Antidiabetic and antioxidant effects of extracts from Potentilla discolor Bunge on diabetic rats induced by high fat diet and streptozotocin

Exploring the therapeutic potential of Potentilla fragarioides var. major (Rosaceae) extract in Alzheimer's disease using in vitro and in vivo models: A multi-faceted approach

Alzheimer's disease (AD) is the most common cause of dementia and is caused by various factors including amyloid-beta (Aβ) aggregation. We investigated the pharmacological effects of the ethanol extract of Potentilla fragarioides var. major (Rosaceae) (EEPF) on AD-related pathogenesis, which remain elusive. We observed the effects of EEPF on Aβ disaggregation and free-radical scavenging activities for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) using in vitro assays, evaluated the effects of EEPF on memory loss in two animal models, and examined the molecular regulatory mechanisms of EEPF using an antibody-protein microarray in EEPF-treated neuronal cell lines. EEPF inhibited Aβ aggregation in a concentration-dependent manner and enhanced free-radical scavenging activities for ABTS and DPPH. EEPF significantly inhibited memory impairment in the passive avoidance task, Y-maze test, and Morris water maze test in scopolamine-induced short-term memory loss mice and Aβ-injected AD-like mice. Nissl staining and immunohistochemistry for NeuN and Iba-1 confirmed the neuroprotective and anti-inflammatory effects of EEPF in both animal models. In H2O2-treated HT22 hippocampal cells, EEPF significantly prevented cell damage, enhanced CaMK2, and reduced ferric reductase. In lipopolysaccharide (LPS)-stimulated BV-2 microglia, EEPF significantly inhibited LPS-induced production of inflammatory factors, such as nitric oxide, prostaglandin E2, tumor necrosis factor-α, and interleukin-6, and decreased the phosphorylation of Smad3 and cyclin D3. High-performance liquid chromatography confirmed that EEPF has five major components: neochlorogenic acid, chlorogenic acid, polydatin, isochlorogenic acid A, and buddleoside, with amounts ranging across 1.91-9.41 mg/g. EEPF may be a promising drug for treatment of AD and AD-related brain disorders.

Mechanisms of Action of Potentilla discolor Bunge in Type 2 Diabetes Mellitus Based on Network Pharmacology and Experimental Verification in Drosophila

Purpose

Type 2 diabetes mellitus (T2DM) is associated with reduced insulin uptake and glucose metabolic capacity. Potentilla discolor Bunge (PDB) has been used to treat T2DM; however, the fundamental biological mechanisms remain unclear. This study aimed to understand the active ingredients, potential targets, and underlying mechanisms through which PDB treats T2DM.

Methods

Components and action targets were predicted using network pharmacology and molecular docking analyses. PDB extracts were prepared and validated through pharmacological intervention in a Cg>InRK1409A diabetes Drosophila model. Network pharmacology and molecular docking analyses were used to identify the key components and core targets of PDB in the treatment of T2DM, which were subsequently verified in animal experiments.

Results

Network pharmacology analysis revealed five effective compounds made up of 107 T2DM-related therapeutic targets and seven protein-protein interaction network core molecules. Molecular docking results showed that quercetin has a strong preference for interleukin-1 beta (IL1B), IL6, RAC-alpha serine/threonine-protein kinase 1 (AKT1), and cellular tumor antigen p53; kaempferol exhibited superior binding to tumor necrosis factor and AKT1; β-sitosterol demonstrated pronounced binding to Caspase-3 (CASP3). High-performance liquid chromatography data quantified quercetin, kaempferol, and β-sitosterol at proportions of 0.030%, 0.025%, and 0.076%, respectively. The animal experiments revealed that PDB had no effect on the development, viability, or fertility of Drosophila and it ameliorated glycolipid metabolism disorders in the diabetes Cg>InRK1409A fly. Furthermore, PDB improved the body size and weight of Drosophila, suggesting its potential to alleviate insulin resistance. Moreover, PDB improved Akt phosphorylation and suppressed CASP3 activity to improve insulin resistance in Drosophila with T2DM.

Conclusion

Our findings suggest that PDB ameliorates diabetes metabolism disorders in the fly model by enhancing Akt activity and suppressing CASP3 expression. This will facilitate the development of key drug targets and a potential therapeutic strategy for the clinical treatment of T2DM and related metabolic diseases.

CD62E- and ROS-Responsive ETS Improves Cartilage Repair by Inhibiting Endothelial Cell Activation through OPA1-Mediated Mitochondrial Homeostasis

Background: In the environment of cartilage injury, the activation of vascular endothelial cell (VEC), marked with excessive CD62E and reactive oxygen species (ROS), can affect the formation of hyaluronic cartilage. Therefore, we developed a CD62E- and ROS-responsive drug delivery system using E-selectin binding peptide, Thioketal, and silk fibroin (ETS) to achieve targeted delivery and controlled release of Clematis triterpenoid saponins (CS) against activated VEC, and thus promote cartilage regeneration. Methods: We prepared and characterized ETS/CS and verified their CD62E- and ROS-responsive properties in vitro. We investigated the effect and underlying mechanism of ETS/CS on inhibiting VEC activation and promoting chondrogenic differentiation of bone marrow stromal cells (BMSCs). We also analyzed the effect of ETS/CS on suppressing the activated VEC-macrophage inflammatory cascade in vitro. Additionally, we constructed a rat knee cartilage defect model and administered ETS/CS combined with BMSC-containing hydrogels. We detected the cartilage differentiation, the level of VEC activation and macrophage in the new tissue, and synovial tissue. Results: ETS/CS was able to interact with VEC and inhibit VEC activation through the carried CS. Coculture experiments verified ETS/CS promoted chondrogenic differentiation of BMSCs by inhibiting the activated VEC-induced inflammatory cascade of macrophages via OPA1-mediated mitochondrial homeostasis. In the rat knee cartilage defect model, ETS/CS reduced VEC activation, migration, angiogenesis in new tissues, inhibited macrophage infiltration and inflammation, promoted chondrogenic differentiation of BMSCs in the defective areas. Conclusions: CD62E- and ROS-responsive ETS/CS promoted cartilage repair by inhibiting VEC activation and macrophage inflammation and promoting BMSC chondrogenesis. Therefore, it is a promising therapeutic strategy to promote articular cartilage repair.

Effects of potentilla discolor bunge extracts on oxidative stress and glycolipid metabolism in animal models of diabetes: a systematic review and meta-analysis

Background/aim: Potentilla discolor Bunge (PDB) is an ancient herb of traditional Chinese medicine. Studies have suggested that extracts of PDB may ameliorate diabetes mellitus (DM). This study aimed to systematically assess the efficacy of PDB extracts on glycolipid metabolism and oxidative stress in animal models of diabetes and to provide evidence-based references for the use of PDB extracts. Methods: This study followed the PRISMA 2020 guidelines. Studies were searched from eight databases until January 2023. Statistical analysis was performed using StataSE 15.0 and RevMan 5.3. The standard mean difference (SMD) and 95% confidence intervals (CI) were computed using the random-effects model. SYRCLE's risk of bias tool was used to assess the risk of bias. Results: In total, 32 studies with 574 animals were included. The findings demonstrated that PDB extracts considerably lowered fasting blood glucose (SMD: -3.56, 95%CI: -4.40 to -2.72, p < 0.00001); insulin resistance (SMD: -3.19, 95% CI: -5.46 to -0.92, p = 0.006), total cholesterol (SMD: -2.18, 95%CI: -2.89 to -1.46, p < 0.00001), triglyceride (SMD: -1.48, 95% CI: -2.01 to -0.96, p < 0.00001), low-density lipoprotein cholesterol (SMD: -1.80, 95% CI: -2.58 to -1.02], p < 0.00001), malondialdehyde (SMD: -3.46, 95% CI: -4.64 to -2.29, p < 0.00001) and free fatty acid levels (SMD: -3.25, 95%CI: -5.33 to -1.16, p = 0.002), meanwhile, increased insulin sensitivity index (SMD: 2.51 95% CI: 1.10 to 3.92, p = 0.0005), body weight (SMD:1.20, 95% CI: 0.38 to 2.01, p = 0.004), and the levels of high-density lipoprotein cholesterol (SMD: 1.04, 95% CI: 0.40 to 1.69, p = 0.001), superoxide dismutase (SMD:2.63, 95% CI: 1.53 to 3.73, p < 0.00001), glutathione peroxidase (SMD:1.13, 95%CI: 0.42 to1.83, p = 0.002), and catalase (SMD:0.75, 95% CI: 0.11 to 1.40], p = 0.02). Conclusion: These findings suggest that PDB extracts can ameliorate DM by improving glycolipid metabolism and oxidative stress. PDB may be a promising medication for DM; however, due to significant heterogeneity between studies, these findings should be interpreted with caution. In addition, future well-designed trials should determine which components of the PDB play a major role in ameliorating DM and whether these benefits persist in humans. Systematic Review Registration: https://www.crd.york.ac.uk/prospero, CRD42023379391.

The water extract of Potentilla discolor Bunge (PDW) ameliorates high-sugar diet-induced type II diabetes model in Drosophila melanogaster via JAK/STAT signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla discolor Bunge (PD) is a member of the Rosaceae family. It has been traditionally used in folk medicine for the treatment of diabetes. Additionally, people in folk also eat fresh and tender PD stems as vegetables or brew them as tea.

AIM OF THE STUDY

The aim of this study was to explore the antidiabetic effects and underlying mechanisms of the water extract of Potentilla discolor (PDW) in a fruit fly model of high-sugar diet-induced type 2 diabetes.

MATERIALS AND METHODS

The antidiabetic efficacy of PDW was evaluated in a fruit fly model of diabetes induced by a high-sugar diet (HSD). Various physiological parameters were tested to evaluate the anti-diabetic effect of PDW. Gene expression levels related to insulin signaling pathways, glucose metabolism, lipid metabolism, and JAK/STAT signaling pathways were primarily analyzed using RT-qPCR to investigate the therapeutic mechanisms.

RESULTS

In this study, we found that the water extract of Potentilla discolor (PDW) can ameliorate type II diabetes phenotypes induced by the HSD in fruit flies. These phenotypes include growth rate, body size, hyperglycemia, glycogen metabolism, fat storage, and intestinal microflora homeostasis. PDW also improved the body size of s6k and rheb knockdown flies, suggesting its potential to activate the downstream insulin pathway and alleviate insulin resistance. Furthermore, we demonstrated that PDW reduced the expression of two target genes of the JAK/STAT signaling pathway, namely the insulin antagonist Impl2 and insulin receptor inhibitor Socs36E, which act as regulators inhibiting the activation of the insulin signaling pathway.

CONCLUSIONS

This study provides evidence for the anti-diabetic activity of PDW and suggests that its underlying mechanism may involve the improvement of insulin resistance by inhibiting the JAK/STAT signaling pathway.

Ternary Inclusion Complex of Sinapic Acid with Hydroxypropyl-β-cyclodextrin and Hydrophilic Polymer Prepared by Microwave Technology

Sinapic acid (SA) is a poorly water-soluble substance which could result in poor bioavailability. The aim of this study was to determine the “hydroxypropyl β-cyclodextrin (HPβCD)” solubilization of SA in the presence of the auxiliary substance hydroxypropyl methylcellulose (HPMC) and to evaluate the ternary inclusion complex prepared by microwave technology. Phase-solubility profiles showed that HPβCD exhibited the greatest solubilizing effect on SA in the presence of HPMC. The enhanced rate of SA dissolution was exhibited by a ternary complex. Outcomes of analyses such as “DSC, FTIR, NMR, and SEM” confirmed the embedding of SA into the cavity of the HPβCD and the formation of a ternary inclusion complex. The outcomes of antioxidant activity (ABTS and nitric oxide scavenging activity) demonstrated that SA ternary inclusion complex (TIC) presented strong antioxidant activity, which might be a result of the enhanced solubility of SA in the TIC prepared by microwave technology. Hence, SA-TIC formulation could be a better dosage form which may protect the body from free radical damage and oxidative stress. Microwave technology greatly boosted the interaction of SA with HPβCD and HPMC, and such findings are expected to contribute to raising the solubility of SA, thereby improving the bioavailability of SA.

Cytotoxic Effects of Some Nepeta Species against Breast Cancer Cell Lines and Their Associated Phytochemical Properties

Nepeta is one of the largest genera of the Lamiaceae family. Nepeta species are commonly employed in traditional medicine for a variety of ailments, as well as food additives. In addition, they also come to the fore with their rich phytochemical content. In the present study, the quantitative phytochemical content of methanolic extracts and infusions prepared from the aerial parts of 14 Nepeta taxa collected from Turkey and their cytotoxic effects on two breast cancer cell lines, MCF-7 and MDA-MB-231, were investigated by using the MTT (3-(4,5-dimethylthiazol-2-yl))-2,5-diphenyltetrazolium-bromide) test. According to HPLC-PDA analysis, N. racemosa methanolic extract had the highest ursolic acid content with 165.9 mg/g extract. Total sterol, total iridoid, and total triterpenoid content were determined to be greatest in the methanolic extracts of N. meyeri, N. trichocalyx and N. phyllochlamys. The MTT experiment demonstrated that certain Nepeta species suppressed the growth of MCF-7 and MDA-MB-231 cells in a dose-dependent manner. Statistical analysis revealed a strong correlation between the cytotoxic effects of the extracts and their triterpene content. In conclusion, the data obtained from this study are important in terms of forming a basis for advanced anticancer activity studies on breast cancer with Nepeta sp.

Therapeutic potential of traditional Chinese medicine for the treatment of NAFLD: a promising drug Potentilla discolor Bunge

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of hepatic lipids and metabolic stress-induced liver injury. There are currently no approved effective pharmacological treatments for NAFLD. Traditional Chinese medicine (TCM) has been used for centuries to treat patients with chronic liver diseases without clear disease types and mechanisms. More recently, TCM has been shown to have unique advantages in the treatment of NAFLD. We performed a systematic review of the medical literature published over the last two decades and found that many TCM formulas have been reported to be beneficial for the treatment of metabolic dysfunctions, including Potentilla discolor Bunge (PDB). PDB has a variety of active compounds, including flavonoids, terpenoids, organic acids, steroids and tannins. Many compounds have been shown to exhibit a series of beneficial effects for the treatment of NAFLD, including anti-oxidative and anti-inflammatory functions, improvement of lipid metabolism and reversal of insulin resistance. In this review, we summarize potential therapeutic effects of TCM formulas for the treatment of NAFLD, focusing on the medicinal properties of natural active compounds from PDB and their underlying mechanisms. We point out that PDB can be classified as a novel candidate for the treatment and prevention of NAFLD.

Ameliorative Effect of Ocimum forskolei Benth on Diabetic, Apoptotic, and Adipogenic Biomarkers of Diabetic Rats and 3T3-L1 Fibroblasts Assisted by In Silico Approach

Diabetes mellitus (DM) is a complicated condition that is accompanied by a plethora of metabolic symptoms, including disturbed serum glucose and lipid profiles. Several herbs are reputed as traditional medicine to improve DM. The current study was designed to explore the chemical composition and possible ameliorative effects of Ocimum forskolei on blood glucose and lipid profile in high-fat diet/streptozotocin-induced diabetic rats and in 3T3-L1 cell lines as a first report of its bioactivity. Histopathological study of pancreatic and adipose tissues was performed in control and treatment groups, along with quantification of glucose and lipid profiles and the assessment of NF-κB, cleaved caspase-3, BAX, and BCL2 markers in rat pancreatic tissue. Glucose uptake, adipogenic markers, DGAT1, CEBP/α, and PPARγ levels were evaluated in the 3T3-L1 cell line. Hesperidin was isolated from total methanol extract (TME). TME and hesperidin significantly controlled the glucose and lipid profile in DM rats. Glibenclamide was used as a positive control. Histopathological assessment showed that TME and hesperidin averted necrosis and infiltration in pancreatic tissues, and led to a substantial improvement in the cellular structure of adipose tissue. TME and hesperidin distinctly diminished the mRNA and protein expression of NF-κB, cleaved caspase-3, and BAX, and increased BCL2 expression (reflecting its protective and antiapoptotic actions). Interestingly, TME and hesperidin reduced glucose uptake and oxidative lipid accumulation in the 3T3-L1 cell line. TME and hesperidin reduced DGAT1, CEBP/α, and PPARγ mRNA and protein expression in 3T3-L1 cells. Moreover, docking studies supported the results via deep interaction of hesperidin with the tested biomarkers. Taken together, the current study demonstrates Ocimum forskolei and hesperidin as possible candidates for treating diabetes mellitus.

Antidiabetic with antilipidemic and antioxidant effects of flindersine by enhanced glucose uptake through GLUT4 translocation and PPARγ agonism in type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants have been used by the people of developing countries to treat various diseases. WHO also recommends the use of medicines from plants source. In that, diabetes also one of the diseases that have been treated traditionally by several people all over the world. In India, Toddalia asiatica (L.) Lam. (Rutaceae) is also a medicinal plant used traditionally for the treatment of diabetes in Ayurveda. Moreover, T. asiatica is also used in a polyherbal formulation to treat diabetes.

AIM OF THE STUDY

This study examined the antidiabetic with antilipidemic and antioxidant effects of flindersine isolated from T. asiatica leaves.

MATERIALS AND METHODS

Diabetes was induced in Wistar rats by feeding a high-fat diet (HFD) for 15 days and injecting a single dose of 40 mg/kg b. wt. of Streptozotocin (STZ). Five days post-injection, the grouped diabetic rats were treated with 20 and 40 mg/kg of flindersine.

RESULTS

Flindersine resulted in a clear decline of blood glucose levels during 28 days of treatment in two different doses. Flindersine also significantly (P ≤ 0.05; P ≤ 0.005) reduced the body weight gain, plasma insulin concentration, urea, creatinine, total cholesterol (TC), triglycerides (TG) and free fatty acids (FFA) levels and significantly increased (P ≤ 0.05; P ≤ 0.005) the total protein level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities compared to the standard drug, pioglitazone. Additionally, flindersine restored the glucose transporter protein 4 (GLUT4), adenosine monophosphate protein kinase (AMPK) and peroxisome proliferator-activated receptor γ (PPARγ) expressions in adipose tissues and skeletal muscles.

CONCLUSION

It has been found that flindersine has potent antilipidemic and antidiabetic activities by improving insulin sensitivity by enhancing the phosphorylation of AMPK, GLUT4 translocation, and PPARγ agonism on adipose tissue and skeletal muscles of diabetic rats.

Cartilage Repair Using Clematis Triterpenoid Saponin Delivery Microcarrier, Cultured in a Microgravity Bioreactor Prior to Application in Rabbit Model

Cartilage tissue engineering provides a promising method for the repair of articular cartilage defects, requiring appropriate biological scaffolds and necessary growth factors to enhance the efficiency of cartilage regeneration. Here, a silk fibroin (SF) microcarrier and a clematis triterpenoid saponin delivery SF (CTS-SF) microcarrier were prepared by the high-voltage electrostatic differentiation and lyophilization method, and chondrocytes were carried under the simulated microgravity condition by a rotating cell culture system. SF and CTS-SF microspheres were relatively uniform in size and had a porous structure with good swelling and cytocompatibility. Further, CTS-SF microcarriers could sustainably release CTSs in the monitored 10 days. Compared with the monolayer culture, chondrocytes under the microgravity condition maintained a better chondrogenic phenotype and showed better proliferation ability after culture on microcarriers. Moreover, the sustained release of CTS from CTS-SF microcarriers upregulated transforming growth factor-β, Smad2, and Smad3 signals, contributing to promote chondrogenesis. Hence, the biophysical effects of microgravity and bioactivities of CTS-ST were used for chondrocyte expansion and phenotype maintenance in vitro. With prolonged expansion, SF- and CTS-SF-based microcarrier-cell composites were directly implanted in vivo to repair rabbit articular defects. Gross evaluations, histopathological examinations, and biochemical analysis indicated that SF- and CTS-SF-based composites exhibited cartilage-like tissue repair compared with the nontreated group. Further, CTS-SF-based composites displayed superior hyaline cartilage-like repair that integrated with the surrounding cartilage better and higher cartilage extracellular matrix content. In conclusion, these results provide an alternative preparation method for drug-delivered SF microcarrier and a culture method for maintaining the chondrogenic phenotype of seed cells based on the microgravity environment. CTS showed its bioactive function, and the application of CTS-SF microcarriers can help repair and regenerate cartilage defects.

Potentilla discolor ameliorates LPS-induced inflammatory responses through suppressing NF-κB and AP-1 pathways

Potentilla discolor Bunge (PD) is a traditional Chinese medicine which has been widely used for the treatment of various inflammatory diseases (e.g., diarrhea, fever and furuncle). However, few studies focused on its effect on classical inflammation. This study aimed to investigate the anti-inflammatory effect and potential mechanism of the ethanol extract of the whole herbs of PD (EPD) in lipopolysaccharide (LPS)-induced inflammatory models. The obtained results showed that EPD decreased supernatant NO, tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) in LPS-activated RAW264.7 cells and mouse peritoneal macrophages. Moreover, its effect on NO was attributed to the suppression of iNOS expression rather than its activity. At the transcriptional level, EPD suppressed iNOS, TNF-α and MCP-1 mRNA expressions in LPS-stimulated RAW264.7 cells. Further study showed that EPD didn't affect the phosphorylation and degradation of IκBα, but yet impeded the nuclear translocation of p65 to inhibit NF-κB activation. Meanwhile, it also prevented JNK, ERK1/2 and p38 phosphorylation to dampen the activation of AP-1. In endotoxemia mouse model, EPD not only decreased interleukin-6, TNF-α and MCP-1 levels in serum, but also potently ameliorated diarrhea. These findings provide the theoretical basis for PD to treat inflammatory diseases, especially intestinal inflammation.

Recent phytochemical and pharmacological advances in the genus Potentilla L. sensu lato - An update covering the period from 2009 to 2020

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla plants are still common herbal medicines used in folk medicine. This review provides an update of research undertaken on Potentilla from 2009 until 2020.

AIM OF THE STUDY

This comprehensive review considers biological updates, recent advances in phytochemical and pharmacological research, and toxicological reports on Potentilla sensu lato based on available data since 2009.

METHODS

A literature search was conducted using available databases including ScienceDirect, PubMed, Scopus, Web of Science, China National Knowledge Infrastructure and Google Scholar.

RESULTS

Until now, more than 210 new and known compounds, including flavonoids, tannins, triterpenes and phenolic compounds, have been confirmed and elucidated for numerous Potentilla species, i.e., in the underground and aerial parts of this genus. Modern pharmacology studies have revealed that those structures are responsible for a broad spectrum of pharmacological activities, such as anti-neoplastic, antihyperglycemic, anti-inflammatory, antioxidant, hepatoprotective, neuroprotective, antibacterial and anti-yeast effects.

CONCLUSIONS

However, in vitro studies must be re-considered due to the discovery of urolithins and their origins, including microbiota, which can lead to different results when applying Potentilla species and their extracts to in vivo conditions. Thus, future research should focus more on in vivo and particularly clinical studies to confirm the validity and safety of traditional uses. Particularly, the use of Potentilla alba extracts in the treatment of thyroid gland disorders should be further explored to confirm the underlying mechanism of their action, efficacy and safety. In addition, more clinical studies should focus on Potentilla erecta rhizome extracts for application as herbal remedies against dysentery, diarrhoea and inflammation of the skin.

Exploring the protective effect of Gynura procumbens against type 2 diabetes mellitus by network pharmacology and validation in C57BL/KsJ db/db mice

Flowchart of the experimental procedures.

Influence of Accelerated Solvent Extraction Conditions on the LC-ESI-MS/MS Polyphenolic Profile, Triterpenoid Content, and Antioxidant and Anti-lipoxygenase Activity of Rhododendron luteum Sweet Leaves

Evaluation of native plant resources and their efficient use is one of the current trends in phytochemistry. The main aim of the present study was to investigate the biological activities of different Rhododendron luteum Sweet leaf extracts obtained with the use of accelerated solvent extraction using different solvents and extraction temperatures. All extracts were subjected to bioactivity assays, which revealed considerable anti-lipoxygenase (23.07-90.13% lipoxygenase inhibition) and antiradical potential. All samples exhibited high 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) (234.18-621.90 mg Trolox equivalents (TE)/g) and 2,2'-azino-bis-3(ethylbenzthiazoline-6-sulphonic acid) (ABTS^•+) (88.79-349.41 mg TE/g) scavenging activity, high antioxidant potential in the Oxygen Radical Absorbance Capacity (ORAC) assay (495.77-1011.59 mg TE/g), and moderate ion chelating (Fe2+) capacity. The chemical profile of each sample was determined using liquid chromatography/electrospray ionization triple quadrupole mass spectrometry (LC-ESI-MS/MS) and spectrophotometric procedures. Twenty-three compounds representing seven polyphenol subclasses were detected and quantified, including some phenolic acids and flavonoids that had not been previously reported for this plant material. It was shown that 5-O-caffeoylquinic acid, protocatechuic acid, catechin, quercetin and its glycosides (hyperoside, isoquercetin, quercitrin), and pentacyclic triterpenes were the dominant secondary metabolites in R. luteum leaves. The antioxidant activity was found to be strongly related to different polyphenol groups and total triterpene content, while the anti-lipoxygenase potential was highly dependent on catechin.

The protective effect of Ferula elaeochytris on age-related erectile dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE

Ferula elaeochytris Korovin (FE) is a perennial medicinal plant of Apiaceae family. Ferula elaeochytris Korovin, known as 'Çakşır' in Anatolia, is widely used as an aphrodisiac as well as antioxidant, anti-inflammatory, and anti-diabetic.

AIM OF THE STUDY

Erectile dysfunction (ED) is a serious public health problem that has a high prevalence and negatively affects the quality of life in elderly men. In the treatment and prophylaxis of many diseases, because of widely increasing use of plant extracts as therapeutic agents, preclinical studies related to plant extracts are becoming more important by the day. In this study, we aimed to investigate the protective effect of Ferula elaeochytris Korovin (FE) root extract on age-related ED.

MATERIALS AND METHODS

Seventy-two male Wistar albino rats were equally divided into four groups: 4-month aged rats (Y), 24-month aged rats (AG), and FE-administered (20 and 40 mg/kg/day; oral gavage; over 8 weeks) 24-month aged rats (AG + FE). The measurements included: changes in smooth muscle cells and collagen fibrils, tumor necrosis factor alpha (TNF-α), penile neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS) expression, serum testosterone concentrations (ST), neurogenic- and endothelial-dependent relaxations of the corpus cavernosum (CC), intracavernosal pressure/mean arterial pressure (ICP/MAP), area under the curve (total ICP), total antioxidant status (TAS), and total oxidant status (TOS) on corpus cavernosal tissue.

RESULTS

These results have an important role in the development of ED. ICP/MAP, total ICP, eNOS/nNOS expressions and ST levels increased in AG+40 mg FE group compared to the AG group, whereas TNF-α levels decreased and oxidative and antioxidant parameters balanced.

CONCLUSIONS

Our findings show that FE may have a useful effect on decelerating the development of age-related ED.

Effect of diet supplemented with P. ostreatus and L. subnudus on memory index and key enzymes linked with Alzheimer's disease in streptozotocin-induced diabetes rats

Mushrooms have been reported in folklore for the management of Alzheimer's disease (AD) and diabetes with limited scientific prove. This study aims to unravel the effect of diets supplemented with P. ostreatus and L. subnudus on diabetic encephalopathy (DE) in streptozotocin (STZ)-induced diabetic rats. The memory index, brain cholinesterase, arginase activity, and markers for oxidative stress were evaluated. STZ-induced diabetic rats exhibited memory deficits, elevated brain cholinesterase, arginase activity in comparison with nondiabetic rats. Also, markers for oxidative stress were altered in the brain of diabetic rat when compare with nondiabetic rats. Meanwhile, diabetic rats fed with supplemented-diets exhibited better memory index, reduced cholinesterase, arginase activity in comparison with untreated diabetic rats placed on a basal diet. Also, supplemented-diets restored altered markers of oxidative stress. Our findings indicated that P. ostreatus and L. subnudus-supplemented diets could prevent DE. Nevertheless, diets supplemented with L. subnudus had better nutraceutical potential than P. ostreatus. PRACTICAL APPLICATIONS: Diabetes mellitus is one of the most chronic diseases in the world. Also, it is a risk factor for several complications such as cognitive dysfunction, hypertension, and other health issues. Mushrooms are commonly consumed as food or as food supplements in many countries of the world and are a rich source of protein, chitin, and vitamins. Diet supplemented with P. ostreatus and L. subnudus were able to restore memory deficit in diabetic rats, proven to be a dietary intervention in the management of memory deficit linked with diabetes mellitus. Findings from this study show that consumption of P. ostreatus and L. subnudus as food or supplement could help in a diabetic state.

Antidiabetes constituents, cycloartenol and 24-methylenecycloartanol, from Ficus krishnae

Ficus krishnae stem bark and leaves are used for diabetes treatment in traditional medicines. Stem bark of F. krishnae was sequentially extracted with hexane, methanol and water, and these extracts were tested for their antihyperglyceamic activity by oral glucose tolerance test (OGTT) in overnight fasted glucose loaded normal rats. Hexane extract showed significant glucose lowering activity in OGTT, and the triterpene alcohols (cycloartenol+24-methylenecycloartanol) (CA+24-MCA) were isolated together from it by activity guided isolation and characterized by NMR and mass spectroscopy. The ratio of the chemical constituents CA and 24-MCA in (CA+24-MCA) was determined as 2.27:1.00 by chemical derivatization and gas chromatographic quantification. (CA+24-MCA) in high fat diet-streptozotocin induced type II diabetic rats showed significant antidiabetes activity at 1 mg/kg and ameliorated derailed blood glucose and other serum biochemical parameters. Cytoprotective activity of (CA+24-MCA) from glucose toxicity was evaluated in cultured RIN-5F cells by MTT assay and fluorescent microscopy. (CA+24-MCA) in in vitro studies showed enhanced cell viability in RIN-5F cells and significant protection of beta cells from glucose toxicity. Both in in vivo and in vitro studies (CA+24-MCA) showed enhancement in insulin release from the beta cells. In short term toxicity studies in mice (CA+24-MCA) did not show any conspicuous toxic symptoms. The combination of the phytosterols (CA+24-MCA) obtained through activity guided isolation of the stem bark of F. krishnae showed significant activity, and therefore is a promising candidate for new generation antidiabetes drug development.

Antidiabetic Potency, Antioxidant Effects, and Mode of Actions of Citrus reticulata Fruit Peel Hydroethanolic Extract, Hesperidin, and Quercetin in Nicotinamide/Streptozotocin-Induced Wistar Diabetic Rats

This study is aimed at assessing the antihyperglycemic, antihyperlipidemic, and antioxidant effects of Citrus reticulata (C. reticulata) fruit peel hydroethanolic extract and two flavonoids, hesperidin and quercetin, in nicotinamide (NA)/streptozotocin- (STZ-) induced type 2 diabetic rats. In addition, GC-MS and HPLC-MS analyses of the extract were performed and the results indicated the presence of multiple flavonoids including hesperidin, quercetin, naringin, and polymethoxylated flavones (nobiletin and tangeretin). To achieve the aim of the study, diabetic rats with NA/STZ-induced T2DM were orally treated with C. reticulata fruit peel hydroethanolic extract, hesperidin, and quercetin at a dose of 100 mg/kg b.w./day for four weeks. The treatments with C. reticulata fruit peel extract, hesperidin, and quercetin significantly ameliorated the impaired oral glucose tolerance; the elevated serum fructosamine level; the diminished serum insulin and C-peptide levels; the altered HOMA-IR, HOMA-IS, and HOMA-β cell function; the decreased liver glycogen content; the increased liver glucose-6-phosphatase and glycogen phosphorylase activities; the deleteriously affected serum lipid profile; the elevated serum AST and ALT activities; and the raised serum creatinine and urea levels in the diabetic rats. The treatments also produced remarkable improvement in the antioxidant defense system manifested by a decrease in the elevated liver lipid peroxidation and an increase in the lowered glutathione content and GPx, GST, and SOD activities. Furthermore, the three treatments enhanced the mRNA expression of GLUT-4 and the insulin receptor β-subunit, but only quercetin produced a significant increase in the expression of adiponectin in adipose tissue of diabetic rats. In conclusion, C. reticulata fruit peel hydroethanolic extract, hesperidin, and quercetin have potent antidiabetic effects which may be mediated through their insulinotropic effects and insulin-sensitizing actions. In addition, the alleviation of the antioxidant defense system by the extract, hesperidin, and naringin may have an important action to enhance the antidiabetic actions and to improve liver and kidney functions in NA/STZ-induced diabetic rats.

Network pharmacology-based analysis on bioactive anti-diabetic compounds in Potentilla discolor bunge

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla discolor Bunge (PDB) is a commonly used herbal for alleviating diabetes mellitus and its complications. Although accumulating evidences show the anti-diabetic efficacy of PDB, the vital anti-diabetic compounds and their functional targets remain elusive.

AIM OF THE STUDY

To investigate the anti-diabetic ingredients and their functional mechanisms in PDB, gas chromatograph-mass spectrometry analysis was performed on PDB extract and 21 were testified as anti-diabetic compounds.

MATERIALS AND METHODS

Subsequently their potential protein targets were also identified. The bioinformatics analysis was implemented by network pharmacology-based approaches. STRING analysis was performed to reveal enrichment of these target proteins, protein-protein interactions, pathways and related diseases. Cytoscape was used to determine the potential protein targets for these components in PDB, indicating that 21 anti-diabetic compounds in PDB regulate 33 diabetes-related proteins in 28 signal pathways and involve 21 kinds of diabetes-related diseases. Among the 21 potential anti-diabetic components predicted by network analysis, tricetin was firstly experimentally validated at the molecular and cellular level.

RESULTS

Results indicated that this active small-molecule compound may have beneficial effects on improving glucose uptake.

CONCLUSIONS

We envisage that network analysis will be useful in screening bioactive compounds of medicinal plants.

Antidiabetic Activity and Potential Mechanism of Amentoflavone in Diabetic Mice

Aim: To investigate the anti-diabetic activity of amentoflavone (AME) in diabetic mice, and to explore the potential mechanisms. Methods: Diabetic mice induced by high fat diet and streptozotocin were administered with amentoflavone for 8 weeks. Biochemical indexes were tested to evaluate its anti-diabetic effect. Hepatic steatosis, the histopathology change of the pancreas was evaluated. The activity of glucose metabolic enzymes, the expression of Akt and pAkt, and the glucose transporter type 4 (GLUT4) immunoreactivity were detected. Results: AME decreased the level of glucose, total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and glucagon, and increased the levels of high density lipoprotein cholesterol (HDL-C) and insulin. Additionally, AME increased the activity of glucokinase (GCK), phosphofructokinase-1 (PFK-1), and pyruvate kinase (PK), and inhibited the activity of glycogen synthase kinase-3 (GSK-3), phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6-phosphatase (G-6-Pase). Mechanistically, AME increased superoxide dismutase (SOD), decreased malondialdehyde (MDA), activation of several key signaling molecules including pAkt (Ser473), and increased the translocation to the sedimenting membranes of GLUT4 in skeletal muscle tissue. Conclusions: AME exerted anti-diabetic effects by regulating glucose and lipid metabolism, perhaps via anti-oxidant effects and activating the PI3K/Akt pathway. Our study provided novel insight into the role and underlying mechanisms of AME in diabetes.

Beneficial Effects of Potentilla discolor Bunge Water Extract on Inflammatory Cytokines Release and Gut Microbiota in High-Fat Diet and Streptozotocin-Induced Type 2 Diabetic Mice

Potentilla discolor Bunge (PDB), a perennial herb, has been used as a traditional Chinese medicine in the therapy of many diseases. The aim of the current study was to investigate the effect of PDB water extract on systemic inflammation and gut microbiota in type 2 diabetic (T2D) mice induced by high-fat diet (HFD) and streptozotocin (STZ) injection. C57BL/6J mice were randomly divided into a normal diet (ND) group, T2D group, and PDB group (diabetic mice treated with PDB water extract at a dose of 400 mg/kg body weight). Results showed that PDB significantly decreased the levels of lipopolysaccharide (LPS) and pro-inflammatory cytokines in serum. Further investigation showed that PDB significantly reduced the ratio of Firmicutes/Bacteroidetes and the relative abundance of Proteobacteria in fecal samples of diabetic mice. In addition, PDB notably alleviated intestinal inflammation as evidenced by decreased expression of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor-κB (NF-κB), and inflammatory cytokines. PDB also reversed the decreased expression of intestinal mucosal tight junction proteins including Claudin3, ZO-1, and Occludin. Meanwhile, the levels of fecal acetic acid and butyric acid and their specific receptors including G-protein-coupled receptor (GPR) 41 and 43 expression in the colon were also increased after PDB treatment. Our results indicated that PDB might serve as a potential functional ingredient against diabetes and related inflammation.

Antidiabetic, Antihyperlipidemic, Antioxidant, Anti-inflammatory Activities of Ethanolic Seed Extract of Annona reticulata L. in Streptozotocin Induced Diabetic Rats

Annona reticulata L. (Bullock's heart) is a pantropic tree commonly known as custard apple, which is used therapeutically for a variety of maladies. The present research was carried out to evaluate the possible protective effects of Annona reticulata L. (A. reticulata) ethanolic seed extract on an experimentally induced type 2 diabetes rat model. Male Albino Wistar rats were randomly divided into five groups with six animals in each group viz., control rats in group I, diabetic rats in group II, diabetic rats with 50 and 100 mg/kg/bw of ethanolic seed extract of A. reticulata in groups III and IV, respectively, and diabetic rats with metformin in group V. Treatment was given for 42 consecutive days through oral route by oro-gastric gavage. Administration of A. reticulata seed extract to diabetes rats significantly restored the alterations in the levels of body weight, food and water intake, fasting blood glucose (FBG), insulin levels, insulin sensitivity, HbA1c, HOMA-IR, islet area and insulin positive cells. Furthermore, A. reticulata significantly decreased the levels of triglycerides, cholesterol, LDL, and significantly increased the HDL in diabetic rats. A. reticulata effectively ameliorated the enzymatic (ALT, AST, ALP, GGT) and modification of histopathological changes in diabetic rats. The serum levels of the BUN, creatinine levels, uric acid, urine volume, and urinary protein were significantly declined with a significant elevation in CCr in diabetic rats treated with A. reticulata. MDA and NO levels were significantly reduced with an enhancement in SOD, CAT, and GPx antioxidant enzyme activities in the kidney, liver, and pancreas of diabetic rats treated with A. reticulata. Diabetic rats treated with A. reticulata have shown up-regulation in mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1), Heme oxygenase-1 (HO-1) and protein expression level of Nrf2 with diminution in Keap1 mRNA expression level in pancreas, kidney, and liver. From the outcome of the current results, it can be inferred that seed extract of A. reticulata exhibits a protective effect in diabetic rats through its anti-diabetic, anti-hyperlipidemic, antioxidant and anti-inflammatory effects and could be considered as a promising treatment therapy in the treatment of diabetes mellitus.

Characterization of a new heteropolysaccharide from green guava and its application as an α-glucosidase inhibitor for the treatment of type II diabetes

Psidium guajava fruit is a subtropical fruit, functional food and traditional medicine for the adjuvant treatment of diabetes mellitus in China. To investigate the active components responsible for its health benefits, a novel heteropolysaccharide GP70-3 was purified by water extraction, ethanol precipitation and column chromatography. Structural characterization of GP70-3 was elucidated for the first time by monosaccharide composition assay, Fourier transform-infrared spectroscopy (FT-IR), methylation analysis, gas chromatography coupled with mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). The data revealed that GP70-3 contained a backbone of 1→3,6)-linked β-d-Galp, 1→5)-linked α-l-Araf, 1→6)-linked β-d-Galp and 1→3)-linked β-d-Galp, branched with 1→2,3,5)-linked α-l-Araf, 1→3)-linked α-l-Araf, 1→3)-linked α-l-Rhap, 1→3)-linked β-d-GlcpA, 1→3)-linked β-d-GalpA and terminated with →1)-linked β-d-Galp. Advanced structure studies showed GP70-3 consisted of irregular flakes with rounded-spherical pores. Moreover, GP70-3 exhibited outstanding α-glucosidase inhibitory activity in vitro, with an IC50 value of 2.539 ± 0.144 μM, which was 1867 times higher than that of the positive control acarbose (IC50 value of 4.744 ± 0.026 mM). Therefore, consumption of guava polysaccharides may be beneficial as an α-glucosidase inhibitor for reducing the postprandial blood glucose level and treating type II diabetes.

Stability of a type 2 diabetes rat model induced by high-fat diet feeding with low-dose streptozotocin injection

OBJECTIVE

The present study aims at determining the stability of a popular type 2 diabetes rat model induced by a high-fat diet combined with a low-dose streptozotocin injection.

METHODS

Wistar rats were fed with a high-fat diet for 8 weeks followed by a one-time injection of 25 or 35 mg/kg streptozotocin to induce type 2 diabetes. Then the diabetic rats were fed with regular diet/high-fat diet for 4 weeks. Changes in biochemical parameters were monitored during the 4 weeks.

RESULTS

All the rats developed more severe dyslipidemia and hepatic dysfunction after streptozotocin injection. The features of 35 mg/kg streptozotocin rats more resembled type 1 diabetes with decreased body weight and blood insulin. Rats with 25 mg/kg streptozotocin followed by normal diet feeding showed normalized blood glucose level and pancreatic structure, indicating that normal diet might help recovery from certain symptoms of type 2 diabetes. In comparison, diabetic rats fed with high-fat diet presented decreased but relatively stable blood glucose level, and this was significantly higher than that of the control group (P<0.05).

CONCLUSIONS

This model easily recovers with normal diet feeding. A high-fat diet is suggested as the background diet in future pharmacological studies using this model.

Apoptosis induced by methanol extract of Potentilla discolor in human mucoepidermoid carcinoma cells through STAT3/PUMA signaling axis

Potentilla discolor has been used in traditional Chinese medicine for the treatment of hyperglycemia. However, the potential role of Potentilla discolor against cancer and its mode of action remain to be fully elucidated. The present study explored the apoptotic effect of methanol extract of Potentilla discolor (MEPD) in human mucoepidermoid carcinoma (MEC) cell lines of salivary glands. MEPD markedly suppressed the growth and induced apoptotic cell death in MC3 and YD15 cells. MEPD treatment significantly upregulated the expression of PUMA and reduced STAT3 phosphorylation. Overexpression of STAT3 partially recovered the growth of MEC cells inhibited by MEPD. In addition, dephosphorylation of STAT3 by cryptotanshinone (a potent STAT3 inhibitor) was sufficient to inhibit the growth of MEC cells and induce apoptosis via affecting PUMA protein. These results suggest that MEPD has a potential anticancer property via the STAT3/PUMA signaling axis in human MEC cells of salivary gland.

Protective effects of Ficus carica leaves on glucose and lipids levels, carbohydrate metabolism enzymes and β-cells in type 2 diabetic rats

CONTEXT

The decoctions of Ficus carica Linn. (Moraceae) leaves are used in the folklore treatment of diabetes.

OBJECTIVE

To evaluate the effect of F. carica on glucose and lipids levels, carbohydrate metabolism enzymes and β-cells protective effects in type 2 diabetes.

MATERIAL AND METHODS

Diabetes was induced in 15 days high-fat diet (HFD)-fed Wistar rats by intraperitoneal injection of streptozotocin (STZ) (40 mg/kg). The ethyl acetate extract (250 and 500 mg/kg) of F. carica leaves was administered for 28 days. Oral glucose tolerance (OGTT) and intraperitoneal insulin tolerance tests (ITT) were evaluated on 15th and 25th days, respectively.

RESULTS

The ethyl acetate extract (250 and 500 mg/kg) of n F. carica leaves showed significant effect (p < 0.005) in the levels of blood glucose, total cholesterol (TC), triglycerides (TG), body weight and hepatic glycogen. In OGTT, F. carica (250 and 500 mg/kg) significantly (p < 0.005) detained the increase in blood glucose levels at 60 and 120 min and in ITT, F. carica enhanced the glucose utilization significantly (p < 0.005) over 30 and 60 min compared to diabetic control. Further, the altered activities of key carbohydrate metabolizing enzymes such as glucose-6-phosphatase, fructose-1,6-bisphosphatase and hexokinase in the liver tissue of diabetic rats were significantly (p < 0.005) reverted to near normal levels upon treatment with F. carica. Immumohistochemical studies of islets substantiated the cytoprotective effect on pancreatic β-cells.

DISCUSSION AND CONCLUSIONS

F. carica leaves exerted significant effect on carbohydrate metabolism enzymes with promising hypoglycemic and hypolipidemic activities in type 2 diabetic rats.

In vivo pharmacokinetic interaction by ethanolic extract of Gymnema sylvestre with CYP2C9 (Tolbutamide), CYP3A4 (Amlodipine) and CYP1A2 (Phenacetin) in rats

Gymnema sylvestre (GS) is a medicinal herb used for diabetes mellitus (DM). Herbs are gaining popularity as medicines in DM for its safety purpose. The aim of the present study was to evaluate in vivo pharmacokinetic (PK) interaction between allopathic drugs tolbutamide (TOLBU), amlodipine (AMLO), and phenacetin (PHENA) at low (L) and high (H) doses with ethanolic extract (EL) from GS. EL was extracted and subjected to TLC, total triterpenoid content (19.76 ± 0.02 W/W) and sterol content (0.1837 ± 0.0046 W/W) estimation followed by identification of phytoconstituents using HRLC-MS and GC-MS. PK interaction study with CYP2C9, CYP3A4 and CYP1A2 enzymes were assessed using TOLBU, AMLO and PHENA respectively to index cytochrome (CYP) mediated interaction in rats after concomitant administration of EL extract (400 mg/kg) from GS for 7 days. The rats were divided into four groups for each PK study where, group I and II were positive control for low and high dose of test drugs (CYP substrates) while group II and IV were orally administered EL. The PK study result of PHENA indicated that area under the plasma concentration-time curve (AUC_0-24) was significantly (P < 0.0001) increased by 1.4 (L) and 1.3-fold (H), plasma concentration (C_max) was significantly (P < 0.001) increased by 1.6 (L) and 1.4-fold (H). Whereas for TOLBU; clearance rate (CL) was significantly (P < 0.0001) decreased by 2.4 (L) and 2.3-fold (H), C_max, was significantly (P < 0.001) decreased by 26.5% (L) and 50.4% (H) and AUC_0-24 was significantly (P < 0.0001) decreased by 59.8% (L) and 57.5% (H). Thus, EL is seen to be interacting with CYP1A2 by inhibiting its metabolic activity. HRLC-MS and GC-MS helped identify the presence of gymnemic acid (GA), triterpenoids and steroids in EL which could be the reason for PK interaction of CYP1A2 and CYP2C9. Also, in silico structure based site of metabolism study showed Fe accessibility and intrinsic activity for GA-IV, GA-VI, GA-VII and GA-X with CYP2C9. PK parameters of AMLO were not significantly affected by pre-treatment of EL. Thereby our findings indicate that co-administration of GS with drugs that are metabolized by CYP2C9 and CYP1A2 could lead to potential HDI.

In vitro Inhibitory Effect of Gymnema sylvestre Extracts and Total Gymnemic Acids Fraction on Select Cytochrome P450 Activities in Rat Liver Microsomes

BACKGROUND AND OBJECTIVES

Gymnema sylvestre R. Br. is a well-known Indian medicinal herb. Gymnemic acids are pentacyclic triterpenes saponins and active phytoconstituents of Gymnema sylvestre. The study aimed at evaluation of the in vitro rat liver cytochrome P450 (CYP) inhibition potential of extracts and total gymnemic acid (TA)-enriched fractions from G. sylvestre.

METHODS

Standardization of G. sylvestre [ethanolic (EL), hydroethanolic (HE), total acid of ethanolic (TAE), total acid of hydroethanolic (TAHE) and total acid of aqueous (TAAQ) extract] was done with respect to deacyl gymnemic acid (DAGA), using reverse phase-high performance liquid chromatography (RP-HPLC). Total triterpenoid content was determined by vanillin perchloric acid assay.

RESULTS

Total triterpene content was found to be the highest in TAAQ (59.86 ± 0.005% w/w) and TAE (49.77 ± 0.009% w/w). TAAQ showed IC₅₀ ≤ 50 µg/ml for all selected CYP activities. Testosterone 6β-hydroxylation was strongly inhibited by TAE (IC₅₀: 15.48 ± 2.13 µg/ml) and was moderately by TAAQ and EL with IC₅₀ ≥ 50 µg/ml. Flurbiprofen 4'-hydroxylation was subject to strong, weak and moderate inhibition by TAAQ (IC₅₀: 34.67 ± 1.38 µg/ml), TAE (IC₅₀: ≥ 50 µg/ml) and EL (IC₅₀: > 50 µg/ml), respectively. Dextromethorphan O-demethylation was inhibited by TAHE and TAAQ.

CONCLUSIONS

In vitro inhibition studies suggested that TA strongly inhibits activity of selected CYP. This inhibition may possibly be due to triterpenoids and gymnemic acids that have been reported to be present in it. Data also suggest a potential for possible in vivo herb-drug interactions involving G. sylvestre and other medications that are metabolized by the same CYP.

Cytotoxic and Enzyme Inhibitory Potential of Two Potentilla species (P. speciosa L. and P. reptans Willd.) and Their Chemical Composition

In this work, the biological and chemical fingerprints of three extracts (ethyl acetate, methanol, and water) from two Potentilla species (Potentilla reptans and P. speciosa) were investigated. Antioxidant, enzyme inhibitory, and cytotoxic activities were performed for the biological fingerprint. For the chemical characterization, total bioactive components, and individual phenolic components were determined using photometric and HPLC methods, respectively. The main identified phenolic compounds in these extracts were rutin and catechin. Methanol and water extracts contained the highest total phenolic and flavonoid content. The results of antioxidant assays showed that methanol and water extracts displayed higher antioxidant activity compared to the ethyl acetate extract. Generally, methanol and water extracts exhibited higher biological activities correlated with higher levels the bioactive components. For P. speciosa, the methanol extract exhibited the highest enzyme inhibitory activity (except BChE inhibitory activity). P. reptans exhibited also high antiproliferative activity against MCF-7 cells whilst P. speciosa had weak to moderate activity against both of A549 and MCF-7 cell lines. The results suggest that Potentilla species could be potential candidates for developing new phyto-pharmaceuticals and functional ingredients.

A Protein Isolate from Moringa oleifera Leaves Has Hypoglycemic and Antioxidant Effects in Alloxan-Induced Diabetic Mice

Moringa oleifera has been used in traditional medicine to treat diabetes. However, few studies have been conducted to relate its antidiabetic properties to proteins. In this study, a leaf protein isolate was obtained from M. oleifera leaves, named Mo-LPI, and the hypoglycemic and antioxidant effects on alloxan-induced diabetic mice were assessed. Mo-LPI was obtained by aqueous extraction, ammonium sulphate precipitation and dialysis. The electrophoresis profile and proteolytic hydrolysis confirmed its protein nature. Mo-LPI showed hemagglutinating activity, cross-reaction with anti-insulin antibodies and precipitation after zinc addition. Single-dose intraperitoneal (i.p.) administration of Mo-LPI (500 mg/kg·bw) reduced the blood glucose level (reductions of 34.3%, 60.9% and 66.4% after 1, 3 and 5 h, respectively). The effect of Mo-LPI was also evidenced in the repeated dose test with a 56.2% reduction in the blood glucose level on the 7th day after i.p. administration. Mo-LPI did not stimulate insulin secretion in diabetic mice. Mo-LPI was also effective in reducing the oxidative stress in diabetic mice by a decrease in malondialdehyde level and increase in catalase activity. Mo-LPI (2500 mg/kg·bw) did not cause acute toxicity to mice. Mo-LPI is a promising alternative or complementary agent to treat diabetes.

Evaluation of antidiabetic effect of total calystegines extracted from Hyoscyamus albus

BACKGROUND

Hyoscyamus albus L. (Solanaceae) an old medicinal plant is a rich source of tropane and nortropane alkaloids which confers to this plant a number of very interesting and beneficial therapeutic effects.

PURPOSE

Calystegines that are polyhydroxylated alkaloids and imino-sugars poccess significant glycosidases inhibitory activities and are therefore good candidats for the treatment of diabetes mellitus.

STUDY DESIGN

Calystegines extracted from Hyoscyamys albus seeds were tested for teir acute oral toxicity and investigated for their in-vivo antidiabetic effect on Streptozotocine induced diabetes in mice.

METHODES

Calystegines were extracted from the seeds plant using an Ion exchange column; the remaining extract was then administrated orally to mice at several single doses for acute toxicity assay. A dose of 130mg/kg streptozotocine was injected to mice to induce diabetes mellitus, and diabetic mice were treated orally during 20days with 10mg/kg and 20mg/kg calystegines and 20mg/kg glibenclamide as the reference drug.

RESULTS

Acute oral toxicity showed that calystegines are not toxic up to a dose of 2000mg/kg with absence of any signs of intoxication and damages in Liver and kidney tissues. The nortropane alkaloids markedly reduced blood glucose levels and lipid parameters of diabetic mice to normal concentrations after 20days of treatment at 10mg/kg and 20mg/kg (p<0.05). Histopathological study of diabetic mice pancreas indicated that calystegines of Hyoscyamus albus have minimized streptozotocine damages on β-cells of islets of langerhans, stimulated β-cells regeneration and improved with this insulin secretion.

CONCLUSION

The findings of this study suggest that calystegines are potent antidiabetic agents with antihyperglicemic and hypolipidemic effects, and a protective fonction on pancreas in streptozotocin induced diabetes in mice.

Hypoglycemic activity of 6-bromoembelin and vilangin in high-fat diet fed-streptozotocin-induced type 2 diabetic rats and molecular docking studies

AIMS

This paper investigates the hypoglycemic activity of two derivatives of embelin (1) viz. 6-bromoembelin (2) and vilangin (3), in high-fat diet - STZ induced diabetic rats.

MAIN METHODS

The effects of 6-bromoembelin (2) and vilangin (3) on insulin resistance, β-cell dysfunction and glucose transport in high-fat diet (HFD) fed-streptozotocin (STZ) (40mg/kg) induced type 2 diabetic rats were evaluated. The binding modes of 6-bromoembelin (2) and vilangin (3) into PPARγ, PI3K, Akt, and GLUT4 were also studied using Autodock 4.2 and ADT 1.5.6 programs.

KEY FINDINGS

At the dose of 30mg/kg, the plasma glucose, plasma insulin and body weight were reduced by both embelin derivatives in diabetic rats. Additionally the altered lipid profiles and hexokinase, glucose-6-phosphatase and fructose-1,6-bisphosphatase levels were brought to normal. Compared to diabetic control group, there was a significant increase in the expression of PPARγ in epididymal adipose tissue. Inhibition of adipogenic activity and mild activation of PPARγ levels in the skeletal muscle and liver were observed. In epididymal adipose tissue, the compounds increased the insulin-mediated glucose uptake through the activation and translocation of GLUT4 in PI3K/p-Akt signaling cascade.

SIGNIFICANCE

The derivatives of embelin such as 6-bromoembelin (2) and vilangin (3) may be useful in the prevention and treatment of obesity-linked type 2 diabetes mellitus.

Neuroinflammation is not a Prerequisite for Diabetes-induced Tau Phosphorylation

Abnormal phosphorylation and aggregation of tau is a key hallmark of Alzheimer's disease (AD). AD is a multifactorial neurodegenerative disorder for which Diabetes Mellitus (DM) is a risk factor. In animal models for DM, the phosphorylation and aggregation of tau is induced or exacerbated, however the underlying mechanism is unknown. In addition to the metabolic dysfunction, DM is characterized by chronic low-grade inflammation. This was reported to be associated with a neuroinflammatory response in the hypothalamus of DM animal models. Neuroinflammation is also implicated in the development and progression of AD. It is unknown whether DM also induces neuroinflammation in brain areas affected in AD, the cortex and hippocampus. Here we investigated whether neuroinflammation could be the mechanistic trigger to induce tau phosphorylation in the brain of DM animals. Two distinct diabetic animal models were used; rats on free-choice high-fat high-sugar (fcHFHS) diet that are insulin resistant and streptozotocin-treated rats that are insulin deficient. The streptozotocin-treated animals demonstrated increased tau phosphorylation in the brain as expected, whereas the fcHFHS diet fed animals did not. Remarkably, neither of the diabetic animal models showed reactive microglia or increased GFAP and COX-2 levels in the cortex or hippocampus. From this, we conclude: 1. DM does not induce neuroinflammation in brain regions affected in AD, and 2. Neuroinflammation is not a prerequisite for tau phosphorylation. Neuroinflammation is therefore not the mechanism that explains the close connection between DM and AD.

Antinociceptive and hypoglycaemic evaluation of Conyza filaginoides (D.C.) Hieron Asteraceae

Objectives

This work was undertaken to assess the antinociceptive and hypoglycaemic properties of a quantified extract of Conyza filaginoides (CFOE), as well as the antinociceptive potential of rutin, the main active compound of the plant, in normoglycaemic and/or hyperglycaemic mice (nicotinamide-streptozotocin, NA-STZ).

Methods

The antinociceptive effect of CFOE was evaluated using the writhing, hotplate and formalin tests in mice. Rutin was also examined with the formalin test. In addition, the antihyperalgesic effect of CFOE was evaluated in hyperglycaemic mice. The hypoglycaemic effect of CFOE was tested using an acute hypoglycaemic assay, and oral glucose and sucrose tests in normoglycaemic and hyperglycaemic mice.

Key findings

CFOE showed antinociceptive effect when tested in normoglycaemic mice in the writhing and hotplate tests (31.6–316 mg/kg). CFOE was also active in both normoglycaemic and hyperglycaemic mice in the formalin test (10–100 μg/paw) revealing its antihyperalgesic property. Rutin reduced the nociceptive behaviour in the formalin test; its mechanism of action seems to involve GABAergic and opioid pathways. CFOE possessed noted hypoglycaemic and antihyperglycaemic effects in normoglycaemic and hyperglycaemic mice (31.6–316 mg/kg).

Conclusions

The antinociceptive, antihyperalgesic and hypoglycaemic effects of C. filaginoides found in this study support the contemporary uses of the plant in Mexican folk medicine.

Quantitative combination of natural anti-oxidants prevents metabolic syndrome by reducing oxidative stress

Insulin resistance and abdominal obesity are present in the majority of people with the metabolic syndrome. Antioxidant therapy might be a useful strategy for type 2 diabetes and other insulin-resistant states. The combination of vitamin C (Vc) and vitamin E has synthetic scavenging effect on free radicals and inhibition effect on lipid peroxidation. However, there are few studies about how to define the best combination of more than three anti-oxidants as it is difficult or impossible to test the anti-oxidant effect of the combination of every concentration of each ingredient experimentally. Here we present a math model, which is based on the classical Hill equation to determine the best combination, called Fixed Dose Combination (FDC), of several natural anti-oxidants, including Vc, green tea polyphenols (GTP) and grape seed extract proanthocyanidin (GSEP). Then we investigated the effects of FDC on oxidative stress, blood glucose and serum lipid levels in cultured 3T3-L1 adipocytes, high fat diet (HFD)-fed rats which serve as obesity model, and KK-ay mice as diabetic model. The level of serum malondialdehyde (MDA) in the treated rats was studied and Hematoxylin-Eosin (HE) staining or Oil red slices of liver and adipose tissue in the rats were examined as well. FDC shows excellent antioxidant and anti-glycation activity by attenuating lipid peroxidation. FDC determined in this investigation can become a potential solution to reduce obesity, to improve insulin sensitivity and be beneficial for the treatment of fat and diabetic patients. It is the first time to use the math model to determine the best ratio of three anti-oxidants, which can save much more time and chemical materials than traditional experimental method. This quantitative method represents a potentially new and useful strategy to screen all possible combinations of many natural anti-oxidants, therefore may help develop novel therapeutics with the potential to ameliorate the worldwide metabolic abnormalities.

Ancient records and modern research on the mechanisms of chinese herbal medicines in the treatment of diabetes mellitus

Over the past decades, Chinese herbal medicines (CHM) have been extensively and intensively studied through from both clinical and experimental perspectives and CHM have been proved to be effective in the treatment of diabetes mellitus (DM). This study, by searching ancient records and modern research papers, reviewed CHM in terms of their clinical application and principal mechanism in the treatment of DM. We summarized the use of CHM mentioned in 54 famous ancient materia medica monographs and searched papers on the hypoglycemic effect of several representative CHM. Main mechanisms and limitations of CHM and further research direction for DM were discussed. On the basis of the study, we were led to conclude that TCM, as a main form of complementary and alternative medicine (CAM), was well recorded in ancient literatures and has less adverse effects as shown by modern studies. The mechanisms of CHM treatment of DM are complex, multilink, and multitarget, so we should find main hypoglycemic mechanism through doing research on CHM monomer active constituents. Many CHM monomer constituents possess noteworthy hypoglycemic effects. Therefore, developing a novel natural product for DM and its complications is of much significance. It is strongly significant to pay close attention to CHM for treatment of DM and its complications.

Antioxidant, α-glucosidase inhibitory activity and sub-chronic toxicity of Derris reticulata extract: its antidiabetic potential

Background

Antidiabetic activity of Derris reticulata extract on alloxan-induced diabetic rats has been reported. The extract was found to lower blood glucose and inhibit intestinal glucose absorption. The aim of this study was to further investigate mechanisms underlying the antihyperglycemic activity of D. reticulata extract in vitro.

Methods

The aqueous extract was obtained from D. reticulata stem. Phytochemical screening, total phenolic, and flavanoid contents were examined. ABTS and DPPH scavenging assays, and FRAP method were used to determine in vitro antioxidant activities. Measurement of cell viability on alloxan-induced cellular damage was performed in the insulin-secreting RINm5F cells by MTT assay. The effects of the extract on α-glucosidase activity and insulin release were studied. In addition, sub-chronic toxicity test in rats was also conducted.

Results

The results revealed that the extract, which consisted of terpenoids, saponins, tannins and flavonoids, possessed moderate radical scavenging activities. Pre-treatment of RINm5F cells with the extract was also found to exert moderate, but significant, in vitro protection against alloxan, an oxidative stress producing agent. Unlike glibenclamide, the extract did not stimulate insulin secretion. However, the extract was found to inhibit α-glucosidase activity similar to acarbose. It was found that in sub-chronic toxicity studies D. reticulata extract did not cause mortality or produce any remarkable haematological, biochemical and histopathological adverse effects in rats.

Conclusions

The data suggest that the possible mechanisms underlying antihyperglycemic activity of D. reticulata extract are cytoprotective effect on pancreatic cells, presumably by its antioxidant activity, and inhibition of α-glucosidase. Sub-chronic toxicity study also provides scientific evidence to corroborate the safety of this plant as an alternative antidiabetic agent.