Blueberry Stem Extract Prevents Lacrimal Hyposecretion in Non-obese Diabetic Mice via Activation of AMPK.

BACKGROUND/AIM: Tears secreted from the lacrimal gland are essential for preserving the ocular surface. Thus, dysfunction of the lacrimal gland in Sjögren's syndrome (SS) can lead to dry eye, resulting in a reduced quality of life. We previously reported that blueberry 'leaf' water extract prevents lacrimal hyposecretion in male non-obese diabetic (NOD) mice in a SS-like model. In this study, we investigated the effect of blueberry 'stem' water extract (BStEx) on lacrimal hyposecretion in NOD mice. MATERIALS AND METHODS: Male NOD mice were fed 1% BStEx or control (AIN-93G) for 2, 4, or 6 weeks from 4 weeks of age. Pilocarpine-induced tear secretion was measured using a phenol red-impregnated thread. The lacrimal glands were histologically evaluated by HE staining. Inflammatory cytokine levels in the lacrimal glands were measured using ELISA. Immunostaining was performed to examine aquaporin 5 (AQP5) localization. The expression levels of autophagy-related proteins, AQP5, and phosphorylated AMPK were measured using western blotting. RESULTS: After feeding BStEx to mice for 4 or 6 weeks, tear volume was observed to have increased in the BStEx group compared with that in the control group. There were no significant differences in inflammatory cell infiltration, autophagy-related protein expression, or the localization and expression of AQP5 in the lacrimal glands between the two groups. In contrast, AMPK phosphorylation increased in the BStEx group. CONCLUSION: BStEx prevented lacrimal hyposecretion in the SS-like model of male NOD mice, probably by opening tight junctions via the activation of AMPK in lacrimal acinar cells.

Blueberry stem extract and stem active components prevent blue light-emitting diode light-induced retinal photoreceptor cell damage in vitro.

Blue light causes retinal damage that can lead to ocular diseases such as age-related macular degeneration. In this study, we determined the protective effect of blueberry stem extract (BStEx) and active components on blue light-emitting diode (LED) light-induced retinal photoreceptor cell damage in vitro. Photoreceptor cells cultured in the presence of BStEx or components were exposed to blue light to induce cell damage. BStEx, fractions of BStEx containing proanthocyanidins, chlorogenic acid, catechin, and epicatechin prevented the cell damage and/or inhibited the generation of reactive oxygen species (ROS). Furthermore, BStEx reduced apoptosis and cell death, and inhibited the phosphorylation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase leading to cellular apoptosis induced by blue light exposure. These findings suggest that BStEx and components exert a protective effect against blue light-induced photoreceptor cell damage through the inhibition of MAPK phosphorylation and ROS production.

Blueberry Leaf Extract Prevents Lacrimal Hyposecretion in Sjögren's Syndrome-like Model of Non-obese Diabetic Mice.

BACKGROUND/AIM: This study evaluated the effect of blueberry leaf hot water extract (BLEx) on Sjögren's syndrome (SS)-like lacrimal hyposecretion in male non-obese diabetic (NOD) mice. MATERIALS AND METHODS: NOD or BALB/c mice were fed 1% BLEx or control (AIN-93G) for 2 weeks from the age of 4 to 6 weeks. Pilocarpine-induced tear volume was measured using a phenol red-impregnated thread. The lacrimal glands were evaluated histologically by H&E staining. The IL-1ß and TNF-α levels in the lacrimal gland tissue were measured by ELISA. The mRNA expression levels of secretion-related proteins were measured by real-time PCR. LC3 I/II and arginase 1 expression levels were measured by western blot. RESULTS: After feeding with BLEx, pilocarpine-induced tear secretion in NOD mice was increased. In contrast, the mRNA expression levels of the cholinergic muscarinic M3 receptor, aquaporin 5, and ion channels related to lacrimal secretion were not changed by BLEx administration. In addition, the protein expression of arginase 1, which was recently reported to be involved in tear hyposecretion in NOD mice, was also not improved by BLEx administration. Although infiltration in the lacrimal gland of NOD mice was not decreased, the levels of TNF-α and the autophagy-related protein LC3 were significantly suppressed by BLEx treatment. CONCLUSION: BLEx treatment may ameliorate lacrimal hyposecretion in NOD mice by delaying the progression of autoimmune disease by suppressing autophagy in lacrimal glands.

Spearmint Extract Containing Rosmarinic Acid Suppresses Amyloid Fibril Formation of Proteins Associated with Dementia.

Neurological dementias such as Alzheimer's disease and Lewy body dementia are thought to be caused in part by the formation and deposition of characteristic insoluble fibrils of polypeptides such as amyloid beta (Aß), Tau, and/or α-synuclein (αSyn). In this context, it is critical to suppress and remove such aggregates in order to prevent and/or delay the progression of dementia in these ailments. In this report, we investigated the effects of spearmint extract (SME) and rosmarinic acid (RA; the major component of SME) on the amyloid fibril formation reactions of αSyn, Aß, and Tau proteins in vitro. SME or RA was added to soluble samples of each protein and the formation of fibrils was monitored by thioflavin T (ThioT) binding assays and transmission electron microscopy (TEM). We also evaluated whether preformed amyloid fibrils could be dissolved by the addition of RA. Our results reveal for the first time that SME and RA both suppress amyloid fibril formation, and that RA could disassemble preformed fibrils of αSyn, Aß, and Tau into non-toxic species. Our results suggest that SME and RA may potentially suppress amyloid fibrils implicated in the progression of Alzheimer's disease and Lewy body dementia in vivo, as well.

Analysis and characterization of anthocyanins and carotenoids in Japanese blue tomato.

Tomato (Solanum lycopersicum) is rich in anthocyanins, which are polyphenolic pigments. This study aimed to analyze and characterize the anthocyanin composition in cultivated blue tomato in Japan. The extracts of peel, seed, and pulp of tomatoes were purified following which anthocyanins and lycopene contents were analyzed using high-performance liquid chromatography and electrospray ionization mass spectrometry. Eleven types of anthocyanins were identified, including delphinidin, petunidin, and malvidin. Further, the antioxidant activity of anthocyanins was evaluated using 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt radical quenching assays and electron spin resonance. "Blue tomato" extracts exert antioxidant activity. Thus, we showed that petunidin was present in the "blue tomato" peel while lycopene was present in the peel and pulp. Additionally, the blue tomato peel extract was found to significantly inhibit H2O2-induced cell death in vitro. This is the first study on cell protective effects of Japanese blue tomato extract and petunidin in murine photoreceptor cells.

Protective effects of bilberry and lingonberry extracts against blue light-emitting diode light-induced retinal photoreceptor cell damage in vitro.

BACKGROUND: Blue light is a high-energy or short-wavelength visible light, which induces retinal diseases such as age-related macular degeneration and retinitis pigmentosa. Bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea) contain high amounts of polyphenols (anthocyanins, resveratrol, and proanthocyanidins) and thus confer health benefits. This study aimed to determine the protective effects and mechanism of action of bilberry extract (B-ext) and lingonberry extract (L-ext) and their active components against blue light-emitting diode (LED) light-induced retinal photoreceptor cell damage. METHODS: Cultured murine photoreceptor (661 W) cells were exposed to blue LED light following treatment with B-ext, L-ext, or their constituents (cyanidin, delphinidin, malvidin, trans-resveratrol, and procyanidin B2). 661 W cell viability was assessed using a tetrazolium salt (WST-8) assay and Hoechst 33342 nuclear staining, and intracellular reactive oxygen species (ROS) production was determined using CM-H2DCFDA after blue LED light exposure. Activation of p38 mitogen-activated protein kinase (p38 MAPK), nuclear factor-kappa B (NF-κB), and LC3, an ubiquitin-like protein that is necessary for the formation of autophagosomes, were analyzed using Western blotting. Caspase-3/7 activation caused by blue LED light exposure in 661 W cells was determined using a caspase-3/7 assay kit. RESULTS: B-ext, L-ext, NAC, and their active components improved the viability of 661 W cells and inhibited the generation of intracellular ROS induced by blue LED light irradiation. Furthermore, B-ext and L-ext inhibited the activation of p38 MAPK and NF-κB induced by blue LED light exposure. Finally, B-ext, L-ext, and NAC inhibited caspase-3/7 activation and autophagy. CONCLUSIONS: These findings suggest that B-ext and L-ext containing high amounts of polyphenols exert protective effects against blue LED light-induced retinal photoreceptor cell damage mainly through inhibition of ROS production and activation of pro-apoptotic proteins.

The protective effects of bilberry and lingonberry extracts against UV light-induced retinal photoreceptor cell damage in vitro.

Bilberry extract (B-ext) and lingonberry extract (L-ext) are currently used as health supplements. We investigated the protective mechanisms of the B-ext and L-ext against ultraviolet A (UVA)-induced retinal photoreceptor cell damage. Cultured murine photoreceptor (661W) cells were exposed to UVA following treatment with B-ext and L-ext and their main constituents (cyanidin, delphinidin, malvidin, trans-resveratrol, and procyanidin). B-ext, L-ext, and constituents improved cell viability and suppressed ROS generation. Phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase (JNK), and protein kinase B (Akt) were analyzed by Western blotting. B-ext and cyanidin inhibited phosphorylation of p38 MAPK, and B-ext also inhibited phosphorylation of JNK by UVA. L-ext, trans-resveratrol, and procyanidin alleviated the reduction of phosphorylated Akt levels by UVA. Finally, a cotreatment with B-ext and L-ext showed an additive effect on cell viability. Our findings suggest that both B-ext and L-ext endow protective effects against UVA-induced retinal damage.

Maqui berry (Aristotelia chilensis) and the constituent delphinidin glycoside inhibit photoreceptor cell death induced by visible light.

The protective effects of maqui berry (Aristotelia chilensis) extract (MBE) and its major anthocyanins [delphinidin 3,5-O-diglucoside (D3G5G) and delphinidin 3-O-sambubioside-5-O-glucoside (D3S5G)] against light-induced murine photoreceptor cells (661W) death were evaluated. Viability of 661W after light treatment for 24 h, assessed by the tetrazolium salt (WST-8) assay and Hoechst 33342 nuclear staining, was improved by addition of MBE, D3G5G, and D3S5G. Intracellular radical activation in 661W, evaluated using the reactive oxygen species (ROS)-sensitive probe 5-(and-6)-chloromethyl-2,7-dichlorodihydro fluorescein diacetate acetyl ester (CM-H2DCFDA), was reduced by MBE and its anthocyanins. The anti-apoptosis mechanism of MBE was evaluated by light-induced phosphorylation of p38. MBE significantly suppressed the light-induced phosphorylation of p38. These findings indicate that MBE and its anthocyanidins suppress the light-induced photoreceptor cell death by inhibiting ROS production, suggesting that the inhibition of phosphorylated-p38 may be involved in the underlying mechanism.

The protective effect and action mechanism of Vaccinium myrtillus L. on gastric ulcer in mice.

Vaccinium myrtillus L. anthocyanoside (VMA) is used as a folk medicine to treat diseases related to gastric ulcers in northern Europe. However, the effects of VMA and its detailed mechanism on gastric ulcer have not been investigated sufficiently. Therefore, the aim of the present study was to investigate the protective effects of VMA on gastric mucosal damage in a murine gastric ulcer model. First the effects of VMA on ethanol-induced gastric ulcers in mice were investigated. Then, the levels of lipid peroxide in murine stomach homogenates were measured to investigate the antioxidative effects of VMA. In addition, the free radical scavenging activity of VMA and its main anthocyanidins were evaluated by electron spin resonance measurement. Oral administration of VMA (10, 30 and 100 mg/kg) significantly protected gastric mucosa against HCl/ethanol-induced gastric ulcers. Furthermore, VMA inhibited lipid peroxide levels in a concentration-dependent manner and showed high scavenging activity against the superoxide anion radical (·O(2) (-) ) and the hydroxyl radical (·OH). Anthocyanidins also showed scavenging activity against the ·O(2) (-) , while only delphinidin showed high scavenging activity against the ·OH. These findings indicate that the protective effects of VMA on HCl/ethanol-induced gastric mucosal injury may be partially due to the antiperoxidative effects of anthocyanidins.

Purple rice extract and anthocyanidins of the constituents protect against light-induced retinal damage in vitro and in vivo.

This study evaluated the protective effects of purple rice ( Oryza sativa L.) bran extract (PRE) and its major anthocyanidins (cyanidin and peonidin) against light-induced retinal damage. In an in vitro experiment, cultured murine photoreceptor cells (661W) were damaged by a 24 h exposure to light. Viability of 661W after light treatment, assessed by the tetrazolium salt (WST-8) assay and Hoechst 33342 nuclear staining, was improved by the addition of PRE, cyanidin, and peonidin. Intracellular radical activation in 661W, evaluated using the reactive oxygen species (ROS) sensitive probe 5-(and 6)-chloromethyl-2,7-dichlorodihydrofluorescein diacetate acetyl ester (CM-H(2)DCFDA), was reduced by PRE and its anthocyanidins. Electron spin resonance (ESR) measurements showed that PRE, peonidin, and cyanidin all exhibited radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide anion radical ((•)O(2)(-)), and hydroxyl radical ((•)OH). In an in vivo mouse experiment, intravitreous injection of PRE significantly suppressed photoreceptor degeneration induced by exposure to light as revealed by histological analysis using hematoxylin-eosin staining. These findings suggest that PRE and its anthocyanidins possess protective effects with antioxidation mechanism in both in vitro and in vivo models of retinal diseases.

Protective effects of a gastrointestinal agent containing Korean red ginseng on gastric ulcer models in mice.

BACKGROUND: Korean red ginseng (KRG) is a ginseng that has been cultivated and aged for 4-6 years or more, and goes through an extensive cleaning, steaming and drying process. KRG contains more than 30 kinds of saponin components and has been reported as having various biological properties, such as anti-fatigue action, immune restoration, and neurovegetative effect. The purpose of this study was to assess the effects of a KRG-containing drug (KRGCD) on gastric ulcer models in mice. METHODS: Stomach ulcers were induced by oral ingestion of hydrochloride (HCl)/ethanol or indomethacin. Treatment with KRGCD (30, 100, and 300 mg/kg, p.o.) occurred 1 hr before the ulcer induction. Effect of KRGCD on anti-oxidant activity and gastric mucosal blood flow with a laser Doppler flowmeter in mice stomach tissue was evaluated. RESULTS: KRGCD (100 and 300 mg/kg, p.o.) significantly decreased ethanol- and indomethacin-induced gastric ulcer compared with the vehicle-treated (control) group. KRGCD (100 and 300 mg/kg) also decreased the level of thiobarbituric acid reactive substance (TBARS) and increased gastric mucosal blood flow compared with the control group. CONCLUSIONS: These results suggest that the gastroprotective effects of KRGCD on mice ulcer models can be attributed to its ameliorating effect on oxidative damage and improving effect of gastric mucosal blood flow.