Anthocyanin-Rich Sour Cherry Extract Attenuates the Lipopolysaccharide-Induced Endothelial Inflammatory Response.

The anthocyanin content of Hungarian sour cherry is remarkable based on our preliminary investigations. Nutraceutical and pharmaceutical effects of anthocyanins have been extensively studied. The objective of this work was to investigate the the effect of purified sour cherry extract using human umbilical cord vein endothelial cells (HUVECs) as the inflammatory model. HUVECs were isolated by enzymatic digestion and characterized by flow cytometry. The optimal concentration range of sour cherry extract was selected based on MTT, apoptosis, and necrosis assays. Cells were divided into three groups, incubating with M199 medium as control, or with lipopolysaccharide (LPS) or with LPS plus anthocyanin extract (ACE). The effect of sour cherry extract on oxidative stress, pro-inflammatory factors, and arachidonic pathway was investigated. An amount of 50 µg/mL ACE (ACE50) was able to increase the level of glutathione and decrease the ROS, thereby improving the unbalanced redox status in inflammation. ACE50 lowered pro-inflammatory cytokine levels including Interleukin-6 (IL-6), regulated on activation, normal T cell expressed and secreted (RANTES), granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor alpha (TNF-α). ACE50 affected the arachidonic acid pathway by reducing the LPS-induced enzyme expression (cyclooxygenase-1, cyclooxygenase-2, and prostacyclin synthase). The extract under investigation seems to have a pleiotropic effect including anti-oxidative, anti-inflammatory, hemostatic, and vasoactive effects. Our results indicate that purified sour cherry extract could reduce the LPS-induced inflammatory response, thereby improving endothelial dysfunction.

Effect of Anthocyanin-Rich Tart Cherry Extract on Inflammatory Mediators and Adipokines Involved in Type 2 Diabetes in a High Fat Diet Induced Obesity Mouse Model.

Male C57BL/6J mice were used to determine the possible therapeutic effects of our previously described tart cherry extract in a chronic obesity mouse model on metabolic parameters, glucose tolerance, inflammatory mediators, and antioxidant capacity. The control group received standard mouse chow, and the high fat control group was switched to a high fat diet and tap water supplemented with 5% sucrose. The high fat + anthocyanin group received the high fat and sucrose diet, but received the anthocyanin-rich tart cherry extract dissolved in their drinking water. After six weeks, an oral glucose tolerance test was performed, and the water-soluble antioxidant capacity (ACW), superoxide dismutase (SOD) activity, and the plasma levels of insulin, C-peptide, leptin, IL-6, MCP-1, adiponectin and resistin were measured. The high fat diet increased body weight, reduced glucose tolerance, and caused an elevation in leptin, IL-6, MCP-1, and resistin levels. Furthermore, antioxidant capacity was decreased with a significant elevation of SOD activity. Anthocyanin treatment failed to reverse the effects of the high fat diet on body weight and glucose tolerance, but significantly reduced the leptin and IL-6 levels. The tart cherry extract also made a significant enhancement in antioxidant capacity and SOD activity. Our results show that chronic anthocyanin intake has a potential to enhance redox status and alleviate inflammation associated with obesity.

Determination of Flavonoid and Proanthocyanidin Profile of Hungarian Sour Cherry.

Hungarian sour cherries (SC) are excellent source of anthocyanin (concentrations (100⁻300 mg in 100 g fresh fruit) and melatonin (0.15 mg in 100 g fresh fruit), but other flavonoid derivatives also can be isolated by aqueous alcoholic extraction. We have developed a new process for extracting non-extractable procyanidines bound to the membrane, proteins, and fibers. These compounds were seperated with UHPLC-MS methods, and the structure of individual components were identified on the basis of their mass fragmentation spectra. The antioxidant capacity of soluble and non-soluble antioxidants were measured with ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH), trolox equivalent antioxidant capacity (TEAC) assays, and compared to the new measurement methods of water-soluble antioxidant capacity (ACW), lipid-soluble antioxidant capacity (ACL). Furthermore, total phenolic content (TPC) and total procyanidin content (PAC) were determinated. As a result of our investigation, we found that the solvent combination, where in the first step is water⁻ethanol (1:1), then 100% ethanol were suitable for the extraction of the extractable antioxidants. However, the chemiluminescence method that is based on the elimination of the superoxide radical is more accurate than other colorimetric methods which measure antioxidant capacity.

Sour cherry extract inhibits human salivary α-amylase and growth of Streptococcus mutans (a pilot clinical study).

The purpose of this study was to determine whether cherry extract has any effect on salivary α-amylase activity (sAA) or on the level of Streptococcus mutans in human saliva. 70 patients (45 females and 25 males) in three age groups (22 children, 25 young adults, and 23 adults) were examined. All participants completed a questionnaire to obtain information on their oral health behaviour and life style. Clinical examination was performed to record the number of decayed, missing and filled teeth (DMF-T). Saliva samples were collected for the measurement of sAA and the salivary S. mutans level before and after chewing a gum with or without cherry extract. Statistical evaluation of data was performed. S. mutans and the sAA level of unstimulated saliva samples did not depend on either age or gender. The basal sAA value of adult patients was in linear correlation with the dental caries status. Habitual chewing-gum use decreased the resting sAA and the mean of DMF-T. The number of S. mutans cells was significantly lower in the resting saliva of allergic patients. The applied mechanical and gustatory stimuli by chewing gum resulted in higher sAA and S. mutans levels and a slow decrease of values was observed in the control group for the next 30 min. Thereafter, sAA and S. mutans levels decreased earlier in the presence of sour cherry extract than those of control cases. Chewing gum with sour cherry extract may be useful for the prevention of dental caries.

Protective Effect of Pure Sour Cherry Anthocyanin Extract on Cytokine-Induced Inflammatory Caco-2 Monolayers.

Anthocyanins have several beneficial effects, especially on inflammatory and oxidative conditions. The pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), induce damage in the intestinal barrier and participate in the pathogenesis of chronic bowel diseases. A number of fruits have high anthocyanin contents with strong biological activity which can support protective actions. Sour cherry (Prunus cerassus) is one of the richest fruits in anthocyanins; especially it has high content of cyanidins. The aim of this study was to test the biological effects of a pure sour cherry anthocyanin extract under inflammatory conditions on the intestinal barrier. Caco-2 monolayers were stimulated with 50 ng/mL TNF-α and 25 ng/mL IL-1β, and the protective effects of the anthocyanin extract were examined. We demonstrated the safety of 500, 50, 5 and 0.5 µM anthocyanin extracts through cell impedance measurements. The 50 µM anthocyanin extract inhibited the cytokine-induced Caco-2 permeability and the nuclear translocation of NF-κB p65 subunits. The extract significantly reduced the release of IL-6 and IL-8 production in intestinal cells and glutathione peroxidase activity stimulated by cytokines. We demonstrated, for the first time, the beneficial effects of pure sour cherry anthocyanin extract on inflammatory Caco-2 monolayers, indicating that this substance could be protective in inflammatory bowel diseases and is an excellent raw material for further applications and formulations.

Anthocyanin composition, antioxidant efficiency, and α-amylase inhibitor activity of different Hungarian sour cherry varieties (Prunus cerasus L.).

Five Hungarian sour cherry cultivars were studied to determine their anthocyanin contents and their possible inhibitory properties. The water and methanol soluble antioxidant capacities were separately assessed by photoluminescence showing values ranged from 3.4µgmg(-1) to 15.4µgmg(-1), respectively. The "VN1" variety (selected from "Csengodi csokros") showed the highest antioxidant capacity. The anthocyanin content, measured by pH differential method or isolated by solid phase extraction, was the highest also in "VN1". Correlation was found between the anthocyanin content and the high antioxidant capacity. The main anthocyanin components were cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside. The presence of malvidin-3,5-O-diglycoside was verified by MALDI-TOF MS. Sour cherry extracts and selected anthocyanins inhibited the human salivary alpha-amylase catalyzed hydrolysis competitively. The lowest IC50 value, 55µgmL(-1) or 80µM, was measured for malvidin-3,5-O-diglycoside, for which possible binding modes within the alpha-amylase active site could be investigated in silico using molecular docking and molecular dynamics.