Cytotoxic and Apoptotic-inducing Effects of Purple Rice Extracts and Chemotherapeutic Drugs on Human Cancer Cell Lines

Abstract

Pigmented rice is mainly black, red, and dark purple, and contains a variety of flavones, tannin, polyphenols, sterols, tocopherols, γ-oryzanols, amino acids, and essential oils. The present study evaluated the cytotoxic effects of purple rice extracts (PREs) combined with chemotherapeutic drugs on human cancer cells and mechanisms of cell death. Methanolic (MeOH) and dichloromethane (DCM) extracts of three cultivars of purple rice in Thailand: Doisaket (DSK), Nan and Payao (PYO), were tested and compared with white rice (KK6) Rice bran, a byproduct of the rice milling process, contains most of the phytochemicals. The phenolic, anthocyanin, and proanthocyanidin content of three brown, purple, and red rice brans isolated from different rice varieties using HPLC-PDA is high (Chen et al., 2012). Antioxidative capacities, which are determined by (2,2-diphenyl-1-picrylhydrazyl) DPPH and oxygen radical absorbance capacity (ORAC) and cell-inhibiting effects using an MTT assay, the light-brown bran has no effect, the purple bran exhibits a minor effect on leukemia and cervical cancer cells, and the red bran exhibits strong inhibitory effects on leukemia, cervical, and stomach cancer cells, based on the IC 50 levels. High concentrations of protocatechuic acid and anthocyanins in purple bran and proanthocyanidins in red bran are identified (Chen et al., 2012)..The concentrations of lipophilic, solvent-extractable (free), and cell wall-bound (bound) phytochemicals and their antioxidant capacities from brans of white, light brown, brown, purple, and red colors, are compared by Ratana Banjerdpongchai et al

Mutagenicity and Antimutagenicity of Hydrophilic and Lipophilic Extracts of Thai Northern Purple Rice

“…Several investigations have demonstrated that pigmented rice extract exhibits antioxidant, antiinflammatory, and in vitro anticarcinogenic activities (Kong and Lee, 2010;Leardkamolkarn et al, 2010;Min et al, 2010). In addition, pigmented rice extract showed cytotoxic and apoptotic-inducing effects on human hepatocellular carcinoma HepG2 cells and also exhibited anti-metastasis activity against human breast cancer cells (Banjerdpongchai et al, 2013;Luo et al, 2014).…”

Anti-invasive Activity against Cancer Cells of Phytochemicals in Red Jasmine Rice (Oryza sativa L.)

“…Cytotoxicity of red rice extracts on HT1080 and MDA-MB-231 cells were determined by MTT assay as described previously (Banjerdpongchai et al, 2013). HT1080 and MDA-MB-231 cells were plated at 1.5x103 cells per well in 96-well plates and cultured in DMEM with 10% FBS.…”

Purple rice extract inhibits testosterone‐induced rat prostatic hyperplasia and growth of human prostate cancer cell line by reduction of androgen receptor activation

“…Although the anticancer activities of purple rice have been reported in vitro and in vivo ( Wongjaikam et al, ), (Summart & Chewonarin, ), (Banjerdpongchai et al, ), its effects on prostate cancer have been less clearly demonstrated. The researchers therefore decided to determine the effect of PRE on the development of BPH.…”

“…In the previous studies, purple rice crude ethanolic extract (PRE) showed anticancer effects in both the pre‐ and post‐initiation stages of colon cancer (Wongjaikam, Summart, & Chewonarin, ), (Summart & Chewonarin, ). Furthermore, various strains of purple rice extract showed cytotoxic effects against human hepatocellular carcinoma (HepG2) and prostate cancer cells (LNCaP) (Banjerdpongchai, Wudtiwai, & Sringarm, ). This study therefore sought to investigate the effect of PRE on testosterone‐induced BPH in castrated rats, and explore the mechanisms of its action on the androgen‐responsive human prostate cancer cell line LNCaP and on bacterial mutagenicity.…”