Free radical scavenging, enzyme inhibitory constituents from antidiabetic Ayurvedic medicinal plantHydnocarpus wightiana Blume

Discovery of components in honeysuckle for treating COVID-19 and diabetes based on molecular docking, network analysis and experimental validation

Molecular docking screening identified ochnaflavone, madreselvin B and hydnocarpin as key components for treating COVID-19 with diabetes in honeysuckle using 3 C-like protease (Mpro), angiotensin-converting enzyme 2 (ACE2), and dipeptidyl peptidase 4 (DPP4) as molecular docking targets, ACE2, DPP4, IL2, NFKB1, PLG, TBK1, TLR4 and TNF were the core targets, and multiple antiviral and anti-inflammatory signalling pathways were involved. Further, the levels of IL-1β and DPP4 in cell supernatant that had been activated by LPS was decreased by hypnocarpin, and ACE2 protein and DPP4 mRNA in cells were down-regulated. Overall, we have identified three components from honeysuckle that have potency to treat COVID-19 combined with diabetes. SARS-CoV-2 transcription may be inhibited by these components in honeysuckle, reducing virus invasion, inhibiting inflammatory factors, and improving immune response. Our findings could provide a basis for the clinical application and further development of honeysuckle.

Potential applications of ferroptosis inducers and regulatory molecules in hematological malignancy therapy

Ferroptosis, a novel form of iron-dependent cell death, has emerged as a potential avenue for promoting tumor cell death by causing cell membrane rupture and the accumulation of lipid peroxides (LPO) in the cell. Since its discovery in 2012, extensive research has been conducted to explore the mechanism of ferroptosis inducers, including erastin, sulfasalazine, and sorafenib. These compounds inhibit system XC-, while Ras-selective lethal small molecule 3 (RSL3) and FION2 specifically target GPX4 to promote ferroptosis. Therefore, targeting ferroptosis presents a promising therapeutic approach for malignant tumors. While the study of ferroptosis in solid tumors has made significant progress, there is limited information available on its role in hematological tumors. This review aims to summarize the molecular mechanisms of ferroptosis inducers and discuss their clinical applications in hematological malignancies. Furthermore, the identification of non-coding RNAs (ncRNAs) and genes that regulate key molecules in the ferroptosis pathway could provide new targets and establish a molecular theoretical foundation for exploring novel ferroptosis inducers in hematological malignancies.

Ferroptosis in acute leukemia

ABSTRACT

Ferroptosis is an iron-dependent cell death pathway that is different from apoptosis, pyroptosis, and necrosis. The main characteristics of ferroptosis are the Fenton reaction mediated by intracellular free divalent iron ions, lipid peroxidation of cell membrane lipids, and inhibition of the anti-lipid peroxidation activity of intracellular glutathione peroxidase 4 (GPX4). Recent studies have shown that ferroptosis can be involved in the pathological processes of many disorders, such as ischemia-reperfusion injury, nervous system diseases, and blood diseases. However, the specific mechanisms by which ferroptosis participates in the occurrence and development of acute leukemia still need to be more fully and deeply studied. This article reviews the characteristics of ferroptosis and the regulatory mechanisms promoting or inhibiting ferroptosis. More importantly, it further discusses the role of ferroptosis in acute leukemia and predicts a change in treatment strategy brought about by increased knowledge of the role of ferroptosis in acute leukemia.

Luteolin: A promising natural agent in management of pain in chronic conditions

Pain due to chronic conditions is a frequent and insufficiently addressed problem. Current drug options for pain management (either in cases of chronic inflammatory conditions or neuropathy) do not adequately treat pain. Moreover, they are associated with important adverse events in long term use. Luteolin is a flavonoid widely present in the plant kingdom and its sources have been assembled in a comprehensive list of this paper. Luteolin has shown in several research studies a range of pharmacological properties; anti-inflammatory, antioxidant, neuroprotective, and analgesic. In this article, we summarize the effects and potential benefits from introducing luteolin as an adjuvant agent in established protocols for pain management. We review the most indicative in vivo and in vitro evidence of how luteolin can target the molecular pathways involved in pathogenesis of chronic inflammatory and neuropathic pain. The data reviewed strongly support luteolin's promising benefits in pain management and raise the need for further clinical trials that can establish its role in clinical practice.

Phytochemical characterization and evaluation of antioxidant, antimicrobial, antibiofilm and anticancer activities of ethyl acetate seed extract of Hydnocarpus laurifolia (Dennst) Sleummer

Various functional groups were observed in the FTIR analysis of Hydnocarpus laurifolia seeds ethyl acetate extract such as O-H, N-H, C-H, -CH2, O=C=O, C=O, C=O-NH, and CH3, etc. Eleven bioactive compounds were detected via GC-MS and the predominant compounds include (1S)-2-cyclopentene-1-tridecanoicacid (chaulmoogric acid) (80.59%); 2-cyclopentene-1-undecanoic acid (hydnocarpic acid) (6.76%); cyclobutylamine (5.28%); methyl thioacetate (ethanethioic acid) (4.84%); lignoceric acid (2.21%). The TPC and TFC values were 0.110 ± 0.04 GAE g-1 and 0.175 ± 0.05 g CE g-1 respectively. Ethyl acetate extract showed strong DDPH free radical scavenging activity with IC50 value 10.64 ± 0.48 µg ml-1 and antioxidant activity index 3.759. The ethyl acetate extract also exhibited potential ABTS radical scavenging efficacy with a very low IC50 value, i.e., 07.81 ± 0.48 µg ml-1. P. aeruginosa was the most sensitive bacteria to the extract with 33.16 ± 0.88 mm inhibition zone and MIC: 3.12 mg ml-1, MBC: 6.25 mg ml-1. P. aeruginosa biofilm was inhibited by ethyl acetate extract 99.22% at MIC concentration. The LM images displayed a decrease in the number of biofilm cells and FE-SEM micrographs showcased the extensive decrease as well as disintegration in biofilm. Additionally, ethyl acetate extract was found selectively cytotoxic to the K562 cancer cells having an IC50 of 25.41 μg ml-1 and barely cytotoxic to normal PBMCs having an IC50 of 482.54 μg ml-1, and the selectivity index value was 18.99. Data validate scientifically the traditional use of H. laurifolia seeds in folk medicines and confirmed that it can be used in modern phytomedicines as an antioxidant, antimicrobial, antibiofilm, and anticancer agent and is toxicologically safe.

Hydnocarpin D attenuates lipopolysaccharide-induced acute lung injury via MAPK/NF-κB and Keap1/Nrf2/HO-1 pathway

BACKGROUND

Acute lung injury (ALI) is a complex pulmonary destructive disease with limited therapeutic approaches. Hydnocarpin D (HD) is a flavonolignan isolated from Hydnocarpus wightiana which possesses antioxidant and anti-inflammatory properties. However, whether HD has beneficial effects on ALI as well as its underlying mechanism remains to be elucidated.

PURPOSE

This study evaluated the protective effect of HD in ALI and the underlying molecular mechanisms.

METHODS

In vivo, the role of HD on lipopolysaccharide (LPS)-induced ALI in mice was tested by determination of neutrophil infiltration, levels of inflammatory cytokines, lung histology and edema, vascular and alveolar barrier disruption. In vitro, murine macrophage RAW 264.7 cells were used to investigate the molecular mechanisms RESULTS: Administration of HD protected mice against LPS-induced ALI, including ameliorating the histological alterations in the lung tissues, and decreasing lung edema, protein content of bronchoalveolar lavage fluid, infiltration of inflammatory cell and secretion of cytokines. Moreover, HD blocked the phosphorylation of TLR-4, NF-κB, and ERK in LPS-induced lung injury. In vitro, HD inhibited LPS-induced oxidative stress and inflammation in RAW 264.7 cells, which largely depend upon the upregulation of antioxidant defensive Nrf2 pathway, thereby suppressing LPS-activated proinflammatory mediator secretion, NLRP3 inflammasome, and MAPK/NF-κB signaling pathway.

CONCLUSION

HD attenuates oxidative stress and inflammation against LPS-induced ALI via MAPK/NF-κB and Keap1/Nrf2/HO-1 pathway, and is a promising novel therapeutic candidate for ALI.

Function of selected natural antidiabetic compounds with potential against cancer via modulation of the PI3K/AKT/mTOR cascade

Diabetes mellitus (DM) is a metabolic disorder with growing global incidence, as 387 million people were diagnosed in 2014 with an expected projection of 642 million in 2040. Several complications are associated with DM including heart attack, stroke, kidney failure, blindness, and cancer. The latter is the second leading cause of death worldwide accounting for one in every six deaths, with liver, pancreas, and endometrium cancers are the most abundant among patients with diabetes. Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway plays a vital role in developing a wide array of pathological disorders, among them diabetes and cancer. Natural secondary metabolites that counteract the deleterious effects of reactive oxygen species (ROS) and modulate PI3K/Akt/mTOR pathway could be a promising approach in cancer therapy. Here, 717 medicinal plants with antidiabetic activities were highlighted along with 357 bioactive compounds responsible for the antidiabetic activity. Also, 43 individual plant compounds with potential antidiabetic activities against cancer via the modulation of PI3K/Akt/mTOR cascade were identified. Taken together, the available data give an insight of the potential of repurposing medicinal plants and/or the individual secondary metabolites with antidiabetic activities for cancer therapy.

Evaluation of pancreatic regeneration activity of Tephrosia purpurea leaves in rats with streptozotocin-induced diabetes

Background and aim

Flavonoid rich plant Tephrosia purpurea (T. purpurea), commonly known as Sarpunkha has been used in traditional systems of medicine to treat diabetes mellitus. However, its effectiveness in promoting regeneration of pancreas in diabetes has not been investigated. Therefore, the present study was undertaken to evaluate pancreatic β-cells regeneration, antioxidant and antihyperlipidemic potentials of T. purpurea leaves extract, its fractions and main constituent Rutin in diabetic rats.

Experimental procedure

The leaves extract and its fractions were first screened for acute and sub-chronic antidiabetic activity in a dose range of 250–500 mg/kg orally. Further, fractions with potent antidiabetic activity were screened for pancreatic β-cells regeneration activity using histopathological studies and morphometric analysis, which was followed by estimation of biochemical parameters.

Results and conclusion

The most significant antidiabetic, pancreatic regeneration and antihyperlipidemic activity was exhibited by n-butanol soluble fraction of ethanol extract at the dose level of 500 mg/kg. Histopathology revealed that treatment with this fraction improved the β-cell granulation of islets and prevented the β-cells damage which was further confirmed by morphometric analysis. Thus, the present study validated the traditional use of T. purpurea plant in the treatment of diabetes, which might be attributed to pancreatic β-cells regeneration potential of its active constituent Rutin.

Taxonomy (classification by EVISE)

Traditional Medicine; Metabolic Disorder; Experimental Design; Cell Regeneration and Histopathology.

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Polyphenol rich extract possesses potent in vitro antioxidant activity.

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Extract and its fractions are having pancreatic regeneration potential in STZ induced diabetic model.

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Histopathological study of the pancreas extract and fraction treated diabetic rats showed islets expansion and decreased fatty infiltrate of the islets.

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Study validates the use of plant in treatment of diabetes.

Inhibitory effect of hydnocarpin D on T-cell acute lymphoblastic leukemia via induction of autophagy-dependent ferroptosis

Hydnocarpin D (HD) is a bioactive flavonolignan compound that possesses promising anti-tumor activity, although the mechanism is not fully understood. Using T cell acute lymphoblastic leukemia (T-ALL) cell lines Jurkat and Molt-4 as model system, we found that HD suppressed T-ALL proliferation in vitro, via induction of cell cycle arrest and subsequent apoptosis. Furthermore, HD increased the LC3-II levels and the formation of autophagolysosome vacuoles, both of which are markers for autophagy. The inhibition of autophagy by either knockdown of ATG5/7 or pre-treatment of 3-MA partially rescued HD-induced apoptosis, thus suggesting that autophagy enhanced the efficacy of HD. Interestingly, this cytotoxic autophagy triggered ferroptosis, as evidenced by the accumulation of lipid ROS and decrease of GSH and GPX4, while inhibition of autophagy impeded ferroptotic cell death. Our study suggests that HD triggers multiple cell death processes and is an interesting compound that should be evaluated in future preclinical studies.

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.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

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

Inhibitory effect of saccharides and phenolic compounds from maize silks on intestinal α-glucosidases

Maize silks have been used in Mexico for centuries as a natural-based treatment for various illnesses, including obesity and diabetes. It has been shown in mice that intake of maize silk extracts reduces the levels of blood glucose. However, it is not clear how or what maize silk compounds are involved in such an effect. A hypothesized mechanism is that some maize silk compounds can inhibit carbohydrate hydrolyzing enzymes like α-glucosidases. This work aimed to assess the capability of both saccharides and phenolic compounds from maize silks to inhibit intestinal α-glucosidases. Results showed that saccharides from maize silks did not produce inhibition on intestinal α-glucosidases, but phenolics did. Maize silk phenolics increased the value of K_m significantly and decreased the V_max slightly, indicating a mixed inhibition of α-glucosidases. According to the molecular docking analysis, the phenolics maysin, methoxymaysin, and apimaysin, which had the highest predicted binding energies, could be responsible for the inhibition of α-glucosidases. PRACTICAL APPLICATIONS: The International Diabetes Federation (IDF) reported in 2017 that diabetes affects over 424 million people worldwide, and caused 4 million deaths. Non-insulin-dependent diabetes or type 2 diabetes mellitus (T2DM) accounts for ∼90% of cases. T2DM is characterized by insulin resistance and pancreatic β-cell failure. Therapy for T2DM includes the use of sulfonylureas, thiazolidinediones, biguanides, and α-glucosidase inhibitors. Regarding the α-glucosidase inhibitors, only few are commercially available, and these have been associated with severe gastrointestinal side effects. This work aimed to assess the capability of both saccharides and phenolic compounds from maize silks to inhibit intestinal α-glucosidases. Results from this work evidenced that maize silk polyphenols acted as effective inhibitors of intestinal rat α-glucosidases. Computational analysis of maize silk polyphenols indicated that maysin, a particular flavonoid from maize silks, could be responsible for the inhibition of α-glucosidases.

Antidiabetic effects of extracts of red and yellow fruits of cornelian cherries (Cornus mas L.) on rats with streptozotocin-induced diabetes mellitus

The effects of extracts of red and yellow fruits of cornelian cherries have been evaluated in rats with streptozotocin-induced diabetes mellitus.

Identification of Digestive Enzyme Inhibitors from Ludwigia octovalvis (Jacq.) P.H.Raven

Current antiobesity and antidiabetic tools have been insufficient to curb these diseases and frequently cause side effects; therefore, new pancreatic lipase and α–glucosidase inhibitors could be excellent aids for the prevention and treatment of these diseases. The aim of this study was to identify, quantify, and characterize the chemical compounds with the highest degree of inhibitory activity of these enzymes, contained in a Ludwigia octovalvis hydroalcoholic extract. Chemical purification was performed by liquid–liquid separation and column chromatography. Inhibitory activities were measured in vitro, employing acarbose, orlistat, and a Camellia sinensis hydroalcoholic extract as references. For structural elucidation, Nuclear Magnetic Resonance was carried out, and High Performance Liquid Chromatography was used to quantify the compounds. For α–glucosidases, L. octovalvis hydroalcoholic extract and its ethyl acetate fraction showed half–maximal Inhibitory Concentration (IC₅₀) values of 700 and 250 μg/mL, for lipase, 480 and 718 μg/mL, while C. sinensis showed 260 and 587 μg/mL. The most active compounds were identified as ethyl gallate (1, IC₅₀ 832 μM) and gallic acid (2, IC₅₀ 969 μM); both displayed competitive inhibition of α–glucosidases and isoorientin (3, IC₅₀ 201 μM), which displayed uncompetitive inhibition of lipase. These data could be useful in the development of a novel phytopharmaceutical drug.

Cytokine Secretion of Peripheral Blood Mononuclear Cells by Hydnocarpus anthelminthicus Seeds

Background

Hydnocarpus anthelminthicus is primarily used as a traditional medicine for the treatment of leprosy. Previous studies demonstrated that the clinical course of leprosy and the susceptibility to mycobacteria are recognized by the immune response of the host. The current study aims to investigate the effect of H. anthelminthicus seed oil and extracts on the secretion of cytokines from PBMCs involved in immune regulation.

Methods

PBMCs from healthy volunteers were cultured and treated with LPS and H. anthelminthicus seed oil or extracts. Cell viability was detected with WST-1 cell proliferation assay reagent. Proinflammatory cytokines were quantified using ELISA with a specific antibody.

Results

LPS-treated PBMCs significantly increased IL6 and TNF-α secretion. H. anthelminthicus seed oil had a synergistic effect with LPS on TNF-α secretion. The aqueous extract of H. anthelminthicus seed kernels and hulls significantly induced IL6 and TNF-α secretion. However, the ethanol extract of H. anthelminthicus seed kernels and hulls significantly decreased IL6, IL8, and TNF-α secretion in LPS-treated PBMCs.

Conclusions

Extracts of H. anthelminthicus seeds demonstrated various effects on the proinflammatory cytokine secretion of PBMCs. The application of these extracts should depend on the immune response of the host, which determines the manifestation of the disease.

New Cyclopentyl Fatty Acid and Cyanohydrin Glycosides from Fruits of Hydnocarpus hainanensis

Three new compounds, hydnohainanic acid (1), and hydnohainanin A (2) and B (3) were isolated from the fruits of Hydnocarpus hainanensis (Achariaceae). Their structures were determined by spectroscopic analysis, including 2D NMR, and MS. Compounds 1-3 were evaluated for their cytotoxic activity against the KB cell line. Compound 1 had a moderate cytotoxicity with an IC50 value of 32.5 μg/mL, while the two remaining compounds did not exhibit inhibition, even at a concentration of 128 μg/mL.

Hydnocarpin-Type Flavonolignans: Semisynthesis and Inhibitory Effects on Staphylococcus aureus Biofilm Formation

A new, efficient, and general semisynthesis of hydnocarpin-type flavonolignans was developed and optimized, enabling gram-scale production of hydnocarpin D (2). Moreover, the syntheses of optically pure hydnocarpin isomers [(10R,11R)-hydnocarpin (1a), (10R,11R)-hydnocarpin D (2a), and (10S,11S)-hydnocarpin D (2b)], as well as the synthesis of isohydnocarpin (8), were achieved for the first time utilizing this new method. The synthesis is based on the two-step transformation of the readily available flavonolignans from milk thistle (Silybum marianum), accessible by isolation from the commercial extract silymarin. The first step relies on the regioselective formylation of the C-3 hydroxy group of the dihydroflavonol-type precursor using the Vilsmeier-Haack reagent, followed by formic acid elimination by triethylamine in the second step. The synthesized compounds were effective inhibitors of Staphylococcus aureus biofilm formation, with (10S,11S)-hydnocarpin D (2b) being the most potent inhibitor. Furthermore, the effect of glucose on biofilm formation was tested, and glucose decreased the biofilm inhibitory activity of 2b. Moreover, 2b increased the susceptibility of Staph. aureus to enrofloxacin.

Finding needles in a haystack: application of network analysis and target enrichment studies for the identification of potential anti-diabetic phytochemicals

Diabetes mellitus is a debilitating metabolic disorder and remains a significant threat to public health. Herbal medicines have been proven to be effective anti-diabetic agents compared to synthetic drugs in terms of side effects. However, the complexity in their chemical constituents and mechanism of action, hinder the effort to discover novel anti-diabetic drugs. Hence, understanding the biological and chemical basis of pharmacological action of phytochemicals is essential for the discovery of potential anti-diabetic drugs. Identifying important active compounds, their protein targets and the pathways involved in diabetes would serve this purpose. In this context, the present study was aimed at exploring the mechanism of action of anti-diabetic plants phytochemicals through network and chemical-based approaches. This study also involves a focused and constructive strategy for preparing new effective anti-diabetic formulations. Further, a protocol for target enrichment was proposed, to identify novel protein targets for important active compounds. Therefore, the successive use of network analysis combined with target enrichment studies would accelerate the discovery of potential anti-diabetic phytochemicals.

Hydnocarpus: an ethnopharmacological, phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Hydnocarpus (Flacourtiaceae) includes forty species that are spread across the globe. In the Indian System of Medicine, Hydnocarpus pentandrus (Buch.-Ham.) Oken. is primarily used for treating leprosy and other skin disorders. It is known as "Chaulmoogra" and is also used to treat other indications including constipation, inflammation, blood disorders, and worm infestations. Various species of Hydnocarpus are also used in traditional medicine in China, Thailand, Malaysia, and Myanmar for several skin disorders. To assess the therapeutic potential of species from the Hydnocarpus genus and to determine future avenues for research.

METHODS

All relevant scientific literature published up to the end of December 2013 was retrieved via a library and electronic search (SciFinder, PubMed, ScienceDirect, and Google Scholar). Manual searches of traditional books like to ancient classics, including Vaidya Yoga Ratnavali, Siddha Materia Medica, and contemporary references including The Ayurvedic Pharmacopoeia of India and The Ayurveda Formulary, were also performed.

RESULTS

Seed oil from species of the Hydnocarpus genus is used for medicinal purposes, predominantly for various skin disorders. This oil is reported to contain a characteristic class of compounds known as cyclopentenyl fatty acids. Furthermore, seeds of this genus are reported to contain triglycerides of fatty acids, sterols, flavonoids, and flavonolignans. Hydnocarpin, a flavonolignan, is reported to potentiate antimicrobial and anticancer activity. The extracts and compounds isolated from this plant show a wide spectrum of pharmacological properties, including antibacterial, antileprotic, antitubercular, antipsoriatic, antirheumatic, hypolipidemic, antidiabetic, anticancer, anti-inflammatory, and antioxidant activities. The antileprotic activity is postulated to be due to the cyclopentenyl fatty acids present in the seed oil.

CONCLUSION

Flavonolignans have an interesting chemical motif, and hydnocarpin and its congeners should be investigated for their activities and the mechanism underlying these activities. Multi-drug-resistant microbes are on the increase, and the possible inhibitory effect of these compounds when used with current antimicrobials should also be evaluated. Furthermore, unique cyclopentenyl fatty acids should also be investigated to understand the exact mechanism of action underlying antileprotic activity. Additional in depth phytochemical investigations of seed oil and extracts are required to tap the true potential of species from the Hydnocarpus genus.

Anti-proliferative activity of hydnocarpin, a natural lignan, is associated with the suppression of Wnt/β-catenin signaling pathway in colon cancer cells

Based on the Wnt inhibitors as potential targets in the development of anticancer agents, natural compounds were evaluated for β-catenin-mediated transcriptional activity. A natural lignan hydnocarpin isolated from Lonicera japonica was considered a potential inhibitor for Wnt/β-catenin signalings. The anti-proliferative activity of hydnocarpin was also found to be associated with the suppression of Wnt/β-catenin-mediated signaling pathway in human colon cancer cells. These data suggest that hydnocarpin might be a novel Wnt inhibitor and has a potential of signaling regulator in β-catenin-mediated signaling pathways.

Antidiabetic, antihyperlipidemic and antioxidant activities of a novel proteoglycan from ganoderma lucidum fruiting bodies on db/db mice and the possible mechanism

Previously, we screened a proteoglycan for anti-hyperglycemic, named FYGL, from Ganoderma Lucidum. For further research of the antidiabetic mechanisms of FYGL in vivo, the glucose homeostasis, activities of insulin-sensitive enzymes, glucose transporter expression and pancreatic function were analyzed using db/db mice as diabetic models in the present work. FYGL not only lead to a reduction in glycated hemoglobin level, but also an increase in insulin and C-peptide level, whereas a decrease in glucagons level and showed a potential for the remediation of pancreatic islets. FYGL also increased the glucokinase activities, and simultaneously lowered the phosphoenol pyruvate carboxykinase activities, accompanied by a reduction in the expression of hepatic glucose transporter protein 2, while the expression of adipose and skeletal glucose transporter protein 4 was increased. Moreover, the antioxidant enzyme activities were also increased by FYGL treatment. Thus, FYGL was an effective antidiabetic agent by enhancing insulin secretion and decreasing hepatic glucose output along with increase of adipose and skeletal muscle glucose disposal in the late stage of diabetes. Furthermore, FYGL is beneficial against oxidative stress, thereby being helpful in preventing the diabetic complications.

Potentiating effect of the flavonolignan (-)-hydnocarpin in combination with vincristine in a sensitive and P-gp-expressing acute lymphoblastic leukemia cell line

The potentiating action of the flavonolignan, (-)-hydnocarpin, in combination with vincristine was evaluated in the 697 acute lymphoblastic leukemia cell line and a P-gp-expressing variant, 697-R. Vincristine at 3 nM caused nearly complete growth inhibition in 697 cells versus a 17% growth inhibition in 697-R cells. When combined with (-)-hydnocarpin at concentrations of 10 and 5 μM, vincristine-mediated growth inhibition in the 697-R cells increased significantly over the sum of the individual agents to 72% (p ≤ 0.0001) and 41% (p = 0.0256), respectively. Vincristine at 1.5 nM (66% growth inhibition) and 0.75 nM (39% growth inhibition) combined with (-)-hydnocarpin at 10 μM (42% growth inhibition) in the 697 cells caused a significant increase in growth inhibition to 83% (p = 0.03) and to 61% (p < 0.0001), respectively, when compared to vincristine treatment as a single agent. To investigate the mechanism for the vincristine re-sensitization caused by (-)-hydnocarpin, the P-gp inhibitory effect of (-)-hydnocarpin was evaluated.

Hesperidin and naringin attenuate hyperglycemia-mediated oxidative stress and proinflammatory cytokine production in high fat fed/streptozotocin-induced type 2 diabetic rats

Abnormal regulation of glucose and impaired carbohydrate utilization that result from a defective or deficient insulin are the key pathogenic events in type 2 diabetes mellitus (T2DM). The present study was hypothesized to investigate the beneficial effects of hesperidin and naringin on hyperglycemia-induced oxidative damage in HFD/STZ-induced diabetic rats. Diabetes was induced by feeding rats with an HFD for 2 weeks followed by an intraperitoneal injection of STZ (35 mg/kg body weight). An oral dose of 50mg/kg hesperidin or naringin was daily given for 4 weeks after diabetes induction. At the end of the experimental period, blood was obtained from jugular vein and livers were rapidly excised and homogenized for biochemical assays. In the diabetic control group, levels of glucose, glycosylated hemoglobin (HbA1c%), MDA, NO, TNF-α and IL-6 were significantly increased, while serum insulin, GSH, vitamin C, and vitamin E levels were decreased. Both hesperidin and naringin administration significantly reversed these alterations. Moreover, supplementation with either compound significantly ameliorated serum and liver MDA, NO and glutathione, and liver antioxidant enzymes. Although detailed studies are required for the evaluation of the exact mechanism of the ameliorative effects of hesperidin and naringin against diabetic complications, these preliminary experimental findings demonstrate that both hesperidin and naringin exhibit antidiabetic effects in a rat model of T2DM by potentiating the antioxidant defense system and suppressing proinflammatory cytokine production.

Antidiabetic effects of Corni Fructus extract in streptozotocin-induced diabetic rats

PURPOSE

Diabetes is the leading cause of end-stage renal failure. The present study was undertaken to characterize the effects of Corni Fructus on diabetic nephropathy in streptozotocin-induced diabetic rats and their mechanisms.

MATERIALS AND METHODS

Streptozotocin-diabetic rats were orally administrated with Corni Fructus at a dose of 100, 200 or 400 mg/kg body mass for 40 days.

RESULTS

Corni Fructus-treated diabetic rats showed significant decreases of blood glucose, urinary protein levels and water consumption. Corni Fructus also reduced serum total cholesterol, total triglyceride and low-density lipoprotein cholesterol levels, and showed a tendency of enhancing high-density lipoprotein cholesterol level. Levels of serum albumin and creatinine in diabetic rats were also significantly reduced by Corni Fructus administration at a dose of 200 and 400 mg/kg body mass compared with non-treated diabetic rats. Corni Fructus increased catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidose (GSH-px) activities in the kidneys of diabetic rats. Furthermore, Corni Fructus treatment enhanced renal peroxisome proliferator-activated receptor-γ (PPARγ) expression in diabetic rats.

CONCLUSION

These results demonstrated that Corni Fructus may have the potential to protect the animals from diabetic nephropathy by amelioration of oxidative stress and stimulation of PPARγ expression.

Antidiabetic and antioxidant effects of oleanolic acid from Ligustrum lucidum Ait in alloxan-induced diabetic rats

The present study evaluated the antidiabetic and antioxidant effects of oleanolic acid (OA) from Ligustrum lucidum Ait (LLA) in alloxan-induced diabetic rats. OA in the alloxan-induced diabetic rats showed significant hypoglycemic activity by lowering blood glucose (at doses of 60 and 100 mg/kg for 40 days). The levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-c) in the OA-treated diabetic rats were lower, and the high-density lipoprotein cholesterol (HDL-c) level was higher than in the control diabetic rats. A significant reduction in the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels of diabetic rats following OA treatment was also observed. Furthermore, OA treatment decreased the malondialdehyde (MDA) level, but increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activities of the liver and kidney in diabetic rats. These results indicate that OA could protect the liver function avoiding alloxan-induced damage; OA had hypoglycemic, hypolipidemic and antioxidant efficacy in the diabetic rats. The antioxidant ability of OA might be one of the mechanisms of its hypoglycemic and hypolipidemic effects.

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

AIM OF THE STUDY

Potentilla discolor Bunge, commonly found at the north temperate and boreal zone, has been used for diabetes in China for a long time. Flavonoids and triterpenoids are two major types of compounds in P. discolor. This study was designed primarily to investigate the effects of total flavonoids extract (TFE) and total triterpenoids extract (TTE) of P. discolor Bunge on blood glucose, lipid profiles and antioxidant parameters on diabetic rats induced by high fat diet and streptozotocin.

MATERIALS AND METHODS

High fat diet-fed and streptozotocin-induced diabetic rats were treated with the TFE and TTE for 15 days, respectively. A range of parameters were tested including fasting blood glucose (FBG), serum insulin (SI), blood lipid profile, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glycosylated serum protein (GSP), and nitric oxide (NO).

RESULTS

Diabetic rats treated with TFE or TTE had decreased concentration of FBG and GSP compared with the control group. Meanwhile, the levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-c) in the TFE or TTE treated diabetic rats were lower, and the high-density lipoprotein cholesterol (HDL-c) level was higher than in the control diabetic rats. Furthermore, the extracts treatment decreased the MDA and NO level, while increased SOD and GSH levels in diabetic rats. Histopathologic examination also showed that the extracts have protective effects on β-cells in diabetic rats which are supported by the increase of SI.

CONCLUSIONS

All these experimental results highlighted the hypoglycemic and hypolipidemic properties of the two extracts from Potentilla discolor Bunge on diabetes and its complications, possibly through a strong antioxidant activity and a protective action on β-cells.

Interaction of Aqueous Extract of Pleurotus pulmonarius (Fr.) Quel-Champ. with Glyburide in Alloxan Induced Diabetic Mice

Mushrooms are low calorie food with very little fat and are highly suitable for obese persons. With no starch and very low sugars, they are the 'delight of the diabetics'. Combination of herbal drugs (or isolated phytochemicals) is found to be beneficial in certain diseases when given along with conventional drugs. The aim of the present study was to evaluate the effects of aqueous extract of Pleurotus pulmonarius (Lentinaceae) (called as PP-aqu) and its interaction with glyburide in alloxan induced diabetic mice. The diabetic mice treated were with PP-aqu (500 mg/kg, p.o.) alone or combination with glyburide (10 mg/kg, p.o.) for 28 days. Blood samples were collected by orbital sinus puncture using heparinized capillary glass tubes and were analyzed for serum glucose on 0, 7th, 14th, 21st and 28th days. Body weights and mortality were noted during the study period. In oral glucose tolerance test (OGTT), glucose (2.5 g/kg, p.o.) was administered with either vehicle, PP-aqu alone or in combination with glyburide and serum glucose level analyzed at 0, 30, 60 and 120 min after drug administration. Administration of PP-aqu (500 mg/kg) and its combination with glyburide (10 mg/kg) significantly (P < 0.001) decreased serum glucose level in diabetic mice. In OGTT, glyburide or PP-aqu treatment alone or their combination produced significant (P < 0.001) increase in glucose threshold. Thus we suggest that P. pulmonarius showed potent and synergistic antihyperglycemic effect in combination with glyburide.

Bioassay-guided isolation of antiatherosclerotic phytochemicals fromArtocarpus altilis

The cytoprotective effects of various solvent extracts of Artocarpus altilis (Parkinson) Fosberg were evaluated. The cytoprotective effects were determined in human U937 cells incubated with oxidized LDL (OxLDL) using the 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1, 3-benzene disulfonate (WST-1) assay. The results demonstrated that the ethyl acetate extract showed cytoprotective activities. To identify the main cytoprotective components, a bioassay guided isolation of the ethyl acetate extract afforded b-sitosterol (1) and six flavonoids (2-7). Their chemical structures were established on the basis of spectroscopic evidence and comparison with literature data. Of these compounds, compound 6 was obtained from A. altilis for the first time. The cytoprotective effect offers good prospects for the medicinal applications of A. altilis.