemic injury via modulating NR2B and NR2A signaling pathways.…”