Flavonoids, Antioxidant Activity and Aroma Compounds Analysis from Different Kinds of Tartary Buckwheat Tea.

The rutin, quercetin concentrations, antioxidant activity, and aroma compounds in different commercial tartary buckwheat tea were analyzed in our study. Results revealed that the materials and the processing protocol affected the chemical composition and activity of tartary buckwheat tea. Rutin and quercetin concentrations, antioxidant activity were significantly different in various kinds of tartary buckwheat tea, where the whole bran tea and the whole plant tea had the lower rutin, but higher quercetin concentrations and higher antioxidant activity. The whole embryo tea had the converse results. There was strong correlation between quercetin concentration and antioxidant activity (r>0.98, P<0.05). Meanwhile, Twenty eight different aroma compounds in tartary buckwheat tea were identified by gas chromatography-mass spectrometry. Those compounds were mainly composed of pyrazine, aldehydes, fatty acids and ketones. The main type of aroma compounds in different tartary buckwheat tea were similar, but their relative contents were different. The implications to the quality control of buckwheat tea were extensively discussed.

Chimeric adenoviral vector Ad5/F35-mediated APE1 siRNA enhances sensitivity of human colorectal cancer cells to radiotherapy in vitro and in vivo.

Apurinic/apyrimidinic endonuclease (APE1), a bifunctional AP endonuclease/redox factor, is important in DNA repair and redox signaling, may be associated with radioresistance. Here we investigate whether targeted inhibition of APE1 can sensitize tumor cells to irradiation in vitro and in vivo. We first constructed chimeric adenoviral vector Ad5/F35 carrying human APE1 siRNA (Ad5/F35-APE1 siRNA). The infectivity of chimeric Ad5/F35 to LOVO colon cancer cells was greater than that of Ad5. APE1 was strongly expressed and nuclear factor kappaB (NF-kappaB), a downstream molecule of APE1, known as a radioresistance factor, was constitutively active in LOVO cells. Infection of LOVO cells with Ad5/F35-APE1 siRNA resulted in a dose-dependent decrease of APE1 protein and AP endonuclease activity in vitro. Ad5/F35-APE1 siRNA significantly enhanced sensitivity of LOVO cells to irradiation in clonogenic survival assays, associated with increased cell apoptosis. The APE1 expression in LOVO cells was induced by irradiation in a dose-dependent manner, accompanied with the enhancement of DNA-binding activity of NF-kappaB and Ad5/F35-APE1 siRNA effectively inhibited constitutive and irradiation-induced APE1 expression and NF-kappaB activation. In a subcutaneous nude mouse colon cancer model, Ad5/F35-APE1 siRNA (5 x 10(8) IU, intratumoral injection) inhibited the expression of APE1 protein in LOVO xenografts, and significantly enhanced inhibition of tumor growth by irradiation. In conclusion, APE1 may be involved as one of the radioresistance factors, and targeted inhibition of APE1 shows an effective means of enhancing tumor sensitivity to radiotherapy.

Antitumor activity and immuno-potentiating actions of Achyranthes bidentata polysaccharides.

Achyranthes bidentata polysaccharides (ABP), isolated from the root of Achyranthes bidentata Blume, 50 mg.kg-1 ip or 250 mg.kg-1 to ICR mice inhibited the growth of sarcoma 180. ABP 50 and 100 mg.kg-1 ip prolongated the survival days of mice bearing Ehrlich carcinoma. ABP 50-800 micrograms.ml-1 did not exert direct cytotoxic effect in vitro on S180 cells, but enhanced the cytotoxicity of peritoneal macrophages against S180 cells. ABP 50 mg.kg-1 ip x 17 d or 250 mg.kg-1 ig x 16 d promoted the plaque forming cells (PFC) response to sheep red blood cells (SRBC) and serum IgG level as well as splenocyte proliferation induced by mitogen Con A or LPS in tumor-induced immunodeficient mice. ABP also elevated the NK cell activity and serum TNF content in mice bearing S180. These results indicated that the antitumor effect of ABP may be related to its potentiating effect on both specific and nonspecific host immunological responses.

Effects of Achyranthes bidentata polysaccharides on interleukin-1 and tumor necrosis factor-alpha production from mouse peritoneal macrophages.

Achyranthes bidentata polysaccharides (ABP), extracted from the root of Achyranthes bidentata, induced interleukin-1 (IL-1) synthesis as well as tumor necrosis factor-alpha (TNF-alpha) synthesis and secretion from thioglycolate-primed mouse peritoneal macrophages in vitro. ABP 100-800 micrograms.ml-1 enhanced both synthesis and release of IL-1 when stimulated by lipopolysaccharides (LPS) (5 micrograms.ml-1), but had no significant influences on synthesis and release of TNF-alpha induced by LPS (10 micrograms.ml-1). Studies on IL-1 and TNF-alpha production induced by ABP (200 micrograms.ml-1) alone or plus LPS showed that peak levels of IL-1 release reached at 24 h and that of TNF-alpha release at about 2-6 h after incubation. Peritoneal macrophages from mice ip ABP 25 and 50 mg.kg-1.d-1 x 5 d produced much more IL-1 than those from control group. Peritoneal macrophages from ip ABP 100 mg.kg-1.d-1 x 6 d alone released more TNF-alpha vs control group, and showed a synergetic action with LPS (10 micrograms.ml-1), which was as strong as the positive control agent BCG. These results provide an explanation for the immunopotentiating effect of ABP.