Triterpenoids from Alisma orientale and their NF-кB Inhibitory Activity

The rhizome of Alisma orientale (sam.) Juz. is used in clinics for eliminating dampness, reducing edema, and promoting diuresis. This study aimed to elucidate the compounds and investigate their nuclear factor-kappa inhibitory activities in human embryonic kidney 293 cells. A new triterpene, alismaketone B (1); a new natural nortriterpene, noralisolic acid A (2); and 13 known protostane-type triterpenes were isolated from the rhizome of A. orientale. The new structures and their absolute configurations were established using HRESIMS, NMR, and electronic circular dichroism experiments. All isolated compounds were evaluated for their inhibitory activity on NF-κB. The compounds 8, 9, 10, and 14 showed moderate NF-κB inhibitory activities with their IC50 values being 64.7, 32.3, 47.3, and 37.3 μM, respectively.

Alisol A 24-acetate stimulates lipolysis in 3 T3-L1 adipocytes

Background Alisol A 24-acetate (AA-24-a), one of the main active triterpenes isolated from the well-known medicinal plant Alisma orientale (Sam.) Juz., exhibits multiple biological activities including hypolipidemic activity. However, its effect on lipid metabolism in adipocytes remains unclear. The present study aimed to clarify the effect of AA-24-a on adipocyte lipolysis and to determine its potential mechanism of action using 3 T3-L1 cells. Methods We assayed the release of glycerol into culture medium of 3 T3-L1 cells under treatment with AA-24-a. Protein and mRNA expression and phosphorylation levels of the main lipases and kinases involved in lipolysis regulation were determined by quantitative polymerase chain reaction and western blotting. Specific inhibitors of protein kinase A (PKA; H89) and extracellular signal-regulated kinase (ERK; PD98059), which are key enzymes in relevant signaling pathways, were used to examine their roles in AA-24-a-stimulated lipolysis. Results AA-24-a significantly stimulated neutral lipolysis in fully differentiated adipocytes. To determine the underlying mechanism, we assessed the changes in mRNA and protein levels of key lipolysis-related genes in the presence or absence of H89 and PD98059. Both inhibitors reduced AA-24-a-induced lipolysis. Moreover, pretreatment with H89 attenuated AA-24-a-induced phosphorylation of hormone-sensitive lipase at Ser660, while pretreatment with PD98059 attenuated AA-24-a-induced downregulation of peroxisome proliferator-activated receptor-γ and perilipin A. Conclusions Our results indicate that AA-24-a promoted neutral lipolysis in 3 T3-L1 adipocytes by activating PKA-mediated phosphorylation of hormone-sensitive lipase and ERK- mediated downregulation of expression of perilipin A.

Alismatis Rhizoma Triterpenes Alleviate High-Fat Diet-Induced Insulin Resistance in Skeletal Muscle of Mice

Alismatis rhizoma (AR), which is the dried rhizome of Alisma orientale (Sam.) Juz. (Alismataceae), is an important component of many famous Chinese formulas for hypoglycemic. This study aimed to evaluate the insulin resistance (IR) alleviating effects of AR triterpenes (ART) and ART component compatibility (ARTC, the mixture of 16-oxo-alisol A, 16-oxo-alisol A 23-acetate, 16-oxo-alisol A 24-acetate, alisol C, alisol C 23-acetate, alisol L, alisol A, alisol A 23-acetate, alisol A 24-acetate, alisol L 23-acetate, alisol B, alisol B 23-acetate, 11-deoxy-alisol B and 11-deoxy-alisol B 23-acetate) in high-fat diet-induced IR mice and plamitate-treated IR C2C12 cells, respectively. A dose of 200 mg/kg of ART was orally administered to IR mice, and different doses (25, 50, and 100 μg/ml) of ARTC groups were treated to IR C2C12 cells. IPGTT, IPITT, body weight, Hb1AC, FFA, TNF- α , MCP-1, and IR-associated gene expression (p-AMPK, p-IRS-1, PI3K, p-AKT, p-JNK, and GLUT4) were measured in IR mice. Glucose uptake, TNF- α , MCP-1, and IR-associated gene expression were also measured in IR C2C12 cells. Results showed that ART alleviated high-fat diet-induced IR in the skeletal muscle of mice, and this finding was further validated by ARTC. This study demonstrated that ART presented a notable IR alleviating effect by regulating IR-associated gene expression, and triterpenes were the material basis for the IR alleviating activity of AR.

The Hypolipidemic Effect of Active Components in the Decoction of Alisma Orientale and their Chemical Structures Characterized by LC-QTOF-MS/MS

Background: The decoction of Alisma orientale is used as a traditional medicine for the treatment of hyperlipidemia in China with a long clinical history. The present study undertook a detailed investigation to compare the hypolipidemic effect and chemical composition of two extracts of Alisma orientale prepared by boiling water and organic reagent, respectively. Methods: The hyperlipidemic mice were induced by administration of a High-Fat Diet (HFD) for one month. The body weight of mice and the serum Cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), Superoxide Dismutase (SOD), malondialdehyde (MDA), aspartate Aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined. Meanwhile, the chemical constituents of the extracts were characterized using liquid chromatography-quadrupole time of flight mass spectrometry (LC-QTOF-MS/MS). Results: The better hypolipidemic effect was observed in mice administered with the decoction compared to that of methanol extract. In addition, the liver protective effects were confirmed by the photographs stained with oil red lipid stain. As for the chemical constituents in the extracts, twenty major components were identified or characterized using LC-QTOF-MS/MS. Among them, eight oligopeptides were characterized for the first time and proved to only exist in the decoction of Alisma orientale. Conclusion: It is reasonable to assume that the oligopeptides may partially contribute to the hypolipidemic effect of Alisma orientale. The structural characterization procedures also provide a suitable method to analyze oligopeptide analogues in plant samples.