Polysaccharide Derived from Nelumbo nucifera Lotus Plumule Shows Potential Prebiotic Activity and Ameliorates Insulin Resistance in HepG2 Cells

Abstract

Polysaccharides are key bioactive compounds in lotus plumule tea, but their anti-diabetes activities remain unclear. The purpose of this study was to investigate the prebiotic activities of a novel polysaccharide fraction from the Nelumbo nucifera lotus plumule, and to examine its regulation of glucose metabolism in insulin-resistant HepG2 cells. The N. nucifera polysaccharide (NNP) was purified after discoloration, hot water extraction, ethanol precipitation, and DEAE-cellulose chromatography to obtain purified polysaccharide fractions (NNP-2). Fourier transform infrared spectroscopy was used to analyze the main structural characteristics and functional group of NNP-2. Physicochemical characterization indicated that NNP-2 had a molecular weight of 110.47 kDa and consisted of xylose, glucose, fructose, galactose, and fucose in a molar ratio of 33.4:25.7:22.0:10.5:8.1. The prebiotic activity of NNP-2 was demonstrated in vitro using Lactobacillus and Bifidobacterium. Furthermore, NNP-2 showed bioactivity against α-glucosidase (IC50 = 97.32 µg/mL). High glucose-induced insulin-resistant HepG2 cells were used to study the effect of NNP-2 on glucose consumption, and the molecular mechanism of the insulin transduction pathway was studied using RT-qPCR. NNP-2 could improve insulin resistance by modulating the IRS1/PI3K/Akt pathway in insulin-resistant HepG2 cells. Our data demonstrated that the Nelumbo nucifera polysaccharides are potential sources for nutraceuticals, and we propose functional food developments from the bioactive polysaccharides of N. nucifera for the management of diabetes.

Extraction optimization, physicochemical property, antioxidant activity, and α‐glucosidase inhibitory effect of polysaccharides from lotus seedpods

“…25 In this study, stronger inhibitory activity of LSCP on ⊍-glucosidase might be explained by its higher contents of uronic acids (Gal-UA + Glc-UA) and the higher ratio of low-M w fractions. Compared with previous studies, the IC 50 values of LSCP and LSRP were lower than that of the polysaccharides from lotus plumules, 62 whereas they were higher than that of the polysaccharides from lotus leaves. 63,64 At a concentration of 250 μg mL −1 , the inhibition rates of LSCP, LSRP, and acarbose were as high as 92.69%, 86.74%, and 100.00% respectively.…”

Flavonoids from Sacred Lotus Stamen Extract Slows Chronological Aging in Yeast Model by Reducing Oxidative Stress and Maintaining Cellular Metabolism

“…According to the preparation of various traditional medicines; for example, Chinese traditional medicines, Kampo medicines (the traditional Japanese herbal medicines), and Thai traditional medicines, these raw plant materials are commonly used in the form of an extract [ 12 , 13 , 14 , 15 ], following the traditional knowledge that the extract, which consists of major bioactive compounds, will provided synergistic effects for the health benefits of mankind. Nowadays, the number of research studies on the potential pharmacological activities of N. nucifera are considerably increased [ 7 , 8 , 9 , 10 , 11 , 16 , 17 , 18 , 19 , 20 ].…”

Validation of a High-Performance Liquid Chromatography with Photodiode Array Detection Method for the Separation and Quantification of Antioxidant and Skin Anti-Aging Flavonoids from Nelumbo nucifera Gaertn. Stamen Extract

“…This lotus plant is recognized using various vernacular names depending on its distribution, e.g., บัวหลวง (Bau Luang) in Thailand, 莲 (Lian) in China and ロータス (Ro Tasu) in Japan. Furthermore, this plant is also called by its common name such as sacred lotus, water lily or Indian lotus [ 1 , 6 , 9 , 10 , 11 ]. However, the legitimate name or the scientific name of this plant species is known as Nelumbo nucifera Gaertn.…”

“…As this lotus plant is widely used in both foods and herbal medicines, there are a large number of studies on its biological activities [ 8 , 9 , 10 , 11 , 12 , 13 ]. Most of the previous research studies focus on the leaves of N. nucifera ; for example, Lin and his team [ 3 ] isolated flavonoid phytochemical compounds from a leaf extract and reported on their antioxidant activity.…”