Anise (Pimpinella anisum L.) attenuates azoxymethane-induced colorectal cancer by antioxidant, anti-inflammatory, and anti-apoptotic pathways in rats

Abstract

Herbal medicine is one of the most common fields explored for combating colon cancers, and Pimpinella anisum L. seeds (PAS) have been utilized widely as medicinal agents because of their increased essential oil (trans-anethole) contents. In this essence, our study investigates the toxic effect and chemoprotective potentials of PAS against azoxymethane (AOM)-induced colon cancer in rats. The toxicity trial for PAS conducted by clustering fifteen rats into three groups (five rats each): A, normal control had 10% Tween 20; B, ingested with 2 g/kg PAS; and C, supplemented with 4 g/kg PAS. The in vivo cancer trial was performed by using 30 rats (Sprague-Dawley) that were randomly adapted in five steel cages (six rats each): group A, normal controls received two subcutaneous injections of normal saline 0.09% and ingested orally 10% Tween 20; groups B-E, rats received two injections of 15 mg/kg of azoxymethane (AOM) subcutaneously in 2 weeks and treated orally with 10% Tween 20 (group B) or intraperitoneal injection of 5-fluorouracil (35 mg/kg) (group C), or orally given 200 mg/kg PAS (group D) and 400 mg/kg PAS (group E) for 8 weeks. After the scarification of rats, the colon tissues were dissected for gross and histopathological evaluations. The acute toxicity trial showed the absence of any toxic signs in rats even after 14 days of ingesting 4 g/kg of PAS. The chemoprotective experiment revealed significant inhibitory potentials (65.93%) of PAS (400 mg/kg) against aberrant crypto foci incidence that could be correlated with its positive modulation of the immunohistochemically proteins represented by a significant up-regulation of the Bax protein and a decrease of the Bcl-2 protein expressions in colon tissues. Furthermore, PAS-treated rats had notably lower oxidative stress in colon tissues evidenced by decreased MDA levels and increased antiradical defense enzymes (SOD, CAT, and GPx). The outcomes suggest 400 mg/kg PAS as a viable additive for the development of potential pharmaceuticals against colorectal cancer.

Keywords: Acute toxicity; Azoxymethane (AOM); Colon cancer; Histopathology; Pimpinella anisum.