[Antioxidant activity of Euryale ferox seed shell extract and its therapeutic effects on oral ulcer in rats].

OBJECTIVE: To investigate the therapeutic effect of Euryale ferox seed shell extract on oral ulcer in rats and its underlying mechanism. METHODS: The contents of polyphenols and flavonoids in Euryale ferox seed shells were determined by Folin-phenol assay and aluminum nitrate colorimetry, respectively. DPPH·, ABTS+·, ·OH and·O2- scavenging experiments were performed to evaluate the antioxidant activities of Euryale ferox seed shell extract in vitro. In a rat model of oral ulcer induced by burning with glacial acetic acid, the therapeutic effect of Euryale ferox seed shell extract was assessed by detecting changes in serum levels of oxidative factors by enzyme-linked immunosorbent assay (ELISA) and observing pathological changes of the ulcerous mucosa using HE staining; the therapeutic mechanism of the extract was explored by detecting the expression levels of Keap1, Nrf2, Nes-Nrf2 and HO-1 proteins in ulcerous mucosa using Western blotting. RESULTS: The ethyl acetate extract of Euryale ferox seed shells contained 306.74±1.04 mg/g polyphenols and 23.43±0.61 mg/g flavonoids and had IC50 values for scavenging DPPH· and ABTS+· free radicals of 3.42 ± 0.97 µg/mL and 3.32 ± 0.90 µg/mL, respectively. In the rat models, the ethyl acetate extract significantly ameliorated oral mucosal ulcer, increased serum CAT level, and decreased serum MDA level. The protein expression levels of Nes-Nrf2 and HO-1 were increased and Keap1 protein expression was lowered significantly in the ulcerous mucosa of the rats after treatment with the extract (P<0.05 or 0.01). CONCLUSION: The therapeutic effect of Euryale ferox seed shell extract on oral ulcers in rats is mediated probably by activation of the Keap1/Nrf2/HO-1 signaling pathway.

The Ethnopharmacological, Phytochemical, and Pharmacological Review of Euryale ferox Salisb.: A Chinese Medicine Food Homology.

Euryale ferox Salisb. (prickly water lily) is the only extent of the genus Euryale that has been widely distributed in China, India, Korea, and Japan. The seeds of E. ferox (EFS) have been categorized as superior food for 2000 years in China, based on their abundant nutrients including polysaccharides, polyphenols, sesquineolignans, tocopherols, cyclic dipeptides, glucosylsterols, cerebrosides, and triterpenoids. These constituents exert multiple pharmacological effects, such as antioxidant, hypoglycemic, cardioprotective, antibacterial, anticancer, antidepression, and hepatoprotective properties. There are very few summarized reports on E. ferox, albeit with its high nutritional value and beneficial activities. Therefore, we collected the reported literature (since 1980), medical classics, database, and pharmacopeia of E. ferox, and summarized the botanical classification, traditional uses, phytochemicals, and pharmacological effects of E. ferox, which will provide new insights for further research and development of EFS-derived functional products.

Hepatoprotective Effect of Seed Coat ofEuryale ferox Extract in Non-alcoholic Fatty Liver Disease Induced by High-fat Diet in Mice by Increasing IRs-1 and Inhibiting CYP2E1.

Non-alcoholic fatty liver disease (NAFLD), a common chronic liver disease characterized by hepatic steatosis, affects 30-40% of the population in the world. The seed of Euryale ferox salisb. possesses several pharmacological actions, including metabolic syndrome. However, the seed coat of E. ferox was usually discarded as waste, which contains comparatively abundant polyphenols, and its biological activity has been rarely investigated. In this work, we evaluate the hepatoprotective effect of E. ferox seed coat extract (EFSCE), in NAFLD mice induced by high-fat diet (HFD). The HPLC-MS analysis indicated that the main components of EFSCE were polyphenols. And then, mice were treated with HFD for 4 weeks to induce NAFLD. The result showed that the body weight, weight of adipose tissue, the ratio of liver to body weight in NAFLD mice increased compared with control group. In addition, blood lipids parameters including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL) also increased in NAFLD mouse model. It was showed that, after treated with EFSCE (15 and 30 mg/kg/day) for 4 weeks, the body weight, lipids deposition in the liver and blood lipids in HFD-induced NAFLD mice markedly reduced. Compared with NAFLD mice, EFSCE administration could also prevent malondialdehyde (MDA) overproduction and strengthen Superoxide Dismutase (SOD) activity to counteract oxidative stress. Moreover, EFSCE was also found effective in reducing alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity in HFD-induced NAFLD model, which indicated liver injury in NAFLD. Therefore, EFSCE (rich in polyphenols) is indicated as bioactive nature product for HFD-induced NAFLD treatment, by eliminating lipid accumulation and oxidative stress via regulation of IRs-1 and CYP2E1.

Structural characterization and in vitro hypoglycemic activity of a glucan from Euryale ferox Salisb. seeds.

In this research, a polysaccharide fraction (EFSP-1) was obtained from the seeds of Euryale ferox Salisb. by DEAE sepharose FF and Superdex™ 75 gel chromatography. The average molecular weight (Mw) of EFSP-1 was 8.75 kDa. Monosaccharides composition analysis indicated that EFSP-1 was a glucan. The structure of EFSP-1 was characterized by analysis of FT-IR, GC-MS and NMR, which indicated that the backbone of EFSP-1 was mainly composed of (1→4)-α-D-Glcp with branches substituted at O-6 and terminated with T-α-D-Glcp. Moreover, the hypoglycemic effect of EFSP-1 was investigated by establishing insulin resistance HepG2 and 3T3-L1 cells. The results showed that EFSP-1 could increase glucose consumption by up-regulating the expression of GLUT-4 via activating PI3K/Akt signal pathway in IR cells. Hence, EFSP-1 could be a potential functional food to ameliorate insulin resistance for diabetes therapy.

Extract of Euryale ferox Salisb exerts antidepressant effects and regulates autophagy through the adenosine monophosphate-activated protein kinase-UNC-51-like kinase 1 pathway.

Positive regulation of autophagy by Euryale ferox Salisb (ES) leads to antidepressant effects. This study focused on the potential antidepressant mechanisms induced by the petroleum ether fraction of ES (ES-PE) in the chronically unpredictable mild stress (CUMS) mouse model. Deficits in the sucrose preference test, open field test, tail suspension test, and forced swim test were observed following CUMS, and were reversed following ES-PE administration. Contrary to the expression of mammalian target of rapamycin, autophagy was decreased after establishment of the CUMS model. We also observed trends for downregulation of adenosine mononphosphate-activated protein kinase (AMPK) and mammalian autophagy-initiating kinase (ULK1), which were differentially affected by ES-PE. HT22 cells and Compound C, an inhibitor of AMPK, were used to verify the results in mice. Gas chromatography-mass spectrometry analysis revealed high level of vitamin E acetate in ES-PE. Taken together, our data indicate that ES-PE activated autophagy by regulating the AMPK pathway. © 2018 IUBMB Life, 70(4):300-309, 2018.

Prophylactic effects of alkaloids from Ba lotus seeds on L-NNA-induced hypertension in mice.

Alkaloids from Ba lotus seeds (ABLS) are a kind of important functional compounds in lotus seeds. The present study was designed to determine its hypertension prophylactic effects in the L-NNA-induced mouse hypertension model. The mice were treated with ABLS, the serum and tissues levels of NO, MDA, ET-1, VEGF, and CGRP were determined using the experimental kits, the mRNA levels of various genes in the heart muscle and blood vessel tissues were further determined by RT-PCR assay. ABLS could reduce the systolic blood pressure (SBP), mean blood pressure (MBP), and diastolic blood pressure (DBP), compared to that of the model control group. After ABLS treatment, the NO (nitric oxide) contents in serum, heart, liver, kidney and stomach of the mice were higher than that of the control mice, but the MDA (malonaldehyde) contents were lower than that of the control mice. The serum levels of ET-1 (endothelin-1), VEGF (vascular endothelial growth factor) were decreased after ABLS treatment, but CGRP (calcium gene related peptide) level was increased. The ABLS treated mice had higher mRNA expressions of HO-1, nNOS, and eNOS and lower expressions of ADM, RAMP2, IL-1ß, TNF-α, and iNOS than the control mice. Higher concentration of ABLS had greater prophylactic effects, which were close to that of the hypertension drug captopril. These results indicated the hypertension prophylactic effects of ABLS could be further explored as novel medicine or functional food in the future.

Isolation and identification of compounds responsible for antioxidant capacity of Euryale ferox seeds.

Euryale ferox seed is consumed medicinally or for food in China. The present study revealed it to contain significant antioxidant activity, which may be associated with its medical applications as a proteinuria inhibitor of diabetic nephropathy. This study resulted in the identification of 3 new sesquineolignans, named euryalins A-C (1-3), and 16 known compounds, which were all first isolated from this plant apart from 5,7,4-trihydroxy-flavanone. The antioxidant potential of the partial isolates was evaluated using the DPPH radical scavenging assay and mesangial cellular assay. Compounds 2, rel-(2α,3ß)-7-O-methylcedrusin (4), syringylglycerol-8-O-4-(sinapyl alcohol) ether (5), and (+)-syringaresinol (7) were found to be most active on DPPH assay, whereas compounds 2, 4, 7, (1R,2R,5R,6S)-2-(3,4-dimethoxyphenyl)-6-(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane, and buddlenol E could significantly inhibit high glucose-stimulated reactive oxygen species production in mesangial cells. The results suggested that E. ferox seed could be considered as an excellent source of natural antioxidants and is useful in the prevention of diabetic nephropathy.