Euonymus alatus: A Review on Its Phytochemistry and Antidiabetic Activity

Euonymus alatus (Thunb.) Siebold Prevents Osteoclast Differentiation and Osteoporosis

Euonymus alatus (Thunb.) Siebold, a traditional medicinal plant, has been used in China and several other Asian countries to address a variety of health concerns. The extensive research conducted on E. alatus is driven by its diverse pharmacological applications. However, its biological effects on osteoclastogenesis and osteoporosis have not been previously studied. In this research, we investigated the impact of an ethanolic extract of E. alatus (EEEA) on osteoclast differentiation and function as well as estrogen deficiency-induced bone loss. We found that EEEA inhibits osteoclast differentiation by downregulating the expression of the receptor activator of nuclear factor-κB ligand (RANKL) in osteoclast-supporting cells and by directly impeding RANKL-mediated signaling pathways for osteoclastogenesis in precursor cells. In addition, EEEA inhibited the bone-resorptive function of mature osteoclasts in vitro. Furthermore, oral administration of EEEA significantly alleviated bone loss in an ovariectomy-induced osteoporosis mouse model. Additionally, we identified phytochemicals in EEEA that have suppressive effects on osteoclast differentiation and bone loss. Collectively, these results suggest that EEEA holds potential as a biotherapeutic candidate for anti-postmenopausal osteoporosis.

Microalgal and Nitrogen-Fixing Bacterial Consortia: From Interaction to Biotechnological Potential

Microalgae are used in various biotechnological processes, such as biofuel production due to their high biomass yields, agriculture as biofertilizers, production of high-value-added products, decontamination of wastewater, or as biological models for carbon sequestration. The number of these biotechnological applications is increasing, and as such, any advances that contribute to reducing costs and increasing economic profitability can have a significant impact. Nitrogen fixing organisms, often called diazotroph, also have great biotechnological potential, mainly in agriculture as an alternative to chemical fertilizers. Microbial consortia typically perform more complex tasks than monocultures and can execute functions that are challenging or even impossible for individual strains or species. Interestingly, microalgae and diazotrophic organisms are capable to embrace different types of symbiotic associations. Certain corals and lichens exhibit this symbiotic relationship in nature, which enhances their fitness. However, this relationship can also be artificially created in laboratory conditions with the objective of enhancing some of the biotechnological processes that each organism carries out independently. As a result, the utilization of microalgae and diazotrophic organisms in consortia is garnering significant interest as a potential alternative for reducing production costs and increasing yields of microalgae biomass, as well as for producing derived products and serving biotechnological purposes. This review makes an effort to examine the associations of microalgae and diazotrophic organisms, with the aim of highlighting the potential of these associations in improving various biotechnological processes.

Euonymus alatus (Thunb.) Siebold leaf extract enhanced immunostimulatory effects in a cyclophosphamide-induced immunosuppressed rat model

Background

Euonymus alatus (Thunb.) Siebold (EA) is a medicinal plant used in some Asian countries to treat various diseases, including cancer, hyperglycemia, diabetes, urticaria, dysmenorrhea, and arthritis. Owing to the wide range of pharmacological applications of EA, various roles of EA are being studied.

Objective

We evaluated the immune-enhancing effect of EA treatment in a cyclophosphamide (Cy)-induced immunosuppressed rat model.

Design

We analyzed the immune enhancement effect of EA on macrophages by western blotting. In addition, cell viability and natural killer (NK) cell activity were analyzed in splenocytes following EA treatment. For in vivo studies, analysis of weekly body weight, spleen weight, immune cell count, cytokine levels, and spleen histological findings was performed following EA administration in Cy-induced immunocompromised rats.

Results

EA significantly increased cell viability and phospho-nuclear factor-kappa B and phospho-extracellular signal-regulated kinase protein levels in the macrophages. EA significantly increased NK cell activity in splenocytes compared with the control group. In Cy-induced immunosuppressed rats, EA administration increased spleen tissue weight and the contents of leukocytes, lymphocytes, granulocytes, intermediate cells, and plasma cytokines (tumor necrosis factor-α and interferon-γ). In addition, improvement in the damaged spleen tissue was observed.

Conclusions

These findings confirm that EA exerts an immune-enhancing effect, thereby suggesting its potential as an immunostimulatory agent or functional food.

Euonymus alatus Twig Extract Protects against Scopolamine-Induced Changes in Brain and Brain-Derived Cells via Cholinergic and BDNF Pathways

In the current study, the therapeutic and preventive effects of Euonymus alatus (EA) twig extract were investigated in a mouse model of cognitive deficit and B35 cells. Twig extract 1 was extracted with 70% ethanol and later twig extract 2 was extracted through liquid-liquid extraction with 70% ethanol and hexane. EA twig 2 (300 mg/kg) along with the standard drug donepezil (5 mg/kg) were orally administered to the mice for 34 days. Scopolamine was given intraperitoneally for 7 days. Administration of EA twig extract 2 significantly improved the passive avoidance test (PAT) in mice. EA twigs extract also restored the scopolamine-reduced brain-derived neurotrophic factor (BDNF)/extracellular regulated kinase (ERK)/cyclic AMP responsive element binding protein (CREB) signaling in B35 cells and the mouse hippocampus. In addition, EA twig extract significantly inhibited the acetylcholine esterase (AChE) activity in B35 cells in a dose-dependent manner. Chromatography and ESI MS analysis of EA twig extract revealed the presence of flavonoids; epicatechin, taxifolin, aromadendrin, and naringenin with catechin being the most abundant. These flavonoids exerted protective effects alone and had the possibility of synergistic effects in combination. Our work unmasks the ameliorating effect of EA twig extract 2 on scopolamine-associated cognitive impairments through the restoration of cholinergic systems and the BDNF/ERK/CREB pathway.

Protective role of Pandanus tectorius Parkinson ex Du Roi in diabetes, hyperlipidemia, liver and kidney dysfunction in alloxan diabetic rats

Background

Diabetes mellitus (DM), an endocrine disease is characterized by increased level of blood glucose. Diabetes may affect other functions of the body and organs including, renal function and lipid metabolism. Pandanus tectorius (P. tectorius) Parkinson ex Du Roi is a small tree used in folk medicine in treatment of many diseases.

Methods

Diabetes in rats was induced by intraperitoneal injection of alloxan at a dose of 100 mg/kg body weight for 3 days. Water and ethanol extracts of root, stem and leave of P. tectorius were given to rats at 200 mg/kg body weight at day 3. Rats were sacrificed on day 4 after 12 h fasting. Serum glucose and other biochemical parameters like liver enzymes; [alanine aminotransferases (ALT), aspartate aminotransferases (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH)], kidney parameters (urea & creatinine), lipid profile [total cholesterol, HDL and LDL cholesterol and triglycerides] and coronary artery risk index (CRI) were estimated in blood serum. Antioxidant potential, polyphenol content and phytochemical constituents in different parts of P. tectorius were also determined.

Results

Results showed that water extract of stem and ethanol extract of root of P. tectorius produced maximum fall in sugar level of alloxan diabetic rats. Extracts of all three plant parts significantly dropped the increased level of urea and creatinine with maximum reduction in creatinine was observed by water extract of root. P.tectorius extracts showed positive effect on liver enzymes and lipid profile by bringing them closer to normal range in comparison to alloxan diabetic control rats. Phytochemical screening indicated presence of flavonoids, alkaloids, tannins and saponin in P. tectorius. In DPPH free radical scavenging test the highest antioxidant potential was found in water extract of roots, while ethanol extract of stem also showed good activity.

Conclusion

The study demonstrated that different parts of P.tectorius have potential to attenuate diabetes and diabetes related complications like, liver, kidney dysfunction and lipid metabolism.

The complete mitochondrial genome of Euonymus alatus (celastraceae, Euonymus L.)

The complete mitochondrial genome of medicinal plant, Euonymus alatus, was sequenced for the first time. The genome sequence is 1,045,106 bp in length (GenBank accession number MW009108), with 44.98% GC contents. There are 72 genes in the genome, including 41 known protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), and three ribosomal RNAs (rRNAs). The phylogenetic trees of 28 species are constructed using the maximum-likelihood method. The information will provide references for phylogenetic research.

Alterations in allocation and composition of lipid classes in Euonymus fruits and seeds

The spindle tree (Euonymus europaeus L.) is a much-branched deciduous shrub or small tree. Its fruit capsules contain seeds with remarkably high content of oil interesting for industry, especially the 3-acetyl-1,2-diacyl-sn-glycerols (AcDAG) synthesized by a specific acetyl-CoA diacylglycerol acetyltransferase. The distribution and amount of individual triacylglycerols (TAG) and especially acetyl-triacylglycerols (AcDAG) in Euonymus fruit have previously been assigned to specific tissues. Using anatomical and microscopical observations, we studied the fruit morphology, and for the first time, we identified a more detailed allocation of oil bodies in individual tissue structures. Thin layer chromatography separation of extracts from immature and mature fruits confirmed TAG and AcDAG as the most abundant lipid classes in both endosperm and embryo, followed by fatty acids and polar lipids. The abundance of fatty acids was further studied in the TAG and AcDAG fractions using gas chromatography. Data revealed particular FAs in both fractions allocated in tissue-specific manner and/or as indicators of maturation of E. europaeus seeds. While the abundance of cis-vaccenic-, linoleic as well as α-linolenic acids in the AcDAG structures generally drop with maturation in both embryo and endosperm, content of oleic acid increases. Abundance of cis-vaccenic acid in TAG was recorded in immature endosperm. For embryo, the abundance of stearic acid in AcDAG and oleic acid in TAG fraction was distinctive. Deeper understanding of underlying metabolic processes will be essential for targeted metabolic engineering and/or application for oilseed crops.

Sequential extraction and enrichment of flavonoids from Euonymus alatus by ultrasonic-assisted polyethylene glycol-based extraction coupled to temperature-induced cloud point extraction

A green method for simultaneous extraction and enrichment of flavonoids from Euonymus alatus was developed by ultrasonic-assisted extraction (UAE) and temperature-induced cloud point extraction (TICPE) using PEG-base aqueous solution as the extractant. Based on screening different molecular weights of PEGs, PEG-400/water was used as the extractant, and the effects of key factors on extraction yields of flavonoids were investigated by single-factor experiments and response surface methodology (RSM). The optimum conditions of UAE were as follows: PEG-400 concentration of 16% (w/w), particle size of 80 mesh, solvent-to-material ratio of 60:1, extraction temperature of 90 °C and extraction time of 15 min. The results obtained by validation experiments were consistent with the values predicted by RSM. Temperature-induced formation of the aqueous two-phase system (ATPS) and TICPE process were further investigated by controlling temperature and adding (NH₄)₂SO₄. In the presence of (NH₄)₂SO₄, the ATPS formed at 75 ℃ and pH 3.5 could effectively improve separation and recovery of flavonoids with enrichment factor of above five times. Gallic acid, catechin, dihydromyricetin and ellagic acid in the extract were identified and confirmed by UPLC-Q-TOF-MS and the corresponding standards. The UAE-TICPE coupled to HPLC was successfully applied for extraction and determination of flavonoids in two batches of Euonymus alatus. The extraction yields of catechin, dihydromyricetin and total flavonoids were 0.377-0.684 mg/g, 1.091-1.353 mg/g and 2.612-3.146 mg/g, respectively. Compared to conventional extraction methods, PEG-based UAE integrated with TICPE in one-step procedure exhibited higher extraction efficiency and better extraction selectivity.

Neuroprotective Effects of Euonymus alatus Extract on Scopolamine-Induced Memory Deficits in Mice

Euonymus alatus is considered to elicit various beneficial effects against cancer, hyperglycemia, menstrual discomfort, diabetic complications, and detoxification. The young leaves of this plant are exploited as food and also utilized for traditional medicine in East Asian countries, including Korea and China. Our preliminary study demonstrated that ethanolic extract from the Euonymus alatus leaf (EAE) exhibited the strongest antioxidant enzyme-inducing activity among more than 100 kinds of edible tree leaf extracts. This study investigated whether EAE could attenuate the cognitive deficits caused by oxidative stress in mice. Oral intubation of EAE at 100 mg/kg bw or higher resulted in significant improvements to the memory and behavioral impairment induced via i.p. injection of scopolamine. Furthermore, EAE enhanced the expression levels of hippocampal neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor in mice, activated the Nrf2, and the downstream heme oxygenase-1 (HO-1) a quintessential antioxidant enzyme. As rutin (quercetin-3-O-rutinose) was abundantly present in EAE and free quercetin was able to induce defensive antioxidant enzymes in an Nrf2-dependent manner, our findings suggested that quercetin derived from rutin via the intestinal microflora played a significant role in the protection of the mouse hippocampus from scopolamine-induced damage through BDNF-mediated Nrf2 activation, thereby dampening cognitive decline.

Euonymus alatus and its monomers alleviate liver fibrosis both in mice and LX2 cells by blocking TβR1-Smad2/3 and TNF-α-NF-κB pathways

This study aimed to investigate the protective effects, effective constituents and preliminary mechanisms of Euonymus alatus on liver fibrosis and screen new high-efficacy drug for fibrosis. 112 male C57BL/6 mice were randomly divided into 14 groups: control group (CG), CCL₄ group (CTG), low/medium/high dose of Euonymus alatus ethanol extracts (EAE), catechin (CA), dihydroquercetin (DHQ) and kaempferol (KA) groups. The study lasted for 30 days by injecting CCL₄ in peritoneal cavity to make fibrosis model, all mice were sacrificed to observe morphological changes and collagenous fiber by HE and Masson staining, to test liver index, ALT, AST, to measure the expression of α-SMA and collagen I by immunohistochemistry and western blotting, to discuss the pathways of TβR1-Smad2/3 and TNF-α-NF-κB by WB and Elisa; after being evaluated the efficacy, anti-fibrosis drug of highest efficacy was chosen to repeat these indexes in human hepatic stellate cells-LX2. Results showed that EAE/CA/DHQ/KA prevented increases in liver index, ALT, AST, α-SMA, collagen I, TβR1, Smad2/3, TNF-α and p-NF-κB caused by CCL₄ in dose-dependence, they also improved the liver morphology, decreased inflammatory cell infiltration and collagenous fiber in dose-dependence, CA' efficacy was best in mice; in LX-2, CA also decreased the expression of α-SMA, collagen I, TGF-β, Smad2/3. All findings suggested that Euonymus alatus could alleviate liver inflammation and fibrosis by inhibiting TβR1-Smad2/3 and TNF-α-NF-κB pathways, flavonoid were effective constituents and catechin was screened as a new star for its best performance.

The protective effect of the active components of ERPC on diabetic peripheral neuropathy in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Euonymus alatus, Radix trichosanthis, Panax notoginseng and Coptis chinensis are popular plants used in traditional Chinese medicine to treat diabetes.

AIM OF THE STUDY

The aim of the study is to investigate the therapeutic effect of the active components of Euonymus alatus, Radix trichosanthis, Panax notoginseng and Coptis chinensis (cERPC) on diabetic peripheral neuropathy in the rats and explore the underlying mechanism involved.

METHODS

After diabetes was induced in rats for 20 weeks, cERPC or water was administered for 12 weeks. After a hot plate test, motor nerve conduction velocity and sciatic nerve blood flow were determined; the sciatic nerves were isolated for toluidine blue staining; and the fibre area, fibre diameter, axon area, axon diameter and myelin thickness were evaluated. The levels of the myelin basic protein, myelin protein zero, Oct6 and Krox20 were measured by western blot or immunofluorescence.

RESULTS

cERPC was efficient in reducing the response latency, increasing motor nerve conduction velocity, enhancing sciatic nerve blood flow and ameliorating the pathological changes in diabetic rats. cERPC also had a role in increasing the levels of myelin basic protein and myelin protein zero and improving the expression of Oct6 and Krox20 in sciatic nerves of diabetic rats.

CONCLUSIONS

cERPC ameliorates diabetic peripheral neuropathy by attenuating electrophysiological, circulatory and morphological alterations, which is mediated by the Oct6-Krox20 pathway.