Department of Veterinary Science, University of Parma, 43126 Parma, Italy.
Department of Food and Drugs, University of Parma, 43124 Parma, Italy.
Molecules. 2020 Feb 19;25(4):940. doi: 10.3390/molecules25040940.
Turmeric ( L.) is the only edible plant recognized as a dietary source of curcuminoids, among which curcumin, demethoxycurcumin (DMC) and bis-demethoxycurcumin (Bis-DMC) are the most representative ones. Curcumin shows a very low systemic bioavailability and for this reason, several technologies have been adopted to improve it. These technologies generally improve curcuminoid absorption in the small intestine, however, no data are available about the effect of curcuminoid formulation on colonic biotransformation. The present study aims at investigating the human colonic metabolism of curcuminoids, prepared with two different technologies, using an in vitro model. Unformulated curcuminoid and lecithin-curcuminoid botanical extracts were fermented using an in vitro fecal model and colonic catabolites were identified and quantified by uHPLC-MS. Native compounds, mainly curcumin, DMC and bis-DMC, were metabolized by colonic microbiota within the 24-h incubation. The degradation of curcuminoids led to the formation of specific curcuminoid metabolites, among which higher concentrations of bis(demethyl)-tetrahydrocurcumin and bis(demethyl)-hexahydrocurcumin were found after lecithin-extract fermentation compared to the concentration detected after unformulated extract. In conclusion, both curcumin-based botanical extracts can be considered important sources of curcuminoids, although the lecithin-formulated extract led to a higher production of curcuminoid catabolites. Moreover, a new curcuminoid catabolite, namely bis(demethyl)-hexahydrocurcumin, has been putatively identified, opening new perspectives in the investigation of curcuminoid bioavailability and their potential metabolite bioactivity.
姜黄（ L.）是唯一被认可的食用植物，可作为膳食中姜黄素类的来源，其中姜黄素、脱甲氧基姜黄素（DMC）和双脱甲氧基姜黄素（Bis-DMC）是最具代表性的。姜黄素的全身生物利用度非常低，因此采用了多种技术来提高其生物利用度。这些技术通常可以提高姜黄素类在小肠中的吸收，但关于姜黄素类配方对结肠生物转化的影响尚无数据。本研究旨在使用体外模型研究两种不同技术制备的姜黄素类在人体结肠中的代谢情况。未配方的姜黄素类和卵磷脂-姜黄素类植物提取物采用体外粪便模型进行发酵，并用 uHPLC-MS 鉴定和定量分析结肠代谢产物。天然化合物，主要是姜黄素、DMC 和 Bis-DMC，在 24 小时孵育过程中被结肠微生物群代谢。姜黄素类的降解导致了特定的姜黄素类代谢产物的形成，其中在卵磷脂提取物发酵后，比未配方提取物检测到的浓度更高的是双（去甲基）-四氢姜黄素和双（去甲基）-六氢姜黄素。总之，基于姜黄素的植物提取物都可以被认为是姜黄素类的重要来源，尽管卵磷脂配方的提取物导致了更多的姜黄素类代谢产物的生成。此外，还推测出了一种新的姜黄素类代谢产物，即双（去甲基）-六氢姜黄素，为姜黄素类生物利用度及其潜在代谢物生物活性的研究开辟了新的前景。
