Α-amylase Inhibitory Effects Research Articles

Acronychia pedunculata Essential Oils from Vietnam: Chemical Constituents, Enzymatic Inhibitory Activities and Molecular Docking Study

Objective/Background: Acronychia pedunculata is commonly found in mountainous regions across Vietnam. The species has been widely used in traditional medicine to treat various ailments. Methods: The essential oils (EOs) of A. pedunculata roots, leaves, and flowers were extracted by hydrodistillation process and their chemical compositions were determined by gas chromatography-mass spectrometry (GC/MS). Besides, the EOs were assayed for in vitro α-amylase and tyrosinase inhibitory activities. In silico molecular docking simulations on the major components of the EOs were conducted. Results: The EOs from A. pedunculata roots and leaves consisted of 41 compounds (97.6 and 95.1%, respectively) while the flower EO comprised 37 compounds (98.7%). α-Pinene was found to be the most abundant component in the root and flower EOs, with the percentages of 63.9% and 52.6%, respectively. (E)-β-Caryophyllene was detected at the highest level (22.8%) in the leaf EO. The root EO had the most potent anti-α-amylase and antityrosinase activities, with IC50 values of 53.73 ± 1.94 and 815.53 ± 3.24 μg/mL, respectively. Its inhibitory activity against α-amylase was stronger than that of acarbose (88.80 ± 1.87 μg/mL). In molecular docking results, limonene was the potential compound in the EOs with the best binding affinity against tyrosinase. Moreover, the evaluation of potential interactions between the main components of the EOs and the selected proteins was elucidated. Conclusions: The findings unveiled that the EOs of A. pedunculata possessed α-amylase and tyrosinase inhibitory effects and potential applications in nutraceutical and cosmeceutical industries.

Black and Red Currant Pomaces as Raw Materials to Create Smoothies with In Vitro Health-Promoting Potential.

Pomace is a by-product resulting from the pressing of fruits and vegetables into juices, and it is typically treated as waste. Interestingly, pomace contains minimal amounts of protein and fat but is characterized by its high polyphenol and dietary fiber contents, which may have health benefits for human physiology. Therefore, they are a potentially attractive raw material for the food industry, but to our knowledge, no smoothies with their addition have been prepared and described so far. Consequently, products derived from apple juice, incorporating different doses of fresh (6% and 12%) and dried (3% and 6%) black or red currant pomace, were formulated, and their physical properties, chemical composition, bioactive compound content, and health-promoting potential (in vitro antioxidant and antidiabetic activity) were evaluated. Additionally, the products underwent sensory assessment by consumers. The fortified beverages exhibited different physical characteristics and chemical compositions than apple juice. All smoothies were characterized by higher concentrations of anthocyanins, flavonols, and procyanidin polymers compared to the base product. Moreover, 75% of them exhibited a significantly elevated phenolic acid content as well as a higher concentration of flavan-3-ols. The majority of fresh smoothies exhibited significantly higher in vitro antioxidant capacities and increased in vitro α-amylase and α-glucosidase inhibitory effects compared to the base product. The highest ABTS activity was recorded in the variant with 6% dried black currant pomace. In turn, the smoothie with 3% dried red currant pomace had the most effective FRAP effect and, together with the product containing 12% fresh black currant pomace, ORAC antioxidant activity and α-glucosidase inhibition also. The introduction of 6% dried red currant pomace led to the creation of a beverage that most effectively inhibited α-glucosidase. The study showed that the application of various types of pomace, mainly that of black currant, into apple juice enables the development of new functional products with sensory attributes that are favorably evaluated by consumers.

In vitro α-amylase and α-glucosidase inhibitory effects and antioxidant potential of new dihydrochalcones from Baphia massaiensis Taub

Two previously undescribed dihydrochalcones, 4,2′-dihydroxy- [2″, 2″-dimethylpyrano (3″, 4″: 4′, 5′]) dihydrochalcone (1) and 4, 2′, 4′, 2″-tetrahydroxy-5′-(3″-methylbut-3″-enyl) dihydrochalcone (2), along with six known compounds (3-8) were isolated from chloroform-methanol (1:1) extract of Baphia Massaiensis twigs. Their chemical structures were determined using NMR analysis, mass spectrometry, electronic circular dichroism (ECD), density functional theory (DFT) calculations, and a thorough comparison with reported data from the literature. All the isolated compounds (1−8) were assessed for their antioxidant activities, α-amylase and α-glucosidase inhibition effects. Dihydrochalcone 1 showed significant antioxidant activity with IC50 value of 118.8 ± 2.95 µM, and a more potent antioxidant activity was exhibited by compounds 3 and 6 with IC50 values of 84.3 ± 0.07 µM and 62.1 ± 1.59 µM, respectively, compared to the positive control, gallic acid with IC50 value of 92.9 µM. Dihydrochalcone 2 showed moderate inhibition against α-amylase and α-glucosidase with IC50 values of 44.0 ± 4.83 µM and 51.7 ± 9.72 µM compared to the standard acarbose with IC50 values of 22.9 ± 0.92 µM and 31.5 ± 0.63 µM, respectively. Molecular docking studies of the new dihydrochalcones 1 and 2, revealed the active binding sites which support the observed α-amylase and α-glucosidase inhibitory effects.

Preclinical antidiabetic and antioxidant effects of Erythrophleum africanum (benth.) harms in streptozotocin-induced diabetic nephropathy.

This study investigated the antidiabetic effects of the methanolic extract of E.africanum (MEEA) stem bark on streptozotocin (STZ)-induced diabetic nephropathy (DN) in Wistar rats. The invitro enzyme (α-amylase) inhibitory activity of MEEA was measured using a standard procedure. Diabetic rats with fasting blood glucose above 250 mg/dL were considered diabetic and were divided intothe following groups: control (distilled water-treated), diabetic-control, diabetic metformin (100 mg/kg), diabetes + MEEA (150 mg/kg), and diabetes + MEEA (300 mg/kg) via oral gavage once daily for 14days. At the end of the experimental period, kidney tissues were collected for biochemical and histological analyses. Kidney apoptosis and marker gene expression were measured by real-time quantitative PCR. MEEA exhibited α-amylase inhibitory effects. MEEA significantly (p<0.05) reduced the STZ-induced increases in blood glucose, serum urea, serum creatinine, uric acid, alanine aminotransferase, alkaline phosphatase, and malondialdehyde and increased the STZ-induced decreases in superoxide dismutase, catalase, and reduced glutathione. In addition, MEEA protects against DN by significantly downregulating the mRNA expression of cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP-response binding protein (CREB), and cFOS and upregulating B-cell lymphoma 2 (Bcl-2), suggesting that the nephroprotective ability of MEEA is due to the modulation of the cAMP/PKA/CREB/cFOS signaling pathway. Furthermore, MEEA treatment protected against histopathological alterations observed in diabetic rats. The data from this study suggest that MEEA modulates glucose homeostasis and inhibits redox imbalance in DN rats.

Chemical Profile and Healthy Properties of Sicilian Diplotaxis harra subsp. crassifolia (Raf.) Maire.

This study was aimed at investigating the phytochemical profile and bioactivity of Diplotaxis harra subsp. crassifolia (Brassicaceae), a species from central-southern Sicily (Italy), where it is consumed as a salad. For this purpose, LC-ESI/HRMSn analysis of the ethanolic extract was performed, highlighting the occurrence, along with flavonoids, hydroxycinnamic acid derivatives, and oxylipins, of sulfated secondary metabolites, including glucosinolates and various sulfooxy derivatives (e.g., C13 nor-isoprenoids, hydroxyphenyl, and hydroxybenzoic acid derivatives), most of which were never reported before in the Brassicaeae family or in the Diplotaxis genus. Following ethnomedicinal information regarding this species used for the treatment of various pathologies such as diabetes and hypercholesterolemia, D. harra ethanolic extract was evaluated for its antioxidant potential using different in vitro tests such as 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), Ferric Reducing Ability Power, and β-carotene bleaching tests. The inhibitory activity of carbohydrate-hydrolyzing enzymes (α-amylase and α-glucosidase) and pancreatic lipase was also assessed. In the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid assay, an IC50 value comparable to the positive control ascorbic acid (2.87 vs. 1.70 μg/mL, respectively) was obtained. The wild-wall rocket salad extract showed a significant α-amylase inhibitory effect. Obtained results indicate that Sicilian wild-wall rocket contains phytochemicals that can prevent hyperglycemia, hyperlipidemia, and obesity.

ANTIOXIDANT, ANTI-INFLAMMATORY, ANTIDIABETIC, ANTHELMINTHIC, AND THROMBOLYTIC ACTIVITY OF THE METHANOL EXTRACT OF CITRULLUS LANATUS PEEL

Background: The present study aimed for in vitro evaluation of Citrullus lanatus Peel (CLP) methanol extract for antioxidative, anti-inflammatory, antidiabetic, anthelmintic, and thrombolytic activity. Method: CLP was extracted with methanol and tested for in vitro antioxidative (DPPH and H2O2 scavenging method), thrombolytic, anthelmintic, antidiabetic, and anti-inflammatory properties (human red blood cell membrane stabilization method, α-amylase inhibitory effect by using Iodine-Starch method. Results: The percentage yield was 7% and phytochemical profile showed the presence of steroid, tannins, saponins, flavonoids, glycoside and reducing sugar. In DPPH scavenging assay, 88.7% was at 1000 g/ml, whereas 34% to 48.9% (IC50 27.65 µg/ml) in H2O2 and from 61.8% to 95.2% (IC50 value: 07 µg/ml) in ASCOR. In in vitro anti-inflammatory activity, the maximum protection percentage was observed 58% and 44%. Consecutively, in anti-diabetic activity, IC50 values of 1137.64 μg/ml whereas reference (Acarbose) exhibited IC50 at 671.71 μg/ml. On the other hand, the inhibitory effect of Acarbose showed 57% and 98% respectively at 2000 μg/ml. In earthworms, it considered as very potential for the helminthic infection and helminthiasis. A significant clot lysis activity of 44% was noticed when the clots were treated with 100 µl of CLP extract (10 mg/ml) in in-vitro thrombolytic activity assay. Conclusions: The findings of this study revealed that the peel possessed the antioxidant, anti-inflammatory, antidiabetic, anthelminthic and thrombolytic activities. These findings will be motivated to do further research on molecular level to finds into more depth which is considered as the limitation of this study. Peer Review History: Received 3 February 2024; Revised 12 March 2024; Accepted 20 April; Available online 15 May 2024 Academic Editor: Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, amaka_mgbahurike@yahoo.com Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Dr. Gehan Fawzy Abdel Raoof Kandeel, Pharmacognosy Department, National Research Centre, Dokki, 12622, Giza, Egypt, gehankandeel9@yahoo.com Dr. Francis Adou Yapo, Felix Houphouet Boigny, University of Abidjan, Ivory Coast, fyapo@yahoo.fr

Labdanum Resin from Cistus ladanifer L. as a Source of Compounds with Anti-Diabetic, Neuroprotective and Anti-Proliferative Activity.

Labdanum resin or "gum" can be obtained from Cistus ladanifer L. by two different extraction methods: the Zamorean and the Andalusian processes. Although its main use is in the fragrance and perfumery sectors, ethnobotanical reports describe its use for medicinal purposes in managing hyperglycemia and mental illnesses. However, data concerning the bioactivities and pharmacological applications are scarce. In this work, it was found that the yield of labdanum resin extracted by the Andalusian process was 25-fold higher than the Zamorean one. Both resins were purified as absolutes, and the Andalusian absolute was purified into diterpenoid and flavonoid fractions. GC-EI-MS analysis confirmed the presence of phenylpropanoids, labdane-type diterpenoids, and methylated flavonoids, which are already described in the literature, but revealed other compounds, and showed that the different extracts presented distinct chemical profile. The potential antidiabetic activity, by inhibition of α-amylase and α-glucosidase, and the potential neuroprotective activity, by inhibition of acetylcholinesterase, were investigated. Diterpenoid fraction produced the higher α-amylase inhibitory effect (~30% and ~40% at 0.5 and 1 mg/mL, respectively). Zamorean absolute showed the highest α-glucosidase inhibitory effect (~14% and ~24%, at 0.5 and 1 mg/mL, respectively). Andalusian absolute showed the highest acetylcholinesterase inhibitory effect (~70% and ~75%, at 0.5 and 1 mg/mL, respectively). Using Caco-2 and HepG2 cell lines, Andalusian absolute and its purified fractions showed moderate cytotoxic/anti-proliferative activity at 24 h exposure (IC50 = 45-70 µg/mL, for Caco-2; IC50 = 60-80 µg/mL, for HepG2), whereas Zamorean absolute did not produce cytotoxicity (IC50 ≥ 200.00 µg/mL). Here we show, for the first time, that labdanum resin obtained by the Andalusian process, and its fractions, are composed of phytochemicals with anti-diabetic, neuroprotective and anti-proliferative potential, which are worth investigating for the pharmaceutical industry. However, toxic side-effects must also be addressed when using these products by ingestion, as done traditionally.

Comparative Phytochemical, In-vitro Anti-Hyperglycemic Activities of Napoleona vogelii Hook &amp; Planch Stem Bark and Cassia occidentalis L. Root Extracts

This work investigated the comparative phytochemical, proximate and anti-hyperglycemic activities of stem bark of Napoleonaea vogelii and root of Cassia occidentals extracts. Stem bark and N. vogelii root of C. occidentalis were cold extracted with methanol, ethyl acetate, and n-hexane. The extracts were subjected to proximate, phytochemical analyses and anti-hyperglycemic assays. The result of proximate analysis revealed that stem bark of N. vogelii was made up of 40.28 ± 0.49 % crude fibre, 37.05 ± 0.05 % carbohydrates, 7.45 ± 0.45 % protein and more than 6.00 % oil content. whereas 22.33±0.08 % crude fibre, 44.70± 0.93 % carbohydrates, 10.72± 0.05 % protein and 11.00± 0.00 % oil contents in roots of C. occidentalis. Alkaloids and terpenoids were present in all the extracts of N. vogelii and C. occidentalis. Flavonoids were also found in all extracts of N. vogelii, whereas tannins and glycosides were also found in all extracts of C. occidentalis. In vitro antidiabetic screening of the methanol extracts indicated that both plants showed a good concentration-dependent percentage glucose uptake. In all concentrations, extracts of C. occidentalis exhibited better glucose uptake than N. vogelii extracts. comparable to the activity of the standard drug- metronidazole (68.44±0.00 %), From 0.10 – 0.50 mg/mL, the methanol extracts of both plants also showed a dose-dependent α-amylase inhibitory effect. But the inhibition decreased as the concentration was increased to 1.00 mg/mL. At 0.50 mg/mL, C. occidentalis and N. vogelii showed percentage inhibitory effect of 50.02±0.035 and35.61±0.01. Both plants’ extracts showed good anti-hyperglycemic activity, which may be due to the presence of alkaloids, terpenoids, saponins and tannins in the extracts, validating the folkloric use of both plants in the treatment of diabetes, and thus are good anti-diabetic agents.

Industrial upcycling of almond skin through production of novel brioches

The global sustainability policy emphasizes reusing of agri-food waste and by-products to enhance food bioactive properties. Thus, brioches were processed incorporating almond skin powder (ASP): control (CTR), without ASP addition; 5-ASP, with 5% (w/w) ASP; and 10-ASP, with 10% (w/w) ASP. Seven different brioches shapes were obtained for each recipe. Flavonoids were mainly detected in Tuono almond skin by Ultra-High Performance Liquid Chromatography coupled to High-Resolution Mass Spectrometry (UHPLC-HRMSMS), in particular, flavan-3-ol monomers. The ethanolic extract of Tuono almond skins contained polar lipids (oxylipins and phospholipids). Gas Chromatography–Mass Spectrometry (GC-MS) identified six major fatty acids, mainly oleic acid (48.01%). Photothermal degradation impact on bioactive compounds was evaluated using a first-order kinetic model. Antioxidant activity was studied using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), 2,2-diphenyl-1-picrylhydrazyl and β-carotene bleaching test. α-amylase, α-glucosidase, and lipase inhibitory effect were also tested. The acidification of the doughs was consistent across all trials. Lactic acid bacteria and yeast levels increased. Importantly, the final products were free from undesirable microorganisms. The addition of ASP led to reduced weight loss and specific volume for all seven brioche types. Furthermore, the firmness, crumb structure, and sensory profile of the final products were noticeably influenced. Tasters clearly favoured the Treccina brioches. The production of sweet leavened baked goods was carried out in triplicate in two independent experiments. The statistical model applied to the data considered the effects of brioche shape and the addition of ASP. Kinetic data revealed that the half-life extension for both total phenol and flavonoid content was observed in the 10-ASP sample (18.00382). 10-ASP sample exhibited promising ABTS radical scavenging activity, with inhibitory concentration 50% (IC50) values of 18.64 mg/mL after 9 days of photothermal degradation. Moreover, when testing 10-ASP Treccina against α-amylase and α-glucosidase, the IC50 values were 198.16 and 190.23 μg/mL, respectively, even after 9 days.

Phytochemistry and Biological Assessment of Thuja articulata Trunk Barks: HPLC-PDA-ESI-MS Analysis, Bioevaluation, and Molecular Docking

Background: Thuja articulata is a Mediterranean forest species from the Cupressaceae family, it has been used in popular medicine to treat several diseases. Various studies have been carried out in vitro using diverse T. articulata extracts to understand its traditional use. Methods: In this study, the ethyl acetate extract of T. articulata trunk barks was chemically identified using HPLC-PDA-ESI-MS, then examined in vitro for its antioxidant and α-amylase inhibitory effects. A molecular docking study was also performed to reinforce the noted bioactivities. Results: HPLC-PDA-ESI-MS analysis led to the identification of 22 polyphenolic compounds in the ethyl acetate extract of T. articulata trunk barks. This extract revealed interesting in vitro antioxidant properties and a significant α-amylase inhibitory action (IC50 = 16.08 ± 1.27 μg/mL). In silico analysis was found to agree with the in vitro studies in which major constituents of the ethyl acetate extract revealed low binding energy and a correct mode of interaction in the active pocket of the enzyme (PDB: 7TAA). The anti-a-amylase potential could be due either to a synergistic or individual action of certain constituents present in this extract. Conclusion: This study illustrates that the ethyl acetate extract of T. articulata trunk barks has potent sources of antioxidants and α-amylase inhibitors to be explored.

Influential versatile potential of Entada rheedii and Myristica beddomei – an ethnobotanical approach

Aim of the study is to determine the anti-inflammatory, antidiabetic (α-amylase activity) and radical scavenging potentials of both leaf and stem ethanolic extracts of Entada rheedii and Myristica beddomei. DPPH, ABTS, H2O2, superoxide, hydroxyl and nitric oxide activity relate to inhibition ratio with different concentrations of extracts (μg/mL). Antidiabetic (α-amylase activity) and anti-inflammatory activities were also analyzed which showed high radical scavenging activity in a dose depending manner. Comparatively, leaves and stems of Entada rheedii showed higher radical scavenging activities compared to Myristica beddomei. Furthermore, both leaves and stem of Entada rheedii showed appreciable α-amylase inhibitory effects when compared with acarbose (standard drug) and also possess a strong anti-inflammatory effect (Diclofenac sodium, standard drug), compared to Myristica beddomei extracts. Overall, our results established the key evidence for Entada rheedii and Myristica beddomei extracts to be considered as a natural therapeutic aliment as the substitution for oxidative stress.

Essential Oils of Two Species of Zingiberaceae Family from Vietnam: Chemical Compositions and α-Glucosidase, α-Amylase Inhibitory Effects

The ginger family (Zingiberaceae) is one of the most diverse and abundant families in the plant kingdom in terms of number of species. In terms of chemistry, this is a family of plants containing much essential oil with mainly monoterpene and sesquiterpene derivatives, which has been widely used in medicine, food, and flavor industries. In our series of studies on ginger family plants, the two new species including Wurfbainia schmidtii (K. Schum.) Škorničk. &amp; A.D. Poulsen and Zingiber atroporphyreus Škorničk. &amp; Q.B. Nguyen has been investigated for the first time. This study aimed to identify the chemical compositions of essential oils extracted from the rhizomes and leaves of these two species using gas chromatography-mass spectrometry (GC/MS) analysis and evaluate their hypoglycemic effects through the α-glucosidase and α-amylase inhibitory assays. In terms of chemical composition, in general, the main compounds appearing in the essential oils of both leaves and rhizomes of each species are similar but they are differences in the percentage of the main components, for example, 1,8-cineole is a main component in leaves whereas fenchyl acetate is the main one in rhizomes of W. schmidtii. Several distinctive compounds, in comparison with other members in the genus Zingiber, namely β-pinene, α-pinene, β-elemene, and sabinene, were found in the essential oil of Z. atroporphyreus. Regarding hypoglycemic effects, the essential oils from the two species tested possessed weak α-glucosidase and α-amylase inhibitory effects. For the first time, this study was designed to investigate the chemical composition as well as the hypoglycemic effect of essential oils distilled from the rhizomes and leaves of two species W. schmidtii and Z. atroporphyreus have been reported, serving as a premise for further systematic research on their phytochemistry and pharmacological effects being conducted.

Anti-Diabetic Activity And Anti-Oxidant Activity Of Kalanchoe Pinnata And Their Characterization Studies.

Species of Kalanchoe have been used as a remedy for various infectious diseases and cancer treatment. This study evaluates the anti-diabetic properties of the plant, Kalanchoe pinnata. Phytochemical components, anti-oxidant assays were also carried out. Phytochemical analysis showed the presence of alkaloids, flavonoids, steroids, phenolic compounds. The free radical scavenging activity was determined in which the ethanol extract showed the maximum inhibitory effect when compared with aqueous extract .Thin layer chromatography was done to determine the compound in a solvent system of methanol, acetic acid, formic acid and water in the ratio 3:1:1:0.5 . Characterization of the leaf extract was done by UV-visible spectroscopy which showed the peak between 300-350nm. FTIR analysis showed the presence of the various functional group present in the plant. Aqueous and ethanol extract was subjected to α-amylase inhibitory effect and α-glucosidase inhibitory effect to find the antidiabetic potential activity of the plant extract.

Evaluation of phenolics and bioactivities of Camellia quephongensis leaf extracts as affected by various extraction solvents

Camellia quephongensis is an endemic Theaceae species from Central Vietnam. In the present study, phenolics in extracts from leaves of this plant species were quantified. Additionally, free radical scavenging activities, α-amylase and albumin denaturation inhibitory effects of the extracts were evaluated. Catechins were found at significantly higher concentrations in the methanolic and ethanolic extracts compared to the other extracts. The ethanolic extract showed the most potent radical scavenging activities determined by ABTS and DPPH assays, with IC50 values of 57.88 ± 1.89 and 47.87 ± 0.16 μg/mL, respectively. Furthermore, the capacity of this extract to counteract ABTS radicals was comparable with that of ascorbic acid. The ethyl acetate extract exerted the strongest α-amylase inhibitory activity (IC50 = 985.79 ± 16.37 μg/mL). The aqueous methanolic extract with the lowest IC50 value (57.56 ± 3.28 μg/mL) exhibited the highest protective effect on albumin against denaturation, and this was even higher than that of diclofenac. The correlation analysis demonstrated that catechins and ferulic acid may play important roles in radical scavenging activities while gallic acid, chlorogenic acid, and rutin could contribute to albumin denaturation inhibitory effects of the extracts. The findings of the study improve our understanding of bioactive phenolics and potential health benefits associated with C. quephongensis leaves.

Nutritional Composition, Simulated Digestion and Biological Activities of Campomanesia xanthocarpa Fruit.

Gabirobeira fruits are known for their rich nutrient content and bioactive phytochemical compounds that contribute to significant biological activities. Despite these attributes, the antioxidant potential and stability of phenolic compounds in gabiroba by-products after digestion have yet to be studied. The objective of this work was to evaluate the physical-chemical composition, antibacterial activity, α-amylase, and α-glucosidase inhibitory effects, as well as the in vitro digestibility of total phenolic compounds, total flavonoids, and antioxidant activity of powder and extract from gabiroba to valorize these byproducts. The gabiroba powder had low moisture, high carbohydrate and fiber content. The extraction using 80% ethanol demonstrated higher antioxidant, antibacterial, α-amylase, and α-glucosidase inhibition activities compared to the 12% ethanol and water extracts. Catechin and ferulic acid were the major phenolic compounds identified by HPLC-DAD. After digestion, both the powder and the gabiroba extract exhibited a bioaccessibility of more than 30% for total phenolic compounds and antioxidant activity during the gastric phase. However, the dry ethanol extract displayed higher total phenolic compounds after both the gastric and intestinal phases compared to the flour. Processing gabiroba into powder and extract is a promising approach to fully utilize this seasonal fruit, minimize waste, concentrate health-beneficial compounds, and valorize a by-product for use as a functional ingredient and raw material within the food and pharmaceutical industries.

In Vitro α-Glucosidase and α-Amylase Inhibition, Cytotoxicity and Free Radical Scavenging Profiling of the 6-Halogeno and Mixed 6,8-Dihalogenated 2-Aryl-4-methyl-1,2-dihydroquinazoline 3-Oxides.

Series of the 6-bromo/iodo substituted 2-aryl-4-methyl-1,2-dihydroquinazoline-3-oxides and their mixed 6,8-dihalogenated (Br/I and I/Br) derivatives were evaluated for inhibitory properties against α-glucosidase and/or α-amylase activities and for cytotoxicity against breast (MCF-7) and lung (A549) cancer cell lines. The 6-bromo-2-phenyl substituted 3a and its corresponding 6-bromo-8-iodo-2-phenyl-substituted derivative 3i exhibited dual activity against α-glucosidase (IC50 = 1.08 ± 0.02 μM and 1.01 ± 0.05 μM, respectively) and α-amylase (IC50 = 5.33 ± 0.01 μM and 1.18 ± 0.06 μM, respectively) compared to acarbose (IC50 = 4.40 ± 0.05 μM and 2.92 ± 0.02 μM, respectively). The 6-iodo-2-(4-fluorophenyl)-substituted derivative 3f, on the other hand, exhibited strong activity against α-amylase and significant inhibitory effect against α-glucosidase with IC50 values of 0.64 ± 0.01 μM and 9.27 ± 0.02 μM, respectively. Compounds 3c, 3l and 3p exhibited the highest activity against α-glucosidase with IC50 values of 1.04 ± 0.03, 0.92 ± 0.01 and 0.78 ± 0.05 μM, respectively. Moderate cytotoxicity against the MCF-7 and A549 cell lines was observed for these compounds compared to the anticancer drugs doxorubicin (IC50 = 0.25 ± 0.05 μM and 0.36 ± 0.07 μM, respectively) and gefitinib (IC50 = 0.19 ± 0.04 μM and 0.25 ± 0.03 μM, respectively), and their IC50 values are in the range of 10.38 ± 0.08-25.48 ± 0.08 μM and 11.39 ± 0.12-20.00 ± 0.05 μM, respectively. The test compounds generally exhibited moderate to strong antioxidant capabilities, as demonstrated via robust free radical scavenging activity assays, viz., DPPH and NO. The potential of selected derivatives to inhibit superoxide dismutase (SOD) was also investigated via enzymatic assay in vitro. Molecular docking revealed the N-O moiety as essential to facilitate electrostatic interactions of the test compounds with the protein residues in the active site of α-glucosidase and α-amylase. The presence of bromine and/or iodine atoms resulted in increased hydrophobic (alkyl and/or π-alkyl) interactions and therefore increased inhibitory effect against both enzymes.

A comparative study of Ghanaian propolis extracts: Chemometric analysis of the chromatographic profile, antioxidant, and hypoglycemic potential and identification of active constituents

Diabetes is a disease characterized by high post-prandial glucose levels, which lead to other complications such as peripheral end organ damage. The use of enzyme inhibitors in the management of Type-2 diabetes ensure the control of blood glucose levels via the control of carbohydrate metabolism. The use of standard agents such as acarbose is associated with unwanted side effects hence the need to investigate other sources of antihyperglycemic agents. Propolis, a natural substance from bees, possesses diverse biological activities including antioxidant, antimicrobial and antidiabetic properties. However, the phytochemical content of propolis and its extracts may vary depending on the geographical area, the solvent of extraction and type of bees. This study represents the first attempt to compare different extracts of propolis from the same source in sub-Saharan Africa. In this study, the effect of solvent and source of Ghanaian propolis on parameters such as the total phenolic and flavonoid contents, chromatographic profile, antioxidant and α-amylase inhibitory effects were investigated with the aim of identifying and characterizing the most promising extract, which could be of direct or indirect benefit in the management of Type-2 diabetes.Combinations of water, ethanol-water and ethanol extracts were prepared from propolis from three regions. Phytochemical screening was performed on the extracts after which the Folin Ciocalteu method and aluminum chloride colorimetric assay were used to estimate the total phenolic and flavonoid contents respectively. Antioxidant potential of extracts was estimated using DPPH and phosphomolybdenum assays. In-vitro α-amylase inhibition assay was used to investigate hypoglycemic effect of the extracts. Statistical tools such as ANOVA, principal component analysis, hierarchical cluster analysis employed to determine sources of variations within the data obtained, to classify the extracts based on activity and to predict the most effective extract. This extract was then subjected to UHPLC-Q-TOF MS/MS and GC–MS techniques to characterize the constituents.Chemometric analysis of the data obtained showed that the variations in the data could be explained by both propolis source and extraction solvent. Though ethanol extracts generally contained more constituents, the more notable activities were in the ethanol-water extracts. The ethanol-water extract of Bono East propolis (EWBE) was the most potent DPPH radical scavenger (IC50 of 149.37 ± 2.90 µg/mL as compared to 116.60 ± 0.93 µg/mL GAE standard). It was also one of the three extracts which were more potent than acarbose (369.89 µg/mL) in the α-amylase inhibition assay. The predominant constituents from the LC-MS dereplication of EWBE were caffeic acid and flavonoid derivatives whilst 5,5-dimethyl-1-oxa-5 silacyclononanone-9 was the most significant active constituent identified through the GC–MS analysis. The identified constituents are known to have strong antioxidant and antidiabetic properties.The effects of source and solvent of extraction on the biological and physicochemical properties of propolis in Ghana have been quantified using statistical tools. The combined biological effects of propolis suggest a possible role in their usage in the management of type-2-diabetes and its related complications. Ethanol-water extracts were the most promising with EWBE showing the strongest antihyperglycemic activity. Such extracts represent leads towards further research into toxicity and formulation in order to develop safe and useful products for the management of type-2 diabetes.

Microwave-assisted aqueous two-phase extraction of polysaccharides from Hippophae rhamnoide L.: Modeling, characterization and hypoglycemic activity

Natural polysaccharides are concerned for their high biological activity and low toxicity. Two kinds of polysaccharides were extracted from Hippophae rhamnoide L. by microwave-assisted aqueous two-phase system. Under the optimal conditions predicted by RSM model (K2HPO4/ethanol (18.93 %/28.29 %), liquid to material ratio 77 mL/g, power 625 W and temperature 61 °C), the yield of total polysaccharides reached 35.91 ± 0.76 %. Moreover, the polysaccharides extraction was well fitted to the Weibull model. After purification by Sepharose-6B, the polysaccharides from top phase (PHTP, purity of 81.44 ± 1.25 %) and bottom phase (PHBP, purity of 88.85 ± 1.40 %) were obtained. GC, FT-IR, methylation and NMR analyses confirmed the backbone of PHTP was composed of a repeated unit →4)-β-D-Glcp-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1 → 3)-α-L-Araf-(1 → 3)-α-D-Manp-(1→, while the repeated unit in PHBP was →3)-α-L-Araf-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Glcp-(1 → 3)-α-D-Manp-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1→. Compared with PHTP (6.46 × 106 g/mol), PHBP with relatively low molecular weight (8.2 × 105 g/mol) exhibited the smaller particle size, better water-solubility, thermal and rheological property, stronger anti-glycosylation and α-amylase inhibitory effects. Moreover, PHTP and PHBP displayed a reversible inhibition on α-amylase in a competitive manner. This study provides a high-efficient and eco-friendly method for polysaccharides extraction, and lays a foundation for sea buckthorn polysaccharides as potential therapeutic agents in preventing and ameliorating diabetes.

Investigation of α-glucosidase and α-amylase inhibitory effects of phenoxy chalcones and molecular modeling studies.

Diabetes mellitus is one of the most critical health problems affecting the quality of life of people worldwide, especially in developing countries. According to the World Health Organization reports, the number of patients with diabetes is approximately 420 million, and this number is estimated to be 642 million in 2040. There are 2 main types of diabetes: Type 1 (T1DM), where the body cannot produce enough insulin, and Type 2 (T2DM), where the body cannot use insulin properly. Patients with T1DM are treated with insulin injections while oral glucose-lowering drugs are used for patients with T2DM. Oral antihyperglycemic drugs used in the treatment of type 2 diabetes mellitus have different mechanisms. Among these, α-Glucosidase and α-amylase inhibitors are one of the most important inhibitors. The antidiabetic effect of the chalcones, which show rich activity, draws attention. This research aims to synthesize chalcone derivatives that could show potential antidiabetic activity. In this study, the inhibitory activity of the chalcone compounds (4a-4g, 5a-5g) was tested against α-glucosidase and α-amylase enzymes. Besides, molecular modeling was utilized to predict potential interactions of the synthesized compounds that exhibit inhibitory effects. In both in vitro and in silico studies, the analyses revealed that compound 5e exhibits strong inhibitory effects against α-glucosidase enzymes (Binding energy: -7.75 kcal/mol, IC50 : 28.88 μM). Additionally, compound 4f demonstrates encouraging inhibitory effects against α-Amylase (Binding energy: -11.08 kcal/mol, IC50 : 46. 21 μM).

Evaluation of in vitro enzyme inhibitory, anti-inflammatory, antioxidant, and antibacterial activities of Oldenlandia corymbosa L. and Oldenlandia umbellata L. whole plant extracts

BackgroundOldenlandia corymbosa and Oldenlandia umbellata are well-known medicinal plants in various traditional systems of medicine and used to treat bronchitis, asthma, tuberculosis, constipation, and leprosy. We evaluated the phytochemical content, antioxidant potential, enzyme inhibitory action, anti-inflammatory, and antibacterial activities of the whole plant extracts of O. corymbosa and O. umbellata due to their therapeutic importance. MethodsThe phytochemical analysis includes qualitative analysis and quantification of total phenolics, flavonoids, tannins, flavonols, proanthocyanidins, and vitamin E. Enzyme inhibitory assays were studied using α-amylase and α-glucosidase enzymes and anti-inflammatory activity was determined by egg albumin denaturation assay. Antioxidant potential was estimated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethyl benzothiozoline-6-sulfonic acid) diammonium salt (ABTS), ferric reducing antioxidant power (FRAP), hydroxyl radical, superoxide, nitric oxide, metal chelating, and phosphomolybdenum assays. Minimum inhibitory concentrations of extracts were studied against ten bacterial strains by the microdilution method. ResultsThe aqueous extract of O.umbellata showed a higher extract yield (5.0%). The highest amount of total phenolics and flavonoids were observed in the ethanolic extract of O.umbellata (77.23±0.46 mg GAE/g) and O.corymbosa (19.01±0.26 mg GAE/g). Ethanolic extract of O.umbellata (IC50 of 31.71±0.32 µg/mL) and aqueous extract of O.corymbosa (30.53±1.83 µg/mL) showed notable α-amylase inhibitory effect and petroleum ether extract of both plants observed good inhibition against α-glucosidase enzyme. Likewise, petroleum ether extract of O.umbellata (IC50 of 57.16±1.88 µg/mL) showed a moderate anti-inflammatory effect. In all extracts, considerable antioxidant potential was recorded specially with aqueous extract in the nitric oxide scavenging assay with an IC50 of 40.72±1.25 µg/mL. Ethanolic extract of O.umbellata and petroleum ether extract of O.corymbosa (MIC of 56.25 µg/mL) showed good antibiotic potency in lower concentrations which proves these two valuable herb's potential in herbal preparations. ConclusionsThe results of the study provide a basis for further studies aiming to evaluate the possibilities of using the O. umbellata and O. corymbosa as natural sources of antioxidants, enzyme inhibitory, and antibacterial agents. Further studies could be directed to exploit these plants in experimental animal models as potential pharmaceutical agents.