Protection of vascular endothelial cells injured by angiotensin II and hypoxia in vitro by Ginkgo biloba (Ginaton)

Ginkgo biloba in the management of the COVID-19 severity

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is linked with inflammatory disorders and the development of oxidative stress in extreme cases. Therefore, anti-inflammatory and antioxidant drugs may alleviate these complications. Ginkgo biloba L. folium extract (EGb) is a herbal medicine containing various active constituents. This review aims to provide a critical discussion on the potential role of EGb in the management of coronavirus disease 2019 (COVID-19). The antiviral effect of EGb is mediated by different mechanisms, including blocking SARS-CoV-2 3-chymotrypsin-like protease that provides trans-variant effectiveness. Moreover, EGb impedes the development of pulmonary inflammatory disorders through the diminution of neutrophil elastase activity, the release of proinflammatory cytokines, platelet aggregation, and thrombosis. Thus, EGb can attenuate the acute lung injury and acute respiratory distress syndrome in COVID-19. In conclusion, EGb offers the potential of being used as adjuvant antiviral and symptomatic therapy. Nanosystems enabling targeted delivery, personalization, and booster of effects provide the opportunity for the use of EGb in modern phytotherapy.

Ginkgolide B Maintains Calcium Homeostasis in Hypoxic Hippocampal Neurons by Inhibiting Calcium Influx and Intracellular Calcium Release

Ginkgolide B (GB), a terpene lactone and active ingredient of Ginkgo biloba, shows protective effects in neuronal cells subjected to hypoxia. We investigated whether GB might protect neurons from hypoxic injury through regulation of neuronal Ca²⁺ homeostasis. Primary hippocampal neurons subjected to chemical hypoxia (0.7 mM CoCl₂) in vitro exhibited an increase in cytoplasmic Ca²⁺ (measured from the fluorescence of fluo-4), but this effect was significantly diminished by pre-treatment with 0.4 mM GB. Electrophysiological recordings from the brain slices of rats exposed to hypoxia in vivo revealed increases in spontaneous discharge frequency, action potential frequency and calcium current magnitude, and all these effects of hypoxia were suppressed by pre-treatment with 12 mg/kg GB. Western blot analysis demonstrated that hypoxia was associated with enhanced mRNA and protein expressions of Ca_v1.2 (a voltage-gated Ca²⁺ channel), STIM1 (a regulator of store-operated Ca²⁺ entry) and RyR2 (isoforms of Ryanodine Receptor which mediates sarcoplasmic reticulum Ca²⁺ release), and these actions of hypoxia were suppressed by GB. Taken together, our in vitro and in vivo data suggest that GB might protect neurons from hypoxia, in part, by regulating Ca²⁺ influx and intracellular Ca²⁺ release to maintain Ca²⁺ homeostasis.

Gingko biloba Extract (EGb) Inhibits Oxidative Stress in Neuro 2A Cells Overexpressing APPsw

Alzheimer's disease (AD) is a common neurodegenerative disease. Abundant evidence demonstrates that oxidative stress may be not only an early event in this disease, but also a key factor in the pathogenesis of AD. Ginkgo biloba extract (EGb) has a strong ability to scavenge oxygen free radicals and supply hydrogen. The present study aims to investigate the effects of EGb on Neuro 2A cells transfected with Swedish mutant APP (APPsw). Stably transfected Neuro 2A cell lines expressing human wild-type APP (APP695), APPsw, or empty vector(neo) pEGFP-N2 were treated with 100 μg/ml EGb for 0, 2, 4, 6, 8, and 10 h. Oxidative stress was assessed by measuring free radicals and the activities of antioxidant enzymes. Our studies showed that EGb treatment reduced the production of reactive oxygen species (ROS) and the levels of malondialdehyde (MDA) significantly while total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were enhanced in Neuro 2A cells overexpressing APPsw. Meanwhile, Aβ levels in these cells were also reduced compared to the levels in untreated cells and control cells (empty vector(neo) pEGFP-N2). These findings suggest that EGb can reduce oxidative stress by decreasing free radical and enhancing antioxidant status, further leading to reduced Aβ aggregation; EGb might be a potential therapeutic agent for Alzheimer's disease (AD).

Stems and leaves of Aconitum carmichaelii Debx. as potential herbal resources for treating rheumatoid arthritis: Chemical analysis, toxicity and activity evaluation

According to folk usage of Aconitum carmichaelii Debx., the present study was designed to determine the feasibility of the stems and leaves of Aconitum carmichaelii Debx. as a new medicinal resource. Fourteen alkaloids in mother roots, fibrous roots, stems, and leaves of Aconitum carmichaelii Debx. were measured by HPLC-MS/MS. And multivariate analysis methods, such as clustering analysis and principal component analysis, were applied to analyze the difference among various parts. In addition, the acute toxicity, analgesia, and anti-inflammatory tests were carried out. The results suggested that the contents of alkaloids in mother roots and fibrous roots were approximate, but those of leaves and stems were different from mother roots and fibrous roots. The results of the acute toxicity testing demonstrated the toxicity of fibrous root was strongest, and mother roots were slightly less toxic than fibrous roots. The stems and leaves were far less toxic than mother and fibrous roots. In addition, the analgesia and inflammatory tests showed the effects of the various tissues had no difference each other. These results provided a basis for developing new complementary and alternative treatments for rheumatoid arthritis patients. Simultaneously, the approach may also turn wastes into treasure and promote the development of circular economy.

Advances in the Studies of Ginkgo Biloba Leaves Extract on Aging-Related Diseases

The prevalence of degenerative disorders in public health has promoted in-depth investigations of the underlying pathogenesis and the development of new treatment drugs. Ginkgo biloba leaves extract (EGb) is obtained from Ginkgo biloba leaves and has been used for thousands of years. In recent decades, both basic and clinical studies have established the effects of EGb. It is widely used in various degenerative diseases such as cerebrovascular disease, Alzheimer's disease, macroangiopathy and more. Here, we reviewed several pharmacological mechanisms of EGb, including its antioxidant properties, prevention of mitochondrial dysfunctions, and effect on apoptosis. We also described some clinical applications of EGb, such as its effect on neuro and cardiovascular protection, and anticancer properties. The above biological functions of EGb are mainly focused on aging-related disorders, but its effect on other diseases remains unclear. Thus, through this review, we aim to encourage further studies on EGb and discover more potential applications.

Protective effects of diltiazem against vascular endothelial cell injury induced by angiotensin-II and hypoxia

To provide pharmacological data for future clinical studies, this study investigated the protective effects of diltiazem on vascular endothelial cell (VEC) injury induced by angiotensin-II (AngII), hypoxia, and a combination of both treatments. The concentration of intracellular free calcium and the mitochondrial membrane potential in VEC were assessed as indicators of cell injury. An in vivo hypoxic animal model was used to test the protective effect of diltiazem on vascular endothelial tissues. Our study showed that AngII and hypoxia decreased the mitochondrial membrane potential in VEC, which was significantly inhibited by diltiazem. Diltiazem protected against VEC injury induced by the increased concentration of intracellular free calcium, which was associated with AngII and hypoxia. Diltiazem reduced the apoptosis of rat VEC under a sustained hypoxic condition. In addition, it reduced AngII and endothelin I levels in rat vascular endothelial tissues. Our study confirmed that AngII and hypoxia induced VEC injury by regulating the levels of mitochondrial membrane potential and intracellular free calcium. Diltiazem, a calcium channel blocker, protected VEC from AngII- and hypoxia-induced injury.