Gynura procumbens Root Extract Ameliorates Ischemia-Induced Neuronal Damage in the Hippocampal CA1 Region by Reducing Neuroinflammation

Abstract

Gynura procumbens has been used in Southeast Asia for the treatment of hypertension, hyperglycemia, and skin problems induced by ultraviolet irradiation. Although considerable studies have reported the biological properties of Gynura procumbens root extract (GPE-R), there are no studies on the effects of GPE-R in brain damages, for example following brain ischemia. In the present study, we screened the neuroprotective effects of GPE-R against ischemic damage and neuroinflammation in the hippocampus based on behavioral, morphological, and biological approaches. Gerbils received oral administration of GPE-R (30 and 300 mg/kg) every day for three weeks and 2 h after the last administration, ischemic surgery was done by occlusion of both common carotid arteries for 5 min. Administration of 300 mg/kg GPE-R significantly reduced ischemia-induced locomotor hyperactivity 1 day after ischemia. Significantly more NeuN-positive neurons were observed in the hippocampal CA1 regions of 300 mg/kg GPE-R-treated animals compared to those in the vehicle-treated group 4 days after ischemia. Administration of GPE-R significantly reduced levels of pro-inflammatory cytokines such as interleukin-1β, -6, and tumor necrosis factor-α 6 h after ischemia/reperfusion. In addition, activated microglia were significantly decreased in the 300 mg/kg GPE-R-treated group four days after ischemia/reperfusion compared to the vehicle-treated group. These results suggest that GPE-R may be one of the possible agents to protect neurons from ischemic damage by reducing inflammatory responses.

Cissus verticillata Extract Decreases Neuronal Damage Induced by Oxidative Stress in HT22 Cells and Ischemia in Gerbils by Reducing the Inflammation and Phosphorylation of MAPKs

“…In addition, CVE treatment significantly reduced the ischemia-induced apoptosis and increased anti-apoptotic protein, consistent with in vitro study. To elucidate the possible mechanisms against ischemic damage in the gerbil hippocampus, we focused on oxidative stress and inflammatory responses in the hippocampus after ischemia, because several studies have demonstrated that CVE has anti-inflammatory activity [28,40], and inflammation is one of the main pathways for neuronal death after ischemia in the gerbil hippocampus [41,42]. Overexpression of ROS induced by ischemia/reperfusion causes lipid peroxidation of polyunsaturated fatty acids in the neuronal membrane and disrupts the cell membrane [43].…”

“…The protocols were approved by the Institutional Animal Care and Use Committee (IACUC) of Seoul National University (SNU-170630-8-2). Forebrain ischemia was induced by the occlusion of both common carotid arteries in the neck region as described previously [41,61]. CVE (30 or 300 mg/kg) or vehicle (distilled water) was administered to gerbils using a feeding needle.…”