China Military Institute of Chinese Materia Medica, 302 Military Hospital, Beijing 100039, PR China.
Phytomedicine. 2010 Jul;17(8-9):684-9. doi: 10.1016/j.phymed.2009.10.009. Epub 2009 Dec 4.
It was found that the intestinal bacteria balance would be deteriorated by rhubarb especially in long term treatment. Bifidobacteria is one of the most common species of probiotics in human intestine. The suppression of this particular probiotic, such as Bifidobacterium adolescentis, one of the dominant anaerobes in the intestines of humans, might lead to imbalance of intestinal flora and is considered to be potentially riskful for human health. Hence, the inhibitory effects of the five main components of hydroxyanthraquinones (HAQs) contained in rhubarb on B. adolescentis growth were investigated by microcalorimetry to discover the suppression potential of rhubarb and the structure-function relationship of such HAQs. The value of the maximum power- output (P(max)) and slope (k) of the thermogenic growth curves of B. adolescentis were found of decrease in the presence of the five HAQs, while the peak time (T(p)) of the thermogenic curves were found to be delayed. The sequence of antimicrobial activity of the five HAQs is rhein>emodin>aloe-emodin>chrysophanol>physicion. The functional groups carboxyl, hydroxyl and hydroxylmethyl on phenyl ring in HAQs could improve the antimicrobial activity. The influence of substituent groups on anti- B. adolescentis activity might be related with the polarity and the sequence was carboxyl>hydroxyl>hydroxylmethyl>methyl and methoxyl.
研究发现，大黄尤其在长期治疗中会破坏肠道细菌平衡。双歧杆菌是人类肠道中最常见的益生菌之一。这种特定益生菌（如双歧杆菌）的抑制作用，可能导致肠道菌群失衡，并被认为对人类健康存在潜在风险。因此，通过微量热法研究了大黄中五种主要羟基蒽醌（HAQs）成分对双歧杆菌生长的抑制作用，以发现大黄的抑制潜力和这些 HAQs 的结构-功能关系。发现五种 HAQs 的存在会降低双歧杆菌热生长曲线的最大功率输出（P(max)）和斜率（k）值，而热曲线的峰值时间（T(p)）则会延迟。五种 HAQs 的抗菌活性顺序为大黄酸>大黄素>芦荟大黄素>大黄酚>大黄素甲醚。蒽醌苯环上的羧基、羟基和羟甲基等功能团可以提高抗菌活性。取代基对双歧杆菌活性的影响可能与极性有关，其顺序为羧基>羟基>羟甲基>甲基和甲氧基。
