Study on the lignans in Eucommia ulmoides bark and their protective effects on high glucose induced glomerular mesangial cells
Eucommia ulmoides is the dried bark of Eucommia ulmoides Oliv., a plant in the Eucommia family. It is warm in nature and sweet in taste, and has the effects of nourishing the liver and kidneys, strengthening muscles and bones, and preventing miscarriage. It is used for conditions such as liver and kidney deficiency, waist and knee pain, muscle weakness, dizziness and vertigo, blood leakage during pregnancy, and fetal instability. Eucommia ulmoides is mainly distributed in provinces such as Hunan, Hubei, Henan, Shanxi, and Sichuan. It is a national second-class protected plant, and its main components include lignans, iridoids, flavonoids, phenylpropanoids, terpenes, polysaccharides, etc. Modern pharmacological research has shown that Eucommia ulmoides has pharmacological effects such as lowering blood pressure, regulating blood lipids, lowering blood sugar, anti-tumor, antibacterial, anti-inflammatory, antioxidant, liver and kidney protection, and anti osteoporosis. Diabetes is a metabolic disease with high incidence rate and high mortality. diabetes nephropathy is one of the most common complications of diabetes patients, and is also the most common cause of end-stage renal failure. Finding drugs that can improve renal function in a high glucose environment has important clinical value. Research has shown that Eucommia ulmoides lignans can reduce urinary protein levels in rats with kidney injury, inhibit angiotensin II induced proliferation of glomerular mesangial cells, improve renal function, and have a protective effect against hypertension induced kidney injury. It can also significantly inhibit high glucose induced morphological changes in renal tubular epithelial cells and antagonize high glucose induced transdifferentiation of renal tubular epithelial cells, but the specific active ingredients have not been determined. To enrich the chemical composition and structural types of Eucommia ulmoides, compounds with renal protective activity were screened from Eucommia ulmoides lignans. In this experiment, lignans from Eucommia ulmoides bark water extract were isolated and identified, and compounds from Eucommia ulmoides lignans that could inhibit high glucose induced mesangial cell proliferation were preliminarily screened by MTT assay.

This study isolated and identified six lignans from the water extract of Eucommia ulmoides bark, among which compound 1 was isolated from Eucommia ulmoides for the first time. Research has confirmed that Eucommia ulmoides extract has a good protective effect on kidney injury. At the same time, studies have reported that Eucommia ulmoides lignans can inhibit angiotensin II induced rat mesangial cell proliferation and promote cell apoptosis by promoting the upregulation of P21, P27, and Bax expression, thereby exerting renal protection. However, the specific active ingredients that exert protective effects have not yet been determined. On the basis of chemical composition research, this article found through MTT assay that Eucommia ulmoides lignans compounds 2, 3, and 4 can inhibit high glucose induced proliferation of human glomerular mesangial cells at certain concentrations, and compound 5 can effectively inhibit high glucose induced proliferation of glomerular mesangial cells in a dose-dependent manner, indicating that compound 5 has a good renal cell protective effect. This study enriches the compound library of Eucommia ulmoides medicinal materials and provides a material basis for screening lead compounds with renal protective activity.