Protective effect of bilberry (Vaccinium myrtillus L.) extracts on cultured human corneal limbal epithelial cells (HCLEC)

Functional foods and their impact on health

Functional foods play an important role in maintaining a healthy lifestyle and reducing the risk factors of various diseases. Most foods have a functional element which is responsible for improving the healthy state. All food substances such as fruits, vegetables, cereals, meat, fish, dairy contain functional ingredients. A wide range of naturally occurring substances from plant and animal sources having active components which play a role in physiological actions deserve attention for their optimal use in maintaining health. The market for functional food is keep on expanding, and the global market is projected to reach a value of at least 91 billion USD soon. Overwhelming evidence from preclinical (in vitro and in vivo) and clinical studies have shown that intake of functional foods could have an impact on the prevention of chronic diseases, especially cancer, cardiovascular diseases, gastrointestinal tract disorders and neurological diseases. Extensive research needs to be done to determine the potential health benefits for the proper application of these foods to improve health state and combat chronic disease progression. The aim of this review is to conduct a thorough literature survey, to understand the various classification of functional foods and their health benefits.

Cyanidin-3-O-Glucoside Attenuates Lipopolysaccharide-Induced Inflammation in Human Corneal Epithelial Cells by Inducing Let-7b-5p-Mediated HMGA2/PI3K/Akt Pathway

The bacterial keratitis causes viability loss and apoptosis in the corneal epithelial cells (CECs). The cyanidin-3-O-glucoside (C3G) benefits visual system and also possess anti-bacterial and anti-inflammatory potentials. In the current study, the effects of C3G on human CECs (HCECs) against bacterial lipopolysaccharide (LPS)-induced disorders were assessed, and the mechanism driving the protective effect was explored by focusing on let-7b-5p-mediated HMGA2/PI3K/Akt pathway. The HCECs were incubated LPS of P. aeruginosa to induce inflammation and apoptosis, and then treated with C3G. The changes in cell viability, apoptosis, and inflammation were detected. Moreover, the effects of LPS and C3G on let-7b-5p level and HMGA2/PI3K/Akt pathway activity were also assessed. Thereafter, the HCECs were further transfected with let-7b-5p inhibitor to confirm its role in the vision-protective effects of C3G. The interaction between let-7b-5p and HMGA2 was verified with dual luciferase assay. The LPS treatment suppressed viability and induced apoptosis and inflammation in HCECs, which was associated with the down-regulated let-7b-5p level and up-regulated HMGA2/PI3K/Akt pathway activity. The impairments of LPS on HCECs were attenuated by C3G: the compound increased cell viability and inhibited apoptosis and inflammation. The C3G also induced let-7b-5p level and inactivated HMGA2/PI3K/Akt pathway. However, after the inhibition of let-7b-5p, the protective effects of C3G on HCECs against LPS were blocked. The results of dual luciferase assay showed the direct binding let-7b-5p to the promoter of HMGA2 gene. It was inferred that the C3G could ameliorate the LPS-induced disorders in HCECs. The effect depended on the induced level of let-7b-5p, which then inhibited HMGA2/PI3K/Akt pathway.

Recent Research on the Health Benefits of Blueberries and Their Anthocyanins

Awareness of the human health benefits of blueberries is underpinned by a growing body of positive scientific evidence from human observational and clinical research, plus mechanistic research using animal and in vitro models. Blueberries contain a large number of phytochemicals, including abundant anthocyanin pigments. Of their various phytochemicals, anthocyanins probably make the greatest impact on blueberry health functionality. Epidemiological studies associate regular, moderate intake of blueberries and/or anthocyanins with reduced risk of cardiovascular disease, death, and type 2 diabetes, and with improved weight maintenance and neuroprotection. These findings are supported by biomarker-based evidence from human clinical studies. Among the more important healthful aspects of blueberries are their anti-inflammatory and antioxidant actions and their beneficial effects on vascular and glucoregulatory function. Blueberry phytochemicals may affect gastrointestinal microflora and contribute to host health. These aspects have implications in degenerative diseases and conditions as well as the aging process. More evidence, and particularly human clinical evidence, is needed to better understand the potential for anthocyanin-rich blueberries to benefit public health. However, it is widely agreed that the regular consumption of tasty, ripe blueberries can be unconditionally recommended.

Phenolic Antioxidants in Aerial Parts of Wild Vaccinium Species: Towards Pharmaceutical and Biological Properties

Phenolic compounds are a widespread group of secondary metabolites found in all plants, representing the most desirable antioxidants due to their potential to be used as additives in the food industry (inhibition of lipid oxidation), and in cosmetology and medicine (protection against oxidative stress). In recent years, demand for the identification of edible sources rich in phenolic antioxidants, as well as the development of new natural plant products to be used as dietary supplements or pharmaceuticals, has been a great preoccupation. At present, from the "circular economy" perspective, there is an increased interest to use agricultural waste resources to produce high-value compounds. Vaccinium leaves and stems are considered essentially an agro-waste of the berry industry. Scientific studies have shown that phenolic compounds were found in a markedly higher content in the leaves and stems of Vaccinium plants than in the fruits, in agreement with the strongest biological and antioxidant activities displayed by these aerial parts compared to fruits. This paper aims to review the current state of the art regarding the phenolic antioxidants from leaves and stems of two wild Vaccinium species, bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.), as promising natural resources with pharmaceutical and biological activity.

Antioxidant and proapoptotic effects of anthocyanins from bilberry extract in rats exposed to hepatotoxic effects of carbon tetrachloride

AIMS

The aim of this research was to determine the hepatoprotective effects of anthocyanins from bilberry extract in rats exposed to carbon tetrachloride (CCl4) by monitoring the parameters of oxidative stress and apoptosis, and by performing the histopathological and morphometric analyses.

MAIN METHODS

Animals were divided into four groups: Group I (0.9% NaCl-10days), Group II (bilberry extract, 75mg/kg-10days), Group III (0,9% NaCl-9days, and on the tenth day CCl4-2ml/kg), Group IV (bilberry extract, 75mg/kg-10days and on the tenth day CCl4-2ml/kg).

KEY FINDINGS

Bilberry extract led to a significant decrease in the activity of biochemical parameters in serum (AST, GGT, LDH, and ALT), the activity of pro-oxidative enzyme xanthine oxidase, as well as the level of lipid peroxidation in the liver in Group IV compared to Group III (p<0.01). Bilberry extract resulted in a significant increase in the activity of the antioxidant markers-catalase (p<0.05), superoxide dismutase, glutathione S-transferase and glutathione peroxidase (p<0.01), and the concentration of reduced glutathione (p<0.05) in Group IV in relation to Group III. The application of bilberry extract resulted in an increase in the number of apoptotic hepatocytes and the activity of caspase-3 in the liver tissue (p<0.01). The reduction of coagulation necrotic areas was proved (p<0.001) as well as the number of macrovesicular hepatocytes (p<0.01), along with an increased mitotic activity (p<0.01) in Group IV compared to Group III.

SIGNIFICANCE

Anthocyanins from bilberry extract have strong antioxidant properties and therefore can be considered as powerful hepatoprotectives in natural products.

The protective effects of berry-derived anthocyanins against visible light-induced damage in human retinal pigment epithelial cells

BACKGROUND

Studies have shown that anthocyanins (ACNs) in berries contribute to eye health. However, information on the relationship between the chemical structures and visual functions of ACNs is scarce. This study investigated the protection effects of ACNs with different structures against visible light-induced damage in human retinal pigment epithelial (RPE) cells.

RESULTS

Four ACNs with different aglycones, namely, pelargonidin-3-glucoside (Pg-3-glu), cyanidin-3-glucoside (Cy-3-glu), delphinidin-3-glucoside, and malvidin-3-glucoside (Mv-3-glu), were isolated from three berries (blueberry, blackberry and strawberry). Of these ACNs, Cy-3-glu exhibited the highest reactive oxygen species inhibitory capacity in RPE cells, with 40 µg mL(-1) Cy-3-glu showing a ROS clearance of 57.5% ± 4.2%. The expression of vascular endothelial growth factor levels were significantly (P < 0.05) down-regulated by Cy-3-glu and Mv-3-glu in a visible light-induced damage RPE cell model. Cy-3-glu and Pg-3-glu treatments significantly (P < 0.05) inhibited the increase in β-galactosidase during the RPE cell ageing caused by visible light exposure.

CONCLUSION

Our findings suggest that the biological properties of different ACNs significantly vary. Cy-3-glu, which contains an ortho hydroxyl group in its B ring, possibly exerts multiple protective effects (antioxidant, anti-angiogenic and anti-ageing) in RPE cells. Therefore, Cy-3-glu may prove useful as a prophylactic health food for the prevention of retinal diseases.