Impaired tricarboxylic acid cycle flux and mitochondrial aerobic respiration during isoproterenol induced myocardial ischemia is rescued by bilobalide

Abstract

There is an urgent need to elucidate the pathogenesis of myocardial ischemia (MI) and potential drug treatments. Here, the anti-MI mechanism and material basis of Ginkgo biloba L. extract (GBE) were studied from the perspective of energy metabolism flux regulation. Metabolic flux analysis (MFA) was performed to investigate energy metabolism flux disorder and the regulatory nodes of GBE components in isoproterenol (ISO)-induced ischemia-like cardiomyocytes. It showed that [U– 13 C] glucose derived m+2 isotopologues from the upstream tricarboxylic acid (TCA) cycle metabolites were markedly accumulated in ISO-injured cardiomyocytes, but the opposite was seen for the downstream metabolites, while their total cellular concentrations were increased. This indicates a blockage of carbon flow from glycolysis and enhanced anaplerosis from other carbon sources. A Seahorse test was used to screen for GBE components with regulatory effects on mitochondrial aerobic respiratory dysfunction. It showed that bilobalide protected against impaired mitochondrial aerobic respiration. MFA also showed that bilobalide significantly modulated the TCA cycle flux, reduced abnormal metabolite accumulation, and balanced the demand of different carbon sources. Western blotting and PCR analysis showed that bilobalide decreased the enhanced expression of key metabolic enzymes in injured cells. Bilobalide's efficacy was verified by in vivo experiments in rats. This is the first report to show that bilobalide, the active ingredient of GBE, protects against MI by rescuing impaired TCA cycle flux. This provides a new mechanism and potential drug treatment for MI. It also shows the potential of MFA/Seahorse combination as a powerful strategy for pharmacological research on herbal medicine.

Bilobalide: A review of its pharmacology, pharmacokinetics, toxicity, and safety

“…Under normal circumstances, SOD plays an important role in preventing cell peroxidation in the tissue. When and regulating mitochondrial aerobic respiration (Wang et al, 2020).…”

“…In addition, the therapeutic effect of BB on the PD model induced by 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine was observed. It was found that BB can inhibit microglial associated neuroinflammation, upregulate some neurotrophic factors and inhibit α‐Syn antibody to alleviate the progression of PD (Wang et al, 2020). The main histopathological feature of AD is senile plaques, which are composed of extracellular aggregates of Aβ‐peptide.…”

Cardioprotective Effect of Gossypin Against Myocardial Ischemic/Reperfusion in Rats via Alteration of Oxidative Stress, Inflammation and Gut Microbiota

“… 10–12 After autooxidation, ISO produces a huge quantity of free radicals, altering the tissue defense systems, such as antioxidant molecules or chemical scavengers and endogenous antioxidant enzymes, such as glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase (CAT). 13 , 14 This is due to a reduction in the endogenous antioxidant system which increases the level of lipids in the heart tissue. It is well known that ISO-induced I/R model in the rodent similar to the human myocardial ischemia.…”

“… 15 Due to the similarity of this model, ISO model is widely used to evaluate the protective effect of various drugs against myocardial I/R. 13 , 14 …”

“… 6 , 22 Currently, researchers are focusing their research on the plant and its phytoconstituents to scrutinize the cardio-protection against I/R. 13 , 14 Phytoconstituents with cardiac protective effects can be a safe and effective alternative medicine for the treatment of myocardial infarction. 23 Flavonoids are specifically reported to possess anti-inflammatory and antioxidant effects.…”