評估烏梅萃取物之抗下痢活性

Abstract

本研究之目的在探討烏梅萃取物之抗下痢活性，期能用於預防離乳仔豬的下痢，試驗先以小鼠下痢模式進行功效的探討。試驗分為三個部分：（一）烏梅之萃取與製備、（二）烏梅萃取物對蓖麻油誘導下痢與福斯克林活化劑（forskolin）刺激腸道分泌之影響，及（三）長期給予烏梅萃取物對抗下痢效果與腸道菌相之探討。試驗一用丙酮、水及甲醇等不同溶劑萃取烏梅，以70%丙酮萃取出的的檸檬酸含量（23.42 ± 3.42 mg/ml）最高，其烏梅萃取物含有高達52%的檸檬酸。試驗二以烏梅萃取物灌食12週齡之小鼠，並以蓖麻油（Oleum Palmae Christi或castor oil）誘導下痢評估其糞便性狀的改善作用，再利用Ussing chamber systems，測量小鼠腸道上皮組織之離子移動產生電流之變化，評估烏梅萃取物減緩受福斯克林活化劑刺激的腸道分泌作用，結果顯示灌食1400 mg/kg BW的烏梅萃取物可減緩蓖麻油誘導之下痢，給予烏梅萃取物可顯著延緩第一次排水便時間（P < 0.05）及顯著降低糞便評分（P < 0.05）；此外，烏梅萃取物亦可減緩福斯克林活化劑刺激之腸道離子分泌，隨著烏梅萃取物添加的濃度增加，減緩效果漸增，以相對濃度的檸檬酸添加，亦有相同效果，而以檸檬酸達到半抑制效果所需的濃度（half inhibition concentration（IC50）= 0.73 mg/ml）高於烏梅萃取物的半抑制濃度（IC50 = 0.68 mg/ml），顯示除了檸檬酸外，烏梅萃取物中仍含有其他活性成分可幫助減緩腸道過度分泌。試驗三連續給予烏梅萃取物4週用於評估其對腸道菌相改變及減緩蓖麻油誘導下痢之長期效應，結果顯示連續給予4週後，並不會顯著提升其對蓖麻油誘導下痢的減緩效果；然烏梅萃取物處理組的糞便大腸桿菌菌數顯著低於對照組（P < 0.05），且擁有較穩定的腸道菌相。綜觀上述，烏梅萃取物可減緩蓖麻油誘導之下痢及福斯克林活化劑刺激之腸道分泌，具有抗下痢活性，可用於下痢之預防。

The aim of this study was to examine the antidiarrheal activity of Prunus mume Sieb. et Zucc. extract (PME). We adopted the mice diarrheal model to investigate the antidiarrheal activity of PME. The study included three parts: (1) Extraction of Prunus mume Sieb. et Zucc. (2) Evaluate antidiarrheal activity of PME via castor oil-induced diarrhea model and forskolin-stimulated intestinal secretion model. (3) Investigate the long-term effect of PME on antidiarrheal activity and fecal microbiota. In the first part, PME from 70% acetone extraction contained 52% citric acid. In the second part, giving (1400 mg/kg BW) PME attenuated castor oil-induced diarrhea in mice through delaying the onset time of diarrhea and decreasing the stool scores (P < 0.05). In addition, PME showed its ability to attenuate forskolin-stimulated intestinal secretion. The stimulated secretion of colonic tissues was gradually attenuated along with increasing concentration of PME. However, when the effect of stand-alone citric acid was examined, much higher concentration of citric acid (IC50 = 0.73 mg/ml) was needed to achieve similar attenuate effect as PME (IC50 = 0.68 mg/ml). Therefore, besides the effect of citric acid, there could be other active ingredients in PME to regulate intestinal ion transportation. In the last part, giving PME for 4-weeks did not significantly increase the attenuate effect on castor oil-induced diarrhea. Nevertheless, the counts of E. coli in feces of PME group was significantly less than that of control group after 4-weeks (P < 0.05). In summary, PME presented antidiarrheal activity including attenuating castor oil-induced diarrhea and forskolin-stimulated intestinal secretion. It is apparent that PME has potential as feed additives to prevent diarrhea of animals.