Maca, a native plant in the central Andean region, possesses high carbohydrate, protein and unsaturated fatty acid contents. It was found to be effective for treating arthritis, preserving cognitive function in middle-aged mice, improving memory, regulating hormone secretion and enhancing fertility. New areas for maca cultivation have been developed in other highaltitude regions including Yunnan province of China. The macamides are a distinct class of secondary metabolites, which have been identified as major characteristic compounds contributing to the efficacy of maca. Maca polysaccharide exhibited strong radical scavenging, antifatigue, immunomodulatory and hepatoprotective activities. The use of citric acid to extract pectin is an efficient and eco-friendly extraction method. Citric acid extraction showed a positive influence on the antioxidant capacity of Laminaria japonica polysaccharide.
Oxidative stress has been implicated in a number of human diseases as well as in the ageing process. Erythrocytes are particularly susceptible to oxidation damage. The H2O2-induced erythrocyte haemolysis visually revealed the oxidative damage to erythrocytes. However, there is little information on the protective effect of maca polysaccharide on oxidative stress-damaged human erythrocytes. In this study, the macamide profiles of Yunnan and Peru macas were compared. DPPH radical scavenging activities, oxygen radical absorbance capacities and protective effects against oxidative damage in human erythrocytes for all the water, citric acid and alkali-extracted polysaccharides were determined.