Bioassay-guided identification of the antihyperglycaemic constituents of walnut ( Juglans regia ) leaves

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

Ceviz Erkek Çiçeklerinin In Vitro Antioksidan ve Enzim İnhibitör Aktiviteleri

Walnut (Juglans regia L.) male flowers are known for their high phenolic content and associated health benefits, including anti-hypoxic, antihaemolytic, anti-inflammatory, antidepressant, and antioxidant activities. This study represents the first investigation of the inhibitory effects of walnut male flower extract on α-amylase and α-glucosidase enzymes, employing HPAE-PAD (High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection). The inhibitory potential of the extract was compared to that of acarbose, a chemical drug commonly used for this purpose. Furthermore, the antioxidant activity of the extract was also evaluated. The extract demonstrated significant inhibition of α-amylase and α-glucosidase, with half maximal inhibitory concentration (IC50) values of 1.507 mg/mL and 0.803 mg/mL, respectively. In contrast, acarbose exhibited IC50 values of 1.031 mg/mL and 0.985 mg/mL for α-amylase and α-glucosidase, respectively. Although the walnut male flower showed greater inhibition of α-glucosidase than acarbose, acarbose exhibited stronger inhibition of α-amylase activity than walnut male flowers. The extract exhibited a DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) free radical scavenging activity, with an IC50 value of 19.51 µg/mL. Additionally, the total phenolic content of 277 mg GAE (gallic acid equivalent)/g dry weight (dw) was determined in the extract. These results may highlight the potential of walnut male flowers as a novel enzyme inhibitor for managing type 2 diabetes mellitus. The findings of this study could provide valuable insights for further investigation into the potential applications of walnut male flowers in the food and pharmaceutical industries.

Protective Effects of Medicinal Plant-Based Foods against Diabetes: A Review on Pharmacology, Phytochemistry, and Molecular Mechanisms

Diabetes mellitus (DM) comprises a range of metabolic disorders characterized by high blood glucose levels caused by defects in insulin release, insulin action, or both. DM is a widespread condition that affects a substantial portion of the global population, causing high morbidity and mortality rates. The prevalence of this major public health crisis is predicted to increase in the forthcoming years. Although several drugs are available to manage DM, these are associated with adverse side effects, which limits their use. In underdeveloped countries, where such drugs are often costly and not widely available, many people continue to rely on alternative traditional medicine, including medicinal plants. The latter serves as a source of primary healthcare and plant-based foods in many low- and middle-income countries. Interestingly, many of the phytochemicals they contain have been demonstrated to possess antidiabetic activity such as lowering blood glucose levels, stimulating insulin secretion, and alleviating diabetic complications. Therefore, such plants may provide protective effects that could be used in the management of DM. The purpose of this article was to review the medicinal plant-based foods traditionally used for the management of DM, including their therapeutic effects, pharmacologically active phytoconstituents, and antidiabetic mode of action at the molecular level. It also presents future avenues for research in this field.

Nuts as functional foods: Variation of nutritional and phytochemical profiles and their in vitro bioactive properties

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Nutritional, biological and in vitro anti-diabetic, -obesity, -cholinergic of nuts.

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Polymeric procyanidins dominant polyphenols.

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Oleanic and pomolic acids dominant triterpenes.

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Nuts are low in Cu, Zn, Mn, Na, but rich in K and Mg.

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All nuts showed high activity in inhibiting intestinal α-glucosidase.

The aim of the present study was to examine the nutritional (fat, fatty acids, minerals, sugars) and bioactive compounds (polyphenols, tocochromanols, triterpene) and their influence on in vitro anti-diabetic (pancreatic α-amylase and intestinal α-glucosidase), anti-obesity (pancreatic lipase) and anti-cholinergic (AChE and BuChE) inhibitory activity of 8 different popular nuts—pecan, pine, hazelnuts, pistachio, almonds, cashew, walnuts, and macadamia.

The total content of phenolic compounds in nuts ranged from 432.9 (walnuts) to 5.9 (pistachio) mg/100 g. The dominant polyphenols are polymeric procyanidins (walnuts – 415.1 mg/100 g). Nuts are rich in tocochromanols (832.9–4377.5 μg/100 g), especially α- and γ-tocopherols. The highest content of α-tocopherol (vitamin E) was detected in hazelnuts and almonds (2551.0 and 2489.7 μg/100 g, respectively) while the lowest amounts were detected in macadamia, cashew and walnuts. The most abundant in nuts are oleanic and pomolic acids (35 and 22 % of total, respectively), while betulin, uvaol and erythrodiol are less characteristic triterpenes for nuts (<1%). Pine nuts are the nuts with the highest content of triterpene (690.3 mg/100 g). Pistachio and almonds are the richest in total fat (>45 %), but monounsaturated (17.5–79.3 %; hazelnuts, almonds, cashew, macadamia, pistachio and pecan) and polyunsaturated (7.5–69.3 %; pine, walnuts) are the dominant fatty acids. Moreover, nuts are low in Cu, Zn, Mn and Na content, but rich in K (464.5–1772.3 mg/100 g) and Mg (197.0–502.5 mg/100 g). Macadamia, walnuts and cashew are good sources of Se. Pistachio, almonds and cashew were characterized by the highest content of sugars, but the dominant sugar was saccharose (58.2–2399.3 mg/100 g). All nuts showed high activity in inhibiting intestinal α-glucosidase (>90 %), but lower ability to inhibit pancreatic α-amylase and pancreatic lipase activity. The activity in inhibiting acetyl- and butylcholinesterase was up to 30 %.

As described above, all nuts contain various compounds that improve the nutritional value. Therefore they should be one of the important components of the daily human diet rich in functional foods.

Heterocyclic compounds as a magic bullet for diabetes mellitus: a review

Diabetes mellitus (DM) is a major metabolic disorder due to hyperglycemia, which is increasing all over the world. From the last two decades, the use of synthetic agents has risen due to their major involvement in curing of chronic diseases including DM. The core skeleton of drugs has been studied such as thiazolidinone, azole, chalcone, pyrrole and pyrimidine along with their derivatives. Diabetics assays have been performed in consideration of different enzymes such as α-glycosidase, α-amylase, and α-galactosidase against acarbose standard drug. The studied moieties were depicted in both models: in vivo as well as in vitro. Molecular docking of the studied compounds as antidiabetic molecules was performed with the help of Auto Dock and molecular operating environment (MOE) software. Amino acid residues Asp349, Arg312, Arg439, Asn241, Val303, Glu304, Phe158, His103, Lys422 and Thr207 that are present on the active sites of diabetic related enzymes showed interactions with ligand molecules. In this review data were organized for the synthesis of heterocyclic compounds through various routes along with their antidiabetic potential, and further studies such as pharmacokinetic and toxicology studies should be executed before going for clinical trials.

Diabetes mellitus (DM) is a major metabolic disorder due to hyperglycemia, which is increasing all over the world.

Comparison of bioactive compounds and health promoting properties of fruits and leaves of apple, pear and quince

This paper presents characterization of healthy potential new sources of functional constituents with reference to basic plant sources. In this study, the phenolics, triterpene, isoprenoids (chlorophylls and carotenoids), amino acids, minerals, sugars and organic acids of different cultivars of pome species—apple, pear, quince—leaves vs. fruits and their enzymatic in vitro enzyme inhibition of hyperglycemic (α-glucosidase, α-amylase), obesity (pancreatic lipase), cholinesterase (acetylcholinesterase, butylcholinesterase), inflammatory (15-LOX, COX-1 and -2) and antioxidant capacity (ORAC, FRAP, ABTS) were evaluated. Leaves of pome species as a new plant sources were characterized by higher content of bioactive and nutritional compounds than basic fruits. The dominant fraction for quince, pear, and apple fruits was polymeric procyanidins. In quince and pear leaves flavan-3-ols, and in apple dihydrochalcones dominated. Triterpene was present in equal content in leaves and fruits. Leaves are excellent sources of amino acids and minerals (especially Ca, Mg, Fe, and K), with high content of organic acids and low content of sugars compared to fruits of pome species. Leaves of apples and pears most effectively inhibited COX-1, COX-2, α-amylase, and α-glucosidase enzyme but quince leaves showed the most effective inhibition of pancreatic lipase, AChE and BuChE, 15-LOX, and antioxidant capacity, which particularly correlated with bioactive compounds. Present study shows that leaves are promising sources of valuable compounds and may be used to produce functional foods as well as for medical purposes.

Effect of in vitro simulated gastrointestinal digestion on structural characteristics and anti-proliferative activities of the polysaccharides from the shells of Juglans regia L

The present research was designed to investigate the effects of simulated gastrointestinal digestion in vitro on the structural characteristics and anti-proliferative activities of polysaccharides from the shells of Juglans regia L. (JRP). Results suggested that JRP was composed of glucose, ribose, galactose, mannose, arabinose and rhamnose in a molar ratio of 10.7:4.9:16.4:2.3:10.8:2.3, with the molecular weight distributed from 3.21 × 10⁵ to 4.55 × 10⁵ Da. JRP belonged to non-crystalline substance, with irregular, smooth and compact morphological characteristics. Nevertheless, during gastrointestinal digestion in vitro, the physicochemical properties of JRP including molecular weight, monosaccharide composition, crystalline properties and morphology were significantly changed, accompanying with the increase of reducing sugar in digestive juice. Through measurements of anti-proliferation activities, the results showed that the digested JRP could remarkably inhibit the viabilities of HeLa cells by induction of apoptosis as a result of the excessive ROS accumulation and cell cycle arrest at G2/M phase, all of which were pronouncedly stronger than the ones induced by undigested JRP. These findings suggested that JRP processed by gastrointestinal digestion possessed more potential anti-proliferative applications that need to be exploited.

Isolation of secondary metabolites from the Iranian medicinal plant Eremurus persicus

Eremurus persicus (Jaub. & Spach) Boiss. belonging to Xanthorrhoeaceae family is an endemic medicinal plant widely distributed in Iran. Its leaves have been traditionally used as a food and also as medicinal plant. Regarding the widespread application of E. persicus in Iranian folk medicine, and the insignificant investigation of its components, this study aimed at the isolation and identification of major secondary metabolites of this plant. By applying various chromatographic techniques, corchoionoside A (1), 4-amino-4-carboxychroman-2-one (2), isoorientin (3), ziganein 5-methyl ether (4), auraptene (5), and imperatorin (6) were isolated from the EtOAc and CHCl₃ fractions of the crude extract. Except isoorientin (3), all the identified phytoconstituents were reported for the first time from Eremurus genus.

Phytochemical study of Juglans regia L. leaves

A methanolic extract of Juglans regia L. leaves was fractioned by various chromatographic techniques yielding a total of 40 metabolites belonging to megastigmane, tetralone, phenylpropanoid, neolignane and juglone glycosides. Ten unknown megastigmane glucoside derivatives (juglanionosides A-K, 1-10) and six unknown tetralone glucoside derivatives (juglanosides J-O, 11-16) together with 24 known compounds - among them 16 described for the first time in Juglans - were isolated. As characteristic structural feature, the previously undescribed compounds showed acylation of the sugar units with sinapic, ferulic, coumaric, benzoic or salicylic acid. Their chemical structures were elucidated on the basis of 1D and 2D NMR techniques, HRESIMS as well as CD spectroscopy. Absolute stereochemistry was revealed by mild alkaline hydrolysis and comparison of CD and polarimetric data to literature values.