A polysaccharide fraction of adlay seed (Coixlachryma-jobi L.) induces apoptosis in human non-small cell lung cancer A549 cells

• Published in: Biochemical and biophysical research communications 2013-01, Vol.430 (2), p.846-851
• Main Authors: Lu, Xiangyi, Liu, Wei, Wu, Junhua, Li, Mengxian, Wang, Juncheng, Wu, Jihui, Luo, Cheng
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; A549; Antineoplastic Agents, Phytogenic - isolation & purification; Antineoplastic Agents, Phytogenic - pharmacology; APOPTOSIS; Apoptosis - drug effects; Carcinoma, Non-Small-Cell Lung - metabolism; Carcinoma, Non-Small-Cell Lung - pathology; Caspase 3 - metabolism; Caspase 9 - metabolism; Cell Line, Tumor; CELL PROLIFERATION; Cell Proliferation - drug effects; Chemical Fractionation; Coix; Coix - chemistry; Comet Assay; DNA Damage; Drugs, Chinese Herbal - isolation & purification; Drugs, Chinese Herbal - pharmacology; Humans; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; LUNGS; Membrane Potential, Mitochondrial - drug effects; MITOCHONDRIA; NEOPLASMS; POLYSACCHARIDES; Polysaccharides - isolation & purification; Polysaccharides - pharmacology; SACCHAROSE; Seeds - chemistry; THERAPY
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2012.11.058

► A polysaccharide from adlay seed, its molecular mass, optical rotation and sugars was determined. ► We demonstrated that a polysaccharide from adlay can induce apoptosis in cancer cells. ► The polysaccharide inhibited the metabolism and proliferation of NSCLC A549 cells. ► The polysaccharide may trigger apoptosis via the mitochondria-dependent pathway. Different seed extracts from Coix lachryma-jobi (adlay seed) have been used for the treatment of various cancers in China, and clinical data support the use of these extracts for cancer therapy; however, their underlying molecular mechanisms have not been well defined. A polysaccharide fraction, designated as CP-1, was extracted from the C.lachryma-jobi L. var. using the ethanol subsiding method. CP-1 induced apoptosis in A549 cells in a dose-dependent manner, as determined by MTT assay. Apoptotic bodies were observed in the cells by scanning electronic microscopy. Apoptosis and DNA accumulation during S-phase of the cell cycle were determined by annexin V-FITC and PI staining, respectively, and measured by flow cytometry. CP-1 also extended the comet tail length on single cell gel electrophoresis, and disrupted the mitochondrial membrane potential. Further analysis by western blotting showed that the expression of caspase-3 and caspase-9 proteins was increased. Taken together, our results demonstrate that CP-1 is capable of inhibiting A549 cell proliferation and inducing apoptosis via a mechanism primarily involving the activation of the intrinsic mitochondrial pathway. The assay data suggest that in addition to its nutritional properties, CP-1 is a very promising candidate polysaccharide for the development of anti-cancer medicines.