Structural characterization of a new polysaccharide component EP80 from Epimedium sagittatum and its effect on the activity of alcohol metabolism related enzymes
Epimedium Folium, a traditional Chinese medicine, is the dried leaves of medicinal plants in the Epimedium genus of the Berberidaceae family. It contains active ingredients such as polysaccharides, flavonoids, alkaloids, and is closely related to liver health. According to Liu Shanshu’s “Herbal Formula” during the Qing Dynasty, Epimedium is “pungent, sweet, and warm” and can be used to “nourish the liver and kidneys”. Wang Ang’s “Compendium of Materia Medica” believes that Epimedium is “fragrant, sweet, and warm, entering the liver and kidneys” and “nourishing the gate of life”. Huanggong Embroidery’s “Seeking Truth from Materia Medica” also believes that Epimedium “specifically enters the gate of life and also enters the liver and kidneys”. The “Shaanxi Traditional Chinese Medicine Chronicle” edited by the Institute of Traditional Chinese Medicine of Shaanxi Branch of the Chinese Academy of Medical Sciences points out that Epimedium “enters the liver and kidney meridians” and can “nourish the liver and kidneys”. In clinical practice, Epimedium has been added to traditional Chinese patent medicines and simple preparations such as “Yigan Jiedu Capsule” or hospital preparations to eliminate liver injury symptoms. In recent years, the impact of excessive alcohol consumption (drinking excessively) on human health, especially alcoholic liver injury, has received increasing attention worldwide. After entering the human body, alcohol is broken down and metabolized in the liver. It is first oxidized by alcohol dehydrogenase (ALD) to acetaldehyde, then oxidized by aldehyde dehydrogenase (ACD) to acetic acid, and finally broken down into carbon dioxide and water. If alcohol intake is excessive or alcohol metabolism related enzyme activity is low, acetaldehyde accumulation may occur, interfering with mitochondrial respiration, generating protein adducts, and causing liver toxicity. Screening active ingredients with sobering and hepatoprotective effects from medicinal plants, analyzing their chemical structures, has become an important research topic in the field of traditional Chinese medicine chemistry.

Plant polysaccharides may have functions such as regulating immunity, protecting liver, and antioxidation. Deng et al. isolated crude polysaccharides with ethanol dehydrogenase activation and free radical scavenging activity from mulberry (Fructus Mori) using enzyme extraction method. Zhang et al. used the grading alcohol precipitation technique to isolate three polysaccharide components from Chimonobambusa quadrinaris: CPS70, CPS75, and CPS80. Among them, CPS75 exhibited high in vitro antioxidant activity and metal chelating activity. Pan et al. used ultrasonic extraction to obtain total polysaccharides from Epimedium koreanum and investigated its preventive effect on alcoholic liver injury using a mouse model. Our laboratory has found that the total polysaccharides of Epimedium brevicornu can scavenge free radicals and prevent DNA oxidative damage. Ethanol fractionation technology can use ethanol solutions of different concentrations to separate total polysaccharides into polysaccharide components of different molecular sizes, thereby obtaining new components with higher uniformity, stronger activity, and better properties. However, there have been no reports on the use of ethanol fractionation technology to screen for new components from Epimedium polysaccharides that activate alcohol metabolism related enzymes (ethanol dehydrogenase and aldehyde dehydrogenase). This study used Epimedium sagittatum as plant material and isolated a new polysaccharide component EP80 from Epimedium sagittatum using ethanol fractionation technology. The chemical structure of EP80 was characterized using Fourier transform infrared spectroscopy, circular dichroism, Congo red experiment, scanning electron microscopy, and other methods. Its antioxidant activity and effects on ethanol dehydrogenase and aldehyde dehydrogenase were also studied, aiming to provide reference for the scientific development and comprehensive utilization of Epimedium resources.

 

This study isolated and prepared a new polysaccharide component EP80 from the medicinal plant Epimedium sagittatum. The structure of EP80 was characterized by UV spectroscopy, Fourier transform infrared spectroscopy, circular dichroism, Congo red experiment, scanning electron microscopy, and thermogravimetric analysis. Its in vitro antioxidant capacity and effects on the activities of alcohol metabolism related enzymes ethanol dehydrogenase and aldehyde dehydrogenase were investigated. The results showed that EP80 is composed of four monosaccharides, namely galactose, arabinose, glucose, and xylose, with a molecular weight of 3.2 × 104Da. It has a pyranoside skeleton and a triple helix structure. It exhibits a positive Cotton effect near 230nm and a negative Cotton effect near 260nm. The microstructure is irregular and has prominent wrinkled structures. The thermal weight loss range is mainly concentrated between 240-350 ℃. EP80 has certain antioxidant activity and has a significant activating effect on ethanol dehydrogenase and aldehyde dehydrogenase. Its activating effect on aldehyde dehydrogenase is stronger than that on ethanol dehydrogenase, and it is worth further research. This study provides a reference for the development and utilization of polysaccharides from Epimedium.