Combination synergy between β-carotene and lupeol against breast adenocarcinoma in vitro and in vivo using combination index

Abstract

BackgroundBreast adenocarcinoma is one of the leading causes of death among women regardless of development in the field of diagnosis, treatment and prevention. Synergistic approaches are emerging as a strategy to overcome monotherapy resistance in cancer treatment. PurposeEvaluation of the combinatory activity of β-carotene (BC) and lupeol (LUP) for anti-proliferative activity by median effect equation and combination index. Validation was performed by fixed dose combination against murine mammary adenocarcinoma namely Ehrlich ascites carcinoma (EAC). MethodsCytotoxicity assay was performed using the MTT and Trypan blue methods. Isobologram and combination index analysis were used to analyze the type of interaction between β-carotene (BC) and lupeol (LUP). Based on the synergistic dose combination determination of in-vivo antitumor activity was performed using EAC cells inoculated in mice treated with BC, LUP and their combination (BC+LUP). Tumor volume, cell count, weight along with hematological, biochemical and antioxidant parameters were evaluated. ResultsThe combination (BC+LUP) exhibited the highest inhibition (IC50=54.8 ± 1.84) compare to the standard inhibitor, wher eas BC and LUP showed moderate inhibition with an IC50 of 101.5 ± 2.66, and 84.08±3.56 respectively. The hematological, biochemical, and tissue antioxidant parameters were reverted to normal levels in the treated animal groups. BC and Lupeol reduced the volume, weight, and viable cell count of the tumor; increased the life span of EAC tumor-bearing mice. Conclusionβ-Carotene and lupeol were found to be more effective in combination for the anti-proliferative activity. Thus combination techniques must be employed to find out the synergistic activity of the molecules.