In Vitro and Molecular Docking Evaluation of the Anticholinesterase and Antidiabetic Effects of Compounds from Terminalia macroptera Guill. & Perr. (Combretaceae)

Alzheimer's disease (AD) and diabetes are non-communicable diseases with global impacts. Inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are suitable therapies for AD, while α-amylase and α-glucosidase inhibitors are employed as antidiabetic agents. Compounds were isolated from the medicinal plant Terminalia macroptera and evaluated for their AChE, BChE, α-amylase, and α-glucosidase inhibitions. From 1H and 13C NMR data, the compounds were identified as 3,3'-di-O-methyl ellagic acid (1), 3,3',4'-tri-O-methyl ellagic acid-4-O-β-D-xylopyranoside (2), 3,3',4'-tri-O-methyl ellagic acid-4-O-β-D-glucopyranoside (3), 3,3'-di-O-methyl ellagic acid-4-O-β-D-glucopyranoside (4), myricetin-3-O-rhamnoside (5), shikimic acid (6), arjungenin (7), terminolic acid (8), 24-deoxysericoside (9), arjunglucoside I (10), and chebuloside II (11). The derivatives of ellagic acid (1-4) showed moderate to good inhibition of cholinesterases, with the most potent being 3,3'-di-O-methyl ellagic acid, with IC50 values of 46.77 ± 0.90 µg/mL and 50.48 ± 1.10 µg/mL against AChE and BChE, respectively. The compounds exhibited potential inhibition of α-amylase and α-glucosidase, especially the phenolic compounds (1-5). Myricetin-3-O-rhamnoside had the highest α-amylase inhibition with an IC50 value of 65.17 ± 0.43 µg/mL compared to acarbose with an IC50 value of 32.25 ± 0.36 µg/mL. Two compounds, 3,3'-di-O-methyl ellagic acid (IC50 = 74.18 ± 0.29 µg/mL) and myricetin-3-O-rhamnoside (IC50 = 69.02 ± 0.65 µg/mL), were more active than the standard acarbose (IC50 = 87.70 ± 0.68 µg/mL) in the α-glucosidase assay. For α-glucosidase and α-amylase, the molecular docking results for 1-11 reveal that these compounds may fit well into the binding sites of the target enzymes, establishing stable complexes with negative binding energies in the range of -4.03 to -10.20 kcalmol-1. Though not all the compounds showed binding affinities with cholinesterases, some had negative binding energies, indicating that the inhibition was thermodynamically favorable.

Chinese Sumac (Rhus chinensis Mill.) Fruits Prevent Hyperuricemia and Uric Acid Nephropathy in Mice Fed a High-Purine Yeast Diet

Hyperuricemia (HUA) is a prevalent chronic disease, characterized by excessive blood uric acid levels, that poses a significant health risk. In this study, the preventive effects and potential mechanisms of ethanol extracts from Chinese sumac (Rhus chinensis Mill.) fruits on HUA and uric acid nephropathy were comprehensively investigated. The results demonstrated a significant reduction in uric acid levels in hyperuricemia mice after treatment with Chinese sumac fruit extract, especially in the high-dose group, where the blood uric acid level decreased by 39.56%. Visual diagrams of the kidneys and hematoxylin and eosin (H&E)-stained sections showed the extract's effectiveness in protecting against kidney damage caused by excessive uric acid. Further investigation into its mechanism revealed that the extract prevents and treats hyperuricemia by decreasing uric acid production, enhancing uric acid excretion, and mitigating the oxidative stress and inflammatory reactions induced by excessive uric acid in the kidneys. Specifically, the extract markedly decreased xanthine oxidase (XOD) levels and expression in the liver, elevated the expression of uric acid transporters ABCG2, and lowered the expression of uric acid reabsorption proteins URAT1 and SLC2A9. Simultaneously, it significantly elevated the levels of endogenous antioxidant enzymes (SOD and GSH) while reducing the level of malondialdehyde (MDA). Furthermore, the expression of uric-acid-related proteins NLRP3, ACS, and Caspase-3 and the levels of IL-1β and IL-6 were significantly reduced. The experimental results confirm that Chinese sumac fruit extract can improve HUA and uric acid nephropathy in mice fed a high-purine yeast diet. This finding establishes a theoretical foundation for developing Chinese sumac fruit as a functional food or medicine for preventing and treating HUA.

Exploration of natural flavones' bioactivity and bioavailability in chronic inflammation induced-type-2 diabetes mellitus

Diabetes, being the most widespread illness, poses a serious threat to global public health. It seems that inflammation plays a critical role in the pathophysiology of diabetes. This review aims to demonstrate a probable link between type 2 diabetes mellitus (T2DM) and chronic inflammation during its development. Additionally, the current review examined the bioactivity of natural flavones and the possible molecular mechanisms by which they influence diabetes and inflammation. While natural flavones possess remarkable anti-diabetic and anti-inflammatory bioactivities, their therapeutic use is limited by the low oral bioavailability. Several factors contribute to the low bioavailability, including poor water solubility, food interaction, and unsatisfied metabolic behaviors, while the diseases (diabetes, inflammation, etc.) causing even less bioavailability. Throughout the years, different strategies have been developed to boost flavones' bioavailability, including structural alteration, biological transformation, and innovative drug delivery system design. This review addresses current advancements in improving the bioavailability of flavonoids in general, and flavones in particular. Clinical trials were also analyzed to provide insight into the potential application of flavonoids in diabetes and inflammatory therapies.

Chinese Sumac Fruits (Rhus chinesis Mill.) Alleviate Type 2 Diabetes in C57BL/6 Mice through Repairing Islet Cell Functions, Regulating IRS-1/PI3K/AKT Pathways and Promoting the Entry of Nrf2 into the Nucleus

This research aimed to probe the potential alleviative effects of ethanol extracts of Chinese sumac (Rhus chinesis Mill.) fruits against type 2 diabetes mellitus (T2DM) in C57BL/6 mice induced by high-fat/high-fructose diet (HFFD) and streptozotocin. The results showed that the ethanol extracts could significantly regulate blood glucose levels, glycosylated hemoglobin, blood lipids, insulin, and insulin resistance, while also restoring endogenous oxidative stress. Pathological and immunohistochemical analyses revealed that the extracts partially restored the physiological function of islet cells. Furthermore, Western blotting results suggested that the extracts could regulate the protein expression in IRS-1/PI3K/AKT signaling pathway, and immunofluorescence findings demonstrated their potential to promote the translocation of Nrf2 into the nucleus. This study elucidated a novel finding that ethanol extracts derived from Chinese sumac fruits have the potential to alleviate symptoms of T2DM in mice. Moreover, these findings could offer valuable scientific insights into the potential utilization of R. chinensis fruits as nutritional supplement and/or functional food to prevent or ameliorate diabetes.

Bioactivity and nutritional quality of nutgall (Rhus semialata Murray), an underutilized fruit of Manipur

Introduction

Underutilized fruits plays a significant role in socio economic, cultural, nutritional and ethnomedicinal status of tribal people. However, scientific studies on the nutritional and other pharmaceuticals/biological activities of these fruits are meagre. Hence, the present study dealt with the quantification of nutritional quality and deciphering the bioactivity of nutgall (Rhus semialata Murray syn. Rhus chinensis Mill.), an underutilized fruit crop mainly found in foothill tracks of Eastern Himalaya, India, China, Japan, Korea and other South East Asian countries.

Methods

The Rhus semialata Murray fruits were collected from five different locations in Purul sub-division, Senapati district, Manipur, India. The nutritional composition of the fruit pulp was analysed. Further the fruit pulp was extracted in methanol and water. The methanol and water extracts were studied for bioactivity properties such as antioxidant, antihyperglycemic, antihypertensive, antihyperuricemia, anti-tyrosinase, and antimicrobial activity.

Results and discussion

The fruit was rich in essential fatty acids. The presence of linoleic and oleic acids, along with traces of docosahexaenoic acid and eicosapantaenoic acid, revealed the potential food value of the fruit. 59.18% of the total amino acid composition of the protein present was constituted by essential amino acids. The IC₅₀ value of methanolic extract (MExt) and Water extract (WExt) of the fruit were recorded as 4.05 ± 0.22 and 4.45 ± 0.16 μg/mL, respectively, in the DPPH assay and 5.43 ± 0.37 and 11.36 ± 2.9 μg/mL, respectively, in the ABTS assay as compared to Ascorbic acid (3 and 5.4 μg/mL in DPPH and ABTS assay, respectively). The CUPRAC assay also showed a high antioxidant potential of MExt and WExt (1143.84 ± 88.34 and 456.53 ± 30.02 mg Ascorbic Acid Equivalent/g, respectively). MExt and WExt of the fruit were more active against α-glucosidase (IC₅₀ of 1.61 ± 0.34 and 7.74 ± 0.54 μg/ mL, respectively) than α-amylase enzyme (IC₅₀ 14.15 ± 0.57 and 123.33 ± 14.7 μg/mL, respectively). In addition, the methanolic fruit extract showed low to moderate pharmacological potential in terms of antihypertensive (Angiotensin converting enzyme-I inhibition), antihyperuricemia (xanthine oxidase inhibition), anti-tyrosinase, and antimicrobial activity. The IC₅₀ values of angiotensin-converting enzyme I inhibition, xanthine oxidase inhibition and tyrosinase inhibition were recorded as 13.35 ± 1.21 mg/mL, 93.16 ± 4.65 mg/mL, and 862.7 ± 12.62 μg/mL, respectively. The study evidently indicates that nutgall fruit is a potential source of phytonutrients, bestowed with commercially exploitable, multifaceted health benefits.

The stability and degradation products of polyhydroxy flavonols in boiling water

Polyhydroxy flavonols readily degraded during thermal processing. In this study, the UPLC-Q-tof-MS/MS was applied to explore the stability of dietary polyhydroxy flavonols, myricetin, kaempferol, galangin, fisetin, myricitrin, quercitrin and rutin, in boiling water. The decomposition of flavonols was mainly caused by the heterocyclic ring C opening to form simpler aromatic compounds. The degradation products mainly included 1,3,5-benzenetriol, 3,4,5-trihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid and 2,4,6-trihydroxybenzaldehyde, etc. Compared with myricetin with a pyrogallol-type structure on the ring B, the glycoside in myricitrin slightly affects the stability. However, the glycosides in rutin and quercitrin dramatically improved the stability in water. During the boiling process, flavonols underwent a series of chemical reactions, such as hydroxylation, dehydroxylation, deglycosidation, deprotonation, and C-ring cleavage.

The preventive effect of Chinese sumac fruit against monosodium urate-induced gouty arthritis in rats by regulating several inflammatory pathways

Chinese sumac (Rhus chinensis Mill.) fruit is a traditional Chinese medicinal material that can be consumed daily. This study aimed to investigate whether the ethanol extract of sumac fruits can ameliorate monosodium urate-induced gouty arthritis in rats from the perspective of inflammation. Results showed that the extract of Chinese sumac fruits can obviously prevent monosodium urate-induced gouty arthritis in rats. Further analyses revealed that this bioactivity may be mainly achieved by modulating several inflammatory pathways, including NLRP3, NF-κB, and MAPK pathways. In addition, the extract can also improve oxidative stress by reducing the levels of malondialdehyde and myeloperoxidase, increasing the contents of superoxide dismutase and glutathione. In conclusion, this study revealed that the Chinese sumac fruit can alleviate the pathological symptoms of gouty arthritis by inhibiting inflammatory responses and oxidative stress, which can provide a theoretical basis for the use of Chinese sumac fruits as a Chinese herbal medicine and health food for the prevention and treatment of gouty arthritis.

Exploring the Promotive Effects and Mechanisms of Different Polyphenolic Extracts from Prinsepia utilis Royle Seed Shell on Tyrosinase

Prinsepia utilis Royle (P. utilis) is commonly used as a food ingredient and herbal medicine according to folk records, yet little research has been done on the seed shell, a processing waste. The aim of this study was to investigate the distribution of polyphenolic components and the tyrosinase activation activity of different extracts from the seed shell by UHPLC-ESI-HRMS/MS, in vitro tyrosinase activity assay, molecular docking and molecular dynamics. A total of 16 phytochemicals were identified, of which (+)-catechin and (-)-epicatechin were the major polyphenolic compounds. Both the esterified and insoluble bound polyphenols exhibited tyrosinase activation activity, and the esterified polyphenols showed better tyrosinase activation activity. (+)-Catechin and (-)-epicatechin might be the main activators of tyrosinase, both of which may act as substrate to affect tyrosinase activity. By molecular docking and molecular dynamics simulation studies, (+)-catechin and (-)-epicatechin can be efficiently and stably bound to the tyrosinase active site through hydrogen bonds, van der Waals forces and π-bonds. The results of this study may not only provide a scientific basis for exploring P. utilis seed shell as a potential activator of tyrosinase, but also contribute to the high value utilization of P. utilis processing by-products.

Investigation of Enzyme Inhibitory Activities, Antioxidant Activities, and Chemical Properties of Pistacia vera Leaves Using LC-QTOF-MS and RP-HPLC

Since the leaves of some Pistacia species are used in traditional folk medicine for diabetes, this study investigated the in vitro antidiabetic effect (α-glucosidase and α-amylase) of Pistacia vera leaves. Additionally, the current study investigated the antihypercholesterolemic (cholesterol esterase), antiobesity (pancreatic lipase), and antioxidant activities (i.e., total antioxidant capacity, DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging activity, metal chelating activity, and ferric-reducing antioxidant power) of P. vera leaves. The aqueous-alcoholic leaf extract inhibited α-amylase, α-glucosidase, and pancreatic lipase with the half-maximal inhibitory concentration values of 7.74 ± 0.72, 11.08 ± 3.96, and 168.43 ± 26.10 µg/mL, respectively. It was determined that the crude extract had high DPPH radical scavenging activity, ferric-reducing power, and moderate metal chelating activity. The ethyl acetate (EtOAc) subextract obtained by the liquid-liquid fractionation of the crude extract showed potent α-amylase and α-glucosidase inhibitory activities. The EtOAc subextract (5.794 ± 0.027 g/100 g subextract) was standardized by reversed-phase high-performance liquid chromatography based on β-pentagalloyl glucose, which showed inhibitory effects on both amylase and glucosidase enzymes. Fifteen compounds, seven of which are organic acid derivatives and eight of which are flavonoids, were identified by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) analysis in the crude extract of P. vera leaves. Seven of the fifteen phenolic compounds detected in the crude extract by LC-QTOF-MS have both glucosidase and amylase inhibitory effects. As a result, P. vera leaves can be a potential source for compounds with high antioxidant effects that show inhibitory effects on enzymes involved in carbohydrate digestion in the prevention and treatment of diabetes or can be evaluated as a standardized extract.

Water Caltrop (Trapa quadrispinosa Roxb.) Husk Improves Oxidative Stress and Postprandial Blood Glucose in Diabetes: Phenolic Profiles, Antioxidant Activities and α-Glycosidase Inhibition of Different Fractions with In Vitro and In Silico Analyses

The aim of this study was to investigate the phenolic profiles, antioxidant activities and α-glycosidase inhibitory activities of three different phenolic fractions from water caltrop (Trapa quadrispinosa Roxb.) husk and to further explore the predominant compounds and their mechanisms on α-glycosidase inhibition by virtual screening and molecular dynamics. A total of 29 substances were identified and quantified in this study. Tannins were the main constituents of water caltrop husk extract. All of the free phenolic (FP), esterified phenolic (EP) and insoluble-bound phenolic (BP) fractions exhibited good antioxidant activities, and the BP had the highest radical scavenging ability with IC50 values of 0.82 ± 0.12 μg/mL (ABTS) and 1.15 ± 0.02 μg/mL (DPPH), respectively (p < 0.05). However, compared with the EP and BP, the FP showed the strongest inhibition towards the α-glycosidase and the IC50 value of FP was 1.43 ± 0.12 μg/mL. The 1,2,6-trigalloylglucose and α-glycosidase complex had better root mean square deviations (RMSD) stability via molecular dynamics simulation study. Results obtained from this study may provide a good potential natural resource for the improvement of oxidative stress injury and blood glucose control in diabetes mellitus, which could expand the use of water caltrop husk and improve its economic value.

A comprehensive review on ethnobotanical, phytochemical and pharmacological aspects of Rhus chinensis Mill

ETHNOPHARMACOLOGICAL RELEVANCE

Rhus chinensis Mill., firstly recorded as herbal medicine in Shan Hai Jing, have been used for thousands of years to treat various diseases.

AIM OF THIS REVIEW

This review targets on the ethnomedicinal applications of R. chinensis and to gather the phytochemical, pharmacological and toxicological data which support the therapeutic potential of R. chinensis in treatment on different diseases, with emphasis on the naturally occurring compounds and detailed pharmacological developments.

MATERIALS AND METHODS

The information of R. chinensis was collected based on a variety of popular databases such as Scifinder, PubMed, Web of Science, ScienceDirect, Springer, Wiley, ACS, CNKI, Baidu Scholar, Google Scholar and other published materials (books and Ph.D. and M. Sc. Dissertations). The keywords "Rhus chinensis", "Rhus amela", "Rhus javanica", "Rhus osbeckii", "Rhus semialata", and "Schinus indicus" were applied to search the literature related in this review.

RESULTS

152 natural compounds of R. chinensis belong to different classes are presented in this review, including flavonoids, lignans, coumarins, simple phenolics, urushiols, tannins, triterpenoids, steroids and other types of constituents. Among them, flavonoids, lignans, and triterpenoids are most frequently reported components. The pharmacological effects of R. chinensis were numerous and complicated, including anti-viral, anti-bacterial, anti-diarrheal, hepatoprotective, anti-proliferation, enzyme-inhibiting, anti-oxidants and so on.

CONCLUSION

In order to discover more compounds with novel structures to both enrich chemical context of genus Rhus and expand the variety of constituents, the phytochemical research is urgent and indispensable. Anti-diarrhea, the most widely application of R. chinensis traditionally, is insufficient in underlying mechanism exploration. And for other activities, in-depth studies on the mechanism of pharmacological effects in vivo and in vitro are both needed. Meanwhile, pharmacokinetics, toxicology, quality control and preclinical and clinical data are urgent to assess the rationale and safety of the medicinal and food application of R. chinensis.

Screening of potent α-glucosidase inhibitory and antioxidant polyphenols in Prunella vulgaris L. by bioreaction-HPLC-quadrupole-time-of-flight-MS/MS and in silico analysis

Prunella vulgaris L. is a well-known traditional Chinese medicine for blood glucose homeostasis and antioxidant potential. Ethyl acetate fraction of P. vulgaris L. demonstrated higher phenolic content (85.53 ± 6.74 mg gallic acid equivalents per gram dry weight), α-glucosidase inhibitory (IC₅₀ , 69.13 ± 2.86 μg/mL), and antioxidant (IC₅₀ , 8.68 ± 1.01 μg/mL) activities. However, the bioactive polyphenols responsible for the beneficial properties remain unclear. Here, bioreaction-HPLC-quadrupole-time-of-flight-MS/MS method was developed for rapid, accurate, and efficient screening and identification of polyphenols with α-glucosidase inhibitory and antioxidant activities from P. vulgaris L. Bioactive polyphenols can specifically bind with α-glucosidase or react with 1,1-diphenyl-2-picryl-hydrazyl radical, which was easily discriminated from nonactive compounds. Subsequently, twenty bioactive polyphenols (sixteen phenyl propionic acid derivatives and four flavonoids) were screened and identified. Furthermore, molecular docking analysis revealed that screened twenty polyphenols bind with the active sites of α-glucosidase through hydrogen bonding and π-π stacking. Density functional theory calculations demonstrated their electron transport ability and chemical reactivity. The in silico analysis confirmed the screened results. In summary, this study provided a valuable strategy for rapid discovering bioactive compounds from complex natural products, and offered scientific evidence for further development and application of P. vulgaris L. This article is protected by copyright. All rights reserved.

The potential role of extracellular vesicles in bioactive compound-based therapy: A review of recent developments

Recent studies have explored the field of extracellular vesicles (EVs), driving an increasing interest in their application to human health. EVs have unique physicochemical traits to participate in intercellular communication, thus fostering the idea of using EVs to yield synergistic, preventive, and therapeutic effects. Many reports have shown that EVs contain natural bioactive compounds, such as lipids, proteins, RNA, and other active components that regulate biological processes, thereby contributing to human health. Therefore, in this review, we comprehensively elucidate various facets of the relationship between EVs and bioactive compounds that modulate EVs contents, including RNAs and proteins, discussing different forms of biological regulation. The use of EVs for cargo-loading bioactive compounds to exert biological functions and methods to load bioactive compounds into EVs are also discussed. This review highlighted the effect of EV-delivered bioactive compounds on several therapeutic mechanisms and applications, providing new insight into nutrition and pharmacology.

Chinese sumac (Rhus chinensis Mill.) fruits alleviate indomethacin-induced gastric ulcer in mice by improving oxidative stress, inflammation and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

According to traditional Chinese medicine and a previous literature, many parts of Chinese sumac (Rhus chinensis Mill.), including fruits, are used as traditional herb to prevent or cure many diseases, such as inflammation, diarrhea, malaria, and other acute or chronic gastrointestinal diseases. However, the effects of the fruits on the prevention of gastric ulcer and the underlying mechanisms have not been reported.

AIM OF THE STUDY

This experiment aimed to investigate the preventive effect of ethanol extract (RM) from Chinese sumac fruits on indomethacin-induced gastric ulcer in mice and the underlying mechanisms.

MATERIALS AND METHODS

A single gavage of indomethacin was used to induce a gastric ulcer model in Kunming male mice. According to the results of histopathological analysis, immunohistochemistry and immunofluorescence analysis, as well as the expression of prostaglandin E-2, antioxidant enzymes and cytokines, the protective effect of RM on indomethacin-induced gastric ulcer was evaluated. The expression levels of several key proteins involved in oxidative stress, inflammation and apoptosis in gastric tissue were detected to illuminate the underlying mechanisms.

RESULTS

RM significantly reduced the ulcer index and pepsin activity, improved the microstructure of gastric mucosa and the prostaglandin E-2 content, restored the levels of glutathione and superoxide dismutase, and decreased the contents of malondialdehyde, advanced oxidation protein products, TNF-α, IL-1 β and IL-6. Further experimental results showed that RM could improve the expression levels of HO-1 and NQO1 by activating the Nrf2 protein pathway to alleviate oxidative stress in gastric tissue. At the same time, RM significantly down-regulated the expressions of p-NF-κB, p-IκBα and iNOS to relieve inflammatory response, and inhibited the cellular apoptosis of gastric tissue by up-regulating Bcl-2 and down-regulating Bax and cleaved Caspase-3.

CONCLUSIONS

The current work clarified that the ethanol extract from Chinese sumac fruits can improve the oxidative stress level, inflammatory response and cell apoptosis in gastric tissue by interfering with the expressions of several key regulatory proteins to prevent indomethacin-induced gastric ulcer in mice. This study may provide some insights and scientific evidence on the application of Chinese sumac fruits as a traditional herb to prevent or alleviate gastric ulcer.

Advance in dietary polyphenols as dipeptidyl peptidase-IV inhibitors to alleviate type 2 diabetes mellitus: aspects from structure-activity relationship and characterization methods

Dietary polyphenols with great antidiabetic effects are the most abundant components in edible products. Dietary polyphenols have attracted attention as dipeptidyl peptidase-IV (DPP-IV) inhibitors and indirectly improve insulin secretion. The DPP-IV inhibitory activities of dietary polyphenols depend on their structural diversity. Screening methods that can be used to rapidly and accurately identify potential polyphenol DPP-IV inhibitors are urgently needed. This review focuses on the relationship between the structures of dietary polyphenols and their DPP-IV inhibitory effects. Different characterization methods used for polyphenols as DPP-IV inhibitors have been summarized and compared. We conclude that the position and number of hydroxyl groups, methoxy groups, glycosylated groups, and the extent of conjugation influence the efficiency of inhibition of DPP-IV. Various combinations of methods, such as in-vitro enzymatic inhibition, ex-vivo/in-vivo enzymatic inhibition, cell-based in situ, and in-silico virtual screening, are used to evaluate the DPP-IV inhibitory effects of dietary polyphenols. Further investigations of polyphenol DPP-IV inhibitors will improve the bioaccessibility and bioavailability of these bioactive compounds. Exploration of (i) dietary polyphenols derived from multiple targets, that can prevent diabetes, and (ii) actual binding interactions via multispectral analysis, to understand the binding interactions in the complexes, is required.