α-Glucosidase and pancreatic lipase inhibitory activities and glucose uptake stimulatory effect of phenolic compounds from Dendrobium formosum

Antioxidant and Biological Activity of Mexican Madroño Fruit (Arbutus arizonica)

The fruit of the Mexican madroño (Arbutus arizonica) has been consumed since pre-Columbian times by North American tribes and native groups in Mexico. Despite this, reports on its chemical composition and biological activity are limited. This work aims to determine the antioxidant, antiproliferative, and digestive enzyme inhibition activities of the methanol amberlite-retained extract of Mexican madroño. Results showed that madroño fruit is rich in antioxidants: DPPH (EC50 = 0.89 ± 0.03 mg/mL), TEAC (1078 ± 4.9 μM/g), and hemolysis inhibition (IC50 = 358.07 μg/mL), with high phenolic and flavonoid content at 15.92 ± 3.2 mg GAE/g and 4.33 ± 0.3 mg CA/g, respectively. Using analytical chromatography, gallic acid, vanillic acid, chlorogenic acid, ferulic acid, quercetin, and rutin were quantified. The extract also showed α-glucosidase inhibition (IC50 = 3.1 ± 0.17 mg/mL), but no inhibition against α-amylase and lipase (>5 mg/mL), while showing antiproliferative activity against HeLa, HT-29, and MCF-7 cancer cell lines. These results point towards an interesting potential for the fruit of the A. arizonica as chemopreventive and hold potential for elaborating functional foods.

Deciphering the Potential Therapeutic Effects of Hydnocarpus wightianus Seed Extracts using in vitro and in silico approaches

Phytocompounds possess the potential to treat a broad spectrum of disorders due to their remarkable bioactivity. Naturally occurring compounds possess lower toxicity profiles, which making them attractive targets for drug development. Hydnocarpus wightianus seeds were extracted using ethanol, acetone, and hexane solvents. The extracts were evaluated for phytochemicals screening and other therapeutic characteristics, such as free radicals scavenging, anti α-amylase, anti α-glucosidase, and anti-bacterial activities. The ethanolic extract exhibited noteworthy antibacterial characteristics and demonstrated considerable antioxidant, and anti-diabetic effects. The IC50 value of the ethanolic extract for Dpph, α-amylase, and α-glucosidase were found to be 77.299 ± 3.381 μg/mL, 165.56 2.56 μg/mL, and 136.58 ± 5.82 μg/mL, respectively. The ethanolic extract was effective against Methicillin resistant Staphylococcus aureus (26 mm zone of inhibition at 100 μL concentration). Molecular docking investigations revealed the phytoconstituent's inhibitory mechanisms against diabetic, free radicals, and bacterial activity. Docking score for phytocompounds against targeted protein varies from -7.2 to -5.1 kcal/mol. The bioactive compounds present in the ethanolic extract were identified by Gas chromatography/Mass spectrometry analysis, followed by molecular docking and molecular dynamic simulation studies to further explore the phytoconstituent's inhibitory mechanism of α-glucosidase, ∝-amylase, radical scavenging, and bacterial activity. The electronic structure and possible pharmacological actions of the phytocompound were revealed through the use of Density Functional Theory (DFT) analysis. Computational and in vitro studies revealed that these identified compounds have anti-diabetic, anti-oxidant, and anti-bacterial activities against antibiotic-resistant strain of Staphylococcus aureus.

Moscatilin, a potential therapeutic agent for cancer treatment: insights into molecular mechanisms and clinical prospects

Moscatilin, a bibenzyl derivative from the Dendrobium genus, has been traditionally used in Chinese medicine. Recent studies suggest its potential as a powerful anticancer agent due to its diverse pharmacological properties.This review aims to consolidate current research on moscatilin's anticancer mechanisms, structure-activity relationships, and therapeutic potential to assess its viability for clinical use. A literature search was performed in PubMed/MedLine, Scopus, and Web of Science.The search focused on "cancer," "moscatilin," "anticancer," "bioactivity," "dendrobium," and "pharmacological properties." Relevant studies on molecular mechanisms, preclinical and clinical efficacy, and bioavailability were reviewed. Moscatilin exhibits significant anticancer effects in lung, breast, colorectal, and pancreatic cancers. It induces apoptosis via the JNK/SAPK pathway, inhibits cell proliferation, and suppresses metastasis. Structure-activity relationship studies reveal that phenolic groups and a two-carbon bridge are crucial for its efficacy. Additionally, moscatilin shows good bioavailability and a favorable safety profile, with low toxicity to healthy cells. Moscatilin demonstrates considerable potential as an anticancer agent, targeting multiple cancer progression pathways. Further clinical trials are essential to confirm its therapeutic efficacy and safety in humans.

Pistacia lentiscus: Phytochemistry and Antidiabetic Properties

Pistacia lentiscus L. (P. lentiscus) is an evergreen shrub (Anacardiaceae family) primarily found in the Mediterranean region. The plant has been thoroughly characterized, resulting in a high concentration of bioactive compounds as flavonoids and phenolics. Moreover, P. lentiscus was revealed to possess a great nutritional and industrial importance because of its variety of biological activities, including antibacterial, anti-inflammatory, anti-atherogenic and antioxidant properties. Many of its beneficial health properties and applications date back to antiquity, and the European Medicines Agency officially acknowledged it as an herbal medicinal product. Indeed, it is widely employed in conventional medicine to treat several diseases, including type 2 diabetes (T2D). On this basis, this review aims to summarize and describe the chemical composition of different parts of the plant and highlight the potential of P. lentiscus, focusing on its antidiabetic activities. The plant kingdom is drawing increasing attention because of its complexity of natural molecules in the research of novel bioactive compounds for drug development. In this context, P. lentiscus demonstrated several in vitro and in vivo antidiabetic effects, acting upon many therapeutic T2D targets. Therefore, the information available in this review highlighted the multitarget effects of P. lentiscus and its great potential in T2D treatment.

Exploring the inhibitory action of betulinic acid on key digestive enzymes linked to diabetes via in vitro and computational models: approaches to anti-diabetic mechanisms

Phytochemicals are now increasingly exploited as remedial agents for the management of diabetes due to side effects attributable to commercial antidiabetic agents. This study investigated the structural and molecular mechanisms by which betulinic acid exhibits its antidiabetic effect via in vitro and computational techniques. In vitro antidiabetic potential was analysed via on α-amylase, α-glucosidase, pancreatic lipase and α-chymotrypsin inhibitory assays. Its structural and molecular inhibitory mechanisms were investigated using Density Functional Theory (DFT) analysis, molecular docking and molecular dynamics (MD) simulation. Betulinic acid significantly (p < 0.05) inhibited α-amylase, α-glucosidase, pancreatic lipase and α-chymotrypsin enzymes with IC50 of 70.02 μg/mL, 0.27 μg/mL, 1.70 μg/mL and 8.44 μg/mL, respectively. According to DFT studies, betulinic acid possesses similar reaction in gaseous phase and water due to close values observed for highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) and the chemical descriptors. The dipole moment indicates that betulinic acid has high polarity. Molecular electrostatic potential surface revealed the electrophilic and nucleophilic attack-prone atoms of the molecule. Molecular dynamic studies revealed a stable complex between betulinic acid and α-amylase, α-glucosidase, pancreatic lipase and α-chymotrypsin. The study elucidated the potent antidiabetic properties of betulinic acid by revealing its conformational inhibitory mode of action on enzymes involved in the onset of diabetes.

Vanillin improves glucose homeostasis and modulates metabolic activities linked to type 2 diabetes in fructose-streptozotocin induced diabetic rats

OBJECTIVE

This study investigated the antidiabetic effect of vanillin using in vitro, in silico, and in vivo experimental models.

METHODOLOGY

Type 2 diabetes (T2D) was induced in male Sprague-Dawley (SD) rats using fructose-streptozotocin (STZ), then orally administered low (150 mg/kg bodyweight) or high (300 mg/kg bodyweight) dose of vanillin for 5 weeks intervention period.

RESULTS

Vanillin suppressed the levels of blood glucose, serum cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL-c), alanine transaminase (ALT), aspartate transaminase (AST), creatinine, urea, uric acid, when elevated serum insulin, HDL-cholesterol, and concomitantly improved pancreatic β-cell function, glucose tolerance, and pancreatic morphology. It also elevated both serum and pancreatic tissue GSH level, SOD and catalase activities, and hepatic glycogen level, while depleting malondialdehyde level, α-amylase, lipase, acetylcholinesterase, ATPase, ENTPDase and 5'-nucleotidase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and glycogen phosphorylase activities.

CONCLUSIONS

The results indicate the potent antidiabetic effect of vanillin against T2D and its associated complications.

Discovery of N-(phenylsulfonyl)thiazole-2-carboxamides as potent α-glucosidase inhibitors

In a search for novel nonsugar α-glucosidase inhibitors for diabetes treatment, a series of N-(phenylsulfonyl)thiazole-2-carboxamide derivatives were designed and synthesized, the α-glucosidase inhibitory activities were then evaluated. Several compounds with promising α-glucosidase inhibitory effects were identified. Among these, compound W24 which shows low cytotoxicity and good α-glucosidase inhibitory activity with an IC50 value of 53.0 ± 7.7 μM, is more competitive compared with the commercially available drug acarbose (IC50  = 228.3 ± 9.2 μM). W24 was identified as a promising candidate in the development of α-glucosidase inhibitors. Molecular docking studies and molecular dynamics simulation were also performed to reveal the binding pattern of the active compound to α-glucosidase, and the binding free energy of the best compound W24 was 36.3403 ± 3.91 kcal/mol.

Phenolics from Dendrobium officinale Leaf Ameliorate Dextran Sulfate Sodium-Induced Chronic Colitis by Regulating Gut Microbiota and Intestinal Barrier

The increasing incidence of colitis and the side effects of its therapeutic drugs have led to the search for compounds of natural origin, including phenolics, as new treatments for colitis. In this study, the potential mechanism of Dendrobium officinale leaf phenolics (DOP) on the relief of dextran sulfate sodium (DSS)-induced colitis was explored. The results showed that DOP treatment for 36 days reduced the symptoms of colitis caused by DSS, including reduction of the disease activity index and alleviation of colonic tissue damage. In addition, DOP downregulated the expression of key proteins of the TLR4/NF-κB signaling pathway and reduced the production of inflammatory cytokines. Furthermore, DOP could enhance the expression of tight junction proteins including ZO-1, Occludin, and Claudin-1 to restore intestinal mucosal barrier function. DOP also effectively regulates disordered intestinal flora and enhances the production of short-chain fatty acids, which is also beneficial in modulating gut internal environmental homeostasis, inhibiting inflammation, and restoring the intestinal barrier. These findings indicated that DOP can ameliorate DSS-induced chronic colitis by regulating gut microbiota, intestinal barrier, and inflammation, and it is a promising ingredient from D. officinale.

Traceability Research on Dendrobium devonianum Based on SWATHtoMRM

SWATHtoMRM technology was used in this experiment to further identify and trace the sources of Dendrobium devonianum and Dendrobium officinale produced in the same area using TOF and MS-MRM. After the conversion of the R package of SWATHtoMRM, 191 MRM pairs of positive ions and 96 pairs of negative ions were obtained. Dendrobium devonianum and Dendrobium officinale can be separated very well using the PCA and PLS-DA analysis of MRM ion pairs; this shows that there are obvious differences in chemical composition between Dendrobium devonianum and Dendrobium officinale, which clearly proves that the pseudotargeted metabolomics method based on SWATHtoMRM can be used for traceability identification research. A total of 146 characteristic compounds were obtained, with 20 characteristic compounds in Dendrobium devonianum. The enrichment pathways of the characteristic compounds were mainly concentrated in lipids and atherosclerosis, chagas disease, fluid shear stress and atherosclerosis, proteoglycans in cancer, the IL-17 signaling pathway, the sphingolipid signaling pathway, diabetic cardiomyopathy, arginine and proline metabolism, etc., among which the lipid and atherosclerosis pathways were more enriched, and 11 characteristic compounds affected the expression levels of IL-1, TNFα, CD36, IL-1β, etc. These can be used as a reference for research on variety improvement and active substance accumulation in Dendrobium devonianum and Dendrobium officinale.

Chemical compositions and biological activities of Serevenia buxifolia essential oil leaves cultivated in Vietnam (Thua Thien Hue)

Serevenia buxifolia is an evergreen citrus plant and has attracted considerable attention due to its bioactive components and biological activities. In the present study, the essential oil (EO) from S. buxifolia cultivated in Vietnam was demonstrated to exhibit the in vitro antioxidant, thrombolytic, anti-hemolysis, anti-inflammatory, and antidiabetic activities. Briefly, the gas chromatography coupled to mass spectrometry analysis revealed that the leaf EO of S. buxifolia was composed of 33 components, with the main constituents being β-carypphyllene (32.5%), and elixene (9.8%). The extracted oil possessed a fairly high free radical scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH), with an IC₅₀ value of 190.7 μg/mL compared with positive control, α-tocopherol, IC₅₀ value of 42.6 μg/mL. The EO also exhibited thrombolytic activity: the percentage of inhibition was found to be 70.75% at 100 μL, in comparison with 87.2% for the positive control, streptokinase. For hemolytic activity, the percentage of inhibition of the EO was from 27.4% to 59.6% at concentrations from 10 to 100 μg/mL, respectively. The results of in vitro anti-inflammatory activity indicated that the EO of S. buxifolia leaves effectively protects the heat-induced denaturation, with an IC₅₀ value of 40.25 μg/mL. The EO also exhibited antidiabetic potential, with IC₅₀ values of 87.8 and 134.9 μg/mL against α-amylase and α-glucosidase, respectively. It is noteworthy that the potent biological activities of the obtained S. buxifolia oil increased in a dose-dependent manner. The results achieved show that the EO of S. buxifolia leaves can be a potential source for oxidative stress, inflammatory, and diabetic management.

Chemical Constituents and Hypoglycemic Mechanisms of Dendrobium nobile in Treatment of Type 2 Diabetic Rats by UPLC-ESI-Q-Orbitrap, Network Pharmacology and In Vivo Experimental Verification

This study aimed to systematically explore the chemical constituents of D. nobile and its hypoglycemic effect by UPLC-ESI-Q-Orbitrap, network pharmacology and in vivo experiment. The chemical constituents of D. nobile were qualitatively analyzed, and the hypoglycemic compounds were quickly identified. Network pharmacological analysis and molecular docking technique were applied to assist in the elucidation of the hypoglycemic mechanisms of D. nobile. A type 2 diabetic mellitus (T2DM) rat model was established using the HFD and STZ method for in vivo experimental verification, and these T2DM rats were treated with D. nobile extract and D. nobile polysaccharide for two months by gavage. The results showed that a total of 39 chemical constituents of D. nobile, including alkaloids, bibenzyls, phenanthrenes and other types of compounds, were identified. D. nobile extract and D. nobile polysaccharide could significantly ameliorate the body weight, hyperglycemia, insulin resistance, dyslipidemia and morphological impairment of the liver and pancreas in the T2DM rats. α-Linolenic acid, dihydroconiferyl dihydro-p-coumarate, naringenin, trans-N-feruloyltyramine, gigantol, moscatilin, 4-O-methylpinosylvic acid, venlafaxine, nordendrobin and tristin were regarded as the key hypoglycemic compounds of D. nobile, along with the hypoglycemic effect on the PI3K-AKT signaling pathway, the insulin signaling pathway, the FOXO signaling pathway, the improvement of insulin resistance and the AGE-RAGE signaling pathway. The Western blotting experiment results confirmed that D. nobile activated the PI3K/AKT pathway and insulin signaling pathway, promoted glycogen synthesis via regulating the expression of glycogen synthase kinase 3 beta (GSK-3β) and glucose transporter 4 (GLUT4), and inhibited liver gluconeogenesis by regulating the expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6 phosphatase (G6pase) in the liver. The results suggested that the hypoglycemic mechanism of D. nobile might be associated with liver glycogen synthesis and gluconeogenesis, contributing to improving insulin resistance and abnormal glucose metabolism in the T2DM rats.

The standardized Jamu pahitan, an Indonesian antidiabetic formulation, stimulating the glucose uptake and insulin secretion in the in-vitro models

Jamu pahitan is a polyherbal formulation commonly used for the traditional management of diabetes in Indonesia and is mainly prepared from Andrographis paniculata (Burm.f.) Nees. It is widely varied in herbal composition for every region has their own plant component addition to the formulation. A version of the formulation used in the greater Surakarta area contained five plant constituents. This study evaluated the in-vitro glucose uptake and insulin secretion stimulatory activities of Jamu pahitan to provide scientific evidence on its efficacy and safety of use. The water and ethanol extracts of three Jamu pahitan formulations were prepared. The total phenolic content (TPC) of the extracts was evaluated by the standard Folin-Ciocalteau method. Their effects on the viability of L6 skeletal muscle and RIN-m5F pancreatic cells were evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The glucose utilized by L6 myotubes treated with Jamu pahitan was assessed indirectly by the glucose oxidase method. The insulin secreted by RIN-m5F treated with the formulation extracts was analyzed by the enzyme-linked immunosorbent assay (ELISA). The correlation between TPC and the profile of safety and efficacy of the formulation was statistically evaluated. The water extracts of Jamu pahitan were safe and exerted significant glucose uptake and insulin secretion stimulatory activity in L6 and RIN-m5F, respectively. The ethanol extracts showed more potent effects than their water counterpart, albeit they exerted cytotoxic effects on the cells at the higher tested concentrations. The formulations at lower concentrations stimulated the proliferation of RIN-m5F. In addition, the TPC was strongly correlated with the glucose uptake and insulin secretion stimulatory activities and also the IC₅₀ of the cells in positive manner. The present study supported the use of Jamu pahitan for the traditional management of diabetes in Indonesia by stimulating glucose uptake in the muscle cells and improving insulin secretion in β-cells.

Chemistry and Pharmacology of Bergenin or Its Derivatives: A Promising Molecule

Bergenin is a glycosidic derivative of trihydroxybenzoic acid that was discovered in 1880 by Garreau and Machelart from the rhizomes of the medicinal plant Bergenia crassifolia (currently: Saxifraga crassifolia—Saxifragaceae), though was later isolated from several other plant sources. Since its first report, it has aroused interest because it has several pharmacological activities, mainly antioxidant and anti-inflammatory. In addition to this, bergenin has shown potential antimalarial, antileishmanial, trypanocidal, antiviral, antibacterial, antifungal, antinociceptive, antiarthritic, antiulcerogenic, antidiabetic/antiobesity, antiarrhythmic, anticancer, hepatoprotective, neuroprotective and cardioprotective activities. Thus, this review aimed to describe the sources of isolation of bergenin and its in vitro and in vivo biological and pharmacological activities. Bergenin is distributed in many plant species (at least 112 species belonging to 34 families). Both its derivatives (natural and semisynthetic) and extracts with phytochemical proof of its highest concentration are well studied, and none of the studies showed cytotoxicity for healthy cells.

Lentinus squarrosulus Mont. Mushroom: Molecular Identification, In vitro Anti-Diabetic, Anti-Obesity, and Cytotoxicity Assessment

Objectives

Mushrooms are fungi with nutritional and health benefits. Lentinus squarrosulus Mont., an edible fungus, has traditional usage and relevance in local therapy for managing metabolic diseases. In that view, this study aimed to evaluate the in vitro anti-obesity, anti-diabetic, and cytotoxic potential of the chloroform/methanol extract (CME) and aqueous extract (AE) of the mushroom.

Materials and Methods

L. squarrosulus was identified using molecular biology tools. The CME and AE were obtained sequentially and, then, subjected to α-amylase, α-glucosidase, and lipase inhibitory enzyme assays as well as total phenolic content (TPC) and flavonoid content (TFC) estimations. The cytotoxic potential of extract fractions of L. squarrosulus was assessed using the brine shrimp lethality assay.

Results

The molecular identification of the mushroom displayed that the internal transcribed spacer sequence was an equivalent match to that of L. squarrosulus with a high percentage similarity, and thus assigned a unique accession number (KT120043.1). The CME of L. squarrosulus had higher TPC, TFC, and α-glucosidase inhibitory activity than AE. Furthermore, AE of the mushroom showed a higher lipase inhibitory potential with an IC₅₀ value of 22.28 ± 0.65 μg/mL than the CME, while that of the reference, i.e. orlistat was 2.28 ± 0.34 μg/mL. However, these extracts exhibited very low or no α-amylase inhibitory and cytotoxic activity at the tested concentrations.

Conclusion

This study reveals that CME of L. squarrosulus, rich in polyphenols and flavonoids, possesses considerable α-glucosidase and lipase inhibitory activities.

Recent Research Progress on Natural Stilbenes in Dendrobium Species

Dendrobium is the second biggest genus in the Orchidaceae family, and many of them have been utilized as a traditional Chinese medicine (TCM) for thousands of years in China. In the last few decades, constituents with great chemical diversity were isolated from Dendrobium, and a wide range of biological activities were detected, either for crude extracts or for pure compounds. Stilbene compound is one of the primary active constituents in the genus Dendrobium. At present, 267 stilbene compounds with clarified molecular structures have been extracted and isolated from 52 species of Dendrobium, including 124 phenanthrenes and 143 bibenzyls. At the same time, activity studies have indicated that 157 compounds have pharmaceutical activity. Among them, most of the compounds showed antitumor activity, followed by antioxidant, anti-inflammatory and anti-α-glucosidase inhibitory activities. Additionally, 54 compounds have multiple pharmacological activities, such as confusarin (14), 2,4,7-trihydroxy-9,10-dihydro-phenanthrene (43), moscatilin (148), gigantol (150) and batatasin III (151). This review summarizes current knowledge about the chemical composition of stilbene, bioactivities and pharmacologic effects in 52 species of Dendrobium. We also expect to provide a reference for further research, development and utilization of stilbene constituents in the Dendrobium genus.

Inhibition of α-Glucosidase and Pancreatic Lipase Properties of Mitragyna speciosa (Korth.) Havil. (Kratom) Leaves

Kratom (Mitragyna speciosa (Korth.) Havil.) has been used to reduce blood sugar and lipid profiles in traditional medicine, and mitragynine is a major constituent in kratom leaves. Previous data on the blood sugar and lipid-altering effects of kratom are limited. In this study, phytochemical analyses of mitragynine, 7-hydroxymitragynine, quercetin, and rutin were performed in kratom extracts. The effects on α-glucosidase and pancreatic lipase activities were investigated in kratom extracts and mitragynine. The LC-MS/MS analysis showed that the mitragynine, quercetin, and rutin contents from kratom extracts were different. The ethanol extract exhibited the highest total phenolic content (TPC), total flavonoid content (TFC), and total alkaloid content (TAC). Additionally, compared to methanol and aqueous extracts, the ethanol extract showed the strongest inhibition activity against α-glucosidase and pancreatic lipase. Compared with the anti-diabetic agent acarbose, mitragynine showed the most potent α-glucosidase inhibition, with less potent activity of pancreatic lipase inhibition. Analysis of α-glucosidase and pancreatic lipase kinetics revealed that mitragynine inhibited noncompetitive and competitive effects, respectively. Combining mitragynine with acarbose resulted in a synergistic interaction with α-glucosidase inhibition. These results have established the potential of mitragynine from kratom as a herbal supplement for the treatment and prevention of diabetes mellitus.

LC-HRMS-Based Profiling: Antibacterial and Lipase Inhibitory Activities of Some Medicinal Plants for the Remedy of Obesity

Globally, obesity is a serious health concern that causes numerous diseases, including type 2 diabetes, hypertension, cardiovascular diseases, etc. Medicinal plants have been used to aid in weight loss since ancient times. Thus, this research is focused on the exploration of pancreatic lipase inhibitory activity and secondary metabolite profiling of Bergenia ciliata, Mimosa pudica, and Phyllanthus emblica, selected based on an ethnobotanical survey. The lipase inhibition was investigated using 4-nitrophenyl butyrate (p-NPB) as a substrate. To uncover further therapeutic potentials of these medicinal plants, antimicrobial activity and minimum inhibitory concentration (MIC) of the extracts were also determined. The ethyl acetate plant extracts showed higher antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Shigella sonnei. The MIC of ethyl acetate extracts of medicinal plants considered in this study ranges from 1.56 to 6.25 mg/mL. The hexane fraction of Mimosa pudica and Phyllanthus emblica showed a higher lipase inhibitory activity as compared to others, with IC50 values of 0.49 ± 0.02 and 2.45 ± 0.003 mg/mL, respectively. In the case of Bergenia ciliata, the methanolic extract inhibited lipase more effectively than others, with an IC50 value of 1.55 ± 0.02 mg/mL (IC50 value of orlistat was 179.70 ± 3.60 µg/mL). A mass spectrometry analysis of various solvent/solvent partition fractions (extracts) revealed 29 major secondary metabolites. The research offers a multitude of evidence for using medicinal plants as antiobesity and antimicrobial agents.

Secondary Metabolites in the Dendrobium heterocarpum Methanolic Extract and Their Impacts on Viability and Lipid Storage of 3T3-L1 Pre-Adipocytes

Although many natural products have proven their potential to regulate obesity through the modulation of adipocyte biology, none of them has yet been approved for clinical use in obesity therapy. This work aims to isolate valuable secondary metabolites from an orchid species (Dendrobium heterocarpum) and evaluate their possible roles in the growth and differentiation of 3T3-L1 pre-adipocytes. Six compounds were isolated from the orchid’s methanolic extracts and identified as amoenylin (1), methyl 3-(4-hydroxyphenyl) propionate (2), 3,4-dihydroxy-5,4’-dimethoxybibenzyl (3), dendrocandin B (4), dendrofalconerol A (5), and syringaresinol (6). Among these phytochemicals, compounds 2, 3, and 6 exhibited lower effects on the viability of 3T3-L1 cells, offering non-cytotoxic concentrations of ≲ 10 µM. Compared to others tested, compound 3 was responsible for the maximum reduction of lipid storage in 3T3-L1 adipocytes (IC₅₀ = 6.30 ± 0.10 µM). A set of protein expression studies unveiled that compound 3 at non-cytotoxic doses could suppress the expression of some key transcription factors in adipocyte differentiation (i.e., PPARγ and C/EBPα). Furthermore, this compound could deactivate some proteins involved in the MAPK pathways (i.e., JNK, ERK, and p38). Our findings prove that D. heterocarpum is a promising source to explore bioactive molecules capable of modulating adipocytic growth and development, which can potentially be assessed and innovated further as pharmaceutical products to defeat obesity.

Phenanthrenes from Dendrobium senile and their pancreatic lipase inhibitory activity

From the whole plant of Dendrobium senile, a new phenanthrene namely 2,5,7-trihydroxy-4-methoxyphenanthrene (1) was isolated, together with seven known compounds including moscatin (2), 2,5-dihydroxy-4,9-dimethoxyphenanthrene (3), moscatilin (4), aloifol I (5), 4,4',8,8'-tetramethoxy[1,1'-biphenanthrene]-2,2',7,7'-tetrol (6), 2,2',7,7'-tetrahydroxy-4,4'-dimethoxy-1,1'-biphenanthrene (7) and bleformin G (8). The structure of the new compound was elucidated by analysis of its spectroscopic data. Moscatin (2) and 2,5-dihydroxy-4,9-dimethoxyphenanthrene (3) showed appreciable pancreatic lipase inhibitory effects when compared with the positive control orlistat.

Discovery of Natural Lead Compound from Dendrobium sp. against SARS-CoV-2 Infection

Since the pandemic of severe acute respiratory syndrome coronavirus (SARS-CoV-2) in December 2019, the infection cases have quickly increased by more than 511 million people. The long epidemic outbreak over 28 months has affected health and economies worldwide. An alternative medicine appears to be one choice to alleviate symptoms and reduce mortality during drug shortages. Dendrobium extract is one of the traditional medicines used for COVID-19 infection. Several compounds in Dendrobium sp. had been reported to exert pharmacological activities to treat common COVID-19-related symptoms. Herein, in silico screening of 83 compounds from Dendrobium sp. by using the SARS-CoV-2 spike protein receptor-binding domain (RBD) as a drug target was performed in searching for a new lead compound against SARS-CoV-2 infection. Four hit compounds showing good binding affinity were evaluated for antiviral infection activity. The new lead compound DB36, 5-methoxy-7-hydroxy-9,10-dihydro-1,4-phenanthrenequinone, was identified with the IC50 value of 6.87 ± 3.07 µM. The binding mode revealed that DB36 bound with the spike protein at the host receptor, angiotensin-converting enzyme 2 (ACE2) binding motif, resulted in antiviral activity. This study substantiated the use of Dendrobium extract for the treatment of SARS-CoV-2 infection and has identified new potential chemical scaffolds for further drug development of SARS-CoV-2 entry inhibitors.

Adipose and non-adipose perspectives of plant derived natural compounds for mitigation of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Phyto-preparations and phyto-compounds, by their natural origin, easy availability, cost-effectiveness, and fruitful traditional uses based on accumulated experiences, have been extensively explored to mitigate the global burden of obesity.

AIM OF THIS REVIEW

The review aimed to analyse and critically summarize the prospect of future anti-obesity drug leads from the extant array of phytochemicals for mitigation of obesity, using adipose related targets (adipocyte formation, lipid metabolism, and thermogenesis) and non-adipose targets (hepatic lipid metabolism, appetite, satiety, and pancreatic lipase activity). Phytochemicals as inhibitors of adipocyte differentiation, modulators of lipid metabolism, and thermogenic activators of adipocytes are specifically discussed with their non-adipose anti-obesogenic targets.

MATERIALS AND METHODS

PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets. The taxonomically accepted name of each plant in this review has been vetted from "The Plant List" (www.theplantlist.org) or MPNS (http://mpns.kew.org).

RESULTS

Available knowledge of a large number of phytochemicals, across a range of adipose and non-adipose targets, has been critically analysed and delineated by graphical and tabular depictions, towards mitigation of obesity. Neuro-endocrinal modulation in non-adipose targets brought into sharp dual focus, both non-adipose and adipose targets as the future of anti-obesity research. Numerous phytochemicals (Berberine, Xanthohumol, Ursolic acid, Guggulsterone, Tannic acid, etc.) have been found to be effectively reducing weight through lowered adipocyte formation, increased lipolysis, decreased lipogenesis, and enhanced thermogenesis. They have been affirmed as potential anti-obesity drugs of future because of their effectiveness yet having no threat to adipose or systemic insulin sensitivity.

CONCLUSION

Due to high molecular diversity and a greater ratio of benefit to risk, plant derived compounds hold high therapeutic potential to tackle obesity and associated risks. This review has been able to generate fresh perspectives on the anti-diabetic/anti-hyperglycemic/anti-obesity effect of phytochemicals. It has also brought into the focus that many phytochemicals demonstrating in vitro anti-obesogenic effects are yet to undergo in vivo investigation which could lead to potential phyto-molecules for dedicated anti-obesity action.

Phenolic Profiles and Biological Activities of Extracts from Edible Wild Fruits Ehretia tinifolia and Sideroxylon lanuginosum

Ehretia tinifolia Linnaeus (Boraginacea) and Sideroxylon lanuginosum Michaux (Sapotaceae) are wild fruits consumed in North America and are appreciated for their pleasant flavor and sweet taste. However, details regarding their composition and biological properties in the available literature are scarce. This study reports the phenolic composition, antioxidant, antiproliferative activities, and digestive enzymatic inhibition of amberlite-retained methanolic extracts from both fruits. Results revealed that these wild fruit extracts are rich in antioxidants. S. lanuginosum had lower phenolic but higher flavonoid contents (21.4 ± 1.5 mg GAE/100 g FW and 6.42 ± 0.9 mg CE/100 g FW) than E. tinifolia (64.7 ± 2.6 mg GAE/100 g FW and 5.1 ± 0.4 mg CE/100 g FW). HPLC-DAD-MS/MS analysis showed rosmarinic acid as a major polyphenol in E. tinifolia and quercetin glucoside in S. lanuginosum. Polyphenols content in E. tinifolia was related to a significant free radical scavenging ability: DPPH (EC50 = 0.32 ± 0.03 mg/mL), TEAC (4134 ± 9.7 μM TE/g dry extract), and hemolysis inhibition (IC50 = 58.55 ± 2.4 μg/mL). Both extracts were capable of inhibiting α-glucosidase, partially inhibiting α-amylase, and showed no inhibition against lipase, while showing antiproliferative activity against HeLa, HT-29 and MCF-7 cancer cell lines. Our study revealed that these wild fruit extracts are rich in health-beneficial phytochemicals and hold significant potential for elaborating functional foods.

Extraction and purification of total flavonoids from Eupatorium lindleyanum DC. and evaluation of their antioxidant and enzyme inhibitory activities

The health benefits and promising medical treatment potential of total flavonoids from Eupatorium lindleyanum DC. (TFELDC) have been recognized. The process parameters of extracting total flavonoids from Eupatorium lindleyanum DC. by ultrasonic-microwave synergistic extraction (UMSE) were optimized, and they were purified by AB-8 macroporous resin in the current study. In addition, the antioxidant and enzyme inhibitory activities of the purified TFELDC (PTFELDC) were evaluated. The results showed that the optimal parameters of UMSE were as follows: ethanol volume fraction 71.5%, L/S ratio 12.2 ml/g, microwave power 318 W, and extraction time 143 s. After TFELDC were purified by AB-8 macroporous resin, the total flavonoid contents of PTFELDC increased from 208.18 ± 1.60 to 511.19 ± 3.21 mg RE/g FDS. Compared with TFELDC, the content of total flavonoids in PTFELDC was increased by 2.46 times. The antioxidant activities of PTFELDC were assessed using DPPH radical, superoxide anion radical, reducing power, and ferric reducing antioxidant power assays, and the IC50 values were found to be 37.13, 19.62, 81.22, and 24.72 μg/ml, respectively. The enzyme inhibitory activities of PTFELDC were measured using lipase, α-amylase, α-glucosidase, and acetylcholinesterase assays with the IC50 values 1.38, 2.08, 1.63, and 0.58 mg/ml, respectively. By comparing with their positive controls, it was found that PTFELDC had good antioxidant activities, and lipase, α-amylase, and α-glucosidase inhibitory activities, However, the acetylcholinesterase inhibitory activity was relatively weaker. These results suggested that PTFELDC have a promising potential as natural antioxidant, antilipidemic, and hypoglycemic drugs used in functional foods or pharmaceuticals.

Erianthridin Induces Non-small Cell Lung Cancer Cell Apoptosis through the Suppression of Extracellular Signal-regulated Kinase Activity

Due to the high mortality of lung cancer, natural derivative compounds have been promoted as versatile sources for anticancer drug discovery. Erianthridin, a phenanthrene compound isolated from Dendrobium formosum, exhibits intriguing apoptosis-inducing effects in non-small cell lung cancer cells. Apoptotic nuclei staining assays showed that apoptotic cells with DNA fragmentation and apoptotic bodies were apparent, and an increase in annexin V-FITC-positive cells were found in cells treated with erianthridin. The apoptosis protein markers for cleaved caspase-3 and cleaved poly-ADP-ribose polymerase were significantly upregulated in response to erianthridin. A mechanistic investigation revealed that erianthridin was able to attenuate extracellular signal-regulated kinase activity and thereby mediate apoptosis through the modulation of Bcl-2 family protein levels. U0126, an extracellular signal-regulated kinase inhibitor, augmented the apoptosis-inducing effect of erianthridin; in contrast, overexpression of exogenous extracellular signal-regulated kinase substantially abrogated erianthridin activity. Furthermore, an in vitro 3D tumorigenesis assay showed that erianthridin was able to potentially suppress lung cancer cell proliferation. This study is the first to report a promising cytotoxic effect of erianthridin, which provides preclinical evidence for further research and development of this compound.

Three Novel Biphenanthrene Derivatives and a New Phenylpropanoid Ester from Aerides multiflora and Their α-Glucosidase Inhibitory Activity

A phytochemical investigation on the whole plants of Aerides multiflora revealed the presence of three new biphenanthrene derivatives named aerimultins A-C (1-3) and a new natural phenylpropanoid ester dihydrosinapyl dihydroferulate (4), together with six known compounds (5-10). The structures of the new compounds were elucidated by analysis of their spectroscopic data. All of the isolates were evaluated for their α-glucosidase inhibitory activity. Aerimultin C (3) showed the most potent activity. The other compounds, except for compound 4, also exhibited stronger activity than the positive control acarbose. Compound 3 showed non-competitive inhibition of the enzyme as determined from a Lineweaver-Burk plot. This study is the first phytochemical and biological investigation of A. multiflora.

Ferulic acid promotes muscle glucose uptake and modulate dysregulated redox balance and metabolic pathways in ferric-induced pancreatic oxidative injury

The antidiabetic properties of ferulic acid and its protective role against Fe²⁺ -induced oxidative pancreatic injury were investigated in this study using in vitro and ex vivo models. Induction of oxidative injury in the pancreas was achieved by incubating normal pancreatic tissue with 0.1 mM FeSO₄ and treated by co-incubating with different concentrations of ferulic acid for 30 min at 37°C. Ferulic acid inhibited the activities of α-glucosidase, α-amylase, and pancreatic lipase significantly (p < .05) and promoted glucose uptake in isolated rat psoas muscles. Induction of oxidative pancreatic injury caused significant (p < .05) depletion of glutathione (GSH) level, superoxide dismutase (SOD), and catalase activities, as well as elevation of malondialdehyde (MDA) and nitric oxide (NO) levels, acetylcholinesterase and chymotrypsin activities. Treatment of tissues with ferulic acid significantly (p < .05) reversed these levels and activities. LC-MS analysis of the extracted metabolites revealed 25% depletion of the normal metabolites with concomitant generation of m-Chlorohippuric acid, triglyceride, fructose 1,6-bisphosphate, and ganglioside GM1 in oxidative-injured pancreatic tissues. Treatment with ferulic acid restored uridine diphosphate glucuronic acid and adenosine tetraphosphate and generated P1,P4-Bis(5'-uridyl) tetraphosphate and L-Homocysteic acid, while totally inactivating oxidative-generated metabolites. Ferulic acid also inactivated oxidative-activated pathways, with concomitant reactivation of nucleotide sugars metabolism, starch and sucrose metabolism, and rostenedione metabolism, estrone metabolism, androgen and estrogen metabolism, porphyrin metabolism, and purine metabolism pathways. Taken together, our results indicate the antidiabetic and protective potential of ferulic acid as depicted by its ability to facilitate muscle glucose uptake, inhibit carbohydrate and lipid hydrolyzing enzymes, and modulate oxidative-mediated dysregulated metabolisms. PRACTICAL APPLICATIONS: There have been increasing concerns on the side effects associated with the use of synthetic antidiabetic drug, coupled with their expenses particularly in developing countries. This has necessitated continuous search for alternative treatments especially from natural products having less or no side effects and are readily available. Ferulic acid is among the common phenolics commonly found in fruits and vegetables. In this present study, ferulic acid was able to attenuate oxidative stress, cholinergic dysfunction, and proteolysis in oxidative pancreatic injury, as well as inhibit carbohydrate digesting enzymes. Thus, indicating the ability of the phenolic to protect against complications linked to diabetes. Crops rich in ferulic acid maybe beneficial in managing this disease.

Four Novel Phenanthrene Derivatives with α-Glucosidase Inhibitory Activity from Gastrochilus bellinus

Four new phenanthrene derivatives, gastrobellinols A-D (1–4), were isolated from the methanolic extract of Gastrochilus bellinus (Rchb.f.) Kuntze, along with eleven known phenolic compounds including agrostophyllin (5), agrostophyllidin (6), coniferyl aldehyde (7), 4-hydroxybenzaldehyde (8), agrostophyllone (9), gigantol (10), 4-(methoxylmethyl)phenol (11), syringaldehyde (12), 1-(4′-hydroxybenzyl)-imbricartin (13), 6-methoxycoelonin (14), and imbricatin (15). Their structures were determined by spectroscopic methods. Each isolate was evaluated for α-glucosidase inhibitory activity. Compounds 1, 2, 3, 7, 9, 13, and 15 showed higher activity than the drug acarbose. Gastrobellinol C (3) exhibited the strongest α-glucosidase inhibition with an IC₅₀ value of 45.92 μM. A kinetic study of 3 showed competitive inhibition on the α-glucosidase enzyme. This is the first report on the phytochemical constituents and α-glucosidase inhibitory activity of G. bellinus.

Bridelia ferruginea inhibits key carbohydrate digesting enzyme and intestinal glucose absorption and modulates glucose metabolism in diabetic rats

The antidiabetic potentials of the dichloromethene, ethyl acetate, butanol and aqueous fractions of Bridelia ferruginea leaves were investigated using in vitro, ex vivo and in vivo models. In vitro and ex vivo antidiabetic activities revealed the butanol (BFBF) to be the most active of the fractions, and thus selected for in vivo study. Diabetes was induced using the fructose-streptozotocin model. Treatments with BFBF significantly reduced blood glucose level and improved glucose tolerance, serum insulin level and sensitivity as well as suppressed hyperlipidaemia and serum nephropathy markers. Histopathological analysis revealed the ability of BFBF to protect and regenerate pancreatic β-cells. BFBF significantly elevated glutathione level, catalase and superoxide dismutase activities, while depleting MDA level in serums and kidney of diabetic rats. Phenols, steroids, terpenoids, aliphatic and aromatic compounds were identified in the fractions following GC-MS analysis. Overall, results from this study propose that BFBF possess potent antidiabetic activity.

Screening of β-secretase inhibitors from Dendrobii Caulis by covalently enzyme-immobilized magnetic beads coupled with ultra-high-performance liquid chromatography

In the present study, to effectively discover potential β-secretase inhibitors from Dendrobii Caulis, β-secretase was immobilized on magnetic beads via direct covalent connection and coupled with ultra-high-performance liquid chromatography. Mechanochemical-assisted extraction was used to extract active ingredients from Dendrobii Caulis. The main reaction conditions, including screening enzyme inhibitors, were evaluated, and the most important enzyme kinetic parameters were also investigated across the UV-vis spectrophotometer. Five compounds (rutin, scoparone, naringenin, dendrophenol, and erianin) with high binding affinity to magnetic beads were removed from the extract. The results indicated that β-secretase was successfully immobilized and screened out five potential inhibitor compounds by ligand fishing. The lowest IC₅₀ values were noted for rutin (5.437 μM) and erianin (2.039 μM). This is the first report on immobilized β-secretase on magnetic beads for the identification of potential active compounds against Alzheimer's disease from complex biological mixtures.

Profiling the phyto-constituents of Punica granatum fruits peel extract and accessing its in-vitro antioxidant, anti-diabetic, anti-obesity, and angiotensin-converting enzyme inhibitory properties

This context was investigated to assess the in vitro antioxidant, anti-diabetic, anti-obesity, and angiotensin-converting enzyme (ACE) inhibition traits of Punica granatum fruits peel extract. Initially, among various extracts tested, aqueous and ethanolic peel extracts depicted the presence of diverse phytoconstituents. In vitro antioxidative properties of peel extracts were determined using standard methodologies. Results showed that aqueous and ethanolic extracts had IC₅₀ values of 471.7 and 509.16 μg/mL, respectively in terms of 1,1,diphenyl 2,2,picrylhydrazyl scavenging. Likewise, IC₅₀ values of aqueous and ethanol extract were obtained as 488.76 and 478.47 μg/mL towards the degradation of hydrogen peroxide. The ethanolic extract exhibited the highest inhibition of α-glucosidase by showing activity of 53.34 ± 2.0 to 15.18 ± 1.4 U/L in a dose dependent manner (100–1000 µg/mL). Ethanolic extract was reported as the most active inhibitor of lipase with an IC₅₀ value of 603.50 µg/mL. Ethanolic extract showed increased inhibition of ACE in a concentration dependent manner (100–1000 µg/mL) with IC₅₀ value of 519.45 µg/mL. Fourier transform-infrared spectrum revealed the availability of various functional groups in the ethanolic extract of peel. Gas chromatography-mass spectrometry chromatogram of peel extract illustrated 23 diversified chemical constituents including 1,2,3,4-butanetetrol, Dimethyl sulfone, 9-octadecenamide, and Pentadecanoic acid as predominant compounds. In summary, P. granatum fruits peel extract revealed promising antioxidant, anti-diabetic, anti-obesity, and anti-hypertensive properties.

Pharmacokinetic, bioavailability, and metabolism studies of lusianthridin, a dihydrophenanthrene compound, in rats by liquid chromatography/electrospray ionization tandem mass spectrometry

Lusianthridin was reported to possess many biological properties such as anti-oxidant and anti-cancer activities. However, its metabolic profiles and pharmacokinetics in vivo remain unknown. This study was carried out to investigate the metabolic profiles and pharmacokinetics of lusianthridin in rats. The metabolic profiles were obtained by an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). A total of eighteen metabolites involved three phase I metabolites and fifteen phase II metabolites were detected and identified. The major metabolic pathways of lusianthridin were demethylation, oxidation, sulfation, glucuronidation and glutathione conjugation. In addition, a simple and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established for determination of lusianthridin in rat plasma. After extracted by protein precipitation, lusianthridin was quantitated in positive ion mode. The method was linear over the range of 0.5-500 ng/mL (r ≥ 0.995) with the LLOQ of 0.5 ng/mL. The intra- and inter- precision and accuracy, extraction recovery, matrix effect and stability were within the acceptable limits. The validated method was applied to the pre-clinical pharmacokinetic study of lusianthridin in rats. After oral administration, lusianthridin was quickly absorbed into plasma and reached the max concentration of 236.22 ng/mL at 22.00 min. The elimination half life of lusianthridin from plasma was approximately 83.05-104.47 min and the oral absolute bioavailability was calculated as 30.93 %.

Acylated Aminooligosaccharides from the Yellow Sea Streptomyces sp. HO1518 as Both α-Glucosidase and Lipase Inhibitors

Three new acylated aminooligosaccharide (1-3), along with five known congeners (4-8), were isolated from the marine-derived Streptomyces sp. HO1518. Their structures were fully elucidated by extensive spectroscopic analysis, mainly based on 1D-selective and 2D TOCSY, HSQC-TOCSY, and HRESIMS spectrometry measurements, and by chemical transformations. All of the compounds were evaluated for their α-glucosidase and pancreatic lipase inhibitory activities. Among the isolates, D6-O-isobutyryl-acarviostatin II03 (3) and D6-O-acetyl-acarviostatin II03 (8), sharing acarviostatin II03-type structure, showed the most potent α-glucosidase and lipase inhibitory effects, far stronger than the antidiabetic acarbose towards α-glucosidase and almost equal to the anti-obesity orlistat towards lipase in vitro. This is the first report on inhibitory activities against the two major digestive enzymes for acylated aminooligosaccharides. The results from our investigation highlight the potential of acylated aminooligosaccharides for the future development of multi-target anti-diabetic drug.

Identification of lusianthridin metabolites in rat liver microsomes by liquid chromatography combined with electrospray ionization time-of-flight mass spectrometry

Lusianthridin, a bioactive component isolated from Dendrobium venustum, has been demonstrated to have many biological properties such as antioxidant and anticancer activities. However, the metabolic profiles remain unknown. This study was carried out to investigate the metabolic profiles of lusianthridin in liver microsomes. Lusianthridin was co-incubated with liver microsomes in the presence of nicotinamide adenine dinucleotide phosphate and UDP-glucuronic acid or glutathione at 37°C for 1 h. The incubation samples were analyzed by liquid chromatography combined with electrospray ionization high-resolution mass spectrometry. The data were acquired and processed. The structures of the metabolites were proposed by comparing their accurate mass and MS² spectra with those of the parent compound. A total of 15 metabolites were detected in vitro, including two phase I and 13 phase II metabolites. The phase I metabolic pathways were oxidation, demethylation and dehydrogenation. The phase II metabolic pathways referred to glucuronidation and glutathione conjugation. The present study provides an overview pertaining to the metabolic profiles of lusianthridin in vitro, which is indispensable for understanding the efficacy and safety of lusianthridin, as well as the herbal medicine D. venustum.

New Fluorene Derivatives from Dendrobium gibsonii and Their α-Glucosidase Inhibitory Activity

Two new compounds, dihydrodengibsinin (1) and dendrogibsol (2), were isolated from the whole plant of Dendrobium gibsonii, together with seven known compounds (3–9). The structures of the new compounds were elucidated by their spectroscopic data. All these isolates were evaluated for their α-glucosidase inhibitory activities. Dendrogibsol (2) and lusianthridin (7) showed strong α-glucosidase inhibitory activity when compared with acarbose. An enzyme kinetic study revealed that dendrogibsol (2) is a noncompetitive inhibitor of α-glucosidase.

Recent research progress on natural small molecule bibenzyls and its derivatives in Dendrobium species

Orchidaceous plant Dendrobium genus is often used as a tonic, and its phenolic components have attracted attention for its anti-tumor and anti-diabetic complications. Bibenzyls is one of the essential phenolic active ingredients in the Dendrobium genus. At present, 89 bibenzyl derivatives have been extracted and identified from 46 Dendrobium species. The activity studies have shown that 42 compounds have pharmaceutical activity. Among them, 23 compounds showed antitumor activity; 7 compounds showed anti-diabetes and its complications activity; 10 compounds exhibited neuroprotective effects; 18 compounds showed antioxidant effects; 11 compounds had anti-inflammatory activity; 3 compounds had Antiplatelet aggregation effects; 3 compounds had antibacterial and antiviral effects. The Bibenzyls is small-molecular compounds of natural origin and widely sourced. Previous studies showed that the bibenzyls has good anti-tumor, anti-diabetes and its complications, and neuroprotective effects, and it has great potential for treating tumors, diabetes and its complications, Alzheimer's disease (AD) and Parkinson's disease (PD). Additionally, compounds such as moscatilin (1), gigantol (2) and chrysotoxine (3) have been further studied as lead compounds, and compounds exhibited therapeutical effects had been synthesized. Enough pieces of evidences have shown that the Bibenzyls have good development prospects. This article reviews the pharmacological effects of bibenzyls in Dendrobium species and provides an idea for its further development.

Evaluation of ACE, α-glucosidase, and lipase inhibitory activities of peptides obtained by in vitro digestion of selected species of edible insects

The objective of this study was to examine the inhibition of the activity of enzymes associated with development of the metabolic syndrome by peptide fractions received from simulated gastrointestinal digestion and absorption of heat-treated edible insects. The inhibitory activities of insect-derived peptides were determined against key enzymes relevant to the metabolic syndrome such as the angiotensin-converting enzyme (ACE), pancreatic lipase, and α-glucosidase. After the in vitro absorption process, all hydrolysates showed high inhibitory activity; however, the most effective metabolic syndrome-inhibitory peptides were received after separation on Sephadex G10. The best results were found for peptide fractions obtained from Schistocerca gregaria. The highest enzymes inhibitory activities were obtained for peptide fractions from S. gregaria: boiled for ACE (IC50 3.95 µg mL−1), baked for lipase (IC50 9.84 µg mL−1), and raw for α-glucosiadase (IC50 1.89 µg mL−1) S. gregaria, respectively. Twelve sequences of peptides from the edible insects were identified and their chemical synthesis was carried out as well. Among the synthesized peptides, the KVEGDLK, YETGNGIK, AIGVGAIR, IIAPPER, and FDPFPK sequences of peptides exhibited the highest inhibitory activity. Generally, the heat treatment process applied to edible insects has a positive effect on the properties of the peptide fractions studied.

α-Glucosidase Inhibitory and Glucose Uptake Stimulatory Effects of Phenolic Compounds FromDendrobium christyanum

A methanolic extract from the dried root of Dendrobium christyanum Rchb.f. (Orchidaceae) exhibited α-glucosidase inhibitory activity and glucose uptake stimulatory effect. Chromatographic separation of the extract led to the isolation of 13 phenolic compounds (1-13). Their structures were determined by spectroscopic analysis. The isolates were then evaluated for in vitro α-glucosidase inhibitory and glucose uptake stimulatory activities. Methyl haematommate (1), methyl 2,4-dihydroxy-3,6-dimethylbenzoate (3), n-docosyl 4-hydroxy- trans-cinnamate (4), coniferyl aldehyde (6), 4,5-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (7), gigantol (10), and diorcinolic acid (13) showed higher α-glucosidase inhibitory activity than the drug acarbose. Moreover, n-docosyl 4-hydroxyl- trans-cinnamate (4), vanillin (5), and coniferyl aldehyde (6) could enhance glucose uptake by L6 myotubes. Compounds 4 and 6 appear to be potential hypoglycemic agents since they possess both α-glucosidase inhibitory and glucose uptake stimulatory activities. This study is the first report on the chemical constituents and antidiabetic activity of D. christyanum.

Phytopharmacological Strategies in the Management of Type 2 Diabetes Mellitus

Type 2 Diabetes Mellitus (T2DM) is a chronic disease which corresponds to 90% of the worldwide cases of diabetes, mainly due to epigenetic factors such as unhealthy lifestyles. First line therapeutic approaches are based on lifestyle changes, most of the time complemented with medication mostly associated with several side effects and high costs. As a result, the scientific community is constantly working for the discovery and development of natural therapeutic strategies that provide lower financial impact and minimize side effects. This review focus on these nature-based therapeutic strategies for prevention and control of T2DM, with a special emphasis on natural compounds that present pharmacological activity as dipeptidyl peptidase-4 (DPP4), alpha-amylase, alpha-glucosidase, lipase, and protein tyrosine phosphatase 1B (PTP1B) inhibitors.

Phenolic Compounds from the Aerial Parts of Blepharis linariifolia Pers. and Their Free Radical Scavenging and Enzyme Inhibitory Activities

Background:Blepharis linariifolia Pers. (Family: Acanthaceae) is used in traditional medicines as a general tonic and for the treatment of various health problems in Sudan. The main aim of this study was to isolate and identify the major chemical constituents from the aerial parts of B. linariifolia and evaluate their bioactivities. Methods: The dried aerial parts of the plant were extracted successively with 100% acetone and 50% acetone, and thereafter the combined extract was subjected to repeated column chromatography to isolate the main components. Free radical scavenging activity was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical method, and in vitro enzyme inhibitory activities against α-glucosidase, pancreatic lipase, and mushroom tyrosinase were evaluated. Results: From the detailed chemical analysis, verbascoside (1), vanillic acid (2), apigenin (3), and 6″-O-p-coumaroylprunin (4), were isolated and their structures were identified on the basis of their nuclear magnetic resonance (NMR) spectral data. Among the isolated compounds, verbascoside (1) showed the most potent free radical scavenging activity (IC50 = 22.03 ± 0.04 μM). Apigenin (3) and 6″-O-p-coumaroylprunin (4) showed promising inhibitory activities against all tested enzymes. Apigenin (3) showed the most potent inhibitory activity against α-glucosidase and tyrosinase (IC50 = 34.73 ± 1.78 μM and 23.14 ± 1.83 μM, respectively), whereas 6″-O-p-coumaroylprunin (4) showed potent inhibition for lipase (IC50 = 2.25 ± 0.17 μM). Conclusions: Four phenolic compounds were isolated and identified from B. linariifolia acetone extract, which are reported for the first time from this plant. All compounds showed good DPPH free radical scavenging activities, with verbascoside (1) being the most potent. Apigenin (3) was the most active as α-glucosidase and mushroom tyrosinase inhibitor, while 6″-O-p-coumaroylprunin (4) showed potent inhibitory activity for pancreatic lipase.

Exploring African Medicinal Plants for Potential Anti-Diabetic Compounds with the DIA-DB Inverse Virtual Screening Web Server

Medicinal plants containing complex mixtures of several compounds with various potential beneficial biological effects are attractive treatment interventions for a complex multi-faceted disease like diabetes. In this study, compounds identified from African medicinal plants were evaluated for their potential anti-diabetic activity. A total of 867 compounds identified from over 300 medicinal plants were screened in silico with the DIA-DB web server (http://bio-hpc.eu/software/dia-db/) against 17 known anti-diabetic drug targets. Four hundred and thirty compounds were identified as potential inhibitors, with 184 plants being identified as the sources of these compounds. The plants Argemone ochroleuca, Clivia miniata, Crinum bulbispermum, Danais fragans, Dioscorea dregeana, Dodonaea angustifolia, Eucomis autumnalis, Gnidia kraussiana, Melianthus comosus, Mondia whitei, Pelargonium sidoides, Typha capensis, Vinca minor, Voacanga africana, and Xysmalobium undulatum were identified as new sources rich in compounds with a potential anti-diabetic activity. The major targets identified for the natural compounds were aldose reductase, hydroxysteroid 11-beta dehydrogenase 1, dipeptidyl peptidase 4, and peroxisome proliferator-activated receptor delta. More than 30% of the compounds had five or more potential targets. A hierarchical clustering analysis coupled with a maximum common substructure analysis revealed the importance of the flavonoid backbone for predicting potential activity against aldose reductase and hydroxysteroid 11-beta dehydrogenase 1. Filtering with physiochemical and the absorption, distribution, metabolism, excretion and toxicity (ADMET) descriptors identified 28 compounds with favorable ADMET properties. The six compounds—crotofoline A, erythraline, henningsiine, nauclefidine, vinburnine, and voaphylline—were identified as novel potential multi-targeted anti-diabetic compounds, with favorable ADMET properties for further drug development.

A new phenanthrene dimer from Dendrobium palpebrae

A new phenanthrene dimer, namely dendropalpebrone (1), was isolated from the whole plant of Dendrobium palpebre, along with nine known compounds (2-10). All of the isolates were evaluated for their hydroxyl radical scavenging effects using a deoxyribose assay. Dendroflorin (10) showed an appreciable activity, and therefore was selected for further studied in RAW264.7 cells. Compound 10 significantly decreased ROS in H₂O₂-stimulated RAW264.7 cells in a dose-dependent manner, and improved activity of SOD, GPx, and CAT enzymes.