Impacts of delta 9-tetrahydrocannabinol against myocardial ischemia/reperfusion injury in diabetic rats: Role of PTEN/PI3K/Akt signaling pathway

In diabetic rats with myocardial ischemia/reperfusion injury, Δ9-THC significantly reduced heart damage and improved cardiac function. THC pretreatment decreased infarct size as well as blood markers of heart injury, including LDH and cardiac troponin-I.

THC also reduced myocardial apoptosis and oxidative stress, two major contributors to tissue damage when blood flow returns to the heart after a period of ischemia. These protective effects were accompanied by reduced PTEN expression and activation of the PI3K/Akt signaling pathway, which is involved in cell survival.

When researchers blocked PI3K signaling, THC’s cardioprotective effect disappeared, strengthening the evidence that this pathway played an important role in the response. The findings show that THC protected the diabetic rat heart against ischemia/reperfusion injury through multiple measurable effects on cardiac damage, oxidative stress, cell death, and survival signaling.

“Despite the current optimal therapy, patients with myocardial ischemia/reperfusion (IR) injury still experience a high mortality rate, especially when diabetes mellitus is present as a comorbidity. Investigating potential treatments aimed at improving the outcomes of myocardial IR injury in diabetic patients is necessary.

Our objective was to ascertain the cardioprotective effect of delta 9-tetrahydrocannabinol (THC) against myocardial IR injury in diabetic rats and examine the role of phosphatase and tensin homolog (PTEN)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in mediating this effect.

Diabetes was induced in male Wistar rats (8-10 weeks old, 200-250 g; n = 60) by a single injection of streptozotocin. The duration of the diabetic period was 10 weeks. During the last 4 weeks of diabetic period, rats were treated with THC (1.5 mg/kg/day; intraperitoneally), either alone or in combination with LY294002, and then underwent IR intervention. After 24 h of reperfusion, infarct size, cardiac function, lactate dehydrogenase (LDH) and cardiac-specific isoform of troponin-I (cTn-I) levels, myocardial apoptosis, oxidative stress markers, and expression of PTEN, PI3K, and Akt proteins were evaluated.

THC pretreatment resulted in significant improvements in infarct size and cardiac function and decreases in LDH and cTn-I levels (P < 0.05). It also reduced myocardial apoptosis and oxidative stress, accompanied by the downregulation of PTEN expression and activation of the PI3K/Akt signaling pathway (P < 0.05). LY294002 pretreatment abolished the cardioprotective action of THC.

This study revealed the cardioprotective effects of THC against IR-induced myocardial injury in diabetic rats and also suggested that the mechanism may be associated with enhanced activity of the PI3K/Akt signaling pathway through the reduction of PTEN phosphorylation.”

https://pubmed.ncbi.nlm.nih.gov/38149557/

“Delta 9-tetrahydrocannabinol (THC) is the main psychoactive component of cannabis and has been shown to have potential therapeutic effects in various medical conditions. THC has been shown to have anti-inflammatory and antioxidant properties, which may reduce the inflammation and oxidative stress associated with myocardial IR injury. Recent studies have suggested that THC improves glucose metabolism and insulin sensitivity and reduces blood glucose concentrations, oxidative stress, and inflammation associated with diabetic cardiomyopathy.”

https://www.cjphysiology.org/article.asp?issn=0304-4920;year=2023;volume=66;issue=6;spage=446;epage=455;aulast=Zhao

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