Cinnamtannin A2, a tetrameric procyanidin, enhances GLP-1 and insulin secretion in mice, upregulates the expression of corticotrophin releasing hormone (CRH), and exhibits antioxidant, anti-diabetic, and nephroprotective effects.

Cinnamtannin A2, at concentrations ranging from 0.125 to 2.0 μg/mL, effectively inhibits the oxidation of LDL prompted by copper ions or MeO-AMVN[3].

Cinnamtannin A2, administered intraperitoneally (i.p.) at a dose of 10 mg/kg for 30 days, improved biomarkers such as KIM1 and NAGL in 5/6 nephrectomized rats by modulating the Nrf2-Keap1 pathway. Similarly, when given orally (p.o.) at 10 μg/kg, it enhanced insulin and GLP-1 secretion in mouse plasma, and significantly increased the phosphorylation of IRB and IRS-1. In an animal model using male Sprague-Dawley rats (250-300 g) with chronic renal failure (CRF) induced by nephrectomy, the same dosage and administration method regulated creatinine, blood urea nitrogen, neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, and various cytokines in serum, along with a reduction in microalbuminuria. It also mitigated oxidative stress, altered protein expression in the Nrf2-Keap1 pathway, and decreased tubular injury in kidney tissue.