Separation, Purification and Anti-aging Activity of Tobacco Polysaccharides

Abstract

To separate tobacco polysaccharides and investigate their antioxidant and anti-aging properties, crude tobacco polysaccharides were extracted from raw tobacco using hot water, followed by purification through DEAE-52 cellulose column chromatography. The molecular weight and monosaccharide composition of the isolated polysaccharides were analyzed using HPGPC and HPLC. The antioxidant activities of these tobacco polysaccharides were tested using DPPH, ABTS, hydroxyl radicals scavenging test, and total reducing power. HepG-2 cells were treated with D-galactose (D-gal) to establish a senescence model. The anti-aging effects of tobacco polysaccharides were examined through Superoxide Dismutase (SOD) activity assays, Malondialdehyde (MDA) content analysis, qRT-PCR for Sirt1 and Nrf2 mRNA expression. The study found that the molecular weights of tobacco polysaccharides YCH-1, YCH-2, and YCH-3 were 61,708, 66,462, and 69,932 Da, respectively and they exhibited similar monosaccharide type distributions. Tobacco polysaccharides demonstrated strong, dose-dependent antioxidant activities. Cell-based experiments have revealed that these tobacco polysaccharides significantly counteract the senescence of HepG-2 cells induced by D-gal by enhancing SOD levels, while concurrently decreasing MDA content and reducing β-galactosidase positivity rates. This effect may be attributed to elevated mRNA expression levels of Sirt1 and Nrf2 genes within treated cells thereby facilitating their antioxidative functions alongside anti-aging benefits. These findings indicate that the tobacco polysaccharides exhibit significant antioxidant properties and potential anti-aging effects, providing insights into the comprehensive utilization of tobacco resources.