Anti-inflammatory and Anti-melanogenic Proanthocyanidin Oligomers from Peanut Skin

Abstract

Peanut skin (Arachis hypogaea L., Fabaceae) is an abundant source for polyphenols, such as proanthocyanidin oligomers. To determine whether proanthocyanidin has beneficial effects on skin, we tested for inhibitory activity of proanthocyanidins isolated from peanut skin on inflammatory cytokine production and melanin synthesis in cultured cell lines. Administration of peanut skin extract (PSE, 200 µg/mL) decreased melanogenesis in cultured human melanoma HMV-II co-stimulated with phorbol-12-myristate-13-acetate. It also decreased production of inflammatory cytokines (PSE at 100 µg/mL), tumor necrosis factor-α and interleukin-6, in cultured human monocytic THP-1 cells in response to lipopolysaccharide. We isolated ten known proanthocyanidins and one new proanthocyanidin trimer from the PSE. The structure of the new compound (5) was determined by 1D- and 2D-NMR and mass spectrometry analyses, and was determined as epicatechin-(2β→O→7,4β→6)-epicatechin-(4β→6)-epicatechin. The other known proanthocyanidins were identified as proanthocyanidin monomers (1), dimers (6-9), trimers (3-5) and tetramers (2, 10, 11). They showed suppressive activities against melanogenesis and cytokine production at concentrations ranging from 0.1-10 µg/mL. Among the tested compounds, suppressive activities of proanthocyanidin dimers or trimers in two assay systems were stronger than those obtained with monomer or tetramers. These data indicate that proanthocyanidin oligomers from peanut skin have the potential to reduce dermatological conditions such as inflammation and melanogenesis.

Inhibitory Effect of Oligomeric Polyphenols from Peanut-skin on Sugar Digestion Enzymes and Glucose Transport

“…Other research has revealed that the anti-inflammatory and anti-melanogenic activities of procyanidin dimers and trimers from peanut skin were stronger than those of monomer and tetramers (Tatsuno et al, 2012).…”

Absorption and metabolism of proanthocyanidins

“…Cranberry procyanidins may also serve as a chemoprevention agent against esophageal cancer by inducing apoptosis and inhibiting proliferation (Kresty, Howell, & Baird, 2008). Procyanidins from peanut skin decreased the production of inflammatory cytokines, tumor necrosis factor-a, and interleukin-6 in cultured human monocytic THP-1 cells in response to lipopolysaccharide (Tatsuno et al, 2012). Administering grape seed procyanidins reduced lung inflammation and decreased IL-4, IL-5, and IL-13 expression in a mouse model of acute or chronic asthma (Lee et al, 2012).…”

Cocoa procyanidins with different degrees of polymerization possess distinct activities in models of colonic inflammation

“…PCs have been widely studied for their biological activities related to prevention or amelioration of acute and chronic diseases. DP appears to play a role in determining PC efficacy in models of disease including inflammation [3–7] and cancer [8–14]. Unfortunately, no broad generalizations can be made regarding the correlation between PC structure and bioactivity because the DP-activity relationship appears to be system-dependent.…”