莓果萃取物抑制胃幽門螺旋桿菌感染之探討
幽門螺旋桿菌是造成胃癌的重要危險因子之ㄧ，臨床濫用抗生素的結果使得幽門螺旋桿菌極易產生 具有抗藥性之菌株，故亟需發展非抗生素的替代療法協助治療幽門螺旋桿菌之感染。文獻報告指出 蔓越莓可以抑制幽門螺旋桿菌對胃黏膜之吸附而具有輔助治療的效果，然而缺乏相關文獻探討其他 莓果對幽門螺旋桿菌之影響。本研究藉由體外實驗探討並比較蔓越莓萃取物、藍莓萃取物、葡萄籽 萃取物及混合以上三種萃取物之 GI 萃取物對幽門螺旋桿菌生長、感染與致病性的影響。
本研究以瓊脂紙錠擴散法 (agar disc diffusion method) 之抑制圈大小評估此四種莓果萃取物對該菌生 長之抑制情形。利用螢光顯微鏡觀察莓果萃取物是否會干擾螢光標示之幽門螺旋桿菌吸附至人類胃 癌細胞株 AGS 。再藉由尿素試劑與幽門螺旋桿菌中尿素酶的呈色反應，定量吸附於 AGS 細胞表面 之幽門螺旋桿菌數，進而分析、比較各莓果萃取物抑制幽門螺旋桿菌吸附於 AGS 細胞的最高抑制 濃度與抑制率。此外，將 AGS 細胞與莓果萃取物及幽門螺旋桿菌作用 24 小時後，以 ELISA (enzy me-linked immunosorbent assay) 分析上清液 interleukin (IL)-8 的含量，得知各莓果萃取物對幽門螺旋 桿菌誘發 AGS 細胞分泌促發炎細胞激素的影響。
抑制圈結果顯示葡萄籽萃取物抑制幽門螺旋桿菌生長之效果最佳，且具有劑量上之效應，而蔓越莓 萃取物則不具有抑制幽門螺旋桿菌生長之作用。在螢光顯微鏡下觀察到加入莓果萃取物後，螢光標 示之幽門螺旋桿菌吸附於 AGS 細胞之數量明顯減少。尿素酶試驗結果顯示各萃取物抑制幽門螺旋 桿菌吸附於 AGS 細胞之最高抑制濃度與抑制率分別為蔓越莓萃取物 (20 mg/mL ； 84%) 、藍莓萃取 物 (5 mg/mL ； 38%) 、葡萄籽萃取物 (10 mg/mL ； 91%) 及 GI 萃取物 (20 mg/mL ； 88%) 。在不影 響 AGS 細胞活性的前提下，各萃取物抑制幽門螺旋桿菌誘發 AGS 細胞分泌 IL-8 之濃度與抑制率分 別為蔓越莓萃取物 (5 mg/mL ； 84%) 、藍莓萃取物 (1.25 mg/mL ； 97%) 、葡萄籽萃取物 (0.075 mg/
mL ； 84%) 及 GI 萃取物 (0.15 mg/mL ； 88%) 。
由實驗結果得知蔓越莓萃取物、藍莓萃取物、葡萄籽萃取物及混合以上三種萃取物之 GI 萃取物可 能藉由抑制幽門螺旋桿菌之生長，或降低該菌對胃癌細胞吸附性及促發炎細胞激素分泌量，進而減 緩幽門螺旋桿菌的致病性。
Suppressive Effect of Berry Extracts on Helicobacter pylori Infection
Helicobacter pylori (H. pylori) is one of the major risk factors of gastric cancer. Clinical abuses of antibiotics extremely like t o develop the drug resistance of H. pylori. Therefore, it is urgently necessary to develop a non-antibiotic alternative therapy to increase the eradication rates of H. pylori. Some literatures reported that cranberry may inhibit H. pylori adhesion to the huma n gastric mucus. However, the therapeutic possibility of other berries on H. pylori was rarely discussed. Thus, the aims of this experiment were to explore the impact of cranberry, blueberry, grape seed and mixed-berry extract (a mixture of mentioned ex tracts, GI extract) on the growth, infectivity and pathogenicity of H. pylori in vitro.
Agar disc diffusion method was used to compare the antimicrobial activities of the four berry extracts against H. pylori. For e valuating the inhibition of the four berry extracts on the adhesion of H. pylori, we first observed the adhesion of fluorescence-l abeled H. pylori to the human gastric cancer cell line AGS under fluorescence microscope. Then, we used urease test to quanti tate the H. pylori density adhesion to AGS cells. In addition, interleukin (IL)-8 secretion from AGS cells after H. pylori infecti on was measured by enzyme-linked immunosorbent assay (ELISA).
In results, inhibition zone assessment revealed that grape seed extract had the best inhibition effect on H. pylori in a dose-depe ndent manner. However, cranberry extract had no antimicrobial activity against H. pylori. Furthermore, the fluorescence micr oscopic observation showed that significant reduction of fluorescence-labeled H. pylori adhesion to AGS cells by berry extrac ts. The highest concentration of berry extracts against the adhesion of H. pylori to AGS cells and the percentage of adhesion i nhibition determined by urease test were 20 mg/mL and 84% for cranberry extract, 5 mg/mL and 38% for blueberry extract, 1 0 mg/mL and 91% for grape seed extract, 20 mg/mL and 88% for GI extract, respectively. In addition, the berry extract conce ntration and the percentage inhibition of H. pylori-induced IL-8 secretion from AGS cells were cranberry extract (5 mg/mL; 8 4%), blueberry extract (1.25 mg/mL; 97%), grape seed extract (0.075 mg/mL; 84%) and GI extract (0.15 mg/mL; 88%), respe ctively.
