Gene expression profiling to elucidate the pharmacological and toxicological effects of Ricinus communis L. leaf extract in mammalian cells

Ricinus communis is a traditional medicinal plant which has been utilized for centuries for treatment of various conditions. Due to the presence of diverse phytochemicals, Ricinus is an outstanding natural resource to discover new drugs for various diseases such as diabetes, cancer, arthritis, ulcer and asthma. In this study, we performed whole-genome gene expression profiling using RNA-Seq to determine the differentially expressed genes in a mammalian cell line after exposure to Ricinus leaf extract and elucidate their pharmacological effects in order to support its ethnomedicinal uses. Various genes involved in cancer, inflammation, atherosclerosis and diabetes were found to be differentially regulated after exposure to sub-lethal concentrations of the Ricinus extract in MCF7 cells. An important gene involved in cancer progression and metastasis, that is, PIK3R3 (Phosphatidylinositol 3-kinase regulatory subunit gamma), was downregulated in MCF7 cells after treatment with Ricinus extract. PIK3R3 is an important component of the PI3K/AKT signalling pathway which is essential for cell proliferation, angiogenesis, inhibition of apoptosis and metastasis to distant organs. The Ricinus extract downregulated the expression of DPP4 (Dipeptidyl peptidase-4) and upregulated the expression of PPAR-γ (Peroxisome proliferator-activated receptor gamma) which are crucial in controlling blood glucose levels. Expression of TNFAIP6 (Tumor necrosis factor-inducible gene 6), which is shown to mediate anti-inflammatory and protective effects, was increased after treatment with Ricinus extract. We also analyzed the genes which might also confer toxicity. Our gene expression profiling data corroborate the potential therapeutic benefits of Ricinus communis plant.