L. (red clover) extract and doxorubicin synergistically inhibits proliferation of 4T1 breast cancer in tumor-bearing BALB/c mice through modulation of apoptosis and increase antioxidant and anti-inflammatory related pathways.
Food Sci Nutr. 2020 Aug ;8(8):4276-4290. Epub 2020 Jul 6. PMID: 32884708
Therapeutic strategies against triple-negative breast cancer (TNBC) are associated with drug-induced toxicities. The tropical edible red clover (L.) is rich in polyphenolic compounds which confer the plant potential anticancer properties. The aim of this study was to investigate the effects ofand doxorubicin (DOX) on the apoptosis and proliferation of 4T1 tumor cells in an allograft model of tumor-bearing BALB/c mice. Fifty-six female 4T1-tumor bearing- BALB/c mice were randomly divided into 7 groups ( = 8/group) to receive different doses and combinations of DOX andextract for 35 days. On the 36th day, serum estradiol (E2), IL-12 and IFN-γ cytokines, and glutathione peroxidase (GPx) activity were measured. Tumor's ferric reducing antioxidant power (FRAP) and the expressions of apoptosis-related genes (p53, Bax, Bcl-2, and caspase-3) were also evaluated. Immunohistochemical staining for Ki-67 and p53 were performed. Our results showed that the co-treatment of DOX and(100-400 mg/kg) inhibited the proliferation of 4T1 tumor cells in dose- and time-dependent manners. The co-treatment of DOX and(especially at the dose of 400 mg/kg) decreased the serum level of E2 (as a stimulant for breast tumor growth) and increased the serum levels of IL-12 and IFN-γ along with significant increments in serum GPx and tumor FRAP activities. The co-administration of DOX andalso decreased the expression of Ki-67 proliferation marker and increased the number p53 positive (i.e., apoptotic) cells within tumors. This was accompanied with the upregulation of pro-apoptotic and down-regulation of antiapoptotic genes. The key findings indicated the synergistic effects of DOX andagainst TNBC xenografts.