cytochrome-c-t and Carcinoma--Lewis-Lung

Topics: Animals; Antineoplastic Agents; Astragalus Plant; Carcinoma, Lewis Lung; Cell Line, Tumor; Cisplatin; Cytochromes c; Drug Therapy, Combination; Drugs, Chinese Herbal; Female; Humans; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Neoplasm Transplantation; Polysaccharides; Serpins

Although Ocimum sanctum has been used extensively for its medicinal values in India and China, its antitumor activity against human nonsmall cell lung carcinoma (NSCLC) A549 cells has not been investigated until now. Therefore, the antitumor mechanism of ethanol extracts of Ocimum sanctum (EEOS) was elucidated in A549 cells in vitro and the Lewis lung carcinoma (LLC) animal model. EEOS exerted cytotoxicity against A549 cells, increased the sub-G1 population and exhibited apoptotic bodies in A549 cells. Furthermore, EEOS cleaved poly(ADP-ribose)polymerase (PARP), released cytochrome C into cytosol and simultaneously activated caspase-9 and -3 proteins. Also, EEOS increased the ratio of proapoptotic protein Bax/antiapoptotic protein Bcl-2 and inhibited the phosphorylation of Akt and extracellular signal regulated kinase (ERK) in A549 cancer cells. In addition, it was found that EEOS can suppress the growth of LLC inoculated onto C57BL/6 mice in a dose-dependent manner. Overall, these results demonstrate that EEOS induces apoptosis in A549 cells via a mitochondria caspase dependent pathway and inhibits the in vivo growth of LLC, suggesting that EEOS can be applied to lung carcinoma as a chemopreventive candidate.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Carcinoma, Lewis Lung; Carcinoma, Non-Small-Cell Lung; Caspase 3; Caspase 9; Cell Line, Tumor; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Extracellular Signal-Regulated MAP Kinases; Humans; Lung Neoplasms; Mice; Mice, Inbred C57BL; Ocimum; Phosphorylation; Phytotherapy; Plant Extracts; Plant Leaves; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2

Isorhamnetin is a flavanoid present in plants of the Polygonaceae family and is also an immediate metabolite of quercetin in mammals. Since the plasma level of isorhamnetin is maintained longer than quercetin, isorhamnetin may be a key metabolite to mediate the anti-tumor effect of quercetin. In the present study, we investigated the apoptotic mechanism of isorhamnetin in Lewis lung cancer (LLC) cells in vitro and established its in vivo anti-cancer efficacy. In cell culture, isorhamnetin significantly increased DNA fragmentation, and TUNEL positive apoptotic bodies and sub-G(1) apoptotic population in time- and dose-dependent manners. Western blot analyses revealed increased cleavage of caspase-3, and caspase-9 and PARP and increased cytosolic cytochrome C in isorhamnetin-treated cells. These events were accompanied by a reduced mitochondrial potential. Apoptosis was blocked by a general caspase inhibitor or the specific inhibitor of caspase-3 or -9. These in vitro results support mitochondria-dependent caspase activation to mediate isorhamnetin-induced apoptosis. Furthermore, an animal study revealed for the first time that isorhamnetin given by i.p. injection at a dose that is at least one order of magnitude lower than quercetin significantly suppressed the weights of tumors excised from LLC bearing mice. The in vivo anti-tumor efficacy was accompanied by increased TUNEL-positive and cleaved-caspase-3-positive tumor cells. Our data therefore support isorhamnetin as an active anti-cancer metabolite of quercetin in part through caspase-mediated apoptosis.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Lewis Lung; Caspase 9; Caspase Inhibitors; Cell Line, Tumor; Cell Proliferation; Cysteine Proteinase Inhibitors; Cytochromes c; Dose-Response Relationship, Drug; Female; Flavonols; Injections, Intraperitoneal; Membrane Potential, Mitochondrial; Mice; Mice, Inbred C57BL; Mitochondria; Quercetin; Time Factors