Reprotoxicity induced by acute exposure to aqueous tuber extract of Peruvian Maca (Lepidium meyenii Walp.) in Caenorhabditis elegans

Maca (Lepidium meyenii Walp.) has been used in folk medicine to treat fertility disturbances, a claim that has been evidenced in some studies. However, the clinical trials validating this use have shown paradoxical findings and then maca safety is not well known. This study investigated the effects and mechanisms by which maca affects the reproductive system using an in vivo model, the nematode Caenorhabditis elegans. Tuber maca powder, obtained from local commerce, was used to prepare the aqueous extract. Worms were acutely exposed to maca extracts (40, 120, 240, and 330 mu g/mu l), and 48 h after treatments, physiological and biochemical assays were conducted. Maca extract caused a significant decrease in total number of eggs and in the number of eggs per worm. These effects were associated to increased lipid peroxidation, reduced triacylglycerol levels, and also impaired vit-2 (vitellogenin) expression, besides increase in the number of apoptotic germline cells. We have found quantifiable levels of alkaloids in this maca extract, which presence could be related to this toxicity. Collectively, our data suggest that maca extract exposure causes reproductive toxicity to worms that could be, at least in part, associated to both an increase in apoptosis of germline cells and also to a decrease in vitellogenin expression, needed for egg yolk production and, consequently, successful reproduction.