Analysis of Cytotoxic and Antitumor Potential of Passiflora quadrangularis

The cytotoxicity of ethanolic extract of Passiflora quadrangularis (PQ) leaves was analyzed on cancer cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Antitumor effect was analyzed on mouse solid and ascites tumor models. The phytochemical profile of the extract was analyzed by liquid chromatography-mass spectrometry (LC-MS). Apoptosis and cell cycle were analyzed by fluorescence resonance energy transfer (FRET) and flow cytometry. PQ exhibited cytotoxicity on Dalton’s lymphoma ascites (DLA) and Ehrlich’s ascites carcinoma cells with IC50 of 9.4 and 9.2 μg mL−1 and anti-proliferative effect on breast (MCF7) and colorectal (HCT116) cancer cell lines with IC50 of 166.5 and 107.09 μg mL−1, respectively. The extract did not show toxicity in normal rat intestinal cells IEC6 and murine macrophage cells RAW264.7. In ascites tumor model, the mean survival days of the animals increased to 25 ± 4.30 d in the treated group compared to untreated (21.2 ± 2.68 d). In DLA-induced solid model, the tumor weight decreased to 1.6 ± 0.9 g from 4.5 ± 0.58 g by treatment with 400 mg kg−1 b.w. extract. LC-MS analysis revealed the presence of genistein, kaempferol, isovitexin, and quercetin that are known for anticancer potential. The acute toxicity in mice revealed that PQ is nontoxic. FRET and flow cytometry analysis indicated an induction of apoptosis in PQ-treated cells