Larch Arabinogalactan Attenuates Myocardial Injury by Inhibiting Apoptotic Cascades in a Rat Model of Ischemia–Reperfusion

Abstract

We reported previously that supplementation with apple pectin, a dietary fiber, reduced myocardial injury in a rat model of ischemia-reperfusion. In this study, we further investigated an arabinogalactan, one of the constituent polysaccharides of pectin, to determine which domains comprising pectin were responsible for the protection. In a rat model of 30-min ischemia followed by 3-h reperfusion, supplementation with larch arabinogalactan (LAG) over 50 mg/kg/day significantly reduced infarct size. Reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, and immunoblot analyses showed that intake of LAG blocked the steps involved in apoptotic cascades through downregulation of gelsolin gene expression at the protein (Gelsolin) level, inhibition of p38 phosphorylation in mitogen-activated protein kinase (MAPK) pathways, decreased bax/bcl-2 ratio at the protein (Bax/Bcl-2) level, which was correlated with the ratio at the mRNA level, inhibition of the conversion of Procaspase protein to Caspase-3 protein, and consequently a decrease in apoptotic cells. In addition, the intake of LAG reduced the hif1-α gene expression at the protein (HIF1-α) level. These findings suggest that arabinogalactan is an active component of pectin for reducing myocardial injury by inhibiting apoptosis in postocclusion steps, possibly indicating that arabinogalactan can be developed as a cardioprotectant to prevent myocardial injury.

Protective Effects of Arabinogalactan-Peptide Isolated from Wheat Flour against Myocardial Injury in an Ischemia/Reperfusion Rat Model

“…7). Similar observations were reported for larch arabinogalactan, which consists of arabinose and galactose, but not peptides (6), which supports the idea that polysaccharides consisting of arabinose protect against myocardial injury. Our findings are supported by previous studies.…”

“…Accumulation of oxidized LDL eventually leads to atherosclerotic plaque formation. Plaque buildup in turn narrows the coronary arteries and leads to insufficient blood supply, and the resulting symptoms are referred to as angina pectoris (preocclusion steps) (4–6). Occasionally, the plaque ruptures and a thrombus subsequently forms in the lesion, resulting in artery occlusion.…”

Pectin Oligosaccharides Ameliorate Colon Cancer by Regulating Oxidative Stress- and Inflammation-Activated Signaling Pathways

“…Downregulation of MAPK signaling pathway can inhibit the proliferation, invasion, and angiogenesis of CC ( 56 ), and promotes the apoptosis of CC ( 57 ). Larch Arabinogalactan (a kind of POS) has been reported to inhibit p38 phosphorylation in MAPK pathways ( 58 ). Thus, POS may prevent the risk or progression of CC by suppressing MAPK signaling pathway.…”

Micronized flavonoid fraction Daflon 500 protects heart against ischemia–reperfusion injury: an old medicine for a new target

“…IHD eliminates or diminishes coronary perfusion, depriving myocytes of oxygen and essential nutrients (Canty and Suzuki 2012). Lack of oxygen negatively impacts the process of metabolism, resulting in reduced ATP availability, which in turn causes irreversible damage to the heart (Lim 2017). The death of cardiomyocytes produced by hypoxia is attributed to prolonged ischemia with or without reperfusion leading to myocardial infarction (MI) (Canty and Suzuki 2012).…”