Ganoderma atrum polysaccharide protects cardiomyocytes against anoxia/reoxygenation‐induced oxidative stress by mitochondrial pathway

Abstract

It is now well established that oxidative stress plays a causative role in the pathogenesis of anoxia/reoxygenation (A/R) injury. Ganoderma atrum polysaccharide (PSG-1), the most abundant component isolated from G. atrum, has been shown to possess potent antioxidant activity. The goals of this study were to investigate the effect of PSG-1 against oxidative stress induced by A/R injury and the possible mechanisms in cardiomyocytes. In this work, primary cultures of neonatal rat cardiomyocytes pretreated with PSG-1 were subjected to A/R and subsequently monitored for cell viability by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The levels of intracellular reactive oxygen species (ROS), apoptosis, and mitochondrial membrane potential (Deltapsi(m)) were determined by flow cytometry. Western blot analysis was used to measure the expression of cytochrome c, Bcl-2 family, and manganese superoxide dismutase (MnSOD) proteins, and the activities of caspase-3 and caspase-9 were determined by a colorimetric method. The results showed that PSG-1 protected against cell death caused by A/R injury in cardiomyocytes. PSG-1 reduced the A/R-induced ROS generation, the loss of mitochondrial membrane potential (Deltapsi(m)), and the release of cytochrome c from the mitochondria into cytosol. PSG-1 inhibited the A/R-stimulated activation of caspase-9 and caspase-3 and alteration of Bcl-2 family proteins. Moreover, PSG-1 significantly increased the protein expression of MnSOD in cardiomyocytes. These findings suggest that PSG-1 significantly attenuates A/R-induced oxidative stress and improves cell survival in cardiomyocytes through mitochondrial pathway.

A newly identified polysaccharide from Ganoderma atrum attenuates hyperglycemia and hyperlipidemia

“…In our previous studies, we found that PSG-1 significantly attenuated anoxia/reoxygenation-induced oxidative stress [19] and improved cell survival in cultured cardiomyocytes [20]. PSG-1 treatment was also found to decrease formation of reactive oxygen species, attenuate calcium accumulation, and exhibit a potent anti-tumor activity [7].…”

Ganoderma atrum polysaccharide attenuates oxidative stress induced by d-galactose in mouse brain

“…Currently, G. atrum has been developed into a variety of foods, such as G. atrum tea. PSG-1, the most abundant component isolated from G. atrum, has been shown to possess potent antioxidant activity (Li et al, 2010). Consequently, we investigated the protective effect of PSG-1 on the brain toxicity induced by D-gal in the mice.…”

Macrophage Immunomodulatory Activity of a Purified Polysaccharide Isolated from Ganoderma atrum

“…G. atrum polysaccharide was mainly composed of mannose, galactose, and glucose in a molar ratio of 1:1.28:4.91, detected by gas chromatography. Our recent studies have shown that PSG‐1 possesses a variety of biological functions such as antioxidation (Chen et al ., ), antitumor (Li et al ., ), and cardiovascular protection (Li et al ., ). However, the potential immunomodulatory effects of PSG‐1 have not been evaluated.…”