Baicalein, Baicalin, and Wogonin: Protective Effects against Ischemia‐Induced Neurodegeneration in the Brain and Retina

Abstract

Ischemia is a common pathological condition present in many neurodegenerative diseases, including ischemic stroke, retinal vascular occlusion, diabetic retinopathy, and glaucoma, threatening the sight and lives of millions of people globally. Ischemia can trigger excessive oxidative stress, inflammation, and vascular dysfunction, leading to the disruption of tissue homeostasis and, ultimately, cell death. Current therapies are very limited and have a narrow time window for effective treatment. Thus, there is an urgent need to develop more effective therapeutic options for ischemia-induced neural injuries. With emerging reports on the pharmacological properties of natural flavonoids, these compounds present potent antioxidative, anti-inflammatory, and antiapoptotic agents for the treatment of ischemic insults. Three major active flavonoids, baicalein, baicalin, and wogonin, have been extracted from Scutellaria baicalensis Georgi (S. baicalensis); all of which are reported to have low cytotoxicity. They have been demonstrated to exert promising pharmacological capabilities in preventing cell and tissue damage. This review focuses on the therapeutic potentials of these flavonoids against ischemia-induced neurotoxicity and damage in the brain and retina. The bioactivity and bioavailability of baicalein, baicalin, and wogonin are also discussed. It is with hope that the therapeutic potential of these flavonoids can be utilized and developed as natural treatments for ischemia-induced injuries of the central nervous system (CNS).

Baicalein—A Potent Pro-Homeostatic Regulator of Microglia in Retinal Ischemic Injury

“…Proteomic studies were conducted to understand the regulatory mechanisms of baicalein against LPS-induced microglial activation. Previous reports showed that baicalein protects neurons against oxidative stress and lipid metabolism disorders ( 14 , 44 ). Consistently, our enriched GO and MPO analysis also demonstrated that baicalein mediates the biological processes of oxidation–reduction and lipid metabolic process ( Figures S1A, C ) .…”

“…Baicalein (5,6,7-trihydroxyflavone; C 15 H 10 O 5 ; MW 270.2) is a major flavonoid extracted from the roots of the natural herb Scutellaria baicalensis Georgi (SB). SB is widely used in the clinic in Asia to treat various diseases and injuries, such as ischemic stroke and COVID-19 (13)(14)(15). Previous studies have shown that baicalein exerts a broad spectrum of bioactivity, including antioxidation, anti-apoptosis, and anti-excitotoxicity (16).…”

Treatment of Glaucoma with Natural Products and Their Mechanism of Action: An Update

“…Scutellaria baicalensis Georgi, commonly known as Baikal skullcap or Chinese skullcap, is a widely used Chinese medicinal herb [106]. S. baicalensis extract and its three major active flavonoids, namely, baicalin, baicalein and wogonin showed low cytotoxicity and possessed neuroprotective, antioxidant, anti-inflammatory and anti-cancer properties [106][107][108].…”

Flavonoids in Treatment of Chronic Kidney Disease

“…Therefore, flavonoids have been evaluated for possible beneficial effects on a variety of acute and chronic human diseases. In vitro and in vivo studies have shown that flavonoids exert numerous benefits, such as anti-inflammatory [ 54 , 55 ], antioxidant [ 56 , 57 ], anticardiovascular [ 58 ], neuroprotective [ 59 , 60 ], and strong anticancer effects [ 61 , 62 , 63 ].…”