Anticancer effects of Rhinacanthus nasutus and Acanthus ebracteatus extracts against human cervical cancer cells

Abstract

Cervical cancer is second only to breast cancer in terms of incidence; however, it is the most lethal form of cancer among Thai women due to the asymptomatic nature of its early stages. This work aimed to examine cytotoxic and antiproliferative capacities of Rhinacanthus nasutus (RN) and Acanthus ebracteatus (AE) extracts against human cervical cancer cells (HeLa). Plant leaves were used for ethyl acetate extraction. The antioxidant assays, HPLC analysis, a cytotoxic MTT assay, a clonogenic assay and real-time PCR were conducted. Both RN and AE displayed similar DPPH scavenging activity (3.97 and 4.05 mg TE/g DW) and ferric reducing antioxidant power (4.79 and 4.35 mg Fe2+/g DW). However, AE was richer in total phenolic content than RN (13.30 and 10.84 mg GAE/g DW, respectively). Rutin, catechin, chlorogenic acid, and cinnamic acid were found in AE, whilst only cinnamic acid with much higher content was found in RN. Higher cytotoxicity of 91.73% against HeLa cells was found in RN (IC50 value of 62.06 μg/mL). RN showed higher antiproliferative effect (IC50 of 25.24 μg/mL) than AE (34.35 μg/mL). Genes (Bcl-2, Bax, MMP-2, MMP-9, caspase-3, p21, and cyclin D1) and proteins (cytochrome c, caspase-3 and p21) linked to apoptosis and migration were substantially more affected by RN. To conclude, both RN and AE hold promise as anticancer herbal plants against human cervical cancer; however, RN was more cytotoxic and antiproliferative in HeLa cells. RN offers a better alternative herbal medicine or complementary remedy to the standard drug for human cervical cancer treatment.