The present study was supported by a grant obtained from Peruvian National Council of Sciences, Technology and Innovation (CONCYTEC) through the grant PROCOM 2008. All authors participated in the experimental design and development of the study. Also, the authors report no conflicts of interest. The study was performed in 2008. Since 2009, Dr Gustavo F. Gonzales is in charged of CAYENATUR EIRL an enterprise that develops products based on Maca.

Peng Bo, Hu Qin, Xiaming Wen, Yang Keli, Jiang Zhen and Sandra Yucra are acknowledged for their help in this study. Special thanks to the joint financial support for this work from the National Nature Science Foundation of China, NSFC in 2004 (30472016/C03020701) and from Peruvian National Council of Sciences, Technology and Innovation (CONCYTEC) through the grant PROCOM 2005 and support for travel. Julio Rubio was on leave from the Universidad Peruana Cayetano Heredia, Peru (UPCH) through the Memorandum of Understanding between IMPLAD, CONCYTEC and UPCH.

PROCOM 2009

PROCOM 2007-2008