Objective: To investigate antiviral activity of maca to reduce viral load in kidney (MDCK) cells infected with influenza type A and B viruses (Flu-A and MFalud-inB-, Dreasrpbeyc ctiavneilny)e. Methods: Maca were extracted with methanol (1:2, v/v). The cell viability and toxicity of the eaxgtariancstts Fwluer-eA e avnaldu aFtleud- oBn v MirDusCeKs cwealsls a usssianyge dm uetshinogd aM TteTs ta sfosar yd. eAtenrtmiviinrainl ga ctthiev itiyn hoifb citoimonp oouf nthdes cytopathic effect on cell culture and multiplex RT-PCR. Results: The methanol extract of maca showed low cytotoxicity and inhibited influenza-induced cytopathic effect significantly, while viral load was reduced via inhibition of viral growth in MDCK infected cells. Maca contains potent inhibitors of Flu-A and Flu-B with a selectivity index [cytotoxic concentration 50%/IC50] of 157.4 and 110.5, respectively. Conclusions: In vitro assays demonstrated that maca has antiviral activity not only against Flu-A (like most antiviral agents) but also Flu-B viruses, providing remarkable therapeutic benefits. / Financial support of this study was provided by AECID grants (PCI: C/033641/10) and AGAUR (MAT2009-11503, MAT2012-36205, 2009SGR-1208). JDVM support was provided by 1st Concurso Incentivo a la Investigación de la Universidad Peruana de Ciencias Aplicadas, Lima, Peru. / Revisión por pares