Antitumor potential of anethole singly and in combination with cyclophosphamide in murine Sarcoma-180 transplantable tumor model
The clinical outcome of chemotherapy in cancer treatment is limited due to severe side effects. There has been a mixed response in experimenting with combinations of conventional chemotherapy with dietary agents to improve the therapeutic outcome. This study is aimed to explore the anti-tumor potential of a spice-derived phytochemical, anethole singly and in combination with cyclophosphamide. Various doses of anethole (10, 20 and 40 mg kg−1) were administered orally on alternate days to Sarcoma-180 solid tumor bearing Swiss albino mice on appearance of palpable tumor. Cyclophosphamide (100 mg kg−1) was injected into anethole treated or untreated tumor bearing mice for 3 consecutive days before sacrifice. Results demonstrated that anethole and cyclophosphamide, singly as well as in combination, reduced tumor load to a significant extent. Cell cycle analysis revealed that cyclophosphamide and cyclophosphamide+anethole exhibited significantly more tumoricidal activity than anethole alone. AnnexinV/PI assay suggested that necrosis was the principal means of tumor reduction when cyclophosphamide was used alone or in combination contrasting to the induction of apoptosis in anethole-treated groups. The necrotic cell death was also reflected in tumor histology. Although no additive effect in tumor reduction was observed with combinatorial treatment, use of anethole was instrumental in reducing the side-effects namely myelosuppression, hepatotoxicity and urotoxicity of cyclophosphamide treatment. The hepatoprotective effect of anethole was further proven by its ability to reduce CCl4 induced hepatotoxicity. This study indicates that anethole pre-treatment protected the bone marrow, liver and urinary bladder from the adverse toxicity of cyclophosphamide without interfering with its anticancer effect.