Glucosidase inhibitory activity and antioxidant activity of flavonoid compound and triterpenoid compound from Agrimonia Pilosa Ledeb

Anti-Inflammatory Flavonoids from Agrimonia pilosa Ledeb: Focusing on Activity-Guided Isolation

To elucidate the anti-inflammatory properties and constituents of Agrimonia pilosa Ledeb. (A. pilosa), a comprehensive investigation was conducted employing activity-guided isolation. The anti-inflammatory effects were evaluated through an in vitro nitric oxide (NO) assay on lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells. Seven bio-active compounds with anti-inflammatory properties were successfully isolated from the butanol fraction and identified as follows: quercetin-7-O-β-d-rhamnoside (1), apigenin-7-O-β-d-glucopyranoside (2), kaempferol-7-O-β-d-glucopyranoside (3), quercetin (4), kaempferol (5), apigenin (6), and apigenin-7-O-β-d-glucuronide-6″-butylester (7). All isolated compounds showed strong NO inhibitory activity with IC50 values ranging from 1.4 to 31 µM. Compound 6 demonstrated the most potent NO inhibition. Compound 7, a rare flavonoid, was discerned as a novel anti-inflammatory agent, ascertained through its inaugural demonstration of nitric oxide inhibition. Subsequently, a comprehensive structure-activity relationship (SAR) analysis was conducted employing eight flavonoids derived from A. pilosa. The outcomes elucidated that flavones exhibit superior NO inhibitory effects compared to flavonols, and the aglycone form manifests greater potency in NO inhibition than the glycone counterpart. These results highlight A. pilosa as a promising source of effective anti-inflammatory agents and indicate its potential as a health-beneficial dietary supplement and therapeutic material.

Potential Implications of Hyperoside on Oxidative Stress-Induced Human Diseases: A Comprehensive Review

Hyperoside is a flavonol glycoside mainly found in plants of the genera Hypericum and Crataegus, and also detected in many plant species such as Abelmoschus manihot, Ribes nigrum, Rosa rugosa, Agrostis stolonifera, Apocynum venetum and Nelumbo nucifera. This compound exhibits a multitude of biological functions including anti-inflammatory, antidepressant, antioxidative, vascular protective effects and neuroprotective effects, etc. This review summarizes the quantification, original plant, chemical structure and property, structure-activity relationship, pharmacologic effect, pharmacokinetics, toxicity and clinical application of hyperoside, which will be significant for the exploitation for new drug and full utilization of this compound.

Flavonoid compound from Agrimonia pilosa Ledeb improves adipose insulin resistance by alleviating oxidative stress and inflammation

BACKGROUND

Researches and practice of traditional Chinese medicine indicated that Agrimonia pilosa Ledeb could improve insulin resistance (IR) and treat type 2 diabetes (T2DM). To reveal its underling mechanisms, we isolated Flavonoid component (FC) from Agrimonia pilosa Ledeb and elucidated its effects on glucose metabolism to improve IR by suppressing oxidative stress and inflammation.

METHODS

Adipocytes or mice IR model was established with overdosed glucose and insulin or high-fat diet. The uptake of 2-NBDG and glucose consumption were measured to verify insulin sensitivity in vitro and vivo. Reactive oxidative species (ROS) were detected by flow cytometry, and superoxide dismutase (SOD) activity as well as the malondialdehyde (MDA) content were also measured. Meanwhile, factors associated with insulin signal pathway including PPARγ, insulin receptor substrate-1 (IRS-1), GLUT4, and oxidative stress including NF-E2-related factor 2 (Nrf2), as well as the related inflammatory cytokines such as NF-κB, IL-1β, IL-6 and TNF-α were tested. Furthermore, the JNK/PI3K/Akt signal pathway was also explored.

RESULTS

FC extracted from Agrimonia pilosa Ledeb ameliorated the impaired glucose metabolism significantly. Further study indicated that FC could regulate the insulin signal pathway to improve insulin resistance. Moreover, it could upregulate PPARγ with the similar efficacy as pioglitazone (Piog) straightway. FC also decreased the endogenous ROS and MDA content, increased SOD activity and Nrf2 expression to facilitate oxidative homeostasis. It attenuated expression and secretion of inflammatory cytokines obviously. At last, our results indicated JNK/PI3K/Akt pathway was regulated by FC in adipocytes and adipose tissue.

CONCLUSION

FC could ameliorate glucose metabolism and improve IR. It exerted these effects by suppressing oxidative stress and inflammation. FC from Agrimonia pilosa Ledeb has a good prospect to be drugs or functional foods for IR and T2DM.

Therapeutic potential of dietary flavonoid hyperoside against non-communicable diseases: targeting underlying properties of diseases

Non-communicable diseases (NCDs) are a global epidemic with diverse pathogenesis. Among them, oxidative stress and inflammation are the most fundamental co-morbid features. Therefore, multi-targets and multi-pathways therapies with significant anti-oxidant and anti-inflammatory activities are potential effective measures for preventing and treating NCDs. The flavonol glycoside compound hyperoside (Hyp) is widely found in a variety of fruits, vegetables, beverages, and medicinal plants and has various health benefits, especially excellent anti-oxidant and anti-inflammatory properties targeting nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB) signaling pathways. In this review, we summarize the pathogenesis associated with oxidative stress and inflammation in NCDs and the biological activity and therapeutic potential of Hyp. Our findings reveal that the anti-oxidant and anti-inflammatory activities regulated by Hyp are associated with numerous biological mechanisms, including positive regulation of mitochondrial function, apoptosis, autophagy, and higher-level biological damage activities. Hyp is thought to be beneficial against organ injuries, cancer, depression, diabetes, and osteoporosis, and is a potent anti-NCDs agent. Additionally, the sources, bioavailability, pharmacy, and safety of Hyp have been established, highlighting the potential to develop Hyp into dietary supplements and nutraceuticals.

Agrimonia pilosa: A Phytochemical and Pharmacological Review

Agrimonia pilosa Ledeb., which belongs to Agrimonia and Rosaceae, is used in traditional Chinese medicine. It exhibits excellent medicinal properties and has been used to treat various diseases, such as tumors, trichomoniasis, vaginitis, diarrhea, and dysentery. Phytochemical studies have revealed that Agrimonia has over 100 secondary metabolites that can be categorized into six classes, i.e., flavonoids, isocoumarins, triterpenes, phloroglucinol derivatives, tannins, and organic acids. This review summarizes recently published literature on the chemical structures of 90 bioactive compounds that have been identified in A. pilosa and examines their pharmacological properties, including their antitumor, anti-inflammatory, antioxidant, antibacterial, and antidiabetic properties, as well as the potential development of parasitic resistance to these chemicals. This review highlights existing knowledge gap and serves as a basis for developing novel preparations of A. pilosa with medicinal value.

The triterpenoids and sesquiterpenoids from the plant of Agrimonia pilosa

A phytochemistry of the whole plant of Agrimonia pilosa led to the discovery of two new nortriterpenoids, agrimonorterpenes A and B (1 and 2), together with one known triterpenoid fupenzic acid (3) and seven known sesquiterpenoids (4-10). The new structures were determined as 19α-hydroxy-2-oxo-nor-A (3)-urs-11,12-dien-28-oic acid (1) and 2, 19β-dihydroxy-3-oxo-23-noroleana-1, 4, 12-trien-28-oic acid (2) by the spectroscopic data of UV, IR, HR-ESI-MS, and NMR. Notably, the structure of 1 possessed a rare five-membered A ring. And this is the first time to discover the sesquiterpenoids (4-10) from A. pilosa. Compound 3 displayed the selective cytotoxicity against HCT116, BGC823, and HepG2 cell lines with the IC₅₀ values of 16.31 μM, 21.94 μM, and 23.40 μM, respectively.

Anti-Diabetic Potential of Plant-Based Pentacyclic Triterpene Derivatives: Progress Made to Improve Efficacy and Bioavailability

Diabetes mellitus (DM) results from the inability of the pancreas to produce sufficient insulin or weakened cellular response to the insulin produced, which leads to hyperglycemia. Current treatments of DM focus on the use of oral hypoglycemic drugs such as acarbose, alpha-glucose inhibitors, sulphonylureas, thiazolidinediones, and biguanides to control blood glucose levels. However, these medications are known to have various side effects in addition to their bioavailability, efficacy, and safety concerns. These drawbacks have increased interest in the anti-diabetic potential of plant-derived bioactive compounds such as oleanolic and maslinic acids. Although their efficacy in ameliorating blood glucose levels has been reported in several studies, their bioavailability and efficacy remain of concern. The current review examines the anti-diabetic effects of oleanolic, maslinic, asiatic, ursolic, and corosolic acids and their derivatives, as well as the progress made thus far to enhance their bioavailability and efficacy. The literature for the current review was gathered from leading academic databases-including Google Scholar and PubMed-the key words listed below were used. The literature was searched as widely and comprehensively as possible without a defined range of dates.

Phytopharmacological Evaluation of Different Solvent Extract/Fractions From Sphaeranthus indicus L. Flowers: From Traditional Therapies to Bioactive Compounds

Sphaeranthus indicus L. is a medicinal herb having widespread traditional uses for treating common ailments. The present research work aims to explore the in-depth phytochemical composition and in vitro reactivity of six different polarity solvents (methanol, n-hexane, benzene, chloroform, ethyl acetate, and n-butanol) extracts/fractions of S. indicus flowers. The phytochemical composition was accomplished by determining total bioactive contents, HPLC-PDA polyphenolic quantification, and UHPLC-MS secondary metabolomics. The reactivity of the phenolic compounds was tested through the following biochemical assays: antioxidant (DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum, and metal chelation) and enzyme inhibition (AChE, BChE, α-glucosidase, α-amylase, urease, and tyrosinase) assays were performed. The methanol extract showed the highest values for phenolic (94.07 mg GAE/g extract) and flavonoid (78.7 mg QE/g extract) contents and was also the most active for α-glucosidase inhibition as well as radical scavenging and reducing power potential. HPLC-PDA analysis quantified rutin, naringenin, chlorogenic acid, 3-hydroxybenzoic acid, gallic acid, and epicatechin in a significant amount. UHPLC-MS analysis of methanol and ethyl acetate extracts revealed the presence of well-known phytocompounds; most of these were phenolic, flavonoid, and glycoside derivatives. The ethyl acetate fraction exhibited the highest inhibition against tyrosinase and urease, while the n-hexane fraction was most active for α-amylase. Moreover, principal component analysis highlighted the positive correlation between bioactive compounds and the tested extracts. Overall, S. indicus flower extracts were found to contain important phytochemicals, hence could be further explored to discover novel bioactive compounds that could be a valid starting point for future pharmaceutical and nutraceuticals applications.

Structural characterization, anticancer, hypoglycemia and immune activities of polysaccharides from Russula virescens

Russula virescens is an edible wild mushroom that is widely distributed in south of China. This research aimed to analyze the structure characterization and evaluate the hypoglycemic, anticancer and immunological activities of two water soluble polysaccharides RVP-1 and RVP-2 from R. virescens. The results showed RVP-1 and RVP-2 were non-triple helix structured hetero-polysaccharides with different weight-average molecular weight 14,883 and 13,301 Da, respectively. Both RVP-1 and RVP-2 were composed of galactose, glucose, mannose and fructose, and the sugar residues were mainly linked by 1,6→, 1,2→, 1→ and 1,3,6→ glycosidic bonds. Moreover, the antidiabetic, anticancer and immune activities of RVP-1 and RVP-2 were explored in vitro methods. The two polysaccharides have potential for inhibiting α-glucosidase and α-amylase activities, suppressing HepG-2, A549 and MCF-7 cancer cells proliferation, and activating macrophage RAW 264.7 cells to secret immune cytokines for mediating cellular immune response. These findings provided a scientific basis for further utilization of polysaccharide from R. virescens.

Extending the investigation of 4-thiazolidinone derivatives as potential multi-target ligands of enzymes involved in diabetes mellitus and its long-term complications: A study with pancreatic α-amylase

Diabetes mellitus is a multifactorial disease, which is frequently complicated by the development of hyperglycaemia-induced chronic complications. The therapy of diabetes mellitus often requires combinations of two or more drugs in order both to control glycaemic levels and to prevent hyperglycaemia-induced dangerous affairs. The application of multi-target agents, which are able to control simultaneously several pathogenic mechanisms, represents a useful alternative and, in fact, their discovery is a pursued aim of the research. Some (5-arylidene-4-oxo-2-thioxothiazolidin-3-yl)acetic acids, which we had previously reported as inhibitors of selected enzymes critically implicated in diabetes mellitus, were tested against pancreatic α-amylase and intestinal α-glucosidase. These enzymes catalyse the hydrolysis of dietary oligo- and polysaccharides into monosaccharides and, consequently, are responsible for postprandial hyperglycaemia; therefore, their inhibition is one of the possible strategies to control glycaemic levels in diabetes mellitus. In addition, we investigated the aggregation tendency of the tested compounds, through direct and indirect methods, in order to evaluate the mechanism of their multiple action and discover if aggregation may contribute to the inhibition of the target enzymes. Overall, compounds 1, 3 and 4 exhibited the most favourable profile since they were shown to act as multi-target inhibitors of enzymes involved in pathways related to diabetes mellitus, without producing aggregates even at high micromolar concentrations and, therefore, can be promising agents for further developments.

Interventions of natural and synthetic agents in inflammatory bowel disease, modulation of nitric oxide pathways

Inflammatory bowel disease (IBD) refers to a group of disorders characterized by chronic inflammation of the gastrointestinal (GI) tract. The elevated levels of nitric oxide (NO) in serum and affected tissues; mainly synthesized by the inducible nitric oxide synthase (iNOS) enzyme; can exacerbate GI inflammation and is one of the major biomarkers of GI inflammation. Various natural and synthetic agents are able to ameliorate GI inflammation and decrease iNOS expression to the extent comparable with some IBD drugs. Thereby, the purpose of this study was to gather a list of natural or synthetic mediators capable of modulating IBD through the NO pathway. Electronic databases including Google Scholar and PubMed were searched from 1980 to May 2018. We found that polyphenols and particularly flavonoids are able to markedly attenuate NO production and iNOS expression through the nuclear factor κB (NF-κB) and JAK/STAT signaling pathways. Prebiotics and probiotics can also alter the GI microbiota and reduce NO expression in IBD models through a broad array of mechanisms. A number of synthetic molecules have been found to suppress NO expression either dependent on the NF-κB signaling pathway (i.e., dexamethasone, pioglitazone, tropisetron) or independent from this pathway (i.e., nicotine, prednisolone, celecoxib, β-adrenoceptor antagonists). Co-administration of natural and synthetic agents can affect the tissue level of NO and may improve IBD symptoms mainly by modulating the Toll like receptor-4 and NF-κB signaling pathways.

Isolation of Isocoumarins and Flavonoids as α-Glucosidase Inhibitors from Agrimonia pilosa L

Agrimonia pilosa L. (AP) showed potent α-glucosidase inhibitory (AGI) activity, but it is uncertain what phytochemicals play a key factor. The phytochemical study of AP based on AGI activity led to the isolation of four isocoumarins; agrimonolide (1), agrimonolide-6-O-β-d-glucopyranoside (2), desmethylagrimonolide (3), desmethylagrimonolide-6-O-β-d-glucopyranoside (4), and four flavonoids; luteolin (5), quercetin (6), vitexin (7), and isovitexin (8). The four isocoumarins were isolated as α-glucosidase inhibitors for the first time. Isocoumarins, compound 1 (agrimonolide) and 3 (desmethylagrimonolide) showed strong α-glucosidase inhibitory activities with IC₅₀ values of 24.2 and 37.4 µM, respectively. Meanwhile, isocoumarin and flavonoid glycosides showed weak AGI activity. In the kinetic analysis, isocoumarins, compounds 1 and 3 showed non-competitive inhibition, whereas flavonoid, compound 6 showed competitive inhibition.

Triterpenoids with α-glucosidase inhibitory activity from Artemisia argyi

Two new nordammarane-type triterpenoids, 3β-acetoxy-20-oxo-21-nordammaran-23-carboxylic acid methyl ester (1) and 3β-acetoxy-17β-dammaranic acid (2), along with two known cycloartane-type triterpenoids (3-4), were isolated from the petroleum ether-soluble extract of Artemisia argyi. Their structures were elucidated based on 1D and 2D NMR spectroscopic data analysis. All compounds were evaluated for their α-glucosidase inhibitory activity in vitro. Compounds 1-4 exhibited significant inhibitory effects on α-glucosidase with IC₅₀ values ranging from 38.34 ± 0.23 to 105.54 ± 0.33 μM.

Modulation of Cognition: The Role of Gnidia glauca on Spatial Learning and Memory Retention in High-Fat Diet-Induced Obese Rats

Chronic exposures to high-fat diets are linked to neuropathological changes that culminate in obesity-related cognitive dysfunction and brain alteration. Learning, memory performance, and executive function are the main domains affected by an obesogenic diet. There are limited effective therapies for addressing cognitive deficits. Thus, it is important to identify additional and alternative therapies. In African traditional medicine, Gnidia glauca has putative efficacy in the management of obesity and associated complications. The use of Gnidia glauca is largely based on its long-term traditional use. Its therapeutic application has not been accompanied by sufficient scientific evaluation to validate its use. Therefore, the current study sought to explore the modulatory effects of dichloromethane leaf extracts of Gnidia glauca on cognitive function in the high-fat diet- (HFD-) induced obese rats. Obesity was induced by feeding the rats with prepared HFD and water ad libitum for 6 weeks. The in vivo antiobesity effects were determined by oral administration of G. glauca at dosage levels of 200, 250, and 300 mg/kg body weight in HFD-induced obese rats from the 6^th to the 12^th weeks. The Lee obesity index was used as a diagnostic criterion of obesity. The Morris water maze was employed to test spatial learning and memory retention in rats. The results indicated that Gnidia glauca showed potent antiobesity effects as indicated in the reduction of body weight and obesity index in extract-treated rats. Moreover, Gnidia glauca exhibited cognitive-enhancing effects in obese rats. The positive influences on cognitive functions might be attributed to the extracts' phytochemicals that have been suggested to confer protection against obesity-induced oxidative damage, reduction of central inflammation, and increased neurogenesis. The therapeutic effects observed suggest that Gnidia glauca might be an alternative to current medications for the symptomatic complications of obesity, such as learning and memory loss. Further studies are therefore needed to establish its toxicity profiles.

Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Acantholippia salsoloides: Phytochemical Composition and Biological Potential of a Thujonic Population

Acantholippia salsoloides (Verbenaceae) is an aromatic plant widespread in the Andean region. The infusion (leaves and flowers) is widely used as a digestive stimulant as well as for the treatment of various diseases in traditional medicine. A. salsoloides attributes its common name “rica-rica” to the fresh and sweet fragrance of the plant. In this work, 2 different polar extracts and the essential oil of a selected rica-rica population were studied. The phenolic composition was analyzed by high-performance liquid chromatography diode array detector; the essential oil profile was determined by gas-chromatography ion-trap mass spectrometry/flame ionization detection. For all extracts, the antibacterial potential was performed by in vitro assays; the antioxidant and α-glucosidase inhibition were determined in decoction and hydroethanolic extracts. The volatile profile allowed the identification of 26 volatile compounds, β-thujone (84%) being the major one in this rica-rica population. Eighteen phenolic compounds were identified; isoferulic acid (16%-18%) and cynaroside (45%-47%) were the larger ones. In a general way, the hydroethanolic extract was more active against Staphylococcus aureus and Micrococcus luteus (minimum inhibitory concentrations= 0.3- 1.3 mg/mL). Both polar extracts have strong antiradical activities although decoction extract proved to be more active against DPPH· (half-maximal inhibitory concentration [IC50] =36 µg/mL) and O2•− (IC50 =28 µg/mL) while hydroethanolic extract shows higher action over α-glucosidase (IC50 =217 µg/mL). The results suggest that A. salsoloides leaves and flowers may be an interesting source of natural antioxidants, antidiabetics, or antimicrobials, and could be used in dietary supplements, medicinal products and pharmaceutical formulations.

Corosolic acid isolated from Eriobotrya japonica leaves reduces glucose level in human hepatocellular carcinoma cells, zebrafish and rats

Type 2 diabetes (T2D) with high morbidity and mortality is characterized by abnormal glucose and lipid metabolism due in part to insulin resistance in liver, which lead to elevated hyperglycemia and hyperlipidemia. This study sough to explore the effects of corosolic acid (CA) in different T2D models and explored the underlying mechanism. Separated from Eriobotrya japonica leaves, CA purity was above 95% measured by a HPLC method. Compared with cAMP and DEX induced T2D HepG2 model, CA significantly stimulated glucose consumption and improved glycogen accumulation by inhibiting PEPCK mRNA expression. And in cAMP and DEX induced T2D zebrafish model, CA reduced glycogen degradation and increased glucose consumption by regulating some key enzymes in carbon metabolism including GLUT1, GLUT2, GLUT3, LDHA, LDHB, GP, G6Pase, GYS1, and PFKFB3. In addition, insulin receptor signals were also involved in CA-regulated hypoglycemic action. Furthermore, in STZ-induced T2D rat model, compared with diabetic control groups, CA remarkably downregulated the levels of serum lipid, blood glucose, ICAM-1, malonaldehyde and insulin resistance index, while upregulated SOD activity and impaired glucose tolerance. In a conclusion, CA can regulate glucose and lipid metabolic adaptation in T2D like HepG2, zebrafish and rat models partly through reducing inflammation and oxidative stress and suppressing PEPCK.

Ameliorative effects of luteolin against endometriosis progression in vitro and in vivo

Endometriosis is a common gynecological disease in reproductive-aged women. Generally, accumulation of backflow and debris of endometrial tissue develops into a lesion outside of the endometrium, inducing severe pelvic pain and infertility in some patients. Hormone therapy and surgery are the main treatments available, but various therapeutic phytochemicals are being reviewed in animal studies or clinical trials for endometriosis patients nowadays. However, the therapeutic effects of luteolin in human endometriosis have not been studied well. Here, we demonstrate that luteolin exerts antiproliferative and apoptotic effects in human VK2/E6E7 and End1/E6E7 and in an animal endometriosis model. Luteolin inhibits cell proliferation through cell cycle arrest and induces apoptosis through DNA fragmentation in VK2/E6E7 and End1/E6E7 cells. Cytosolic calcium levels, ROS production and lipid peroxidation also increased dose-dependently (0, 5, 10 and 20 μM) in the treatment with luteolin. In VK2/E6E7 and End1/E6E7 cells, luteolin decreased ERK1/2, JNK and PI3K/AKT signal proteins while activating P38. In addition, intraperitoneal injection of luteolin in the endometriosis mouse model reduced lesion size compared to vehicle-injected mice. Ccne1, Cdk2 and Cdk4 were significantly down-regulated in the autoimplanted endometriosis lesions of mice intraperitoneally injected with luteolin. Knockdown of CCNE1 mRNA in VK2/E6E7 and End1/E6E7 cells decreased cell viability through inhibition of G0/G1 phase progression and increased apoptosis. Together, our results imply that luteolin suppresses endometriosis development by regulation of the PI3K/AKT and MAPK signal proteins as well as the expression of CCNE1 in vitro and in vivo.

Inhibitory effects of Inula britannica extract fermented by Lactobacillus plantarum KCCM 11613P on coagulase activity and growth of Staphylococcus aureus including methicillin-resistant strains

The aim of this study was to evaluate the antimicrobial efficacy of fermented Inula britannica extract (FIBE) against Staphylococcus aureus strains including methicillin-resistant S. aureus (MRSA). I. britannica extract was fermented by Lactobacillus plantarum KCCM 11613P, and the pathogenicity of S. aureus strains was determined via assessment of coagulase, DNase, and hemolytic activities. Epicatechin concentration increased from 4.38 to 6.05 μg/mg during fermentation (p < 0.01). FIBE treatment inhibited coagulase release from S. aureus to levels below the inhibitory concentration. FIBE promoted the release of intracellular nucleic acids and N-phenyl-1-naphthylamine absorption. In three S. aureus strains, damaged cells exhibited 21.58, 16.79, and 17.65% decreases in membrane potential induced by cell membrane depolarization, respectively (p < 0.05). Upon FIBE treatment in culture, the minimum inhibitory concentration of FIBE exerted a bacteriostatic effect. In conclusion, FIBE possesses antimicrobial properties, including inhibition of virulence factors, damage to cell membranes, and inhibition of bacterial growth. PRACTICAL APPLICATIONS: Methicillin-resistant Staphylococcus aureus (MRSA) is a serious concern in hospitals because of its known antibiotic resistance. Vancomycin and tigecycline are used for treating MRSA, but the appearance of vancomycin-intermediate and multidrug-resistant strains of these bacteria has created a demand for new antimicrobial agents. This study demonstrates the effective application of Inula britannica and fermentation technology for developing natural antimicrobial agents against methicillin-resistant Staphylococcus aureus.

Identification of N-benzyltetrahydroisoquinolines as novel anti-neuroinflammatory agents

A series of simplified berberine analogs was designed, synthesized, and evaluated for anti-inflammatory activity. SAR studies identified N-benzyltetrahydroisoquinoline 7d as a potent berberine analog. 7d suppressed LPS-induced inflammatory cytokine levels in both BV2 cells and primary microglia. Taken together, our results suggest that simplified BB analogs have therapeutic potential as a novel class of anti-neuroinflammatory agents.

Advances in extraction and analysis of phenolic compounds from plant materials

Phenolic compounds, the most abundant secondary metabolites in plants, have received more and more attention in recent years because of their distinct bioactivities. This review summarizes different types of phenolic compounds and their extraction and analytical methods used in the recent reports, involving 59 phenolic compounds from 52 kinds of plants. The extraction methods include solid-liquid extraction, ultrasound-assisted extractions, microwave-assisted extractions, supercritical fluid extraction, and other methods. The analysis methods include spectrophotometry, gas chromatography, liquid chromatography, thin-layer chromatography, capillary electrophoresis, and near-infrared spectroscopy. After illustrating the specific conditions of the analytical methods, the advantages and disadvantages of each method are also summarized, pointing out their respective suitability. This review provides valuable reference for identification and/or quantification of phenolic compounds from natural products.

Hemostasis and uterine contraction promoting effect of the extract from drugs in the Zi-Yin-Tiao-Jing granule, a traditional Chinese compound preparation

ETHNOPHARMACOLOGICAL RELEVANCE

Zi-Yin-Tiao-Jing granule (ZG) is a traditional Chinese medicine compound preparation for perimenopausal dysfunctional uterine bleeding. It is made from 9 Chinese crude drugs based on a modified traditional Chinese prescription recorded in Fu Qingzhu Nvke as Guben Zhibeng Tang.

AIM OF THE STUDY

This study aimed to investigate the hemostasis and uterine contraction promoting effect of quality controlled ZG extract on animals as a preclinical study.

MATERIALS AND METHODS

ZG extract was quality controlled by determining the contents of asperosaponin Ⅵ and tetrahydroxystilbene glucoside (TSG) with high-performance liquid chromatography (HPLC) and the contents of total tannins, total saponins and total flavonoids with ultraviolet spectrophotometry (UV). Bleeding time, clotting time, prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB) content were assayed to test the hemostasis effect of ZG extract on sixty healthy female Kunming mice. In addition, ten healthy female Sprague-Dawley rats were used to test the effect of ZG extract on uterine contractions in vitro with the BL-420 Biological Function Experiment System.

RESULTS

The ZG extract contained 0.81mgg^-1 asperosaponin Ⅵ, 0.15mgg^-1 TSG, 1.98mgg^-1 total tannins, 1.83mgg^-1 total saponins, and 4.09mgg^-1 total flavonoids. Compared with placebo, the ZG extract shortened the bleeding time at a dosage of 1.2gkg^-1 and 2.4gkg^-1, and shortened the clotting time at 0.6gkg^-1, 1.2gkg^-1 and 2.4gkg^-1 in mice (P < 0.01). It also decurtated the APTT at a dosage of 0.6gkg^-1 (P < 0.05) and raised the content of FIB in the plasma at a dosage of 2.4gkg^-1 (P < 0.05). However, the PT showed no changes after the administration of ZG extract (P > 0.05). In addition, ZG extract at the doses of 1.8mgmL^-1, 3.6mgmL^-1, and 5.4mgmL^-1 increased the amplitude and motoricity of uterine contractions of rats (P < 0.05 or P < 0.01) but maintained the frequency as unchanged.

CONCLUSIONS

The ZG extract was quality controllable by assaying for asperosaponin Ⅵ, TSG, total tannins, total saponins and total flavonoids. It could promote the hemostasis of mice in vivo, as well as the uterine contractions of rats in vitro. Therefore, it may be a promising preparation for clinical treatment of perimenopausal dysfunctional uterine bleeding.

Morphological changes of bacterial cells upon exposure of silver-silver chloride nanoparticles synthesized using Agrimonia pilosa

Facile, eco-friendly synthesis of metal nanoparticles has been proposed as a cost effective method. In the present study, we propose the facile synthesis of silver-silver chloride (Ag-AgCl) nanoparticles (NPs) using the medicinally important Agrimonia pilosa plant extract without addition of capping or stabilizing agents. The Ag-AgCl NPs synthesis was observed at 40 °C after 10 min incubation; the synthesis of Ag-AgCl NPs was indicated by color change and confirmed by UV-vis spectroscopic peak at 454 nm. TEM analysis confirmed Ag-AgCl NPs were 10-20 nm in size and spherical, and oval in shape. Elemental composition was determined by energy dispersive X-ray analysis, and crystalline structure was confirmed by X-ray diffraction spectroscopy. Different phytocomponents present in the plant extract were analyzed by Gas Chromatography-Mass spectrometry, and the interaction of biomolecules in reduction process was analyzed by Fourier transform infrared spectroscopy studies. The synthesized Ag-AgCl NPs showed significant antibacterial efficiency, analyzed by well diffusion assay against pathogenic bacteria including Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus saprophyticus, Escherichia coli, Pseudomonas putida. Minimum inhibitory concentration and minimum bactericidal concentration were evaluated by microbroth dilution, and spread plate method, respectively. The possible mechanism of bacterial growth inhibition is due to changes in bacterial cell wall morphology that was studied by FE-SEM analysis.

Chemical characterization and evaluation of the antioxidants in Chaenomeles fruits by an improved HPLC-TOF/MS coupled to an on-line DPPH-HPLC method

An improved method based on HPLC-TOF/MS was developed to catalog the antioxidants in five species of Chaenomeles (Mugua). Forty-four fractions from the Mugua extracts show appreciable levels of antioxidative activity in scavenging the stable free-radical 2,2-diphenyl-1-picrylhydrazyl and the hydroxyl radicals. Twelve major antioxidant's chemical structures are identified. Antioxidant activities differ between species, but intra-species level of antioxidants, regardless of their ripeness, are similar. C. sinensis has the highest antioxidant level. A rigorous quality control procedure was implemented to ensure accuracy of antioxidant quantification. This improved procedure can be used for rapid discovery of antioxidants in other plant extracts.

Anti-hypoglycemic and hepatocyte-protective effects of hyperoside from Zanthoxylum bungeanum leaves in mice with high-carbohydrate/high-fat diet and alloxan-induced diabetes

The development of diabetes mellitus (DM) is accompanied by hyperglycemia-induced oxidative stress. Hyperoside is a major bioactive component in Zanthoxylum bungeanum leaves (HZL) and is a natural antioxidant. However, the effects of HZL on DM and its mechanisms of action remain undefined. The present study evaluated the anti-hypoglycemic and hepatocyte-protective effects of HZL in mice with diabetes induced by a high-carbohydrate/high-fat diet (HFD) and alloxan. We also aimed to eludicate the underlying mechanisms. Our resutls demonstrated that the administration of HZL significantly reduced body weight gain, serum glucose levels and insulin levels in diabetic mice compared with the vehicle-treated mice. In addition, the levels of dyslipidemia markers including total cholesterol, triglyceride and low-density lipoprotein cholesterol in the HFD-treated mice were markedly decreased. Further experiments using hepatocytes from mice revealed that HZL significantly attenuated liver injury associated with DM compared with vehicle treatment, as evidenced by lower levels of alanine aminotransferase and aspartate aminotransferase in serum and by lower levels of lipid peroxidation, nitric oxide content and inducible nitric oxide synthase activity in liver tissues. Nuclear factor-κB (NF-κB) and mitogen-associated protein kinase (MAPK) signaling pathways were investigated to elucidate the molecular mechanisms responsible for the protective effects of HZL against diabetic liver injury. The results indicated that HZL inhibited the phosphorylation of p65/NF-κB, MAPK (including p38, JNK and ERK1/2) and activating transcription factor 3 protein expression, with an additional suppression of Bax, cytochrome c, caspase-9 and caspase-3 in the liver tissues of diabetic mice. Taken together, our findings suggest that HZL, which was effective in inhibiting oxidative stress-related pathways may be beneficial for use in the treatment of DM.

Chemopreventive Potential of Ethanolic Extracts of Luobuma Leaves (Apocynum venetum L.) in Androgen Insensitive Prostate Cancer

Luobuma (Apocynum venetum L. (AVL)) is a popular beverage in Asia and has been reportedly to be associated with the bioactivities such as cardiotonic, diuretic, antioxidative, and antihypertensive. However, its biofunction as chemoprevention activity is seldom addressed. Herein, we aimed to characterize the anti-androgen-insensitive-prostate-cancer (anti-AIPC) bioactive compounds of Luobuma, and to investigate the associated molecular mechanisms. Activity-guided-fractionation (antioxidative activity and cell survivability) of Luobuma ethanolic extracts was performed to isolate and characterize the major bioactive compounds using Ultra Performance Liquid Chromatography (UPLC), Liquid Chromatography-Mass Spectrometry (LC-MS), and Nuclear Magnetic Resonance (NMR). Plant sterols (lupeol, stigamasterol and β-sitosterol) and polyphenolics (isorhamnetin, kaempferol, and quercetin) were identified. Lupeol, a triterpene found in the fraction (F8) eluted by 10% ethyl acetate/90% hexane and accounted for 19.3% (w/w) of F8, inhibited the proliferation of PC3 cells. Both lupeol and F8 induced G2/M arrest, inhibition of β-catenin signaling, regulation of apoptotic signal molecules (cytochrome c, Bcl-2, P53, and caspase 3 and 8), and suppression DNA repair enzyme expression (Uracil-DNA glycosylase (UNG)). To our knowledge, our study is the first report that lupeol inhibited the expression of UNG to elicit the cytotoxicity against androgen-insensitive-prostate-cancer cells. Collectively, Luobuma, which contains several antitumor bioactive compounds, holds the potential to be a dietary chemopreventive agent for prostate cancer.

A Lanosteryl Triterpene from Protorhus longifolia Improves Glucose Tolerance and Pancreatic Beta Cell Ultrastructure in Type 2 Diabetic Rats

Type 2 diabetes remains one of the leading causes of death worldwide. Persistent hyperglycemia within a diabetic state is implicated in the generation of oxidative stress and aggravated inflammation that is responsible for accelerated modification of pancreatic beta cell structure. Here we investigated whether a lanosteryl triterpene, methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA-3), isolated from Protorhus longifolia can improve glucose tolerance and pancreatic beta cell ultrastructure by reducing oxidative stress and inflammation in high fat diet and streptozotocin-induced type 2 diabetes in rats. In addition to impaired glucose tolerance, the untreated diabetic rats showed increased fasting plasma glucose and C-peptide levels. These untreated diabetic rats further demonstrated raised cholesterol, interleukin-6 (IL-6), and lipid peroxidation levels as well as a destroyed beta cell ultrastructure. Treatment with RA-3 was as effective as metformin in improving glucose tolerance and antioxidant effect in the diabetic rats. Interestingly, RA-3 displayed a slightly more enhanced effect than metformin in reducing elevated IL-6 levels and in improving beta cell ultrastructure. Although the involved molecular mechanisms remain to be established, RA-3 demonstrates a strong potential to improve pancreatic beta cell ultrastructure by attenuating impaired glucose tolerance, reducing oxidative stress and inflammation.

Hyperglycemia-induced oxidative stress and heart disease-cardioprotective effects of rooibos flavonoids and phenylpyruvic acid-2-O-β-D-glucoside

Diabetic patients are at an increased risk of developing heart failure when compared to their non-diabetic counter parts. Accumulative evidence suggests chronic hyperglycemia to be central in the development of myocardial infarction in these patients. At present, there are limited therapies aimed at specifically protecting the diabetic heart at risk from hyperglycemia-induced injury. Oxidative stress, through over production of free radical species, has been hypothesized to alter mitochondrial function and abnormally augment the activity of the NADPH oxidase enzyme system resulting in accelerated myocardial injury within a diabetic state. This has led to a dramatic increase in the exploration of plant-derived materials known to possess antioxidative properties. Several edible plants contain various natural constituents, including polyphenols that may counteract oxidative-induced tissue damage through their modulatory effects of intracellular signaling pathways. Rooibos, an indigenous South African plant, well-known for its use as herbal tea, is increasingly studied for its metabolic benefits. Prospective studies linking diet rich in polyphenols from rooibos to reduced diabetes associated cardiovascular complications have not been extensively assessed. Aspalathin, a flavonoid, and phenylpyruvic acid-2-O-β-D-glucoside, a phenolic precursor, are some of the major compounds found in rooibos that can ameliorate hyperglycemia-induced cardiomyocyte damage in vitro. While the latter has demonstrated potential to protect against cell apoptosis, the proposed mechanism of action of aspalathin is linked to its capacity to enhance the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression, an intracellular antioxidant response element. Thus, here we review literature on the potential cardioprotective properties of flavonoids and a phenylpropenoic acid found in rooibos against diabetes-induced oxidative injury.

Flavonoids from Agrimonia pilosa Ledeb: Free Radical Scavenging and DNA Oxidative Damage Protection Activities and Analysis of Bioactivity-Structure Relationship Based on Molecular and Electronic Structures

To clarify the substantial basis of the excellent antioxidant capacity of Agrimonia pilosa Ledeb. Fourteen flavonoids were isolated and identified from Agrimonia pilosa Ledeb, seven of which have notable DPPH radical scavenging activities, i.e., catechin, luteolin, quercetin, quercitrin, hyperoside, rutin, luteolin-7-O-β-glucoside with IC50 values of 5.06, 7.29, 4.36, 7.12, 6.34, 6.36 and 8.12 µM, respectively. The DNA nicking assay showed that five flavonoids from Agrimonia pilosa Ledeb-taxifolin, catechin, hyperoside, quercitrin and rutin-have good protective activity against DNA oxidative damage. Further, we analyzed the bioactivity-structure relationship of these 14 flavonoids by applying quantum theory. According to their O-H bond dissociation enthalpy (BDE), C ring's spin density and stable molecular structure, the relationship between their structures and radical scavenging capacities was evaluated and clarified. We found that among flavonoid aglycones from Agrimonia pilosa Ledeb, the O-H BDE of quercetin is lowest with the values of 69.02 and the O-H BDE of apigenin is highest with the values of 79.77. It is interesting that the O-H BDE value of isovitexin (78.55) with glycoside at C-6 position is lower than that of its aglycone (79.77) and vitexin (99.20) with glycoside at C-8 position. Further analysis indicated that the glycosidation of flavonoids at C-6 in the A-ring makes a more uniform distribution of spin density and improves the stability of free radicals leading to the increase in antioxidant capacity. Flavonoids with good antioxidant capacity might contribute to the pharmacological effects of Agrimonia pilosa Ledeb.

Phytochemical Analysis of Agrimonia pilosa Ledeb, Its Antioxidant Activity and Aldose Reductase Inhibitory Potential

The aim of this study was to determine aldose reductase (AR) inhibitory activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of compounds from Agrimonia pilosa Ledeb (AP). We isolated agrimoniin (AM), four flavonoid glucosides and two flavonoid glucuronides from the n-butanol fraction of AP 50% methanol extract. In addition to isolated compounds, the AR-inhibitory activity and the DPPH free radical scavenging activity of catechin, 5-flavonoids, and 4-flavonoid glucosides (known components of AP) against rat lens AR (RLAR) and DPPH assay were measured. AM showed IC₅₀ values of 1.6 and 13.0 μM against RLAR and DPPH scavenging activity, respectively. Additionally, AM, luteolin-7-O-glucuronide (LGN), quercitrin (QU), luteolin (LT) and afzelin (AZ) showed high inhibitory activity against AR and were first observed to decrease sorbitol accumulation in the rat lens under high-sorbitol conditions ex vivo with inhibitory values of 47.6%, 91.8%, 76.9%, 91.8% and 93.2%, respectively. Inhibition of recombinant human AR by AM, LGN and AZ exhibited a noncompetitive inhibition pattern. Based on our results, AP and its constituents may play partial roles in RLAR and oxidative radical inhibition. Our results suggest that AM, LGN, QU, LT and AZ may potentially be used as natural drugs for treating diabetic complications.

Proposed mechanisms of Terminalia catappa in hyperglycaemia and associated diabetic complications

Objectives

Terminalia catappa has shown potent antidiabetic activity in the past; however, the exact molecular mechanisms by which it acts have not been elucidated. This review aims at exploring several hypotheses which have been proposed to explain its mechanism of action, including reduction in oxidative stress, inflammation, angiogenesis, lipid profile correction and direct hypoglycaemic actions.

Methods

A thorough review of all the articles, research as well as reviews, available regarding the concerned topic was performed. MEDLINE databases were searched using keywords (and their combinations), such as T. catappa, renin oxidative stress, inflammation, angiogenesis, diabetic retinopathy, α-glucosidase and α-amylase, among several others. English-language articles were preferably selected.

Key findings

Apart from metabolic dysfunctions, several hyperglycaemia-induced pathological conditions come into scene as the after-effects of diabetes. These mainly include inflammation, oxidative stress, angiogenesis and lipid profile alteration, which ultimately result in vascular endothelial dysfunction, hepatic steatosis, lipid peroxidation and apoptosis of endothelial, hepatic and neuronal cells. Terminalia catappa effectively attenuates the progression of diabetic retinopathy and shows significant hypoglycaemic actions. The mechanisms behind these effects were explained.

Conclusion

Terminalia catappa may provide an effective natural product to treat hyperglycaemia and prevent subsequent diabetic complications.

Acylphloroglucinolated Catechin and Phenylethyl Isocoumarin Derivatives from Agrimonia pilosa

Eight new compounds (1-8), including five acylphloroglucinolated catechins (1-5) and three phenylethyl isocoumarin glycosides (6-8), were isolated from Agrimonia pilosa along with six other known compounds (9-14). The new compounds were characterized structurally by NMR, MS, and ECD analyses. Compounds 4 and 5 were assigned as acylphloroglucinolated procyanidin derivatives, which are described for the first time from Nature. The absolute configuration of compound 8 was elucidated by computational analysis of its ECD spectrum. The isolated compounds were evaluated for their inhibitory activity against lipopolysaccharide-induced NO production in BV2 microglial cells.

ANTI-NOCICEPTIVE EFFECT OF AGRIMONIA EUPATORIA EXTRACT ON A CISPLATIN-INDUCED NEUROPATHIC MODEL

BACKGROUND

Natural products including Agrimonia eupatoria are considered an incomparable source of molecular diversity that has led to the medicines, especially for pain treatment. To investigate the antinociception of Agrimonia eupatoria, we examined its activity in a rat model of cisplatin neuropathy.

MATERIALS AND METHODS

Male Sprague-Dawley rats received intraperitoneal (i.p.) cisplatin twice a week at a dose of 2 mg/kg (cumulative dose, 20 mg/kg) for 4 weeks. Before each injection, 2 ml of sterile saline solution was given subcutaneously to prevent renal damage via hyperhydration. The mice were treated with gabapetin as a positive control drug with a 100mg/kg intraperitoneal injection. A. eupatoria extract of 200mg/kg was solved in saline and then treated by oral administration.

RESULTS

The mice treated with A. eupatoria showed lower withdrawal duration in the pin-prick and plantar tests, and a higher withdrawal threshold in the paw-withdrawal threshold test as compared to control animals in a cisplatin-induced neuropathic model. In the case of cold-allodynia, A. eupatoria treatment increased paw-withdrawal duration in a chemical test. A. eupatoria showed a more outstanding effect than gabapentin in all used tests for preventing cisplatin-induced nerve injury for 4 weeks.

CONCLUSIONS

Our results suggest that A. eupatoria extract showed an antinociceptive effect in the pin-prick test, plantar test, and paw-withdrawal threshold test using a cisplatin-induced neuropathic rat model.

Agrimonia eupatoria L. and Cynara cardunculus L. Water Infusions: Comparison of Anti-Diabetic Activities

Diabetes mellitus (DM) is frequently diagnosed at a time when patients already suffer from several cardiovascular complications. Our previously published data (Molecules 201520 (11): 20538-50) on the anti-oxidative properties of Agrimonia eupatoria L. (AE) and Cynara cardunculus L. (CC) prompted us to extend the available evidence on their possible protective activities on selected DM-related parameters in a streptozotocin-induced DM rat model and in a series of in vitro experiments. Male rats were divided into four groups: control group, untreated diabetic group, AE and CC treated diabetic groups. During a five-week period, changes in blood glucose and body weight were monitored. Then, rats were sacrificed and subjected to the assessment of changes in the reactivity of aortas and measurement of butyrylcholinesterase activity. To complete the panel of experiments, α-glucosidase activity was assessed in vitro. Our results demonstrate that both tested extracts exert similar anti-diabetic activities. However, better anti-oxidant activity of the A. eupatoria extract indicates its higher clinical potential in the prevention and/or adjuvant therapy of developing cardiovascular complications related to DM and diseases associated with oxidative stress.

Agrimonolide from Agrimonia pilosa suppresses inflammatory responses through down-regulation of COX-2/iNOS and inactivation of NF-κB in lipopolysaccharide-stimulated macrophages

BACKGROUND

Agrimonolide from Agrimonia pilosa showed a strong anti-inflammatory activity, and the present study aims to reveal potential mechanisms on molecular level explaining its anti-inflammatory effect.

HYPOTHESIS/PURPOSE

To investigate the mechanism of anti-inflammatory activity of agrimonolide.

STUDY DESIGN

Anti-inflammatory activity of agrimonolide in cells was applied.

METHODS

Anti-inflammatory activity of agrimonolide isolated from Agrimonia pilosa was evaluated using lipopolysaccharide (LPS) stimulated RAW 264.7 cell models. The productions of IL-1β, IL-6, TNF-α and NO were determined by ELISA and nitrite analysis, respectively. The expressions of iNOS and COX-2 were measured by western blotting and RT-PCR analysis.

RESULTS

The pre-treatment with agrimonolide significantly reduced the levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), as well as attenuated the expression of iNOS and COX-2 in LPS-stimulated macrophages. Furthermore, agrimonolide inhibited the activation of JNK and p38 MAPKs and decreased the activation of JAK-STAT and NF-κB in LPS-stimulated macrophages.

CONCLUSION

The present study suggested that agrimonolide exerted anti- inflammatory activity, at least in part, via suppressing LPS-induced activation of JAK-STATs and p38 MAPKs signaling pathway.