Structural Characterization and Antifatigue Effect In Vivo of Maca (Lepidium meyenii Walp) Polysaccharide

Abstract

Maca (Lepidium meyenii Walp) polysaccharides (MP) with purity of 99.2% were obtained to investigate their structural characteristics and antifatigue effect in vivo. The physicochemical properties of MP were analyzed through high-performance gel filtration chromatography, IR, monosaccharide composition, methylation, GC-MS, and NMR analyses. The antifatigue effect of MP was evaluated by using a mouse weight-loaded swimming model. MP is an acidic heteropolysaccharide with an average molecular weight (M ) of 793.5 kDa. It is composed of D-GalA: D-Glc: L-Ara: D-Man: D-Gal: L-Rha = 35.07:29.98:16.98:13.01:4.21:0.75 (mol, %). The findings revealed that MP contained β-1,3-Galp(A), β-1,3-Glcp, and α-1, 3-Manp linked alternatingly to form a backbone (5:4:1). MP (above mid-dosage 50 mg/kg bw/d) could effectively elongate swimming durations and accelerate average swimming speeds (within the 1st 5 min) of mice (P < 0.05) and improve the serous biochemical parameters of mice. Compared with the control model, high-dosage (100 mg/kg bw/d) MP treatment could significantly enhance glutathione peroxidase and creatine kinase activities (P < 0.05) and decreased lactate dehydrogenase activity (P < 0.01). High-dosage MP could significantly reduce the levels of blood urea nitrogen, lactic acid, and malondialdehyde (P < 0.05). MP is an acidic polysaccharide with a high D-GalA content, which could be responsible for the antifatigue effect of maca.

Two macamide extracts relieve physical fatigue by attenuating muscle damage in mice

“…It is therefore necessary to carry out related extraction and purification work to obtain maca products with high anti‐fatigue effects. Significant anti‐fatigue effects of aqueous extract have been observed, but they require a high dose of extract (0.1–20 g kg −1 ), as described in previous studies . Choi et al .…”

“…Several classes of secondary metabolites have been isolated from dried maca tubers, including alkaloids, glucosinolates, aromatic isothiocyanates and macamides . To the best of our knowledge, previous studies related to the anti‐fatigue effect of maca mainly concentrated on maca polysaccharides . Compared to biological macromolecules with complex structures, small‐molecule substances also play an important role in many aspects.…”

Maca (Lepidium meyenii) as a source of macamides and polysaccharide in combating of oxidative stress and damage in human erythrocytes

“…However, arabinose was the major monosaccharide in Yunnan maca (Zha et al, 2014). Tibet maca polysaccharide was composed of a high galacturonic acid content (Tang et al, 2017). The different monosaccharide analysis results may be attributed to the different cultivative conditions and the differences in extraction and analysis methods.…”

“…The macamides are a distinct class of secondary metabolites, which have been identified as major characteristic compounds contributing to the efficacy of maca (McCollom et al, 2005;Zhou et al, 2017). Maca polysaccharide exhibited strong radical scavenging, antifatigue, immunomodulatory and hepatoprotective activities (Zha et al, 2014;Zhang et al, 2016Zhang et al, , 2017aTang et al, 2017). The use of citric acid to extract pectin is an efficient and eco-friendly extraction method (Oliveiral et al, 2016).…”

Qualitative Identification and Semi-Quantitative Comparison of Sucrose in Maca (&lt;i&gt;Lepidium meyenii&lt;/i&gt;) by Infrared Spectrum Analysis

“…And secondary metabolites of Maca were Macamides, alkaloid, glucosinolate, sterol and so on [3] [4] [5] [6] [7]. Few reports about small molecule saccharides in Maca had been found [8] [9].…”