Chemical Composition, Antioxidant and α-Glucosidase-Inhibiting Activities of the Aqueous and Hydroethanolic Extracts of Vaccinium myrtillus Leaves

Urban parks biowaste as a sustainable source of new antidiabetics

Biowaste produced in urban parks is composed of large masses of organic matter that is only occasionally used economically. In this work, extracts of six plants widely distributed in urban parks in Central Europe (Achillea millefolium, Cichorium intybus, Malva sylvestris, Medicago sativa, Plantago lanceolata, and Trifolium pratense), prepared using 10 % and 50 % ethanol, were screened for their antidiabetic and related properties. HPLC and UV-Vis analysis revealed the presence of caffeic acid, quercetin, luteolin, and apigenin derivatives. The extracts were active in DPPH antiradical, .-carotene-linoleic acid, ORAC, and reducing power assay. They inhibited lipoxygenase, collagenase, as well as heat-induced ovalbumin coagulation. They were also able to hinder carbohydrate degradation. For example, IC 50 of anti-α-amylase activity of 10 % and 50 % ethanol extract of M. sativa extracts (204.10 ± 2.11 µg mL-1 and 78.27 ± 0.99 µg mL-1, respectively) did not statistically differ from the activity of the positive control, acarbose (284.74 ± 3.81 µg mL-1). Similar results were observed for their anti-.-glucosidase activity. In most assays, the use of 50 % ethanol was shown to be better suited for the extraction of active metabolites. The results indicate that the biowaste obtained from urban parks represents a potential source of plant material for the preparation of high-value antidiabetic products.

Design of Scaffolds Based on Zinc-Modified Marine Collagen and Bilberry Leaves Extract-Loaded Silica Nanoparticles as Wound Dressings

Purpose

In this study, wound dressings were designed using zinc-modified marine collagen porous scaffold as host for wild bilberry (WB) leaves extract immobilized in functionalized mesoporous silica nanoparticles (MSN). These new composites were developed as an alternative to conventional wound dressings. In addition to the antibacterial activity of classic antibiotics, a polyphenolic extract could act as an antioxidant and/or an anti-inflammatory agent as well.

Methods

Wild bilberry leaves extract was prepared by ultrasound-assisted extraction in ethanol and its properties were evaluated by UV-Vis spectroscopy (radical scavenging activity, total amount of polyphenols, flavonoids, anthocyanins, and condensed tannins). The extract components were identified by HPLC, and the antidiabetic properties of the extract were evaluated via α-glucosidase inhibitory activity. Spherical MSN were modified with propionic acid or proline moieties by post-synthesis method and used as carriers for the WB leaves extract. The textural and structural features of functionalized MSN were assessed by nitrogen adsorption/desorption isotherms, small-angle XRD, SEM, TEM, and FTIR spectroscopy. The composite porous scaffolds were prepared by freeze drying of the zinc-modified collagen suspension containing WB extract loaded silica nanoparticles.

Results

The properties of the new composites demonstrated enhanced properties in terms of thermal stability of the zinc-collagen scaffold, without altering the protein conformation, and stimulation of NCTC fibroblasts mobility. The results of the scratch assay showed contributions of both zinc ions from collagen and the polyphenolic extract incorporated in functionalized silica in the wound healing process. The extract encapsulated in functionalized MSN proved enhanced biological activities compared to the extract alone: better inhibition of P. aeruginosa and S. aureus strains, higher biocompatibility on HaCaT keratinocytes, and anti-inflammatory potential demonstrated by reduced IL-1β and TNF-α levels.

Conclusion

The experimental data shows that the novel composites can be used for the development of effective wound dressings.

Anti-Inflammatory, Antidiabetic, and Antioxidant Properties of Extracts Prepared from Pinot Noir Grape Marc, Free and Incorporated in Porous Silica-Based Supports

This study presents properties of hydroethanolic extracts prepared from Pinot Noir (PN) grape pomace through conventional, ultrasound-assisted or solvothermal extraction. The components of the extracts were identified by HPLC. The total content of polyphenols, flavonoids, anthocyanins, and condensed tannins, as well as antioxidant activity and α-glucosidase inhibitory activity of extracts were evaluated using UV-vis spectroscopy. All extracts were rich in phenolic compounds, proving a good radical scavenging activity. The extract obtained by conventional extraction at 80 °C showed the best α-glucosidase inhibitory activity close to that of (-)-epigallocatechin gallate. To improve the chemical stability of polyphenols, the chosen extract was incorporated in porous silica-based supports: amine functionalized silica (MCM-NH2), fucoidan-coated amine functionalized silica (MCM-NH2-Fuc), MCM-41, and diatomite. The PN extract exhibited moderate activity against Gram-positive S. aureus (MIC = 156.25 μg/mL) better than against Gram-negative E. coli (MIC = 312.5 μg/mL). The biocompatibility of PN extract, free and incorporated in MCM-NH2 and MCM-NH2-Fuc, was assessed on RAW 264.7 mouse macrophage cells, and the samples showcased a good cytocompatibility at 10 µg/mL concentration. At this concentration, PN and PN@MCM-NH2-Fuc reduced the inflammation by inhibiting NO production. The anti-inflammatory potential against COX and LOX enzymes of selected samples was evaluated and compared with that of Indomethacin and Zileuton, respectively. The best anti-inflammatory activity was observed when PN extract was loaded on MCM-NH2-Fuc support.

Vaccinium myrtillus L. Leaf Waste as a Source of Biologically Potent Compounds: Optimization of Polyphenol Extractions, Chemical Profile, and Biological Properties of the Extracts

The aims of the present research include (1) optimization of extraction from Vaccinium myrtillus leaf waste via investigation of plant material:medium ratio, extraction medium, and extraction period, employing extractions at room and high temperatures, or using ultrasound and microwaves (M, HAE, UAE, and MAE, respectively), (2) physicochemical characterization, and (3) investigation of extract biological potential. The statistical analysis revealed that optimal levels of parameters for the greatest polyphenolic yield were a proportion of 1:30 g/mL, ethyl alcohol 50% (v/v) during 2 min of microwave irradiation. By LC-MS analysis, 29 phenolic components were detected; HAE showed the highest richness of almost all determined polyphenols, while chlorogenic acid and quercetin 3-O-glucuronide were dominant. All extracts showed a high inhibition of Staphylococcus aureus growth. The effect of different parameters on extracts' antioxidant capacity depended on the used tests. The extracts also showed a stimulative influence on keratinocyte viability and anti-inflammatory activity (proven in cell-based ELISA and erythrocyte stabilization assays). The extraction procedure significantly affected the extraction yield (MAE ≥ maceration ≥ UAE ≥ HAE), whereas conductivity, density, surface tension, and viscosity varied in a narrow range. The presented research provides evidence on the optimal extraction conditions and technique, chemical composition, and antioxidant, antimicrobial, anti-inflammatory, and keratinocyte viability properties of bilberry extracts for potential applications in pharmacy and cosmetics.

Nephroprotective effect of cranberry (Vaccinium oxycoccos) in streptozocin-induced diabetic nephropathy in mice

OBJECTIVES

Diabetic nephropathy is a chief reason of mortality particularly in individuals with renal dysfunction. The current research was aimed to assess the nephroprotective portion of Vaccinium oxycoccos toward mice diabetic nephropathy induced by streptozotocin (STZ). V. oxycoccos was purchased and used for hydroalcoholic extraction.

METHODS

Sixty male mice were subjected to STZ-intraperitoneal injection (45 mg/kg). After diabetes induction, mice were divided into five groups of diabetic control (received only STZ), non-diabetic control (received only citrate buffer), two V. oxycoccos treatment (received V. oxycoccos extract (200 and 400 mg/kg) oral daily by gavage), and metformin treatment (received metformin (500 mg/kg) oral daily by gavage). Glucose and weight of mice were checked weekly.

RESULTS

After 28 days, the effect of V. oxycoccos extract on serum and urine parameters were assessed. STZ caused significant decreased in the mice body weight. Mice treated with the V. oxycoccos (400 mg/kg) harbored the lowest weight loss at day 28 (70.2±1.38 g). STZ caused significant increase in the mice FBS. Mice treated with the V. oxycoccos (400 mg/kg) harbored the lowest FBS at day 28 (189.2±1.20 mg/dL). Treatment of mice with V. oxycoccos (400 mg/kg) caused the lowest increase in the levels of cholesterol, HbA1c and triglycerides compared to the diabetic control mice. Compared to the diabetic control group, mice treated with V. oxycoccos (400 mg/kg) had the highest HDL, insulin, SOD, and GSH (p<0.05). The lowest serum BUN, CR, and UR were found in mice treated with V. oxycoccos (400 mg/kg). Anti-inflammatory effects of V. oxycoccos (400 mg/kg) was shown by the lowest TNF-α, IL-6, and TGF-β1 concentration in mice treated with V. oxycoccos (400 mg/kg).

CONCLUSIONS

The current study disclosed that treatment with V. oxycoccos resulted in substantial development in the serum and urine parameters and also antioxidant and anti-inflammatory response of STZ-induced diabetic mice.

Microencapsulated Bilberry and Chokeberry Leaf Extracts with Potential Health Benefits

The aim of the research was to develop microencapsulated powders of bilberry and chokeberry extracts via the spray drying technique. Two biopolymers, pectin alone and in combination with HP-β-CD, were used to preserve the antioxidant, hypoglycemic, photoprotective, and antimicrobial bioactivity of the berry leaf extracts. Moreover, the formed powders were characterized in terms of technological, chemical, and several biological properties. The obtained micro-sized powders (mean average particle diameter from 3.83 to 5.94 µm) demonstrated a process yield of up to 73%. The added biopolymers improved the flowability and cohesive properties of the powders and increased their thermal stability to 170 °C. The total content of polyphenolics in the powders ranged from 323.35 to 367.76 mg GAE/g DW for bilberry and from 186.85 to 227.59 mg GAE/g DW for chokeberry powders; meanwhile, chlorogenic acid was the predominant compound in powders. All samples showed stronger α-glucosidase inhibitory activity (IC50 values ranged from 5.00 to 19.59 µg/mL) compared with the reference standard. The study confirmed that spray drying is a suitable method for the preservation of the polyphenolic-rich extracts, while the addition of carriers has a positive effect on the improvement of microencapsulated powders' properties.

The Possibility of Using Fruit-Bearing Plants of Temperate Climate in the Treatment and Prevention of Diabetes

Diabetes mellitus is one of the most dangerous metabolic diseases. The incidence of this disease continues to increase and is often associated with severe complications. Plants and natural plant products with a healing effect have been successfully used in the treatment of many disease entities since the beginning of the history of herbalism and medicine. At present, great emphasis is placed on the biodiversity of crops and the replacement of the monoculture production system of popular temperate climate plants, such as apple, pear, plum, and vine, with alternative fruit species. Very promising fruit plants are Cornelian cherry (Cornus mas); mulberry (Morus alba); bird cherry (Prunus padus); sour cherry (Prunus cerasus); plants of the genus Amelanchier, Sorbus, and Crategus; medlar (Mespilus germanica); quince (Cydonia oblonga); plants of the genus Vaccinium; and wild roses. When promoting the cultivation of alternative fruit-bearing plants, it is worth emphasizing their beneficial effects on health. This systematic review indicates that the antidiabetic effect of various parts of fruit plants is attributed to the presence of polyphenols, especially anthocyanins, which have different mechanisms of antidiabetic action and can be used in the treatment of diabetes and various complications associated with this disease.

Extraction, characterization of polyphenols from certain medicinal plants and evaluation of their antioxidant, antitumor, antidiabetic, antimicrobial properties, and potential use in human nutrition

Introduction

Dietary medicinal plants are among the most sought-after topics in alternative medicine today due to their preventive and healing properties against many diseases.

Aim

This study aimed to extract and determine the polyphenols from indigenous plants extracts, i.e., Mentha longifolia, M. arvensis, Tinospora cordifolia, Cymbopogon citratus, Foeniculum vulgare, Cassia absus, Camellia sinensis, Trachyspermum ammi, C. sinensis and M. arvensis, then evaluate the antioxidant, cytotoxicity, and antimicrobial properties, besides enzyme inhibition of isolated polyphenols.

Methods

The antioxidant activity was evaluated by DPPH, Superoxide radical, Hydroxyl radical (OH.), and Nitric oxide (NO.) scavenging activity; the antidiabetic activity was evaluated by enzymatic methods, and anticancer activity using MTT assay, while the antibacterial activity.

Results

The results showed that tested medicinal plants' polyphenolic extracts (MPPE) exhibited the most significant antioxidant activity in DPPH, hydroxyl, nitric oxide, and superoxide radical scavenging methods because of the considerable amounts of total polyphenol and flavonoid contents. UHPLC profile showed twenty-five polyphenol complexes in eight medicinal plant extracts, categorized into phenolic acids, flavonoids, and alkaloids. The main polyphenol was 3-Feroylquinic acid (1,302 mg/L), also found in M. longifolia, C. absus, and C. sinensis, has a higher phenolic content, i.e., rosmarinic acid, vanillic acid, chlorogenic acid, p-coumaric acid, ferulic acid, gallic acid, catechin, luteolin, 7-O-neohesperideside, quercetin 3,7-O-glucoside, hesperidin, rutin, quercetin, and caffeine in the range of (560-780 mg/L). At the same time, other compounds are of medium content (99-312 mg/L). The phenolics in C. sinensis were 20-116% more abundant than those in M. longifolia, C. absus, and other medicinal plants. While T. cordifolia is rich in alkaloids, T. ammi has a lower content. The MTT assay against Caco-2 cells showed that polyphenolic extracts of T. ammi and C. citratus had maximum cytotoxicity. While M. arvensis, C. sinensis, and F. vulgare extracts showed significant enzyme inhibition activity, C. sinensis showed minor inhibition activity against α-amylase. Furthermore, F. vulgare and C. sinensis polyphenolic extracts showed considerable antibacterial activity against S. aureus, B. cereus, E. coli, and S. enterica.

Discussion

The principal component analysis demonstrated clear separation among medicinal plants' extracts based on their functional properties. These findings prove the therapeutic effectiveness of indigenous plants and highlight their importance as natural reserves of phytogenic compounds with untapped potential that needs to be discovered through advanced analytical methods.

Establishment of a Sonotrode Extraction Method and Evaluation of the Antioxidant, Antimicrobial and Anticancer Potential of an Optimized Vaccinium myrtillus L. Leaves Extract as Functional Ingredient

Vaccinium myrtillus L. (bilberry) leaves are an important by-product of berry production that may be used as a source of phenolic compounds which have a positive effect on human health. Therefore, an ultrasound-assisted extraction via sonotrode has been used for the first time to recover bioactive compounds from bilberry leaves. The extraction has been optimized using a Box-Behnken design. The influence of ethanol:water ratio (v/v), time of extraction (min) and amplitude (%) were evaluated considering total phenolic content (TPC) and antioxidant capacity (DPPH and FRAP assays) as dependent variables in a response surface methodology (RSM). Optimum values for the independent factors were 30:70 ethanol/water (v/v), 5 min of extraction and 55% amplitude. The empirical values of the independent variables using the optimized conditions were 217.03 ± 4.92 mg GAE/g d.w. (TPC), 271.13 ± 5.84 mg TE/g d.w. (DPPH) and 312.21 ± 9.30 mg TE/g d.w. (FRAP). The validity of the experimental design was confirmed using ANOVA and the optimal extract was characterized using HPLC-MS. A total of 53 compounds were tentatively identified, of which 22 were found in bilberry leaves for the first time. Among them, chlorogenic acid was the most abundant molecule, representing 53% of the total phenolic compounds identified. Additionally, the antimicrobial and anticancer activities of the optimum extract were tested. Gram-positive bacteria demonstrated high sensitivity to bilberry leaves extract in vitro, with MBC values of 6.25 mg/mL for Listeria monocytogenes, Listeria innocua and Enterococcus faecalis, and 0.8 mg/mL for Staphylococcus aureus and Bacillus cereus. Furthermore, bilberry leaves extract exerted in vitro antiproliferative activity against HT-29, T-84 and SW-837 colon tumor cells with IC₅₀ values of 213.2 ± 2.5, 1140.3 ± 5.2 and 936.5 ± 4.6 μg/mL, respectively. Thus, this rapid ultrasound-assisted extraction method has demonstrated to be an efficient technique to obtain bilberry leaves extract with in vitro antioxidant, antimicrobial and anticancer capacities that may be useful for the food industry as natural preservative or even for the production of functional foods or nutraceuticals.

Phytochemicals Determination, and Antioxidant, Antimicrobial, Anti-Inflammatory and Anticancer Activities of Blackberry Fruits

A comprehensive characterization of the phytochemicals present in a blackberry fruit extract by HPLC-TOF-MS has been carried out. The main compounds in the extract were ursane-type terpenoids which, along with phenolic compounds, may be responsible for the bioactivity of the extract. In vitro antioxidant capacity was assessed through Folin–Ciocalteu (31.05 ± 4.9 mg GAE/g d.w.), FRAP (637.8 ± 3.2 μmol Fe2+/g d.w.), DPPH (IC50 97.1 ± 2.4 μg d.w./mL) and TEAC (576.6 ± 8.3 μmol TE/g d.w.) assays. Furthermore, the extract exerted remarkable effects on in vitro cellular antioxidant activity in HUVEC cells at a concentration of 5 mg/mL. Antimicrobial activity of the extract was also tested. Most sensible microorganisms were Gram-positive bacteria, such as E. faecalis, B. cereus and Gram-negative E. coli (MBC of 12.5 mg/mL). IC50 values against colon tumoral cells HT-29 (4.9 ± 0.2 mg/mL), T-84 (5.9 ± 0.3 mg/mL) and SW-837 (5.9 ± 0.2 mg/mL) were also obtained. Furthermore, blackberry extract demonstrated anti-inflammatory activity inhibiting the secretion of pro-inflammatory IL-8 cytokines in two cellular models (HT-29 and T-84) in a concentration-dependent manner. These results support that blackberry fruits are an interesting source of bioactive compounds that may be useful in the prevention and treatment of different diseases, mainly related to oxidative stress.

Vaccinium Species (Ericaceae): Phytochemistry and Biological Properties of Medicinal Plants

The Vaccinium L. (Ericaceae) genus consists of a globally widespread and diverse genus of around 4250 species, of which the most valuable is the Vaccinioidae subfamily. The current review focuses on the distribution, history, bioactive compounds, and health-related effects of three species: cranberry, blueberry, and huckleberry. Several studies highlight that the consumption of Vaccinium spp. presents numerous beneficial health-related outcomes, including antioxidant, antimicrobial, anti-inflammatory, and protective effects against diabetes, obesity, cancer, neurodegenerative diseases and cardiovascular disorders. These plants' prevalence and commercial value have enhanced in the past several years; thus, the generated by-products have also increased. Consequently, the identified phenolic compounds found in the discarded leaves of these plants are also presented, and their impact on health and economic value is discussed. The main bioactive compounds identified in this genus belong to anthocyanins (cyanidin, malvidin, and delphinidin), flavonoids (quercetin, isoquercetin, and astragalin), phenolic acids (gallic, p-Coumaric, cinnamic, syringic, ferulic, and caffeic acids), and iridoids.

An Updated Systematic Review of Vaccinium myrtillus Leaves: Phytochemistry and Pharmacology

Bilberry leaves are used in many countries in traditional medicine for treating a wide variety of diseases. Due to the high therapeutic potential of Vaccinium myrtillus (VM) leaves, this review aims to present the latest knowledge on the phytochemical profile, as well as the therapeutic effects of this herbal drug. The review was conducted according to the Prisma guidelines, and the scientific databases were searched using combinations of the following keywords: "Vaccinium myrtillus", "leaves", "bilberry". Recent research was focused on the influence of abiotic factors on the phytochemical composition, and it seems that there are significant differences between the herbal drugs collected from different countries. The phytochemical composition is correlated with the broad spectrum of pharmacological effects. The paper outlines the potent antimicrobial activity of VM extracts against multidrug-resistant bacterial strains, and also the pathways that are modulated by the unique "cocktail" of phytoconstituents in different metabolic alterations. Reviewing the research articles published in the last 10 years, it seems that bilberry leaves have been slightly forgotten, although their phytochemical and pharmacological characteristics are unique.

Evidence-Based Anti-Diabetic Properties of Plant from the Occitan Valleys of the Piedmont Alps

Data on urban and rural diabetes prevalence ratios show a significantly lower presence of diabetes in rural areas. Several bioactive compounds of plant origin are known to exert anti-diabetic properties. Interestingly, most of them naturally occur in different plants present in mountainous areas and are linked to traditions of herbal use. This review will aim to evaluate the last 10 years of evidence-based data on the potential anti-diabetic properties of 9 plants used in the Piedmont Alps (North-Western Italy) and identified through an ethnobotanical approach, based on the Occitan language minority of the Cuneo province (Sambucus nigra L., Achillea millefolium L., Cornus mas L., Vaccinium myrtillus L., Fragaria vesca L., Rosa canina L., Rubus idaeus L., Rubus fruticosus/ulmifolius L., Urtica dioica L.), where there is a long history of herbal remedies. The mechanism underlying the anti-hyperglycemic effects and the clinical evidence available are discussed. Overall, this review points to the possible use of these plants as preventive or add-on therapy in treating diabetes. However, studies of a single variety grown in the geographical area, with strict standardization and titration of all the active ingredients, are warranted before applying the WHO strategy 2014-2023.

Bilberries: Curative and Miraculous - A Review on Bioactive Constituents and Clinical Research

Bilberry (Vaccinium myrtillus L.) fruits are an important part of local diets in many countries and are used as a medicinal herb to treat various disorders. Extracts from fruits are often a part of eye health-promoting supplements, whereas extracts from leaves are advertised for type 2 diabetes mellitus and glycemic control. This review provides an overview of the current knowledge of the phytochemical contents of bilberry fruits and leaves and their bioactivities, critically summarizes origins of the health claims and the outcome of clinical trials, with special attention towards those published in the past 10 years. Overall, the three most referenced indications, which are type 2 diabetes mellitus, vision disorders and circulatory diseases, all include contradictory results with no clear conclusion as to the benefits and recommended dosages. Moreover, the indications for vision disorders and diabetes originate from unproven or false claims that have been repeated in research since the 20th century without consistent fact-checking. Beneficial clinical results have been attested for the treatment of dyslipidemia and chronic inflammatory disorders when applied as dietary supplementation of fresh bilberries or as anthocyanin-rich bilberry fruit extracts. However, there is a general lack of double-blinded controlled research with larger sample sizes.

Globularia alypum L. and Related Species: LC-MS Profiles and Antidiabetic, Antioxidant, Anti-Inflammatory, Antibacterial and Anticancer Potential

Species from the genus Globularia L. have been used as healing agents for various ailments, with utilization of Globularia alypum L. being most frequently reported. The aim of this study was to evaluate the antidiabetic, antioxidant, anti-inflammatory, antibacterial and anticancer potential of G. alypum and three related species, G. punctata Lapeyr., G. cordifolia L. and G. meridionalis (Podp.) O.Schwarz, in relation to their phytochemical compositions. Globularin and verbascoside were identified using LC-PDA-ESI-MSn as the major metabolites of G. alypum with known biological activities. G. alypum demonstrated the greatest α-glucosidase inhibitory activity and DPPH radical scavenging activity (IC50 = 17.25 μg/mL), while its anti-inflammatory activity was not significantly different from those of related species. All investigated species showed considerable antibacterial activity against methicillin-resistant Staphylococcus aureus in the broth microdilution method (MIC = 1.42-3.79 mg/mL). G. punctata also showed antibacterial activities against Escherichia coli (MIC = 1.42 mg/mL), Bacillus subtilis (MIC = 1.89 mg/mL), B. cereus (MIC = 2.84 mg/mL) and Enterococcus faecalis (MBC = 5.68 mg/mL). G. punctata, G. cordifolia and G. meridionalis showed greater anticancer potential than G. alypum. Obtained results indicate investigated Globularia species could serve as sources of diverse bioactive molecules, with G. punctata having the greatest antibacterial potential.

Microencapsulation and Bioaccessibility of Phenolic Compounds of Vaccinium Leaf Extracts

In recent years, Vaccinium spp. (bilberry-VMT, lingonberry-VVIT, and blueberry-VCS) have sparked particular interest for their prospective health benefits. The latest investigations have place them as important alternative sources of nutraceuticals as their leaves are the main by-products of berry harvesting. The present study is aimed at investigating the bioaccessibility of phenolic compounds from leaves of the Vaccinium species, both as microencapsulated powder and aqueous extracts, following exposure to in vitro simulated digestion. Moreover, the impact of maltodextrin and glucose microencapsulation carriers on the extracts’ phenolic content was assessed. Prior to encapsulation, the viscosity of the emulsions was shown at a shear stress of 50 s−1 dilatant and a Newtonian behaviour above this value with a final viscosity between 1.024 and 1.049 mPa·s. The final microencapsulation yield for the samples ranged between 79 and 81%. Although the microencapsulated forms presented a targeted release at the intestinal level, the phenolic content decreased after gastrointestinal digestion. The bioaccessibility of the microencapsulated extracts showed higher values than their non-encapsulated counterparts, with the highest value of 45.43% in the VVIT sample, followed by VCS with 41.07%. However, the non-encapsulated VCS sample presented high bioaccessibility after in vitro digestion (38.65%). As concluded, further in vivo research should be conducted on the leaves of the Vaccinium species.

Comparative Antioxidant, Anti-Acetylcholinesterase and Anti-α-Glucosidase Activities of Mediterranean Salvia Species

Salvia species have a cosmopolitan distribution and comprise several well-known plants valuable for pharmaceutical and food industries due to their recognized medicinal, food flavouring, and preservative properties. The present study aimed to evaluate and compare the biological activities of seven wild-growing Salvia species from the Mediterranean area (S. fruticosa, S. glutinosa, S. nemorosa, S. officinalis, S. pratensis, S. sclarea, S. verticillata). All studied ethanolic leaf extracts exhibited significant DPPH and NO radical scavenging ability, lipid peroxidation inhibition, and reducing power, as well as moderate iron-chelating properties. Together with S. officinalis and S. fruticosa, S. verticillata showed anti-acetylcholinesterase activity, while S. glutinosa was also found to possess the ability to inhibit α-glucosidase. Total flavonoid (0.37-0.90%), phenolic acid (3.55-12.44%), tannin (1.22-2.60%), and anthocyanin contents (0.03-0.08%) were determined in Salvia leaves. Rosmarinic acid was the predominant hydroxycinnamic acid in all studied sage plants, ranging from 9400 to 38,800 μg/g. The correlation study showed a strong relationship between biological activities and contents of total phenolic acids, total tannins, and rosmarinic acid, indicating their significant contribution to the efficiency of tested Salvia species. Our results highlighted Mediterranean sage plants as rich sources of potent antioxidant, neuroprotective, and hypoglycemic agents which are worthy of further research.

Phytochemical and pharmacological anti-diabetic properties of bilberries (Vaccinium myrtillus), recommendations for future studies

Nowadays, extensive attention has focused on dietary constituents that may be valuable for treating, eating, and preventing diabetes. Numerous studies have shown that anthocyanin's are one of the most important nutritional factors associated with diabetes. Anthocyanin's are the leading group of water-soluble pigments in the plant kingdom, and they are generally available in some human diet in fruits, vegetables, cereals, beans. Amongst, bilberries (Vaccinium myrtillus), is one of the essential sources for dietary anthocyanin consumption containing vast amounts of anthocyanin's, making them the main plant in the treatment and prevention of diabetes. Although the bilberries have other valuable properties such as anti-cancer, anti-inflammatory, and antioxidant, the main focus of the present study is to present the effects of bilberries (V. myrtillus) on the prevention and treatment of diabetes.

Medical Species Used in Russia for the Management of Diabetes and Related Disorders

Background: Polyherbal mixtures called "medical species" are part of traditional and officinal medicine in Russia. This review aimed to analyze medical species used in Russia for the treatment of diabetes and related disorders. The information relevant to medical species, diabetes, and obesity was collected from local libraries, the online service E-library.ru, and Google Scholar. The prediction of the antidiabetic activity for the principal compounds identified in plants was performed using the free web resource PASS Online. Results: We collected and analyzed information about the compositions, specificities of use, and posology of 227 medical species. The medical species represent mixtures of 2-15 plants, while the most frequently mentioned in the literature are species comprising 3-6 plants. The top 10 plants among the 158 mentioned in the literature include Vaccinium myrtillus L., Phaseolus vulgaris L., Taraxacum campylodes G.E. Haglund., Urtica dioica L., Rosa spp., Hypericum spp., Galega officinalis L., Mentha × piperita L., Arctium spp, and Fragaria vesca L. The leading binary combination found in medical species comprises the leaves of V. myrtillus and pericarp of P. vulgaris; leaves of V. myrtillus and leaves of U. dioica; and leaves of V. myrtillus and aerial parts of G. officinalis. In triple combinations, in addition to the above-mentioned components, the roots of T. campylodes are often used. These combinations can be regarded as basic mixtures. Other plants are added to improve the efficacy, treat associated disorders, improve gastrointestinal function, prevent allergic reactions, etc. Meanwhile, an increase in plants in the mixture necessitates advanced techniques for quality control. A feature of medical species in Russia is the addition of fresh juices, birch sap, seaweeds, and adaptogenic plants. Modern studies of the mechanisms of action and predicted activities of the principal compounds from medicinal plants support the rationality of polyherbal mixtures. Nevertheless, the mechanisms are not well studied and reported due to the limited number of compounds. Further investigations with calculations of synergistic or additive indices are important for strengthening the scientific fundamentals for the wider use of medical species in the therapy of diabetes. Two medical species, "Arfazetin" (7 medicinal plants) and "Myrphasinum" (12 medicinal plants), are approved for use in officinal medicine. The efficacy of these species was confirmed in several in vivo experiments and clinical trials. According to modern regulatory rules, additional experiments and clinical trials are required for more detailed investigations of the mechanisms of action and confirmation of efficacy. Conclusion: We believe that the scientifically based utilization of rich plant resources and knowledge of Russian herbal medicine can significantly contribute to the local economy as well as to the sectors seeking natural healing products.

Vaccinium Species (Ericaceae): From Chemical Composition to Bio-Functional Activities

The genus Vaccinium L. (Ericaceae) includes more than 450 species, which mainly grow in cooler areas of the northern hemisphere. Vaccinium species have been used in traditional medicine of different cultures and the berries are widely consumed as food. Indeed, Vaccinium supplement-based herbal medicine and functional food, mainly from V. myrtillus and V. macrocarpon, are used in Europe and North America. Biological studies support traditional uses since, for many Vaccinium components, important biological functions have been described, including antioxidant, antitumor, anti-inflammatory, antidiabetic and endothelium protective activities. Vaccinium components, such as polyphenols, anthocyanins and flavonoids, are widely recognized as modulators of cellular pathways involved in pathological conditions, thus indicating that Vaccinium may be an important source of bioactive molecules. This review aims to better describe the bioactivity of Vaccinium species, focusing on anti-inflammatory and endothelial protective cellular pathways, modulated by their components, to better understand their importance for public health.

The Potential of Sun-Dried Grape Pomace as a Multi-Functional Ingredient for Herbal Infusion: Effects of Brewing Parameters on Composition and Bioactivity

Wine and by-products are essential elements of a Mediterranean diet and considered as a reservoir of bioactive compounds with various health effects. Grape pomace, an easily available natural material of low cost, shares a similar wealth of health benefiting bioactive phytochemicals. The objective of this study was to explore the utilization of grape pomace from Commandaria dessert wine as main ingredient for functional infusions. Therefore, the ratio of water to grape pomace powder (40–200 mL g⁻¹), infusion time (3–15 min) and temperature (55–95 °C) were optimized in terms of composition and bioactivity. Multiple response optimization indicated that brewing 200 mL water per g of material for 12.2 min at 95 °C, was the optimum method for preparing the infusion. Results also revealed a significant impact of three parameters as well as quadratic and interactive effects on composition and bioactivity of infusions. Furthermore, the infusion presents antimicrobial effects against Listeria monocytogenes serotypes and other common food pathogenic bacteria. Finally, a sensory evaluation was performed to assess the organoleptic attributes of the infusion and its improvement, with the addition of Mediterranean aromatic plants. Overall, the present work describes a promising strategy for the re-use of sun-dried grape pomace as a functional ingredient of infusions.

Old Plant, New Possibilities: Wild Bilberry (Vaccinium myrtillus L., Ericaceae) in Topical Skin Preparation

Bilberry represents a valuable source of antioxidant substances responsible for its application for the treatment of different conditions (such as inflammation, cardiovascular disease, cancer, diabetes, and different age-related diseases) associated with increased oxidative stress. As oxidative stress might cause skin impairments, we aim to evaluate a topical preparation containing bilberry leaves extract and bilberry seeds oil, obtained as a byproduct of the food industry. To obtain the extracts, the conventional maceration technique for leaves, and supercritical carbon dioxide extraction for seeds were employed. The chemical profile of both actives was achieved by HPLC and GC methods, revealing the presence of phenolic acids (chlorogenic being the most abundant), flavonoids (isoquercetin in the highest amount), and resveratrol in leaves extract, while in seeds oil the essential ω-3 and ω-6 fatty acids were determined in favorable ratio, almost being 1. Antioxidant potential of the wild bilberry extract and seed oil was evaluated using in vitro DPPH and FRAP assays. Finally, effects of the oil-in-water creams with mentioned wild bilberry isolates on the skin were investigated in an in vivo study conducted on healthy human volunteers, revealing the significant beneficial effects when topically applied.

Optimization of Two Eco-Friendly Extractions of Black Medick (Medicago lupulina L.) Phenols and Their Antioxidant, Cosmeceutical, α-Glucosidase and α-Amylase Inhibitory Properties

Medicago lupulina is an ancient edible plant from the Fabaceae family. In this work, two eco-friendly methods for extraction of bioactive phenolics from M. lupulina were developed using mixtures of water with two non-toxic, skin- and environmentally-friendly polyol solvents: glycerol and polypropylene glycol. Ultrasound-assisted extractions were optimized using a Box–Behnken design. The independent variables were the concentration of organic solvent in water (X₁), extraction temperature (X₂) and time (X₃), while the response was phenolic content. The optimum conditions for extraction of polyphenols were (X₁, X₂, X₃): (45%, 70 °C, 60 min) and (10%, 80 °C, 60 min) for glycerol and polypropylene glycol extraction, respectively. The extracts prepared at optimum conditions were rich in phenolic compounds, mainly derivatives of apigenin, kaempferol, luteolin, quercetin, caffeic and ferulic acid, as well as coumestrol. Their cosmeceutical and antidiabetic activity was tested. Both extracts demonstrated notable antioxidant, anti-lipoxygenase and anti-α-amylase activity. In addition to those activities, the glycerol extract efficiently inhibited protein coagulation, elastase and α-glucosidase activity. Glycerol present in the extract displayed enzyme-inhibiting activity in several assays and supported the action of the bioactive constituents. Thus, the optimized glycerol extract is a desirable candidate for direct incorporation in antidiabetic food supplements and cosmeceutical products.

Assessment of cytotoxicity and antioxidant properties of berry leaves as by-products with potential application in cosmetic and pharmaceutical products

Vaccinum myrtillus L., Ribes nigrum L., Rubus fruticosus L., Fragaria vesca L. leaves are considered an agro-waste of the berry industry. Although numerous studies indicate fruit is a rich source of bioactive compounds, the authors prove leaves can also be a valuable source of compounds used in the pharmaceutical and cosmetic industries. The study attempts to assess and compare the antioxidant and cytotoxic properties of berry leaves extracts. The total phenolic compounds, flavonoids, anthocyanins and procyanidins content were determined. Antioxidant potential was evaluated using the DPPH radical scavenging method. Cytotoxicity studies were conducted to evaluate the effect of the extracts on the metabolism and proliferation of keratinocytes and fibroblasts in vitro. The effect on the migration capacity of these cells was also assessed. The obtained results show that the examined extracts are a source of valuable bioactive agents. All tested extracts show significant ability to remove free radicals in higher concentrations. Cytotoxicity assessments have shown that leaf extracts of the analyzed plants differ in cytotoxicity, both for keratinocytes and fibroblasts. The results of the assessment of cell migration capacity correlate with cytotoxicity tests, because the concentration of extracts showing cytotoxic activity towards the tested cells also inhibited their migration.

Chemical Composition, Antioxidant, and α-Glucosidase-Inhibiting Activity of Aqueous and Hydroethanolic Extracts of Traditional Antidiabetics from Croatian Ethnomedicine

Type 2 diabetes (T2D) is a chronic disease with a growing prevalence worldwide. In addition to the conventional therapy, many T2D patients use phytotherapeutic preparations. In the present study, chemical composition, antioxidant, and α-glucosidase inhibiting activity of traditional antidiabetics from Croatian ethnomedicine (Achillea millefolium, Artemisia absinthium, Centaurium erythraea, Morusalba, Phaseolus vulgaris, Sambucus nigra, and Salvia officinalis) were assessed. The efficacy of water and 80% ethanol as extraction solvents for bioactive constituents was compared. HPLC analysis revealed that the prepared extracts were rich in phenols, especially rutin, ferulic, and chlorogenic acid. Antiradical (against DPPH and ABTS radicals), reducing (towards Mo6+ and Fe3+ ions), and enzyme inhibiting properties were in linear correlation with the content of phenolic constituents. Ethanolic extracts, richer in phenolic substances, showed dominant efficacy in those assays. Aqueous extracts, on the other hand, were better Fe2+ ion chelators and more active in the β-carotene linoleic acid assay. Extracts from S. officinalis and A. millefolium were particularly active antioxidants and α-glucosidase inhibitors. A. absinthium, another potent α-glucosidase inhibitor, contained chromium, a mineral that promotes insulin action. The investigated plants contained significant amounts of minerals useful in management of T2D, with negligible amounts of heavy metals deeming them safe for human use.

Antidiabetic and Cosmeceutical Potential of Common Barbery (Berberis vulgaris L.) Root Bark Extracts Obtained by Optimization of 'Green' Ultrasound-Assisted Extraction

Berberis vulgaris is rich in berberine, an isoquinoline alkaloid, with antidiabetic activity, often used topically for skin-related problems. The aim of this work was to develop a “green” method for berberine extraction using mixtures of water with glycerol, a non-toxic, environmentally-friendly solvent. Response surface methodology based on Box–Behnken design was used to optimize the experimental conditions for ultrasound-assisted extraction of berberine and anti-radical components from B. vulgaris root bark. The independent variables were temperature (X₁), glycerol concentration (X₂), and ultrasound power (X₃), while the responses were berberine concentration and DPPH radical scavenging activity of the extracts (RSA IC₅₀). The response values of the extracts prepared at optimum conditions were (response, X₁, X₂, X₃): berberine yield (145.5 μg/mL; 80 °C, 50%, 144 W) and RSA IC₅₀ (58.88 μL/mL; 80 °C, 30%, 720 W). The observed values deviated from the predicted values by −3.45% and 6.42% for berberine and RSA IC₅₀, respectively, thus indicating the validity of the selected models. The prepared extracts demonstrated antioxidant, anti-melanogenic, and anti-inflammatory activity, as well excellent α-glucosidase and α-amylase inhibitory activity. The displayed biological properties and lack of glycerol toxicity makes the prepared extracts suitable for direct inclusion into antidiabetic and dermatologic food supplements and topical products.

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

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

Evaluation of anti-obesity and lipid-lowering properties of Vaccinium myrtillus leaves powder extract in a hamster model

Background Vaccinium myrtillus leaves are known to be rich in phenols and have been used in traditional medicine as an antidiabetic remedy. This study evaluated the powder extract of V. myrtillus leaves obtained with the use of L-arginine and myo-inositol for anti-obesity and lipid-lowering potential in hamsters. Methods Standard phytochemical methods were used to determine the total phenolic and total flavonoid contents of the extract. The obesity condition was induced in Syrian hamsters by feeding them with highly palatable fat- and sugar-rich diet (40.3 kcal% fat) for 12 weeks. From the 10th week of diet feeding, the obese hamsters were treated with the powder extract of V. myrtillus leaves (15, 25 and 35 mg/kg/day, respectively) and "Styfimol" (6.2 mg/kg/day of hydroxycitric acid) as a positive control drug. At the end of the treatment period, the biochemical parameters as well as visceral fat mass were determined. Results Vaccinium myrtillus leaves powder extract at 25 and 35 mg/kg/day caused a significant reduction in body weight gain and visceral fat mass in obese hamsters. Serum triacylglycerols, free fatty acids, total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels were also significantly lower. Besides, the hamsters treated with powder extract at 25 and 35 mg/kg/day had the closest intact value ratio of high-density lipoprotein cholesterol and LDL-C compared with positive control animals. Conclusions The results showed that V. myrtillus leaves powder extract is a promising therapeutic agent for the treatment of obesity and obesity-induced diseases.

Wild Bilberry (Vaccinium myrtillus L., Ericaceae) from Montenegro as a Source of Antioxidants for Use in the Production of Nutraceuticals

The aim of this study was to establish correlation of chemical composition and antioxidant activity of bilberry plants from Montenegro. Total phenolic, tannin, flavonoid, procyanidin and anthocyanin contents were determined in fruits and leaves extracts using spectrophotometric methods, while the measurements of metal content was carried out in an Inductively Coupled Atomic Emission Spectrometer. Qualitative and quantitative analyses of major phenolics were achieved by HPLC. In the investigated extracts, the most abundant phenolic was chlorogenic acid, followed by protocatechuic acid, while resveratrol, isoquercetin, quecetin and hyperoside were also present in significant quantities. Antioxidant potential was evaluated using two in vitro assays—FRAP and DPPH—being in the accordance with the cyclic voltammetry tests, performed as well. The results revealed that all the investigated extracts were rich in phenolic and essential mineral constituents, with significant antioxidant activity, depending on the polyphenolic and mineral contents, which was confirmed by principal component analysis.

Vaccinium Extracts as Modulators in Experimental Type 1 Diabetes

Antihyperglycemic effects of four extracts obtained from leaves and fruits of Vaccinium myrtillus and Vaccinium corymbosum were assessed in diabetic rats. In addition, the effects of extracts on diabetic-related complications such as the development of diabetic cataract and oxidative stress were evaluated. Type 1 diabetes was induced with a single dose of streptozotocin in Wistar rats. The rats were randomly divided into seven equal groups: NC-normal control, DC-diabetic control, PC-positive control treated with metformin, VML-received V. myrtillus leaf extract, VMLF-received VML and fruit extract, VCL-received V. corymbosum leaf extract, and VCLF-received VCL and fruit extract. Body weight and glucose levels were monitored every second week. After 8 weeks of treatment, serum glucose, insulin, and malondialdehyde were measured. Lenses were removed after sacrifice and eight lenses from each group were randomly selected for evaluation of cataract development. A decrease in body weight was observed in all diabetic groups in the first weeks. In the VML group, no significant decrease was observed. Glucose levels during the experiment were high in DC, PC, and VCL groups, with no improvement during the 8 weeks. In VML, VMLF, and VCLF groups, a decrease in blood glucose levels was observed. Similar results regarding serum insulin and glucose levels at the end of the experiment were observed within groups. V. myrtillus extracts prevented the development of cataract compared with the DC group (P < .05).

Complex Enzyme-Assisted Extraction Releases Antioxidative Phenolic Compositions from Guava Leaves

Phenolics in food and fruit tree leaves exist in free, soluble-conjugate, and insoluble-bound forms. In this study, in order to enhance the bioavailability of insoluble-bound phenolics from guava leaves (GL), the ability of enzyme-assisted extraction in improving the release of insoluble-bound phenolics was investigated. Compared to untreated GL, single xylanase-assisted extraction did not change the composition and yield of soluble phenolics, whereas single cellulase or β-glucosidase-assisted extraction significantly enhanced the soluble phenolics content of PGL. However, complex enzyme-assisted extraction (CEAE) greatly improved the soluble phenolics content, flavonoids content, ABTS, DPPH, and FRAP by 103.2%, 81.6%, 104.4%, 126.5%, and 90.3%, respectively. Interestingly, after CEAE, a major proportion of phenolics existed in the soluble form, and rarely in the insoluble-bound form. Especially, the contents of quercetin and kaempferol with higher bio-activity were enhanced by 3.5- and 2.2-fold, respectively. More importantly, total soluble phenolics extracts of GL following CEAE exhibited the highest antioxidant activity and protective effect against supercoiled DNA damage. This enzyme-assisted extraction technology can be useful for extracting biochemical components from plant matrix, and has good potential for use in the food and pharmaceutical industries.