AIM： To investigate the impact of arachidonic acid （AA） and docosahexaenoic acid （DHA） and their combination on colon cancer cell growth. METHODS： The LS-174T colon cancer cell line was used to study the role of...AIM： To investigate the impact of arachidonic acid （AA） and docosahexaenoic acid （DHA） and their combination on colon cancer cell growth. METHODS： The LS-174T colon cancer cell line was used to study the role of the prostaglandin precursor AA and the omega-3 polyunsaturated fatty acid DHA on cell growth. Cell viability was assessed in XTT assays. For analysis of cell cycle and cell death, flow cytometry and DAPI staining were applied. Expression of cyclooxygenase-2 （COX-2）, p21 and bcl-2 in ceils incubated with AA or DHA was examined by real-time RT-PCR. Prostaglandin E2 （PGE2） generation in the presence of AA and DHA was measured using a PGE2- ELISA. RESULTS： AA increased cell growth, whereas DHA reduced viability of LS 174T cells in a time- and dosedependent manner. Furthermore, DHA down- regulated mRNA of bcl-2 and up-regulated p21. Interestingly, DHA was able to suppress AA-induced cell proliferation and significantly lowered AA-derived PGE2 formation. DHA also down-regulated COX-2 expression. In addition to the effect on PGE2 formation, DHA directly reduced PGE2-induced cell proliferation in a dosedependent manner. CONCLUSION： These results suggest that DHA can inhibit the pro-proliferative effect of abundant AA or PGE2.展开更多
In the effort to prove the effectiveness of watermelon endocarp extract as a hypolipidemic, the authors have done an initial experiment of lipase inhibition with the extract. The puposes of this study are to evaluate...In the effort to prove the effectiveness of watermelon endocarp extract as a hypolipidemic, the authors have done an initial experiment of lipase inhibition with the extract. The puposes of this study are to evaluate： （1） the optimum condition of lipase in the pankreoflat tablet, （2） the effect of watermelon endocarp extract in inhibition the lipase activity, and （3） the effectiveness of watermelon endocarp extract as lipase inhibitor relative to the hypolipidemic drugs （orlistat）. Watermelon endocarp was extracted by blender, squeezed and filtered. As a source of lipase has been used pankreoflat （Kimia Farina） tablet, inhibition test was performed by mixing 35 mL with substrate （olive oil） that has been coupled with one tablet （0.25 g） ofpankreoflat and extract of 50 g watermelon endocarp and then incubated at 37℃, pH 7.5 for 25 minutes. Lipase activity is indicated by the amount ofNaOH titrant which was used to neutralize the free fatty acid from hydrolysis of olive oil. The results showed that 50 g of watermelon endocarp can produce 26 mL extract and decrease the lipase activity by 70.34%, or equivalent to 85% of the effectiveness of one tablet orlistat （120 mg）, one of the hypolipidemic drugs.展开更多
基金Supported by Grants from the German National Academic Foundation (to P.H.)from the American Cancer Society (RSG-03-140-01-CNE)+2 种基金the NIH (NIH R01 113605) (both to J.X.K.)the German Research Foundation (DFG)a Charité Research Grant (both to K.H.W.)
文摘AIM： To investigate the impact of arachidonic acid （AA） and docosahexaenoic acid （DHA） and their combination on colon cancer cell growth. METHODS： The LS-174T colon cancer cell line was used to study the role of the prostaglandin precursor AA and the omega-3 polyunsaturated fatty acid DHA on cell growth. Cell viability was assessed in XTT assays. For analysis of cell cycle and cell death, flow cytometry and DAPI staining were applied. Expression of cyclooxygenase-2 （COX-2）, p21 and bcl-2 in ceils incubated with AA or DHA was examined by real-time RT-PCR. Prostaglandin E2 （PGE2） generation in the presence of AA and DHA was measured using a PGE2- ELISA. RESULTS： AA increased cell growth, whereas DHA reduced viability of LS 174T cells in a time- and dosedependent manner. Furthermore, DHA down- regulated mRNA of bcl-2 and up-regulated p21. Interestingly, DHA was able to suppress AA-induced cell proliferation and significantly lowered AA-derived PGE2 formation. DHA also down-regulated COX-2 expression. In addition to the effect on PGE2 formation, DHA directly reduced PGE2-induced cell proliferation in a dosedependent manner. CONCLUSION： These results suggest that DHA can inhibit the pro-proliferative effect of abundant AA or PGE2.
文摘In the effort to prove the effectiveness of watermelon endocarp extract as a hypolipidemic, the authors have done an initial experiment of lipase inhibition with the extract. The puposes of this study are to evaluate： （1） the optimum condition of lipase in the pankreoflat tablet, （2） the effect of watermelon endocarp extract in inhibition the lipase activity, and （3） the effectiveness of watermelon endocarp extract as lipase inhibitor relative to the hypolipidemic drugs （orlistat）. Watermelon endocarp was extracted by blender, squeezed and filtered. As a source of lipase has been used pankreoflat （Kimia Farina） tablet, inhibition test was performed by mixing 35 mL with substrate （olive oil） that has been coupled with one tablet （0.25 g） ofpankreoflat and extract of 50 g watermelon endocarp and then incubated at 37℃, pH 7.5 for 25 minutes. Lipase activity is indicated by the amount ofNaOH titrant which was used to neutralize the free fatty acid from hydrolysis of olive oil. The results showed that 50 g of watermelon endocarp can produce 26 mL extract and decrease the lipase activity by 70.34%, or equivalent to 85% of the effectiveness of one tablet orlistat （120 mg）, one of the hypolipidemic drugs.
