Sales, M. E. | Search bioRxiv

bioRxiv2020

HUMAN BREAST TUMOUR CELLS VIABILITY EFFECT OF AFRICAN DIOSCOREA ROTUNDATA TUBER EXTRACTS IN MCF-7 AND MDA-MB231 CELL LINES.

ObjectiveWe aim to test the efficacy of edible Dioscorea species grown and consumed in Nigeria, Africa on two breast cancer cell lines; MCF-7 and MDA-MB231 derived from a luminal and a triple-negative breast cancer (TNBC) respectively and to confirm safety in non-tumour cells MCF-10A using a well established cytotoxic compound paclitaxel as a standard. Metastatic breast cancer is a prevalent cause of mortality in women around the world. Breast cancer therapies have greatly advanced in recent years, but many patients develop cancer re-occurrence and metastasis and subsequently yield to the disease because of chemoresistance. MethodsEthanolic extracts of Dioscorea rotundata boiled and raw (DiosB and DiosR) respectively were chemically analysed for the presence of diosgenin using HPLC and the cytotoxic activity of the extracts were tested on MCF-7, MDA-MB-231 and MCF-10A cells In vitro by MTT assay. ResultsDiosB and DiosR extracts showed a higher maximal effect on MCF-7 cells than on MDA-MB231 after 24 h and 48 h treatments (p<0.0001 and p<0.05 respectively). DiosR, if applied at a range between 50-70 g/ml, can be effective to reduce breast tumor cell viability without affecting non tumorigenic MCF-10A cells either at 24 h or at 48 h. DiosB showed an IC50 of 38.83g/ml while DiosR showed an IC50 of 41.80g/ml. ConclusionThese results show that ethanolic extracts of Dioscorea rotundata tubers could be used effectively to treat breast cancer tumors and this is in sync with its diosgenin content as other Dioscorea species applied for similar treatments in Asia and elsewhere.

cancer biology↗

bioRxiv2019

The metronomic combination of paclitaxel with cholinergic agonists inhibits triple negative breast tumor progression. Participation of M2 receptor subtype

Triple negative tumors are more aggressive than other breast cancer subtypes and there is a lack of specific therapeutic targets on them. Since muscarinic receptors have been linked to tumor progression, we investigated the effect of metronomic therapy employing a traditional anti-cancer drug, paclitaxel plus muscarinic agonists at low doses on this type of tumor. We observed that MDA-MB231 tumor cells express muscarinic receptors, while they are absent in the non-tumorigenic MCF-10A cell line, which was used as control. The addition of carbachol or arecaidine propargyl ester, a non-selective or a selective subtype 2 muscarinic (M2) receptor agonist respectively, plus paclitaxel reduces cell viability involving a down-regulation in the expression of ATP "binding cassette" G2 drug transporter and epidermal growth factor receptor. We also detected an inhibition of tumor cell migration and anti-angiogenic effects produced by those drug combinations in vitro and in vivo (in NUDE mice) respectively. Our findings provide substantial evidence about M2 receptors as therapeutic target for the treatment of triple negative tumors.

pharmacology and toxicology↗