Innovation in traditional medicine: in vitro and in vivo effects of Moringa oleifera callus on breast cancer cell lines and analysis of microRNAs content

In the last years, many studies have highlighted the concept of cross-kingdom, showing the presence of exogenous miRNAs, called xeno-miRNAs, from plants in human body fluids and their potential role in the regulation of human mRNA. Zhang and collaborators (2012) tested the presence of an exogenous miRNA, osa-miR168a, from rice, in the serum of Chinese subjects. The authors have shown for the first time a molecular cross-kingdom interaction in which a plant miRNA can influence the expression of an animal gene. In In light of this and for further investigations, we also performed a comparison between human and plant microRNAs by MirCompare. In this way we identified plant miRNAs with a sequence homologous to human ones. In particular we identified mol-miR398c homologous to hsa-miR4273, a putative regulator of ErbB2. In breast cancer many times there is an overexpression of ErbB2, linked to a worst prognosis. Our future perspective will be to verify on breast cancer cell lines if M. oleifera miRNA could act as a tumor suppressor, inhibiting the ErbB2 expression. In conclusion our study has showed the ability of M. oleifera callus to interfere with the proliferation of cancer cells in vitro and in vivo. Moreover, the presence of secondary metabolites and microRNAs let us to suppose an activity of them to contrast the tumor development. Further studies are necessary to understand better the pathway in which they are involved and their mechanism of action. The future perspective is to develop a nutraceutical with a preventive activity for the breast cancer, especially for women at risk, or that could be used like a supplement to support the standard therapies.