Populus tomentiglandulosa Extract Is Rich in Polyphenols and Protects Neurons, Astrocytes, and the Blood-Brain Barrier in Gerbil Striatum Following Ischemia-Reperfusion Injury

Abstract

Transient ischemia in brains causes neuronal damage, gliosis, and blood–brain barrier (BBB) breakdown, which is related to ischemia-induced brain dysfunction. Populus species have various pharmacological properties including antioxidant and anti-inflammatory activities. In this study, we found that phenolic compounds were rich in Populus tomentiglandulosa extract and examined the effects of Populus tomentiglandulosa extract on neuronal damage/death, astrogliosis, and BBB breakdown in the striatum, which is related to motor behavior, following 15-min transient ischemia in the forebrain in gerbils. The gerbils were pre-treated with 50, 100, and 200 mg/kg of the extract. The latter showed significant effects against ischemia-reperfusion injury. Ischemia-induced hyperactivity using spontaneous motor activity test was significantly attenuated by the treatment. Striatal cells (neurons) were dead at five days after the ischemia; however, pre-treatment with the extract protected the striatal cells from ischemia/reperfusion injury. Ischemia-induced reactive astrogliosis was significantly alleviated, in particular, astrocyte end feet, which are a component of BBB, were significantly preserved. Immunoglobulin G, which is not found in intact brain parenchyma, was apparently shown (an indicator of extravasation) in striatal parenchyma at five days after the ischemia, but IgG leakage was dramatically attenuated in the parenchyma by the pre-treatment. Based on these findings, we suggest that Populus tomentiglandulosa extract rich in phenolic compounds can be employed as a pharmaceutical composition to develop a preventive material against brain ischemic injury.

Populus tomentiglandulosa protects against amyloid-beta25-35-induced neuronal damage in SH-SY5Y cells

“…P. tomentiglandulosa has been demonstrated that phenolic compounds such as catechin, caffeic acid, p-coumaric acid, chlorogenic acid, and gallic acid are the main components which exert various pharmacological effects [20]. Lee et al [21] reported that EtOH extract of P. tomentiglandulosa prevents the death of neurons, astrogliosis, and leakage for blood-brain barrier in gerbil hippocampus against ischemia-reperfusion injury. Lee et al [22] demonstrated that EtOH extract of P. tomentiglandulosa represents hepato-and nephro-protective effects depending on antioxidant activity.…”

Therapeutic effects of stiripentol against ischemia-reperfusion injury in gerbils focusing on cognitive deficit, neuronal death, astrocyte damage and blood brain barrier leakage in the hippocampus

“…It has been reported that astrocytes play significant roles in both healthy and injured brains including ischemic stroke [ 34 - 37 ]. Functional and morphological alterations in astrocytes have been reported in brains with pathological conditions (the process is termed “astrogliosis”) [ 2 , 38 , 39 ]. It is known that astrogliosis is characterized by proliferation and hypertrophy of astrocytes with increased GFAP expression in astrocytes [ 2 , 40 ].…”

“…However, Sofroniew and Vinters [ 41 ] have reported that an increase of cells positive to GFAP does not result from new astrocyte generation, but from an increase in GFAP synthesis and filament condensation in pre-existing astrocytes. Based on this finding, we have recently reported that GFAP positive cells (astrocytes) with strong GFAP immunoreactivity in gerbil striatum are swollen in cell bodies and destroyed (short and thickened) in their processes at five days after TFI [ 39 ]. In the current study, GFAP immunoreactivity was significantly increased in astrocytes of the TFI-vehicle group.…”

Porphyran Attenuates Neuronal Loss in the Hippocampal CA1 Subregion Induced by Ischemia and Reperfusion in Gerbils by Inhibiting NLRP3 Inflammasome-Mediated Neuroinflammation

“…The test of SLA was assessed on day 1 after forebrain IR surgery using a previously published procedure [48]. Briefly, each gerbil was placed in a 25 × 20 × 12 cm Plexiglas cage equipped with infrared-sensitive photocells.…”