Antihyperglycemic Activity of Herb Extracts on Streptozotocin-Induced Diabetic Rats

A comprehensive review of medicinal Toxicodendron (Anacardiaceae): Botany, traditional uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Comprising of about 30 species, the genus Toxicodendron (Anacardiaceae) are mainly distributed in East Asia and North America. Among them, 13 species have been traditionally used as folk medicines in Asia and other parts of the world to treat blood diseases, abnormal bleeding, skin diseases, gastrointestinal diseases, liver diseases, bone injury, lung diseases, neurological diseases, cardiovascular diseases, tonic, cancer, eye diseases, menstrual irregularities, inflammation, rheumatism, diabetes mellitus, rattlesnake bite, internal parasites, contraceptive, vomiting and diarrhea.

AIM OF THE STUDY

To date, no comprehensive review on Toxicodendron has been published and the scientific basis of the traditional medicinal benefits of Toxicodendron have been less reported. Therefore, this review aims to provide a reference for further research and development on medicinal purpose of Toxicodendron by summarizing the works (from 1980 to 2023), and focusing on its botany, traditional uses, phytochemistry and pharmacology.

MATERIALS AND METHODS

The names of the species were from The Plant List Database (http://www.theplantlist.org), World Flora Online (http://www.worldfloraonline.org), Catalogue of Life Database (https://www.catalogueoflife.org/) and Plants for A Future Database (https://pfaf.org/user/Default.aspx). And the search terms "Toxicodendron" and "the names of 31 species and their synonyms" were used to search for information from electronic databases such as Web of Science, Scopus, Google Scholar, Science Direct, PubMed, Baidu Scholar, Springer, and Wiley Online Library. Moreover, PhD and MSc dissertations were also used to support this work.

RESULTS

These species on Toxicodendron are widely used in folkloric medicine and modern pharmacological activities. So far, approximately 238 compounds, mainly phenolic acids and their derivatives, urushiols, flavonoids and terpenoids, are extracted and isolated from Toxicodendron plants, commonly, T. trichocarpum, T. vernicifluum, T. succedaneum, and T. radicans. Among them, phenolic acids and flavonoids are the main compound classes that show pharmacological activities in Toxicodendron plants both in vitro and in vivo. Furthermore, the extracts and single compounds of these species show a wide range of activities, such as antioxidant, antibacterial, anti-inflammatory, anti-tumor, liver protection, fat reduction, nerve protection, and treatment of blood diseases.

CONCLUSIONS

Selected species of Toxicodendron have been used as herbal medicines in the Southeast Asian for a long time. Furthermore, some bioactive constituents have been identified from them, so plants in this genus may be potential new drugs. The existing research on Toxicodendron has been reviewed, and the phytochemistry and pharmacology provide theoretical basis for some of the traditional medicinal uses. Therefore, in this review, the traditional medicinal, phytochemical and modern pharmacology of Toxicodendron plants are summarized to help future researchers to find new drug leads or to get a better understanding of structure-activity relationships.

A fruit extract of Styphnolobium japonicum (L.) counteracts oxidative stress and mediates neuroprotection in Caenorhabditis elegans

BACKGROUND

Despite its widespread uses in Chinese and European medicine, Styphnolobium japonicum (Chinese scholar tree, formerly Sophora japonicum) has not been extensively investigated for its potential to protect against neurodegenerative processes and to promote resistance to oxidative stress. In this study, we evaluated the neuroprotective activities of a hydroalcoholic extract from Chinese scholar tree fruits that could be possibly linked to its antioxidant properties using Caenorhabditis elegans as a well-established in vivo model.

METHODS

Survival rate in mutant daf-16 and skn-1 worms, stressed by the pro-oxidant juglone and treated with the extract, was tested. Localization of the transcription factors SKN-1 and DAF-16, and expression of gst-4 were measured. For evaluation of neuroprotective effects, formation of polyglutamine (polyQ40) clusters, α-synuclein aggregates, loss of amphid sensilla (ASH) neuronal function, and amyloid β (Aβ) accumulation (as markers for Huntington's, Parkinson's, and Alzheimer's) was examined.

RESULTS

The extract, which contains substantial amounts of phenolic phytochemicals, showed an increase in the survival rate of worms challenged with juglone in daf-16 mutants but not in skn-1 mutants. The transcription factor SKN-1 was activated by the extract, while DAF-16 was not affected. Upon application of the extract, a significant decline in GST-4 levels, polyQ40 cluster formation, number of lost ASH sensory neurons, α-synuclein aggregation, and paralysis resulting from Aβ accumulation was observed.

CONCLUSIONS

Styphnolobium japonicum fruit extract activated the SKN-1/Nrf2 pathway, resulting in oxidative stress resistance. It revealed promising pharmacological activities towards treatment of Huntington's, Parkinson's, and Alzheimer's diseases. Polyphenolics from Styphnolobium japonicum may be a promising route towards treatment of CNS disorders, but need to be tested in other in vivo systems.

Phytochemical Investigation and Biological Studies on Selected Searsia Species

Searsia is the more recent name for the genus Rhus, which contains over 250 individual species of flowering plants in the family Anacardiaceae. Several Searsia species are used in folk medicine and have been reported to exhibit various biological activities. Although known to exhibit different terpenoids and flavonoids, the chemistry of the Searsia genus is not comprehensively studied due to the structural complexity of the compounds. In this study, the extraction, isolation, and identification of secondary metabolites from three Searsia species (Searsia glauca, S. lucida, and S. laevigata) were conducted using chromatographic and spectroscopic techniques and afforded five known terpenes, viz., moronic acid (1), 21β-hydroxylolean-12-en-3-one (2), lupeol (11), α-amyrin (9), and β-amyrin (10), in addition to six known flavonoids, myricetin-3-O-β-galactopyranoside (3), rutin (4), quercetin (5), apigenin (6), amentoflavone (7), and quercetin-3-O-β-glucoside (8). The structural elucidation of the isolated compounds was determined based on NMR (1D and 2D) and comparison with the data in the literature. Biological assays, such as antioxidant and enzyme inhibition activity assays, were conducted on the plant extracts and the isolated compounds. The antioxidant capacities of hexane, dichloromethane, ethyl acetate, methanol, and butanol main extracts were investigated using ferric ion reducing power (FRAP), oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC) assays. The results showed high antioxidant activities for methanol and butanol extracts of the three plants. The isolated compounds were tested against alpha-glucosidase and alpha-amylase, and the results showed the potent activity of moronic acid (C1) (IC₅₀ 10.62 ± 0.89 and 20.08 ± 0.56 µg/mL, respectively) and amentoflavone (C7) (IC₅₀ 5.57 ± 1.12 µg/mL and 19.84 ± 1.33 µg/mL, respectively). Isolated compounds of and biological assays for S. glauca, S. lucida, and S. laevigata are reported for the first time.

Quercetin and Quercitrin from Agrimonia pilosa Ledeb Inhibit the Migration and Invasion of Colon Cancer Cells through the JNK Signaling Pathway

Considering the high metastatic potential of colorectal cancer (CRC), the inhibition of metastasis is important for anti-CRC therapy. Agrimonia pilosa Ledeb (A. pilosa) is a perennial herbaceous plant that is widely distributed in Asia. The extracts of A. pilosa have shown diverse pharmacological properties, such as antimicrobial, anti-inflammatory, and antitumor activities. In the present study, the antimetastatic activity of A. pilosa was evaluated. Methanol extraction from the roots of A. pilosa was performed by high-performance liquid chromatography (HPLC) and 12 fractions were obtained. Among these, fraction 4 showed the most potent inhibitory effect on the migration of colon cancer cells. Using LC-HR MS analysis, quercetin and quercitrin were identified as flavonoids contained in fraction 4. Like fraction 4, quercetin and quercitrin effectively inhibited the migration and invasion of RKO cells. While the level of E-cadherin was increased, the levels of N-cadherin and vimentin were decreased by the same agents. Although they all activate the p38, JNK, and ERK signaling pathways, only SP600125, an inhibitor of the JNK pathway, specifically inhibited the effect of fraction 4, quercetin, and quercitrin on cell migration. An in vivo experiment also confirmed the antitumor activity of quercetin and quercitrin. Collectively, these results suggest that A. pilosa and its two flavonoids, quercetin and quercitrin, are candidates for the antimetastatic treatment of CRC.

Enzyme reaction-guided identification of active components from the flowers of Sophora japonica var. violacea

The flower of S. japonica is a favorite food and used as traditional medicine. In the present study, a facile and effective method based on the changes in the composition before and after the enzyme reaction was established to screen the active compounds from complex natural products. The separation of an active compound from the ethanolic extracts of Sophora japonica var. violacea, which exhibited the α-amylase inhibitory activity is presented as an example. The analysis of HPLC showed that one component was reduced by 25% after the enzyme reaction. The potential active compound was isolated via LH-20 gel permeation chromatography and identified as kaempferol 3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-galactopyranosyl-7-O-α-l-rhamnopyranoside by ¹H and ¹³C NMR. The in vitro test indicated that the compound had the α-amylase inhibitory activity, and the IC₅₀ was 88.56 ± 0.60 μg mL^-1. The molecular docking study of this compound showed that the compound enfolded in the active sites of α-amylase completely and interacted with the amino acid residues through hydrogen bonds, van der Waals force and hydrophobic interactions.

Rosemary Leaf Extract Inhibits Glycation, Breast Cancer Proliferation, and Diabetes Risks

Advanced glycation end products (AGEs) generated from glycation can cause inflammation-related diseases such as diabetes and cancer. The bioactive compounds of rosemary extract (RE) were extracted and incubated with sugar-protein rich food and breast cancer cell MCF-7 to investigate its inhibitory effect on glycation and cancer cell proliferation, respectively. The diabetic rat was dosed with RE to investigate its effect on blood glucose, serum malondialdehyde (MDA), cholesterol (CHO), triglycerides (TG), low-density lipoproteins (LDLs), anti-oxidation capacity (T-AOC), superoxide dismutase (SOD) activity, anti-oxidation capacity alkaline phosphatase (ALP), glutamate pyruvate transaminase (GPT), and glutamate oxaloacetate transaminase (GOT). The results show that RE contained seven major phenolics ranging from 17.82 mg/g for rosemarinic acid to 0.01 mg/g for ferulic acid on dry weight basis. It significantly lowered AGEs, carboxymethyl lysine (CML), and protein glycation in a sugar-protein rich intermediate-moisture-food (IMF) model. Furthermore, the survival rates of MCF-7 cells decreased to 6.02 and 2.16% after 96 h of incubation with 1.0 and 2.0 mg/mL of RE, respectively. The blood glucose, MDA, CHO, TG, and LDLs in diabetic rats of RE treatment were decreased. The RE treatment also enhanced the T-AOC and SOD activity. Furthermore, the RE treatment improved liver function through improving ALP, GPT, and GOT activities in diabetic rats. The results provide important information for the nutriaceutical and pharmaceutical application of rosemary extract.

An Integrated Fecal Microbiome and Metabolomics in T2DM Rats Reveal Antidiabetes Effects from Host-Microbial Metabolic Axis of EtOAc Extract from Sophora flavescens

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease. Sophora flavescens (S. flavescens), also named Kushen, is a famous Chinese herbal medicine that has been used to prevent and cure T2DM both in folk medicine and in medical institution. However, its mechanism of action remains unclear. In this study, the pharmacodynamic effects of S. flavescens EtOAc extract (SFE) on high-fat diet and low-dose streptozotocin-induced T2DM rats were examined. Fecal metabolomics analysis and 16S rRNA gene sequencing were applied to determine the influence of T2DM and SFE treatment on gut microbiota and host metabolism. Based on the consistency of the results of metabolic pathways in metabolomics analysis and phylogenetic investigation of communities by reconstruction of unobserved state (PICRUSt) analysis of 16S rRNA gene sequencing, the level of metabolites and the operational taxonomic units of gut bacteria were combined, and Spearman's analysis was implemented. Our data showed that SFE significantly decreased fasted blood glucose levels and improved lipid profile, glycosylated serum protein, glycosylated hemoglobin index, and pancreas damage. Metabolomics and 16S rRNA gene sequencing analysis indicated gut bacteria disorder, disturbed lipid metabolism, carbohydrate metabolism, and especially amino acid metabolism in T2DM and that SFE can regulated these metabolic pathways through the influence on gut bacteria. Spearman's analysis indicated that the amino acid metabolism that included tryptophan, branched chain amino acid, aromatic amino acid, beta-alanine, and glycine, serine and threonine metabolism, lipid metabolism, including lysophosphatidylcholines and lysophosphatidylethanolamines, primary bile acid and linoleic acid metabolism, carbohydrate metabolism, and nucleotide metabolism positively correlated with Faecalibacterium, Flexispira, Phascolarctobacterium, Prevotella, Roseburia, and [Prevotella]. In addition, arginine and proline metabolism, steroid hormone, steroid biosynthesis, and sphingolipid metabolism positively correlated with Lactobacillus, Oscillospira, Parabacteroides, Ruminococcus, and Streptococcus. Taken together, we speculated that SFE may have an effect on T2DM by mediating host-microbial metabolic axis. Exploration of SFE treatment for T2DM by multiomics is expected to provide a reference for clinical treatment.

Antinociceptive Effect of Single Components Isolated from Agrimonia pilosa Ledeb. Extract

Agrimonia pilosa Ledeb. produces an antinociceptive effect in ICR mice in both chemically induced and thermal pain models. In the present study, we examined the antinociceptive effects of single components isolated from Agrimonia pilosa Ledeb. (AP) extract in ICR mice. Three active compounds isolated from AP, including rutin, luteolin-7-O-glucuronide, and apigenin-7-O-glucuronide, were isolated and identified by comparing EI-MS, 1H-, 13C-NMR, and UV. We studied the antinociceptive effects of three single components administered orally at doses of 10 and 20 mg/kg in monosodium urate (MSU)-treated pain model as measured by von Frey test. Among these compounds, apigenin-7-O-glucuronide was more effective in the production of antinociceptive effects. We further characterized the antinociceptive effects and possible mechanisms of apigenin-7-O-glucuronide in writhing and formalin tests. Oral administration of Apigenin-7-O-glucuronide caused a reduction in the number of writhing and effectively reduced the pain behavior observed during the second phase of the formalin test in a dose-dependent manner. In addition, the pretreatment of yohimbine instead of naloxone or methysergide attenuated apigenin-7-O-glucuronide-induced antinociception in the writhing test. Moreover, apigenin-7-O-glucuronide caused reduction in the expression of p-P38, p-CREB, and p-mTOR induced by formalin injection. Our results indicate that apigenin-7-O-glucuronide shows an antinociceptive effect in various pain models. In addition, spinal α2-adrenergic receptors appear to be involved in the production of antinociception induced by apigenin-7-O-glucuronide. Furthermore, the antinociceptive effect of apigenin-7-O-glucuronide appears to be mediated by reduction in the expression of p-P38, p-CREB and p-mTOR levels in the spinal cord.

Capability of polygonum cuspidatum extract in inhibiting AGEs and preventing diabetes

Diabetes is a metabolic disorder disease associated with advanced glycation end products (AGEs) and protein glycation. The effect of polygonum cuspidatum extract (PE) on AGEs and Nε-(Carboxymethyl)-L-lysine formation, protein glycation, and diabetes was investigated. Six primary phenolics in a range of 12.36 mg/g for ellagic acid to 0.01 mg/g for piceid were determined in PE. In an intermediate-moisture-foods model, inhibition rate of PE was as high as 54.2% for AGEs and 78.9% for CML under aw 0.75. The protein glycation was also inhibited by PE. In a diabetic rat model, the levels of blood glucose, serum malondialdehyde, cholesterol, triglycerides, and low-density lipoproteins were effectively reduced by PE treatment. The antioxidation capacity (T-AOC) and superoxide dismutase (SOD) activity were also mediated by PE. Additionally, the activates of liver function-related enzymes including alkaline phosphatase (ALP), glutamate pyruvate transaminase (GPT), and glutamate oxaloacetate transaminase (GOT) in diabetic rat were improved by PE.

An accurate and reproducible method for simultaneous determination of four flavonoids in EtOAc extracts from Sophora flavescens Ait. in rat plasma based on UHPLC Q-Exactive Mass spectrometry: Application to a pharmacokinetics study

In previous studies, it was revealed that ethyl acetate (EtOAc) extracts from Sophora flavescens Ait. improved glucose tolerance, reduced hyperglycemia, and restored insulin levels in diabetic patients. The aim of this study was to develop an accurate and sensitive UHPLC-MS method for simultaneous determination of flavonoids in EtOAc extracts of Kushen in rat plasma. Ethyl acetate-acetonitrile (2:1) was selected as the solvent to extract the four flavonoids from rat plasma. A BEH C₁₈ column (2.1 mm × 100 mm, 1.7 μm) with a C₁₈ guard cartridge was chosen as the separation plant using a gradient elution with acetonitrile (solvent A) and 0.1% formic acid (solvent B) in water. For all four analytes, the method showed good linearity (r²  > 0.991) in 1-500 ng/mL. The inter- and intra-day accuracy ranged from -13.78 to 7.19%, and the precision (RSD) was <8.75%. Recoveries of all four flavonoids ranged from 85.9 to 101.3%. According to the results of multitarget pharmacokinetic studies, four active flavonoids in EtOAc extracts from Kushen have similar absorption kinetics but very different metabolic kinetics, and a double peak phenomenon was observed in the concentration-time curve of norkurarinone, which is different from the previous study. In conclusion, detection and multitarget pharmacokinetic studies successfully determined active flavonoids after oral administration of EtOAc extracts from Kushen by an efficient, sensitive and selective UHPLC-MS method, and the results may provide a foundation for future studies of Kushen.

Antidiabetic potential of methanolic and flavonoid-rich leaf extracts of Synsepalum dulcificum in type 2 diabetic rats

Background

Synsepalum dulcificum is a plant indigenous to West Africa. The fruit is used to modify taste of foods to sweetness.

Objectives

This study aims to investigate the antidiabetic potentials of both methanolic and flavonoid-rich leaf extracts of S. dulcificum (MSD and FSD respectively) in type 2 diabetic Wistar albino rats.

Materials and methods

Sixty three rats were randomly distributed into nine groups of seven animals each with group 1 serving as the normal control. Groups 2 to 7 were given 10% fructose in their drinking water for 14 days, after which 40 mg/kg of streptozotocin was administered. Group 2 animals served as the diabetic control, while groups 3, 4, 5, 6 and 7 were treated with 30 mg/kg MSD, 60 mg/kg MSD, 30 mg/kg FSD, 60 mg/kg FSD and 5 mg/kg glibenclamide respectively. Groups 8 and 9, contained healthy animals, and were treated with only 60 MSD, and 60 mg/kg FSD respectively. Biochemical parameters such as liver and kidney function tests, lipid profile, as well as lipid peroxidation and antioxidant enzymes were assessed in addition to histopathology.

Results

It was observed that daily oral administration of MSD and FSD for 21 days significantly (p < 0.05) improved the observed pathological changes as a result of type 2 diabetes.

Conclusion

It could be deduced from results obtained in this study that methanolic and flavonoid-rich leaf extracts of S.dulcificum have antidiabetic potential in type 2 diabetic rats.

Local and traditional uses, phytochemistry, and pharmacology of Sophora japonica L.: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Sophora japonica (Fabaceae), also known as Huai (Chinese: ), is a medium-sized deciduous tree commonly found in China, Japan, Korea, Vietnam, and other countries. The use of this plant has been recorded in classical medicinal treatises of ancient China, and it is currently recorded in both the Chinese Pharmacopoeia and European Pharmacopoeia. The flower buds and fruits of S. japonica, also known as Flos Sophorae Immaturus and Fructus Sophorae in China, are most commonly used in Asia (especially in China) to treat hemorrhoids, hematochezia, hematuria, hematemesis, hemorrhinia, uterine or intestinal hemorrhage, arteriosclerosis, headache, hypertension, dysentery, dizziness, and pyoderma. To discuss feasible trends for further research on S. japonica, this review highlights the botany, ethnopharmacology, phytochemistry, biological activities, and toxicology of S. japonica based on studies published in the last six decades.

MATERIALS AND METHODS

Information on the S. japonica was collected from major scientific databases (SciFinder, PubMed, Elsevier, SpringerLink, Web of Science, Google Scholar, Medline Plus, China Knowledge Resource Integrated (CNKI), and "Da Yi Yi Xue Sou Suo (http://www.dayi100.com/login.jsp)" for publications between 1957 and 2015 on S. japonica. Information was also obtained from local classic herbal literature, government reports, conference papers, as well as PhD and MSc dissertations.

RESULTS

Approximately 153 chemical compounds, including flavonoids, isoflavonoids, triterpenes, alkaloids, polysaccharides, amino acids, and other compounds, have been isolated from the leaves, branches, flowers, buds, pericarps, and/or fruits of S. japonica. Among these compounds, several flavonoids and isoflavonoids comprise the active constituents of S. japonica, which exhibit a wide range of biological activities in vitro and in vivo such as anti-inflammatory, antibacterial, antiviral, anti-osteoporotic, antioxidant, radical scavenging, antihyperglycemic, antiobesity, antitumor, and hemostatic effects. Furthermore, flavonoids and isoflavonoids can be used as quality control markers for quality identification and evaluation of medicinal materials and their preparations. Information on evaluating the safety of S. japonica is very limited, so further study is required. To enable safer, more effective, and controllable therapeutic preparations, more in-depth information is urgently needed on the quality control, toxicology data, and clinical value of crude extract and active compounds of S. japonica.

CONCLUSIONS

S. japonica has long been used in traditional Chinese medicine (TCM) due to its wide range of biological activities, and is administered orally. Phytochemical and pharmacological studies of S. japonica have increased in the past few years, and the extract and active components of this plant can be used to develop new drugs based on their traditional application as well as their biological activities. Therefore, this review on the ethnopharmacology, phytochemistry, biological activities, and toxicity of S. japonica offers promising data for further studies as well as the commercial exploitation of this traditional medicine.

Tiliroside, the major component of Agrimonia pilosa Ledeb ethanol extract, inhibits MAPK/JNK/p38-mediated inflammation in lipopolysaccharide-activated RAW 264.7 macrophages

In the present study, the in vivo anti-inflammatory activity of Agrimonia pilosa Ledeb (AP) ethanol extract was confirmed in experimental animal models, including xylene-induced ear edema in mice and carrageenan-induced paw edema in rats. Tiliroside, the major component of AP extract, was isolated and purified by high-performance liquid chromatography. The anti-inflammatory mechanism of tiliroside was then examined using lipopolysaccharide (LPS)-activated RAW 264.7 macrophage cells. An MTT assay was used to determine cytotoxicity and a Griess assay was used to determine nitric oxide (NO) production. Concentration levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay. Protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), phosphorylated (p)-extracellular signal-regulated kinase (ERK) 1/2, p-c-Jun N-terminal kinases (JNK), p-p38 and inhibitor of κB-α were detected by western blot analysis. AP ethanol extract was revealed to inhibit xylene-induced ear edema in mice and carrageenan-induced paw edema in rats. Tiliroside significantly suppressed the overproduction of NO (P<0.01), but revealed no notable inhibition of the release of TNF-α and IL-6. In addition, tiliroside significantly downregulated the elevated expression levels of iNOS and COX-2 induced by LPS (P<0.01). The phosphorylation of JNK and p38 proteins were also significantly inhibited (P<0.01), however, tiliroside exhibited no obvious inhibition on the phosphorylation of ERK 1/2 and the degradation of IκB-α protein. In conclusion, the anti-inflammatory molecular mechanism of tiliroside may involve the downregulation of iNOS and COX-2 protein expression levels, and the inactivation of mitogen-activated protein kinase (MAPK)/JNK, in addition to the MAPK/p38 signaling pathway.

Acute and subchronic antihyperglycemic activities of Bowdichia virgilioides roots in non-diabetic and diabetic rats

Aim:

The present study was undertaken to evaluate the acute and subchronic antihyperglycemic effects of methanolic extract of Bowdichia virgilioides root bark of B. virgilioides in streptozotocin (STZ)-induced diabetic rats.

Materials and Methods:

The extract (100, 250 or 500 mg/kg) was orally administered to male Wistar diabetic (STZ, 42 mg/kg i.v.) and non-diabetic rats into two main protocols: (i) subchronic experiments, where animals were treated for 21 days with B. virgilioides extract and the following parameters were evaluated: Body weight, fluid and food intake (determined daily), urinary glucose and urea (every 3 days) and glycemia (every 5 days). At the end of the experimental period, skeletal muscles (extensor digitorum longus [EDL] and soleus), retroperitoneal and epididymal white adipose tissues were collected and weighed; liver samples were used for the determination of the lipid and glycogen contents; (ii) acute experiments, which evaluated the alterations on fasting and post-prandial glycemia and on glucose tolerance using the oral glucose tolerance test (OGTT).

Results:

In subchronic experiments, the treatment with B. virgilioides extract did not change any parameter evaluated in diabetic and non-diabetic animals. On fasting and post-prandial glycemia, the extract treatment did not promote changes in the glycemia values in diabetic or non-diabetic animals. In OGTT, the treatment with 500 mg/kg B. virgilioides extract reduced the hyperglycemia peak after a glucose overload, when compared with non-treated diabetic animals, resulting in a lower area under curve.

Conclusion:

The results of our work indicate that B. virgilioides root extract promotes an acute antihyperglycemic effect in STZ-diabetic rats; this effect probably occurs through an inhibition of the intestinal glucose absorption. The continuity of the research is necessary to elucidate these possibilities.

Integrating traditional medicine into modern inflammatory diseases care: multitargeting by Rhus verniciflua Stokes

Despite the fact that numerous researches were performed on prevention and treatment of inflammation related diseases, the overall incidence has not changed remarkably. This requires new approaches to overcome inflammation mediated diseases, and thus traditional medicine could be an efficacious source for prevention and treatment of these diseases. In this review, we discuss the contribution of traditional medicine, especially Rhus verniciflua Stokes, to modern medicine against diverse inflammation mediated diseases. Traditionally, this remedy has been used in Eastern Asia for the treatment of gastric problems, hepatic disorders, infectious diseases, and blood disorders. Modern science has provided the scientific basis for the use of Rhus verniciflua Stokes against such disorders and diseases. Various chemical constituents have been identified from this plant, including phenolic acid, and flavonoids. Cell-based studies have exhibited the potential of this as antibacterial, antioxidant, neuroprotective, anti-inflammatory, growth inhibitory, and anticancer activities. Enormous animal studies have shown the potential of this against proinflammatory diseases, neurodegenerative diseases, diabetes, liver diseases, and chemical insults. At the molecular level, this medicinal plant has been shown to modulate diverse cell-signaling pathways. In clinical studies, Rhus verniciflua Stokes has shown efficacy against various cancer patients such as colorectal, gastric, hepatic, renal, pancreatic, and pulmonary cancers. Thus, this remedy is now exhibiting activities in the clinic.

Phaseolamin treatment prevents oxidative stress and collagen deposition in the hearts of streptozotocin-induced diabetic rats

The development of cardiovascular complications in patients with diabetes is often associated with an imbalance between reactive oxygen species and antioxidant systems. This imbalance can contribute to high cardiac collagen content, which increases cross-linking and the stiffness of the myocardium. In this study, the protective effect of phaseolamin against damage under oxidative stress and collagen deposition in the cardiac tissue in association with diabetes was evaluated. Non-diabetic and diabetic animals were distributed into groups and treated for 20 days with commercial phaseolamin. The phaseolamin treatment increased total antioxidant activity but reduced the following in diabetic rats: (a) hyperglycaemic state, (b) catalase and superoxide dismutase activity and (c) tissue damage caused by lipid peroxidation. Additionally, the phaseolamin treatment attenuated the collagen levels compared to non-treated diabetic rats. Thus, the short-term anti-hyperglycaemic effect of the phaseolamin treatment may prevent the initial changes caused by oxidative stress and the deposition of collagen, as well as reduce the incidence of heart complications.

Modulation of lipogenesis and glucose consumption in HepG2 cells and C2C12 myotubes by sophoricoside

Sophoricoside, an isoflavone glycoside isolated from Sophora japonica (Leguminosae), has been widely reported as an immunomodulator. In this study, the effects of sophoricoside on lipogenesis and glucose consumption in HepG2 cells and C2C12 myotubes were investigated. Treatment with sophoricoside at concentrations of 1-10 μM inhibited lipid accumulation in HepG2 cells in a dose-dependent manner. At the same concentration range, no effect on cell viability was observed in the MTT assay. Inhibition of lipogenesis was associated with the downregulation of SREBP-1a, SREBP-1c, SREBP-2 and their downstream target genes (FAS, ACC, HMGR) as revealed by realtime quantitative PCR. The lipid-lowering effect was mediated via the phosphorylation of AMPK. Further investigation of the activities of this isoflavone showed that sophoricoside has the capability to increase glucose uptake by C2C12 myotubes. It also effectively inhibited the activities of α-glucosidase and α-amylase in vitro and remarkably lowered postprandial hyperglycaemia in starch-loaded C57BL6/J mice. These results suggest that sophoricoside is an effective regulator of lipogenesis and glucose consumption and may find utility in the treatment of obesity and type 2 diabetes.

The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

OBJECTIVES

The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes.

METHODS

Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days.

RESULTS

The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained.

CONCLUSION

The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients.

Antitumor and immunomodulating activity of a polysaccharide from Sophora flavescens Ait

The immunostimulatory activity of Sophora flavescens polysaccharide (SFPW1) was evaluated by using in vitro cell models and in vivo animal models. The results demonstrated that SFPW1 could effectively inhibit the tumor growth in H22 tumor-bearing mice and promote the splenocyte proliferation, thus resulting in a prolonged life survival. For assay in vitro, SFPW1 significantly strengthened peritoneal macrophages to devour H22 tumor cells and stimulated macrophages to produce nitric oxide (NO) via up-regulation of inducible NO synthase (iNOS) activity. However, no direct cytotoxicity against H22 tumor cells was observed in vitro. These results suggest that SFPW1 might be a strong natural immunomodulator and the antitumor effect of this polysaccharide is associated with its potent immunostimulating effect.

Effect of Agrimonia pilosa Ledeb Extract on the Antinociception and Mechanisms in Mouse

In the present study, the antinociceptive profiles of Agrimonia pilosa Ledeb extract were examined in ICR mice. Agrimonia pilosa Ledeb extract administered orally (200 mg/kg) showed an antinociceptive effect as measured by the tail-flick and hot-plate tests. In addition, Agrimonia pilosa Ledeb extract attenuated the writhing numbers in the acetic acid-induced writhing test. Furthermore, the cumulative nociceptive response time for intrathecal (i.t.) injection of substance P (0.7 µg) was diminished by Agrimonia pilosa Ledeb extract. Intraperitoneal (i.p.) pretreatment with yohimbine (α₂-adrenergic receptor antagonist) attenuated antinociceptive effect induced by Agrimonia pilosa Ledeb extract in the writhing test. However, naloxone (opioid receptor antagonist) or methysergide (5-HT serotonergic receptor antagonist) did not affect antinociception induced by Agrimonia pilosa Ledeb extract in the writhing test. Our results suggest that Agrimonia pilosa Ledeb extract shows an antinociceptive property in various pain models. Furthermore, this antinociceptive effect of Agrimonia pilosa Ledeb extract may be mediated by α₂-adrenergic receptor, but not opioidergic and serotonergic receptors.

Selective Inhibition of Prenylated Flavonoids from Sophora flavescens against BACE1 and Cholinesterases

It was previously reported that certain lavandulylated flavanones from Sophora flavescens are β-site APP cleaving enzyme 1 (BACE1) inhibitors; however, based upon their levels within the extract, their inhibitory effects should be higher than expected. Moreover, chalcones and flavonols were reported to exert higher bioactivities than flavanones. These findings have led to a further search for other possible constituents potentially contributing to the strong inhibitory activity of the S. flavescens extract. In this study, BACE1 activities were significantly inhibited by 8-lavandulylkaempferol (IC50 7.29 μM), kuraridinol (IC50 7.10 μM), kuraridin (IC50 6.03 μM), and kushenol C (IC50 5.45 μM) from the ethyl acetate fraction, along with desmethylanhydroicaritin (IC50 1.86 μM), xanthohumol (IC50 7.19 μM), and leachianone G (IC50 8.56 μM) from the dichloromethane fraction of the extract. The results indicate that the prenyl group, rather than the lavandulyl group, and the flavonols and chalcones, rather than flavanones, might make predominant contributions to BACE1 inhibition. In particular, 8-lavandulylkaempferol exhibited significant inhibitory effects with IC50 values of 7.10 and 8.11 μM for butyrylcholinesterase and acetylcholinesterase, respectively, when compared to its counterpart, desmethylanhydroicaritin. This indicates that the lavandulyl group might play a predominant role in both cholinesterase inhibitions. This is the first study indicating that prenylated flavonoids exert varying degrees of inhibition primarily through their skeleton (flavonols, chalcones, flavanones), as well as their lipophilic chain length (prenyl and lavandulyl groups). Therefore, S. flavescens and its prenylated flavonoids, possessing low molecular weights and lipophilic moieties may be potent preventive and therapeutic candidates for Alzheimer's disease.

Anti-inflammatory and anti-allergic effects of Agrimonia pilosa Ledeb extract on murine cell lines and OVA-induced airway inflammation

ETHNOPHARMACOLOGICAL EVIDENCE

Agrimonia pilosa Ledeb (Rosaceae, AP) has long been used as a traditional medicine in Korea and other Asian countries to treat various diseases.

AIM OF THE STUDY

In the present study, the anti-inflammatory and anti-allergic effects of AP extract in in vitro cell lines and in vivo mouse model of inflammation and the molecular mechanisms involved were reported.

MATERIALS AND METHODS

Using Raw 264.7 murine macrophages the effects of methanol extract of AP in lipopolysaccharide (LPS)-induced production of inflammatory mediators were measured. Further IgE-DNP-induced interleukin (IL)-4 production and degranulation in RBL-2H3 rat basophilic cell lines was also estimated. To investigate the anti-asthmatic effect of AP in vivo, airway inflammation in ovalbumin (OVA)-induced mouse model was used.

RESULTS

AP attenuated the production of inflammatory mediators such as NO, PGE(2) and pro-inflammatory cytokines in LPS-induced Raw 264.7 cells. Further, AP inhibited IL-4 production and degranulation in IgE-DNP-induced RBL-2H3 cells. Furthermore, AP attenuated the infiltration of immune cells into lung, cytokines production in broncho-alveolar lavage fluid (BALF) and airway-hyperresponsiveness (AHR) on OVA-induced mouse model of inflammation.

CONCLUSION

Our results showed that AP attenuated the activation of macrophages, basophils, and inhibited the OVA-induced airway inflammation. The molecular mechanisms leading to AP's potent anti-inflammatory and anti-allergic effects might be through regulation of TRIF-dependent and Syk-PLCγ/AKT signaling pathways, suggesting that AP may provide a valuable therapeutic strategy in treating various inflammatory diseases including asthma.

Review of the effects of the traditional Chinese medicine Rehmannia Six Formula on diabetes mellitus and its complications

Rehmannia Six Formula (RF) is a formula that is commonly used in Traditional Chinese Medicine to treat patients with diabetes. A literature search was performed in PubMed for the years 2000-2009 using the key words RF, Rehmannia glutinosa, Fructus Corni, Dioscorea sp. (D. alata, D. opposita, D. batatas), Poria cocos, Alisma sp. (A. orientalis, A. plantago aquatica), and Paeonia suffruticosa/Cortex Moutan. On the basis of the publications found, RF appears to have beneficial effects on blood glucose, neuropathy, and nephropathy. There is also evidence of anti-inflammatory and antioxidant effects. Although there are many studies on compounds extracted from individual herbs, there are not many studies on RF as a whole. Because there is preliminary evidence that RF may be a useful supplement for the prevention of diabetic complications, clinical studies are warranted. For future clinical studies, it is recommended that details are provided regarding the preparation of RF and that the ratio of the individual components in RF is standardized so that results across studies can be compared.

The mechanism of vasorelaxation induced by ethanol extract of Sophora flavescens in rat aorta

AIM OF THE STUDY

Sophora flavescens (SF) is a known medicinal herb for the treatment of cardiovascular symptoms associated with arrhythmia in China. However, the pharmacological action mechanisms involved have not been well studied. The aim of the present study was to define effects of roots of SF on the vascular tension and responsible mechanisms in rat thoracic aorta.

MATERIALS AND METHODS

Ethanol extract of the roots of SF (ESF) was examined for their vascular relaxant effect in isolated phenylephrine-precontracted rat thoracic aorta.

RESULTS

ESF (0.1-100 μg/ml) induced relaxation of the phenylephrine-precontracted aortic rings in a concentration-dependent manner. Endothelium-denudation abolished the ESF-induced vasorelaxation. Pretreatment of the endothelium-intact aortic rings with l-NAME, an inhibitor of nitric oxide synthase, and ODQ, an inhibitor of soluble guanylyl cyclase (sGC), inhibited ESF-induced vasorelaxation. ESF increased cGMP levels of the aortic rings in a concentration-dependent manner and the effect was blocked by l-NAME and ODQ. Inhibition of K(+) channels with glibenclamide and tetraethylammonium, cyclooxygenase inhibition with indomethacin, and β-adrenergic and muscarinic receptors blockade had no effect on the ESF-induced vasorelaxation.

CONCLUSION

These findings suggest that ESF relaxes vascular smooth muscle via endothelium-dependent NO-sGC-cGMP signaling pathway.

The selected flavonol glycoside derived from Sophorae Flos improves glucose uptake and inhibits adipocyte differentiation via activation AMPK in 3T3-L1 cells

Among nine flavonols (1-9) obtained from Sophorae Flos, we first isolated compounds 4, 5, 8, and 9. These isolates (1-9) were evaluated for the phosphorylation of AMPK and ACC. Administered at 10 μM, 9 possessed high potent activity. Compound 9 displayed a dose-dependent stimulation of glucose uptake in 3T3-L1 cells, and this increase was obviously attenuated by compound C, an AMPK inhibitor. In addition, 9 also phosphorylated AMPK and its downstream substrate ACC in 3T3-L1 cells in a time- and dose-dependent manner. Moreover, we discovered that compound C inhibits 9-stimulated ACC phosphorylation and motivated the 9-inhibited C/EBPα and PPARγ, and FAS gene expression, significantly. These results revealed the role of the AMPK downstream signaling pathway in 9-improved glucose metabolism in 3T3-L1 cells and 9-inhibited adipocyte differentiation. Differentiation was investigated by Oil Red O staining activity after 9 administration (0-20 μM) in 6 days. Compound 9 decreased mean droplet size in a dose-dependent manner. The results revealed that 9 blocked adipogenic conversion in 3T3-L1 cells together with several significant downregulating adipocyte-specific transcription factors, including PPARγ, C/EBPα, and SREBP1. It also reduced FAS gene expression in a dose-dependent manner, which is crucial for adipogenesis in vitro.

Inhibitory activities of prenylated flavonoids from Sophora flavescens against aldose reductase and generation of advanced glycation endproducts

Important targets for the prevention and treatment of diabetic complications include aldose reductase (AR) inhibitors (ARIs) and inhibitors of advanced glycation endproduct (AGE) formation. Here we evaluate the inhibitory activities of prenylated flavonoids isolated from Sophora flavescens, a traditional herbal medicine, on rat lens AR (RLAR), human recombinant AR (HRAR) and AGE formation. Among the tested compounds, two prenylated chalcones — desmethylanhydroicaritin (1) and 8-lavandulylkaempferol (2) — along with five prenylated flavanones — kurarinol (8), kurarinone (9), (2S)-2′-methoxykurarinone (10), (2S)-3β,7,4′-trihydroxy-5-methoxy-8-(γ,γ-dimethylally)-flavanone (11), and kushenol E (13) were potent inhibitors of RLAR, with IC50 values of 0.95, 3.80, 2.13, 2.99, 3.77, 3.63 and 7.74 μM, respectively, compared with quercetin (IC50 7.73 μM). In the HRAR assay, most of the prenylated flavonoids tested showed marked inhibitory activity compared with quercetin (IC50 2.54 μM). In particular, all tested prenylated flavonols, such as desmethylanhydroicaritin (1, IC50 0.45 μM), 8-lavandulylkaempferol (2, IC50 0.79 μM) and kushenol C (3, IC50 0.85 μM), as well as a prenylated chalcone, kuraridin (5, IC50 0.27 μM), and a prenylated flavanone, (2S)-7,4′-dihydroxy-5-methoxy-8-(γ,γ-dimethylally)-flavanone (12, IC50 0.37 μM), showed significant inhibitory activities compared with the potent AR inhibitor epalrestat (IC50 0.28 μM). Interestingly, prenylated flavonoids 1 (IC50 104.3 μgmL−1), 2 (IC50 132.1 μgmL−1), 3 (IC50 84.6 μgmL−1) and 11 (IC50 261.0 μgmL−1), which harbour a 3-hydroxyl group, also possessed good inhibitory activity toward AGE formation compared with the positive control aminoguanidine (IC50 115.7 μgmL−1). Thus, S. flavescens and its prenylated flavonoids inhibit the processes that underlie diabetic complications and related diseases and may therefore have therapeutic benefit.

Screening of herbal medicines for the recovery of cisplatin-induced nephrotoxicity

The goal of this study was to quantitatively determine the recovery effects of herbal medicines (HM) on the cisplatin-induced nephrotoxicity. In the present study, the recovery effects of 239 HM on HEK 293 cells that had been damaged by cisplatin were evaluated by a mitochondrial activity MTS assay. After the first round of screening, candidate HM were selected based on a recovery rate of greater than 20%. The efficacy of the selected herbs was then determined by dose response kinetic analysis. Of the extracts evaluated, 7 HM (Paeonia suffruticosa (PS), Curcuma longa (CL), Centipeda minima (CM), Loranthus parasiticus (LP), Pulsatilla dahurica (PD), Sinapis alba (SA), and Scutellaria barbata (SB)) had a strong recovery effect on cisplatin-induced damage in HEK 293 cells. An LDH assay showed that LP, CM, SB, CL, SA, and PS had the best recovery effect, whereas a comet assay indicated that PS, SB, SA, PD, and CL had the best recovery effect. Taken together, these results suggest that SB, CL, PS, and SA are the best candidate HM for the recovery of cisplatin-induced nephrotoxicity. Therefore, additional studies should be conducted to determine if these HM possess novel therapeutic agents that can be used for the prevention or treatment of renal disorders.

Improvement of inflammatory and toxic stress biomarkers by silymarin in a murine model of type one diabetes mellitus

Type 1 diabetes mellitus (T1DM) is characterized by an impairment of the insulin-secreting beta cells with an immunologic base. Inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and free radicals are believed to play key roles in destruction of pancreatic β cells. The present study was designed to investigate the effect of Silybum marianum seed extract (silymarin), a combination of several flavonolignans with immunomodulatory, anti-oxidant, and anti-inflammatory potential on streptozotocin (STZ)-induced T1DM in mouse. Experimental T1DM was induced in male albino mice by IV injection of multiplelow- doses of STZ for 5 days. Seventy-two male mice in separate groups received various doses of silymarin (20, 40, and 80 mg/kg) concomitant or after induction of diabetes for 21 days. Blood glucose and pancreatic biomarkers of inflammation and toxic stress (IL-1β, TNF-α, myeloperoxidase, lipid peroxidation, protein oxidation, thiol molecules, and total antioxidant capacity) were determined. Silymarin treatment reduced levels of inflammatory cytokines such as TNF-α and IL-1β and oxidative stress mediators like myeloperoxidase activity, lipid peroxidation, carbonyl and thiol content of pancreatic tissue in an almost dose dependent manner. No marked difference between the prevention of T1DM and the reversion of this disease by silymarin was found. Use of silymarin seems to be helpful in T1DM when used as pretreatment or treatment. Benefit of silymarin in human T1DM remains to be elucidated by clinical trials.

Active constituents from Sophora japonica exhibiting cellular tyrosinase inhibition in human epidermal melanocytes

AIM OF THE STUDY

There is greater consumer awareness of plant-based skin-care products. Sophora japonica L. (Fabaceae) has been used traditionally as a hemostatic agent and also has skin-care and whitening benefits. The effect of the isolated active compounds of Sophora japonica L. (Fabaceae) that inhibits tyrosinase activity in human epidermal melanocytes (HEMn) was examined.

MATERIALS AND METHODS

We used the mushroom tyrosinase inhibitory assay to isolate active constituents from the extracts. The structures of these constituents were characterized by physical and spectroscopic analyses. Cellular tyrosinase kinetics were analyzed and showed by Lineweaver-Burk plot.

RESULTS

A new compound, N-feruloyl-N'-cis-feruloyl-putrescine (8), together with four flavonoids and three putrescine derivatives were obtained after assay-guided isolation of S. japonica. In HEMn, compound 8 was minimally cytotoxic (cell viability >90% at 100 microM) and the IC(50) value for suppression of cellular tyrosinase activity was estimated as 85.0 microM. Zymography analysis demonstrated the compound's concentration-dependent effects and the kinetic analysis indicated the compound's mixed-inhibitory action.

CONCLUSIONS

We concluded that the new compound 8 is the most potent component of S. japonica yet discovered. Its pigment inhibition activity may be exploitable cosmetically.

Re-evaluation of the antioxidant prenylated flavonoids from the roots of Sophora flavescens

The objective of this research was to re-evaluate the antioxidant effects of the prenylated flavonoids from Sophora flavescens via in vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), peroxynitrite (ONOO(-)), and total reactive oxygen species (ROS) assays. In addition, a further examination of kuraridinol, kurarinol, and kurarinone, also isolated from S. flavescens, was carried out by the inhibition of tert-butylhydroperoxide (t-BHP)-induced intracellular ROS generation and t-BHP-induced activation of nuclear factor-kappaB (NF-kappaB). Upon re-examination of the ethyl acetate (EtOAc) soluble fraction of S. flavescens, two major prenylated chalcones, including kuraridin and kuraridinol, along with a minor prenylated flavonol, kushenol C, were isolated as good DPPH scavengers. This was in contrast to the prenylated flavanones, sophoraflavanone G and kurarinone, which were isolated from the methylene chloride (CH(2)Cl(2)) fraction of the same source. Five flavanones consisting of kushenol E, leachianone G, kurarinol, sophoraflavanone G, and kurarinone exhibited significant antioxidant potentials in the ABTS, ONOO(-), and total ROS assays; however, the prenylated chalcones and prenylated flavonol showed more potent scavenging/inhibitory activities than the prenylated flavanones. Therefore, the prenylated chalcones and prenylated flavonol, rather than the prenylated flavanones, may make important contributions toward the marked antioxidant capacities of S. flavescens. Furthermore, kuraridinol, kurarinol, and kurarinone showed significant inhibitory activities against intracellular ROS levels as well as NF-kappaB activation by t-BHP. Overall, the results indicate that S. flavescens and its prenylated flavonoids may possess good anti-inflammatory activity, which is implicated in their significant antioxidant activity.