枫糖浆提取物强化抗生素疗效

诸平

据物理学家组织网（Phys.org）2017年4月2日转载来自美国化学会2017年第253届年会消息，富含酚类的枫糖浆提取物（Phenolic rich maple syrup extracts）与抗生素具有协同作用。

枫糖浆是一种100％天然的甜味剂，枫糖的来源是北美尤其是加拿大本土很多品种的枫树，由采集的树液浓缩而成。加拿大糖枫树，学名糖槭，是目前为止最广泛的枫糖来源。全世界85％的枫糖浆都产自加拿大。正因为枫糖源自天然的植物，它应当富含多种植化素，这一点通过分析枫树液也得到了证实。枫糖浆的热蒸馏过程中，也会产生很多有益物质，成为最终提炼出的枫糖浆的成分。

枫糖浆的营养成分

枫糖浆的主要糖成分是蔗糖。枫树液的蔗糖浓度大概在2.0%~2.5%之间。枫糖浆富含氨基酸和多种矿物质。值得一提的是，枫糖浆含有非常高的锰和维他命B₁₂。它的钾、钙、锌含量也相当高。枫糖中这些有益物质的含量要远远高于其它甜味剂中，比如蜂蜜，白砂糖，黄糖。所以，枫糖是迄今最有营养的甜味剂。枫糖浆也被认为是低纳或者零盐分的一种食物。

枫糖浆富含酚类化合物

有趣的是，超过50种植物营养素被发现存在于枫糖中，但最普遍存在的还是酚类化合物。某份科学研究在枫糖浆提取物中，发现了23种不同的酚类化合物，其中包括香草醛，肉桂酸和黄酮类化合物。酚类化合物有抗氧化的功效——一些枫糖浆的分离产物甚至具有和维他命C非常相似的抗氧化性。枫糖浆中提取的酚类化合物还对癌细胞的突变具有抑制作用。

了解枫糖浆成分,尤其是源自枫树液的诸如酚类化合物等成分，是至关重要的，因为这些营养素对人类健康可能有很大助益。就生产过程来说，在熬煮枫糖浆的过程中会产生一种酚类化合物如Quebecol，它和枫糖浆中那些天然的、有抗氧化性的酚类化合物有着极为相似的结构。Quebecol的抗氧化功效有待进一步证实。

枫糖浆含有木酚素和香豆素

除了酚类化合物，枫糖浆中与人类健康相关的重要成分还有木酚素（仅存在于加拿大枫糖浆）。近来，富含木酚素的食物备受关注，比如亚麻籽，就具有强大的保健功效，包括很强的抗癌效果。我们发现香豆素同样存在于枫糖浆提取物中。香豆素及其衍生物具有多种生物效应，包括抗炎，抗病毒，抗微生物，抗凝血和抗肿瘤特性。今后的研究将针对于枫糖浆中的香豆素，得以更确切地阐明香豆素的哪些特性能够通过食用枫糖浆来使人类受益。

加拿大麦吉尔大学(McGill University)Nathalie Tufenkji博士的团队，他们浆枫糖浆的混合酚提取与常用抗生素环丙沙星和羧苄青霉素这两种药物使用,他们确实发现具有协同效应,使他们能够得到相同的抗菌效果，但是抗生素得使用量要减少90%以上。该方法对于各种各样菌株都显示出有效,其中包括大肠杆菌（E. coli）、变形杆菌（Proteus mirabilis）、铜绿假单胞菌（Pseudomonas aeruginosa）等，更多信息请浏览原文。

No more 'superbugs'? Maple syrup extract enhances antibiotic action

April 2, 2017

Antibiotics save lives every day, but there is a downside to their ubiquity. High doses can kill healthy cells along with infection-causing bacteria, while also spurring the creation of "superbugs" that no longer respond to known antibiotics. Now, researchers may have found a natural way to cut down on antibiotic use without sacrificing health: a maple syrup extract that dramatically increases the potency of these medicines.

The researchers will present their work today at the 253rd National Meeting & Exposition of the American Chemical Society (ACS).

"Native populations in Canada have long used maple syrup to fight infections," says Nathalie Tufenkji, Ph.D. "I've always been interested in the science behind these folk medicines."

The idea for the project really gelled when Tufenkji, who had been studying the antimicrobial effects of cranberry extracts, learned of the anti-cancer properties of a phenolic maple syrup extract. "That gave me the idea to check its antimicrobial activity," Tufenkji says. "So, I sent my postdoc to the store to buy some syrup."

Using the same extraction approach as other researchers have in the past, Tufenkji's team at McGill University separated the sugar and water from the syrup's phenolic compounds, which contribute to maple syrup's signature golden hue.

In an initial test, the team exposed several disease-causing bacterial strains to the extract, but they didn't see much of an effect. Rather than give up on maple syrup altogether, Tufenkji decided to check whether the extract could enhance the antimicrobial potency of the commonly used antibiotics ciprofloxacin and carbenicillin. When her team mixed the phenolic extract with either of these medicines, they indeed found a synergistic effect, allowing them to get the same antimicrobial effect with upwards of 90 percent less antibiotic. The approach worked on a variety of bacterial strains, including E. coli, which can cause gastrointestinal problems; Proteus mirabilis, responsible for many urinary tract infections; and Pseudomonas aeruginosa, which can cause infections often acquired by patients in hospitals.

Building on this work, Tufenkji's team next tested the extract in fruit flies and moth larvae. The researchers dosed fly food with pathogenic bacteria and antibiotic, with and without the phenolic extract. Flies with meals doused in maple syrup extract lived for days longer than those denied the syrupy topper. The researchers observed a similar outcome with the moth larvae.

To figure out how the extract makes antibiotics work better, the researchers investigated whether the extract changed the permeability of bacterial cells. The extract increased the permeability of the bacteria, suggesting that it helps antibiotics gain access to the interior of bacterial cells. Another experiment suggested that the extract may work by a second mechanism as well, disabling the bacterial pump that normally removes antibiotics from these cells.

Currently, the researchers are testing the maple syrup extract in mice. While it is likely to be years before it would be available to patients as a prescribed medical protocol, and a pharmaceutical company would likely need to purify the extract further to avoid any potential allergic reactions, Tufenkji says, she's hopeful that it may have an edge over other would-be medications thanks to its source. "There are other products out there that boost antibiotic strength, but this may be the only one that comes from nature," she says.

Explore further: Could maple syrup help cut use of antibiotics? (w/ Video)

More information: Phenolic rich maple syrup extracts synergize with antibiotics, 253rd National Meeting & Exposition of the American Chemical Society (ACS), 2017.