Myricitrin from Physalis pubescensL. leaves and frankincense decrease resistance of MCF-7 cells and ameliorate efficacy of epirubicin

Abstract

Context: It was found that flavonoids and frankincense exert anti-cancer effect through their antioxidant and anti-inflammatory activities. Aims: To evaluate the cytotoxic effect against MCF-7 cells of flavonoids isolated from Physalis pubescens L., frankincense ethanol extract and the combined therapy with epirubicin to reduce the resistance and the side effects. Methods: MTT assay against MCF-7 was carried out for rutin, quercitrin, myricitrin and frankincense. The compound or extract with the best anti-cancer effect was tested against WI-38 cells. 50% inhibitory concentration (IC50) of the different treatments and the combined therapy with epirubicin against MCF-7 was determined. Assessment the effect on expression of ABCB1, TGF-β1 and ATG7 genes was done by RT-qPCR. Results: Isolation and identification of myricitrin from leaves of Physalis pubescens L. was carried out for the first time. IC50 (μg/mL) regarding MCF-7 cells was of epirubicin (0.8 ± 0.052), rutin (350.16 ± 1.241), quercitrin (259.6 ± 1.45), myricitrin (114.0 ± 0.517), frankincense ethanol extract (86.8 ± 0.91), combined epirubicin + myricitrin (EM) (0.37 ± 0.087), combined epirubicin + frankincense (EF) (0.50 ± 0.1732). The IC50 μg/mL regarding WI-38 cells was of epirubicin (1.26 ± 0.0057), myricitrin (462.0 ± 1.062) and frankincense (299.5 ± 1.32). All assays were done at 48 h time interval. Myricitrin and EM reduced ABCB1 expression and upregulated expression of TGF-β1 and ATG7 genes. Frankincense and EF downregulated expression of ABCB1, TGF-β1 and ATG7 genes. Conclusions: Myricitrin and frankincense would be a promising adjuvant therapy to improve epirubicin anticancer activity with minimal adverse effect.