Isoquercetin

Isoquercetin is a flavonoid with diverse biological activities, including antioxidant, antiproliferative, and anti-inflammatory properties^{[1, 2]}. Due to its high bioavailability and low toxicity, Isoquercetin is a promising candidate for preventing congenital defects in diabetic pregnancy^[3].

In vitro, pretreatment of primary cultured rat cortical neurons with Isoquercetin (20, 40, 80µg/mL) for 24h reduced the increase in intracellular calcium concentration and lactate dehydrogenase (LDH) release induced by oxygen-glucose deprivation/reperfusion (OGD/R) injury, and prevented the decrease in cell viability^[4]. Pretreatment of HepG2 cells with Isoquercetin (10μM) for 1h significantly downregulated ethanol-induced iNOS protein expression levels in the cells^[5].

In vivo, intravenous administration of Isoquercetin (50mg/kg) for 7 days to rats subjected to middle cerebral artery occlusion (MCAO) injury reduced the cerebral infarct volume and mitigated the decrease in Nrf2 expression levels in hippocampal tissue^[6]. Oral administration of Isoquercetin (20mg/kg) for 3 days to rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) injury reduced the cerebral infarct volume, improved neurological deficits, and decreased the production of reactive oxygen species (ROS) and malondialdehyde (MDA) in brain tissue^[7].

References:
[1] Mbikay M, Chrétien M. Isoquercetin as an anti-COVID-19 medication: A potential to realize[J]. Frontiers in Pharmacology, 2022, 13: 830205.
[2] Azeem M, Hanif M, Mahmood K, et al. An insight into anticancer, antioxidant, antimicrobial, antidiabetic and anti-inflammatory effects of quercetin: A review[J]. Polymer Bulletin, 2023, 80(1): 241-262.
[3] Cao L, Tan C, Meng F, et al. Amelioration of intracellular stress and reduction of neural tube defects in embryos of diabetic mice by phytochemical quercetin[J]. Scientific Reports, 2016, 6(1): 21491.
[4] Wang C P, Li J L, Zhang L Z, et al. Isoquercetin protects cortical neurons from oxygen–glucose deprivation–reperfusion induced injury via suppression of TLR4–NF-кB signal pathway[J]. Neurochemistry international, 2013, 63(8): 741-749.
[5] Lee S, Lee J, Lee H, et al. Relative protective activities of quercetin, quercetin‐3‐glucoside, and rutin in alcohol‐induced liver injury[J]. Journal of food biochemistry, 2019, 43(11): e13002.
[6] Chen M, Dai L H, Fei A, et al. Isoquercetin activates the ERK1/2-Nrf2 pathway and protects against cerebral ischemia-reperfusion injury in vivo and in vitro[J]. Experimental and Therapeutic Medicine, 2017, 13(4): 1353-1359.
[7] Dai Y, Zhang H, Zhang J, et al. Isoquercetin attenuates oxidative stress and neuronal apoptosis after ischemia/reperfusion injury via Nrf2-mediated inhibition of the NOX4/ROS/NF-κB pathway[J]. Chemico-biological interactions, 2018, 284: 32-40.

Isoquercetin是一种具有多样生物活性的类黄酮，具有抗氧化、抗增殖和抗炎等特性^{[1, 2]}。Isoquercetin具有高生物利用度和低毒性，是预防糖尿病妊娠先天缺陷的有前景候选药物^[3]。

在体外，Isoquercetin（20, 40, 80µg/mL）预处理原代培养的大鼠皮层神经元24h，降低了氧糖剥夺损伤（OGD/R）诱导的细胞内钙离子浓度升高和乳酸脱氢酶（LDH）释放，防止了细胞活力下降^[4]。Isoquercetin（10μM）预处理HepG2细胞1h，显著下调了细胞中乙醇诱导的iNOS蛋白表达水平^[5]。

在体内，Isoquercetin（50mg/kg）通过静脉注射给药治疗接受大脑中动脉闭塞（MCAO）损伤的大鼠7天，减轻了大鼠脑梗死体积，减轻了海马组织中Nrf2表达水平下降程度^[6]。Isoquercetin（20mg/kg）通过灌胃给药治疗接受大脑中动脉闭塞/再灌注（MCAO/R）损伤的大鼠3天，减轻了大鼠脑梗死体积，改善了大鼠的神经功能缺损，降低了大鼠脑组织中活性氧（ROS）和丙二醛（MDA）的产生^[7]。