Effects of Anthocyanins on Components of Metabolic Syndrome-A Review.

Metabolic syndrome (MetS) is a significant health problem. The co-occurrence of obesity, carbohydrate metabolism disorders, hypertension and atherogenic dyslipidaemia is estimated to affect 20-30% of adults worldwide. Researchers are seeking solutions to prevent and treat the conditions related to MetS. Preventive medicine, which focuses on modifiable cardiovascular risk factors, including diet, plays a special role. A diet rich in fruits and vegetables has documented health benefits, mainly due to the polyphenolic compounds it contains. Anthocyanins represent a major group of polyphenols; they exhibit anti-atherosclerotic, antihypertensive, antithrombotic, anti-inflammatory and anticancer activities, as well as beneficial effects on endothelial function and oxidative stress. This review presents recent reports on the mechanisms involved in the protective effects of anthocyanins on the body, especially among people with MetS. It includes epidemiological data, in vivo and in vitro preclinical studies and clinical observational studies. Anthocyanins are effective, widely available compounds that can be used in both the prevention and treatment of MetS and its complications. Increased consumption of anthocyanin-rich foods may contribute to the maintenance of normal body weight and modulation of the lipid profile in adults. However, further investigation is needed to confirm the beneficial effects of anthocyanins on serum glucose levels, improvement in insulin sensitivity and reduction in systolic and diastolic blood pressure.

Extract from Aronia melanocarpa, Lonicera caerulea, and Vaccinium myrtillus Improves near Visual Acuity in People with Presbyopia.

Presbyopia is a global problem with an estimated 1.3 billion patients worldwide. In the area of functional food applications, dietary supplements or herbs, there are very few reports describing the positive effects of their use. In the available literature, there is a lack of studies in humans as well as on an animal model of extracts containing, simultaneously, compounds from the polyphenol group (in particular, anthocyanins) and iridoids, so we undertook a study of the effects of a preparation composed of these compounds on a condition of the organ of vision. Our previous experience on a rabbit model proved the positive effect of taking an oral extract of Cornus mas in stabilizing the intraocular pressure of the eye. The purpose of this study was to evaluate the effect of an orally administered ternary compound preparation on the status of physiological parameters of the ocular organ. The preparation contained an extract of the chokeberry Aronia melanocarpa, the honeysuckle berry Lonicera caerulea L., and the bilberry Vaccinium myrtillus (hereafter AKB) standardized for anthocyanins and iridoids, as bioactive compounds known from the literature. A randomized, double-blind, cross-over study lasting with a "wash-out" period of 17 weeks evaluated a group of 23 people over the age of 50, who were subjects with presbyopia and burdened by prolonged work in front of screen monitors. The group of volunteers was recruited from people who perform white-collar jobs on a daily basis. The effects of the test substances contained in the preparation on visual acuity for distance and near, sense of contrast for distance and near, intraocular pressure, and conjunctival lubrication, tested by Schirmer test, LIPCOF index and TBUT test, and visual field test were evaluated. Anthocyanins (including cyanidin 3-O-galactoside, delphinidin 3-O-arabinoside, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-arabinoside) and iridoids (including loganin, sweroside, loganic acid) were identified as substances present in the extract obtained by HPLC-MS. The preliminary results showed that the composition of AKB applied orally does not change visual acuity in the first 6 weeks of administration. Only in the next cycle of the study was an improvement in near visual acuity observed in 92.3% of the patients. This may indicate potential to correct near vision in presbyopic patients. On the other hand, an improvement in conjunctival wetting was observed in the Schirmer test at the beginning of week 6 of administration in 80% of patients. This effect was weakened in subsequent weeks of conducting the experiment to 61.5%. The improvement in conjunctival hydration in the Schirmer test shows the potential beneficial effect of the AKB formulation in a group of patients with dry eye syndrome. This is the first study of a preparation based on natural, standardized extracts of chokeberry, honeysuckle berry, and bilberry. Preliminary studies show an improvement in near visual acuity and conjunctival hydration on the Schirmer test, but this needs to be confirmed in further studies.

Medicinal Plants Galega officinalis L. and Yacon Leaves as Potential Sources of Antidiabetic Drugs.

Hypoglycemic and antioxidant properties of extracts of medicinal plants Galega officinalis L. (aboveground part) and yacon (Smallanthus sonchifolius Poepp. & Endl.) (leaves) as potential sources of biologically active substances with antidiabetic action have been studied. The pronounced hypoglycemic effect of Galega officinalis extract, devoid of alkaloids, at a dose of 600 mg/kg in experimental diabetes mellitus (DM) has been proven. The established effect is evidenced by a decrease in the concentration of glucose and glycosylated hemoglobin in the blood, increase glucose tolerance of cells, increase C-peptide and insulin content in the plasma of rats' blood. The effective hypoglycemic effect of the extract in the studied pathology was confirmed by histological examination of the pancreas. The cytoprotective effect of the studied extract on pancreatic cells at a dose of 1200 mg/kg was experimentally confirmed. In the standard cut area, an increase was found in the number of Langerhans islets, their average area, diameter, volume, and a number of ß-cells relative to these indicators in animals with diabetes. Comparative screening of the antioxidant properties of 30, 50, 70, and 96% water-ethanol extracts of yacon indicates the highest potential of 50% water-ethanol extract to block free radicals in in vitro model experiments. The non-alkaloid fraction of Galega officinalis extract showed moderate antioxidant activity and was inferior to yacon extract in its ability to neutralize reactive oxygen species (ROS) and bind metal ions of variable valence. The level of antioxidant potential of the studied extracts is due to differences in the quantitative content of compounds of phenolic nature in their compositions. The obtained data on the biological effects of Galega officinalis extract on the structural and functional state of ß-cells of the pancreas and antioxidant properties of Galega officinalis and yacon extracts substantiate the prospects of using these plants to create antidiabetic medicines and functional foods based on them.

Iridoids, Flavonoids, and Antioxidant Capacity of Cornus mas, C. officinalis, and C. mas × C. officinalis Fruits.

The fruits of Cornus mas and Cornus officinalis have been known and appreciated in folk medicine for years and have a high biological value, which is mainly connected with their polyphenols and iridoids content. However, hybrids of C. mas × C. officinalis have not been investigated. The aim of this study was to evaluate the iridoids, anthocyanins, and flavonols content, and antioxidant capacity of Cornus mas, Cornus officinalis, and C. mas × C. officinalis. Iridoids and flavonoids were quantified by the High-Performance Liquid Chromatography (HPLC) method. Antioxidant capacity (AC) was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2'-azino-bis (3-ethyl benzothiazoline-6-sulfonic acid (ABTS•+), and ferric reducing antioxidant power (FRAP) tests. Total phenolic content (TPC) was evaluated using the Folin-Ciocalteu reagent. Among the C. mas cultivars and C. officinalis genotypes, there was considerable variation in the content of iridoids, flavonoids, and AC. Interspecific hybrids C. mas × C. officinalis contained more iridoids than C. mas and more anthocyanins than C. officinalis and additionally had higher AC and TPC than C. officinalis and most C. mas. AC, TPC, and the presence of iridoids, anthocyanins, and flavonols in hybrids C. mas × C. officinalis are reported for the first time. The Cornus species deserve special attention due to their highly biologically active substances, as well as useful medicinal properties.

Cornelian cherry extract ameliorates osteoporosis associated with hypercholesterolemia in New Zealand rabbits.

BACKGROUND: Results of animal studies show that a high-cholesterol diet increases bone resorption and decreases bone formation, thus leading to osteoporosis. Previously, we reported on the beneficial influence of Cornelian cherry (Cornus mas L.) fruit on lipid profile in an animal model of diet-induced hipercholesterolemia. OBJECTIVES: To investigate the influence of Cornus mas L. extract and loganic acid (LA) on cholesterol-induced bone changes. MATERIAL AND METHODS: The study was conducted on 50 New Zealand rabbits. The animals were given either standard chow (group P) or the same standard chow enriched with 1% cholesterol (other groups). Additionally, the group CHOL+EX received Cornus mas L. extract, group CHOL+LA - loganic acid, and group CHOL+SIM - simvastatin. Serum concentration of bone turnover markers, bone mineral density (BMD) and bone micro-computed tomography (microCT) were assessed. RESULTS: In the CHOL group, a decrease in osteocalcin (OC) and an increase in C-terminated telopeptide of type I collagen (CTX) levels were detected (CHOL vs P 0.674 ±0.159 ng/mL vs 1.003 ±0.297 ng/mL and 10.049 ±1.276 ng/mL vs 7.721 ±1.187 ng/mL, respectively). The EX and LA ameliorated cholesterol-induced changes in serum OC (0.857 ±0.160 ng/mL and 1.103 ±0.356 ng/mL, respectively) and CTX (7.735 ±1.045 ng/mL and 8.128 ±1.106 ng/mL, respectively). There was a significant decrease in femoral BMD in CHOL group (0.429 ±0.11 g/cm² vs 0.449 ±0.020 g/cm²). The EX and LA ameliorated those changes (0.458 ±0.016 g/cm² and 0.449 ±0.021 g/cm², respectively). The microCT revealed increased bone volume ratio (BV/TV) and trabecular thickness (Tb.Th.) in the CHOL+EX group. CONCLUSIONS: Cornus mas L. inhibited bone resorption and stimulated bone formation, thereby preventing the development of cholesterol-induced osteoporosis.

Antioxidant activities and phenolic compounds in fruits of various genotypes of American persimmon (Diospyros virginiana L.).

BACKGROUND: American persimmons (Diospyros virginiana L.) are known as a widespread cultivar which were traditionally used by Native Americans as a food source, and since ancient times have been used in folk medicine. The objective of this study was to evaluate the antioxidant activity and phenolic content of Diospyros virginiana genotypes. METHODS: The content of the total antioxidant activity and phenolic compounds from the fruits of the American persimmon (Diospyros virginiana L.) of six genotypes were compared. Antioxidant activity (AOA) was measured using three different photometric methods – DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) and FRAP (ferric-reducing antioxidant power). Total phenolic content (TPC) was evaluated using Folin-Ciocalteu reagent assay. RESULTS: The results for AOA (μMol Trolox/g) determined by the DPPH method varied from 51.68 (DV-05) to 100.87 (DV-03), those obtained by the ABTS method varied from 65.40 (DV-05) to 142.26 (DV-03), and those obtained by the FRAP method varied from 45.06 (DV-05) to 109.30 (DV-03). The results for TPC varied from 590.75 ±27.98 mg/100 g (DV-05) to 1325.12 ±77.30 mg/100 g (DV-03). The highest results for AOA and TPC were achieved for the fruits of genotypes DV-03 and DV-05. A positive linear correlation was found between antioxidant activity and total phenolic content in the examined plant material. CONCLUSIONS: The results showed that all fruit extracts exhibited strong antioxidant activities, which generally correlated positively with the total phenolic content. This study demonstrates the potential of the fruits of Diospyros virginiana grown in Ukraine as a possible source of valuable polyphenol content, with high anti- oxidant activities and health-promoting properties. The high contents of phenolic compounds and significant linear correlation between the values of the concentration of phenolic compounds and antioxidant activity indicated that these compounds contributed to the strong antioxidant activity.

Quantification of tannins and related polyphenols in commercial products of tormentil (Potentilla tormentilla).

INTRODUCTION: Potentilla tormentilla has many biological and pharmacological properties and can be used as an ingredient of some herbal medicines or beverages. OBJECTIVE: The aim of this study was to evaluate the content of individual polyphenols, especially condensed and hydrolysable tannins in commercially available tormentil rhizomes and tinctures using chromatographic methods. METHODS: A quantitative analysis (HPLC-PDA) was preceded by qualitative studies (UPLC-qTOF-MS/MS) and the isolation (CC) of the major tannin compounds. RESULTS: The tested plant material is characterised by a high content of tannins and related polyphenols, i.e. in rhizomes even at the level above 20% and in tinctures above 2%. The main components of tormentil rhizomes are procyanidin B3 (mean ~ 3.6%), procyanidin C2 (mean ~ 2.8%), agrimoniin (mean ~ 2.5%), 3-O-galloylquinic acid (mean ~ 1.7%), catechin (mean ~ 1.6%), other flavan-3-ol oligomers (mean ~ 0.5-1.1) and laevigatins (mean ~ 0.2-0.6%). Free ellagic acid and glycosides of ellagic and methylellagic acids are secondary components. CONCLUSIONS: Underground parts of tormentil are a source of oligomeric proanthocyanidins and ellagitannins, but in smaller quantity of gallotannins. Monogalloylquinic acids are new identified compounds, which had not been described in Potentilla tormentilla before we started our research. In the analysed tormentil tinctures agrimoniin concentration is lower in relation to other tannins.