Vaccinium Bracteatum Thunb Research Articles

New insights into the interactions between dark blue pigment from Vaccinium bracteatum Thunb leaves and digestive enzymes

The dark blue pigment from Vaccinium bracteatum Thunb. leaves (VBTL) is a healthy ingredient for controlling postprandial blood glucose during the stage of dietary carbohydrate digestion. Our previous study has proved that the dark blue pigment has an inhibition effect on pancreatic α-amylase. However, the influence on other digestive enzymes (α-glucosidases, trypsin, and α-chymotrypsin) is still unclear. Therefore, this research evaluated the impact of this dark blue pigment on the three digestive enzymes during in-vitro digestion. The effects of dark blue pigment on the activities and conformations of the α-glucosidase, trypsin, and α-chymotrypsin were confirmed by multi-spectroscopic techniques and molecular docking. The results showed that this pigment possessed a higher inhibition ability on the α-glucosidase. The complexes of three enzymes and the pigment all resulted in the changes in fluorescence quenching and secondary structures of these complexes. However, the interactions between two proteolytic enzymes and pigment slightly impacted their activities. Additionally, molecular docking suggested that the complex between α-glucosidase and pigment formed hydrogen bonds and hydrophobic interactions in the substrate-binding pocket. These findings provide creative insight into the VBTL dark blue pigment controlling postprandial hyperglycemia without side effects on the proteolytic enzymes.

Validation of reference genes for gene expression analysis in fruit development of Vaccinium bracteatum Thunb. using quantitative real-time PCR

Vaccinium bracteatum Thunb. (VBT) is widely distributed in the mountainous areas in eastern and southern China. VBT leaves have great medical value and can be used to stain rice to produce “Wumifan”. Its fruits also contain rich nutrients. However, there has been limited attention to exploring the molecular content of VBT. Previously, we performed RNA-seq on three typical VBT fruits that were at various stages of ripening, although a reliable reference gene was lost in validation.In this study, we selected ten candidate reference genes based on previous studies and transcriptomics analyses. Subsequently, these genes were evaluated using a combination of methods, including geNorm, NormFinder, and Bestkeeper, with a comprehensive ranking assessment. As a result, we found that the actin2, NADH, and ADK genes have high reliability for analysing the expression levels of genes involved in fruit development. Furthermore, the transcript levels of 15 DEGs from transcriptomic analysis were assessed using NADH as a reference gene, and RT-qPCR data were highly consistent with the transcriptomic data. These results provide reliable reference genes for further studying gene expression, which will be beneficial for comprehensively exploring VBT.

Vaccinium bracteatum Thunb Extract Inhibits HSV-1 Infection by Regulating ER Stress and Apoptosis.

Herpes simplex Type 1 (HSV-1) is a neurotropic virus that infects the peripheral and central nervous system. Usually, after primary infection in epithelial cells, HSV-1 migrates retrograde to the peripheral nervous system (PNS), where it establishes a latent infection. HSV-1 can remain latent in the nervous system, and its reactivation in the brain can rarely cause acute HSV-1 encephalitis, often a life-threatening condition, or asymptomatic reactivations that could lead to neuronal damage and ultimately neurodegenerative disorders. Acyclovir and related nucleoside analogs have been used as therapeutic agents for HSV-1 infection, but resistance to the drug can arise, and the protective effect of HSV-1 on brain cells is limited. Therefore, there is an urgent need for research into safe and effective new antiviral agents that can protect brain cells from the damage that is caused by HSV-1 infection. Vaccinium bracteatum Thunb. (VBT) is widely distributed in Korea and China, and has pharmacological actions such as anti-inflammatory, antioxidant, and antidiabetic activity. Studies on the antiviral effect of VBT on HSV-1 infection have not been reported so far. Therefore, we sought to determine the HSV-1 antiviral effect and molecular mechanism of VBT at the cellular level. We confirmed that VBT repressed the VP16 and IE genes in both Vero and SK-N-SH cells. We also found that the generation of HSV-1 virions was inhibited by VBT treatment. VBT inhibited the activities of the HSV-1-induced endoplasmic reticulum (ER) stressors PERK, ATF4, and CHOP. We confirmed that VBT inhibited the activity of apoptosis factors by regulating the expression of death receptor (DR) after HSV-1 infection. As HSV-1 is closely associated with brain diseases, the study of the antiviral drug effects and mechanism of VBT is meaningful. Further studies using animal models of infection will also be performed to determine the potential of VBT as an antiviral agent.

Polyphenol contents, antioxidant activities, and anti-cancer cell proliferation properties at each stage of fruit development in intersectional hybrids between highbush blueberry and shashanbo (Vaccinium bracteatum Thunb.)

BACKGROUND: In blueberries, the total polyphenol contents, total anthocyanin contents, and antioxidant activities of fruits in blueberries and their relatives are becoming important targets for breeders. Recently, intersectional hybrids between Japanese wild species Shashanbo and highbush blueberry were produced using polyploid breeding for the first time. However, the polyphenol contents, antioxidant activities, and anti-cancer cell proliferation properties of the fruits of these intersectional hybrids have not been studied sufficiently. OBJECTIVE: The objectives of this study were to determine the anthocyanin contents, polyphenol contents, and antioxidant activities at each stage of fruit development in intersectional hybrids, and to examine the effects of the fruit extracts on anti-cancer cell proliferation properties using human promyelocytic leukemia (HL-60) cells. METHODS: Freeze-dried fruit samples of three intersectional hybrids and their parents at five developmental stages were used to evaluate their polyphenol contents, anthocyanin contents, and levels of two types of antioxidant activities (DPPH and ORAC). The anti-cancer cell proliferation properties of each extract were also evaluated according to the survival rate of HL-60 cells. RESULTS: The total polyphenol contents in fruits of the intersectional hybrids gradually decreased as the fruits grew, but the contents increased slightly at the mature stage. Meanwhile, the total anthocyanin contents increased strongly to the mature stage. In addition, the fruit extract of intersectional hybrid JM1 was found to be more effective for inhibiting the growth of HL-60 human leukemia cells in vitro. Total polyphenol content correlated highly with antioxidant activities and anti-cancer cell proliferation properties. CONCLUSIONS: We clarified that the intersectional hybrids had produced have abundant bioactive compounds, high levels of antioxidant activities, and anti-cancer cell proliferation properties. The results proved the effectiveness of the use of Japanese wild Vaccinium species for the strategic breeding of blueberries with high levels of bioactive compounds.

Identification of a Strong Anthocyanin Activator, VbMYBA, From Berries of Vaccinium bracteatum Thunb.

Wufanshu (Vaccinium bracteatum Thunb.), which is a wild member of the genus Vaccinium, accumulates high concentration of anthocyanin in its berries. In this study, the accumulated anthocyanins and their derivatives in Wufanshu berries were identified through UHPLC–MS/MS analysis. Candidate anthocyanin biosynthetic genes were identified from the transcriptome of Wufanshu berries. qRT-PCR analyses showed that the expression of anthocyanin structural genes correlated with anthocyanin accumulation in berries. The R2R3-MYB, VbMYBA, which is a homolog of anthocyanin promoting R2R3-MYBs from other Vaccinium species, was also identified. Transient expression of VbMYBA in Nicotiana tabacum leaves confirmed its role as an anthocyanin regulator, and produced a higher anthocyanin concentration when compared with blueberry VcMYBA expression. Dual-luciferase assays further showed that VbMYBA can activate the DFR and UFGT promoters from other Vaccinium species. VbMYBA has an additional 23 aa at the N terminus compared with blueberry VcMYBA, but this was shown not to affect the ability to regulate anthocyanins. Taken together, our results provide important information on the molecular mechanisms responsible for the high anthocyanin content in Wufanshu berries.

Evaluation of the physicochemical properties and in vitro digestibility of the complex formed between rice starch and a novel pigment from Vaccinium bracteatum Thunb. leaf

This study investigated the effect of Vaccinium bracteatum Thunb. leaf (VBTL) dark blue pigment on the physicochemical properties and in vitro digestibility of different rice starches. The results showed that glutinous rice starch (GRS) had a higher pigment loading capacity than indica rice starch (IRS) and japonica rice starch (JRS). Fourier transform infrared spectroscopy showed that these binary complexes between pigment and starch molecules bind through strong hydrogen bonds. All starch-pigment complexes displayed a lower gelatinization enthalpy than the controls. The addition of this pigment reduced the maximum starch in vitro digestion amount. Furthermore, the addition of pigment significantly increased the resistant starch and decreased the rapidly digestible starch in ‘Wu mi’, rice grains dyed by VBTL. This study provided important evidence of the digestion resistibility of VBTL dark blue pigment on ‘Wu mi’ to promote glycaemic regulation as a healthy cereal product.

Isolation and Analytical Method Validation for Phytocomponents of Aqueous Leaf Extracts from Vaccinium bracteatum Thunb. in Korea

In this study, major phytochemical compounds of Vaccinium bracteatum Thunb. (VB) aqueous leaf extract were isolated and analyzed using a HPLC-based method, followed by method validation in accordance with the International Conference on Harmonisation (ICH) guidelines for drug development. Five major compounds were isolated in VB extract. Apart from vaccinoside, which had been the only compound isolated in VB extract to date, vanillic acid and protocatechuic acid were isolated for the first time. Isolation of orientin and isoorientin in the VB extract helped validate the reverse-phase analytical method. A new simple and rapid high-performance liquid chromatography (HPLC)-based method was developed for the validation of orientin and isoorientin in VB extract and was determinated according to the ICH guidelines. The analytical method was validated through a Waters Alliance HPLC System containing an e2695 separation module and a 2998 photodiode array (PDA) detector. The VB extract and solutions of orientin and isoorientin were analyzed using a reverse-phase Eclipse XDB-C18 column (4.6 × 250 mm ID, 5 µm, Waters), which was maintained at 30 °C. A mobile phase of methanol and 0.01% formic acid in water was used at a flow rate of 1.0 mL/min to achieve gradient elution. The linearity of the orientin and isoorientin was excellent results (R2 ≥ 0.9999) in the concentration range of 1.0–50.0 μg/mL. Precision values ranged 98.55–101.70% and 98.70–101.18%, respectively. The intra-day and inter-day relative standard deviation (RSD) values of the orientin and isoorientin were all <2.0%. The average recoveries of orientin ranged 98.30–101.57%, whereas isoorientin ranged 97.81–102.14% with RSD values <2.0%. Quantitative analysis found that VB extract contained 2.90 mg/g of orientin and 3.45 mg/g of isoorientin.

The effect of Vaccinium bracteatum Thunb. leaves addition on antioxidant capacity, physicochemical properties, and in vitro digestibility of rice extrudates.

Vaccinium bracteatum Thunb.leaves (VBTL) are a traditional Chinese herbal medicine with potential natural pigments and antioxidants. Its application information on extrusion is limited. In this study, to increase the usage of foods containing VBTL, rice-based extrudates with VBTL were investigated. The extrusion was performed at a wide temperature range (60-140°C) and with different VBTL supplementations (3%-10%). The extrudates with 10% VBTL showed a significant decrease in total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity upon extrusion. TPC and TFC increased with the rise of barrel temperature. The VBTL color was stable during the wide-temperature extrusion process. The bioactivities of the extrudates were positively correlated with the VBTLsupplement (R=0.943-0.989). In addition, different addition levels of VBTL significantly changed the water absorption index (WAI), water solubility index (WSI), pasting properties, and in vitro starch digestibility of the extrudates. Moreover, extrudates with 3% VBTL showed the highest WAI and peak viscosity but the lowest in vitro starch digestibility. These results may suggest that rice extrudates with a low supplement of VBTL have an acceptable color and may be used as functional additives for high antioxidant and low glycemic response diets. PRACTICAL APPLICATION: The results showed that the Vaccinium bracteatum Thunb. leaves (VBTL) color and antioxidation were stable during the wide-temperature extrusion process. Extrusion processing can be used to enlarge the usage of VBTL and simplify its traditional processing method. Applying VBTL to the process of extrusion appears to be a suitable method of producing value-added and low glycemic response extrudates.

Vaccinium bracteatum Thunb. fruit extract reduces high-fat diet-induced obesity with modulation of the gut microbiota in obese mice.

Vaccinium bracteatum Thunb. fruits have been used as traditional food. This study investigated the effects of a polyphenol-rich Vaccinium bracteatum Thunb. fruit extract (VBTE) on obesity and obesity-related diseases in mice, and the potential role of the gut microbiota in the bioactivity of VBTE was also determined. Chemical constituents of the VBTE were analyzed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS). C57BL/6J mice (weighing 17.8-21.6g) were fed a low-fat diet (LFD) or high-fat diet (HFD) with or without VBTE treatment for 14weeks. The gut microbial changes were determined using 16S rRNA sequencing. Our results showed that VBTE mainly contains 36 kinds of polyphenols. VBTE reduced HFD-induced body weight gain by 33.42% (p<.05), steatosis scores by 56.25% (p<.05), and insulin resistance index by 51.49% (p<.05). Moreover, VBTE altered the composition of the gut microbiota. The correlation analysis indicated that Akkermansia, Alistipes, Bacteroides, Alloprevotella, Ruminiclostridium, Ruminiclostridium_9, and Rikenellaceae_RC9_gut_group were negatively correlated with serum lipids, glucose, and insulin, while Escherichia-Shigella was positively associated with these clinical indicators. In conclusion, VBTE supplement could reduce obesity and be a treatment option for obesity-related diseases by influencing the gut microbiota in mice. PRACTICAL APPLICATIONS: Plant extracts are widely used to treat obesity and related metabolic disorders. Polyphenols, the well-known natural antioxidants present in fruits, are consumed as a dietary supplement to prevent many diseases. Recent pharmacological studies have reported that Vaccinium bracteatum Thunb. fruits have many physiological functions, such as anti-proliferative, anti-inflammatory, and antidepressant-like effects. Despite these properties of Vaccinium bracteatum Thunb. fruits, their anti-obesity effect has not been studied to date. The findings of this study will support VBTE could be used as an important therapeutic application for preventing obesity and related metabolic diseases by modulating the gut microbiota.

Protective Effects of p-Coumaric Acid Isolated from Vaccinium bracteatum Thunb. Leaf Extract on Corticosterone-Induced Neurotoxicity in SH-SY5Y Cells and Primary Rat Cortical Neurons

Corticosterone (CORT)-induced oxidative stress and neurotoxicity can cause neuronal dysfunction and mental disorders. In the present study, we investigated the effects and mechanism of the HP-20 resin fraction of the water extract of Vaccinium bracteatum leaves (NET-D1602) and its bioactive compound p-coumaric acid on neuronal cell damage in SH-SY5Y cells and primary culture of rat cortical cells. NET-D1602 and p-coumaric acid significantly improved cell viability in CORT-induced neurotoxicity in SH-SY5Y cells and primary cultures of rat cortical cells, and increased the activities of antioxidant enzymes (superoxide dismutase and catalase) against CORT-induced neurotoxicity in SH-SY5Y cells. NET-D1602 and p-coumaric acid increased the phosphorylation levels of ERK1/2 and cAMP response element-binding protein (CREB) in cortical neurons. In addition, CREB phosphorylation by NET-D1602 and p-coumaric acid was dramatically reversed by PKA, c-Raf/ERK, PI3K, and mTOR inhibitors. Lastly, we demonstrated the neuroprotective effects of NET-D1602 (3 and 10 μg/mL) and p-coumaric acid (3 and 10 μM) via increased CREB phosphorylation in CORT-induced neurotoxicity mediated via the ERK1/2, Akt, and mTOR pathways. These results suggest that p-coumaric acid is a potential neuroprotective component of NET-D1602, with the ability to protect against CORT-induced neurotoxicity by regulating ERK1/2, Akt, and mTOR-mediated CREB phosphorylation.

Anti-Fatigue Activity of a Mixture of Stauntonia hexaphylla (Thunb.) Decaisne and Vaccinium bracteatum Thunb. Fruit Extract.

Stauntonia hexaphylla (Thunb.) Decaisne and Vaccinium bracteatum Thunb. are commonly used in traditional herbal medicine and food and both exhibit antioxidant and anti-inflammatory effects. Herein, hot-water extracts of Stauntonia hexaphylla (Thunb.) Decaisne and Vaccinium bracteatum Thunb. fruits (1:1 mixture) were used to produce a complex extract NET-1601. The anti-fatigue activity of NET-1601 was evaluated in an in vitro oxidative stress model induced by treating C2C12 myotubes with H2O2. An exhaustive swimming test (EST) in vivo model was established using ICR mice. NET-1601-treated C2C12 myotubes (50, 100, and 200 mg/mL) with H2O2-induced oxidative stress displayed significantly increased cell viability and ATP content, but significantly decreased levels of reactive oxygen species. All NET-1601-treated EST models demonstrated significantly higher maximum swimming rates than control mice. Furthermore, serum lactate, lactate dehydrogenase activity, non-esterified fatty acid, and intramuscular glycogen levels were higher in NET-1601-treated mice than in control mice. In addition, mRNA levels of regulatory factors involved in muscle mitochondrial fatty acid β-oxidation increased upon NET-1601 treatment. Moreover, catalase, superoxide dismutase, glutathione-S-transferase, and liver glutathione content, and antioxidant activity were higher in NET-1601-treated mice than in control mice. Reduced malondialdehyde levels indicated that NET-1601 treatment inhibited exercise-induced lipid peroxidation. Together, these results suggest that NET-1601 retains antioxidant enzyme activity during oxidative stress, simultaneously enhancing both muscle function via glycogen and fatty acid oxidation, thereby exerting a positive effect on recovery from fatigue.

Vaccinium bracteatum Improves Spatial Learning and Memory by Regulating N-methyl-D-aspartate Receptors and Tau Phosphorylation in Chronic Restraint Stress-Induced Memory Impaired Mice.

Vaccinium bracteatum Thunb. Leaves (VBL) are a component of traditional herbal medicines. However, molecular mechanisms of VBL in stress-related memory impairment are still unclear. This study aimed to investigate the spatial memory improvement effects of VBL in an animal model of chronic restraint stress (CRS) by using Y maze test and identified possible protective mechanisms against oxidative stress inducers (e.g., corticosterone and hydrogen peroxide [H2O2]) in SH-SY5Y neuronal cells. VBL showed neuroprotective effects via reduced release of lactate dehydrogenase (LDH) in corticosterone or H2O2-induced cell death that was mediated through the regulation of cleaved caspase-3 and Nrf2 pathways. Furthermore, CRS-exposed mice were orally administered VBL (10, 50, 100, and 200 mg/kg) daily for 21 days. CRS-exposed mice treated with VBL showed significantly increased spontaneous alternation in short-term memory (STM) and long-term memory (LTM) trials, and number of total arm entries in LTM trials as measured by the Y maze test. Moreover, VBL (50, 100, and 200 mg/kg) decreased acetylcholinesterase (AChE) activity in the hippocampus (HC, [Formula: see text] ¡ 0.01 and [Formula: see text] ¡ 0.001, respectively) and prefrontal cortex (PFC). CRS-exposed mice treated with VBL had dramatically decreased total Tau and Tau phosphorylation in the synapse of the HC and PFC which might be mediated by the regulation of CaMKII and GSK3[Formula: see text] phosphorylation. Additionally, VBL reduced CRS-induced upregulation of N-methyl-D-aspartate (NMDA) receptor subunits (NMDAR1, 2A, and 2B). Thus, VBL exerts spatial memory improvement by regulating CRS-induced NMDA receptor neurotoxicity and Tau hyperphosphorylation.

Effects of freezing and thermal pretreatments on drying of Vaccinium bracteatum Thunb leaves: Drying mechanism, physicochemical properties and ability to dye glutinous rices

The influences of freezing pretreatment, thermal pretreatments (water blanching and steam blanching) and their combinations on hot-air drying kinetics of Vaccinium bracteatum Thunb (VBT) leaves at 60°C and key quality attributes were investigated. Generally, all the applied pretreatments accelerated VBT leaf drying process. The sequential freezing (8h) and water blanching (1min) pretreatments shortened the drying time by 65.5%. The diffusion modeling results revealed that all the pretreatments intensified water diffusion and external water exchange with hot air during drying. Freezing pretreatments had no preservative effect on phenolics, iridoids, and antioxidant capacity of VBT leaves after dehydration, whereas both thermal pretreatments significantly improved dried VBT leaf quality in these three aspects. On the contrary, thermal pretreatments had destructive effects on activities of polyphenol oxidase and β-glucosidase. Due to the low β-glucosidase activity in dried VBT leaves with thermal pretreatments that participated in the transformation of iridoids to generate dark colorants eventually, the extracts from dried VBT leaves with only thermal pretreatments had weak ability to dye glutinous rice. However, this problem was fixed once extra β-glucosidase was added before rice cooking. Overall, the obtained results can provide guidance for the preservation and drying of VBT leaves that has been poorly studied.

Metabolomics approach reveals discriminatory metabolites associating with the blue pigments from Vaccinium bracteatum thunb. Leaves at different growth stages

Vaccinium bracteatum Thunb. leaf is a valuable source of natural pigment to dye food, hair, and clothing for a thousand of years in China. However, the seasonal differences of blue hue of pigments have not been fully demonstrated. In this research, V. bracteatum Thunb. leaves were collected from eight months for metabolite analysis. The global metabolic profile in leaves was examined to distinguish the differential metabolites and monitor the dynamic changes. This research revealed that several discriminatory secondary metabolites were monotropein derivatives, flavonoid glycosides and chlorogenic acid isomers by LCMS-untargeted approach. The changes of monotropein derivatives and dimers occurred in a season-dependent manner which almost showed higher abundances in spring. Meanwhile, several free amino acids changed dramatically by HPLC-targeted measurement. Particularly, Ala, Glu, and Asp caused a positive impact on blue color. Ser, Arg, and His were negatively correlated with the color. This research provided the first evidence that the seasonal differences of blue pigment are ascribed to the systemic changes of monotropein derivatives and free amino acids in V. bracteatum Thunb. leaves.

A novel green synthesis approach for natural bluish-violet pigments derived from water extracts of Vaccinium bracteatum Thunb. leaves

Vaccinium bracteatum Thunb. leaves (VBTL) is a historical source of pigments exhibiting potential applications for food and cosmetics. Some iridoid glycosides which could react with primary amines to form bluish-violet pigments were identified as the precursor compounds of VBTL pigments in previous study. However, the original preparing method of VBTL pigment limited further application. In this study, the fraction with higher color formation capability was obtained from the water extracts of VBTL. Some amino acids were selected as the fundamental substrates for preparing the VBTL-derived pigments for the first time. The results showed that the 60% ethanol fraction (Fr-60%) was selected to be the optimum substrate to produce pigments with amino acids. Two iridoid glycosides and chlorogenic acid were the main components in Fr-60%. The preparing parameters of pigments were optimized as follows: reaction temperature, 70 °C; reaction time, 3 h; reaction system pH, 4.0. Isoleucine, glutamine, and glycine had been proved to have high efficiency in the production of bluish-violet pigments. In addition, the storage stabilities under thermo-accelerated condition showed that these three bluish-violet pigments were more stable at lower H+ concentration (pH 4.0∼6.0).

Evaluation of antimicrobial activity of water-soluble flavonoids extract from Vaccinium bracteatum Thunb. leaves

Aqueous extract of Vaccinium bracteatum Thunb. leaves (VWFE) is traditionally used for food preservation in China, which is rich in flavonoids compounds. VWFE could effectively inhibit the growth of both Gram negative (Escherichia coli) and positive bacteria (Staphylococcus aureus and Bacillus subtilis), however, no inhibition effects were observed on mold and yeast. The minimum inhibitory concentration of VWFE were 2.06mg/ml, 1.03mg/ml, and 4.11mg/ml for E. coli, S. aureus and B. subtilis, respectively, which were 13%, 13%, and 26% of sodium benzoate and 23%, 11%, and 46% of potassium sorbate. Cell membrane permeability assays indicated that cell membrane disruption was one of the antibacterial mechanisms of VWFE. VWFE showed a good thermal stability. The expiration date of VWFE was 6months at 25°C, which was predicted using the accelerated aging method. This present work indicated VWFE is a potential natural antibacterial preservative.

Comparative investigation on metabolite changes in ‘wu mi’ production by Vaccinium bracteatum Thunb. leaves based on multivariate data analysis using UPLC–QToF–MS

Vaccinium bracteatum Thunb. leaves (VBTL) are used to juicing and dye rice to produce ‘Wu mi’, which displays a deep blue color. However, little information is known about the formation mechanism of the pigments. In this research, non-targeted metabolic profiling of VBTL and VBTL juice samples at different growth stages was studied for searching the pigment precursors through UPLC–QToF–MS and multivariate data analysis. The results showed the L* and b* values of ‘Wu mi’ produced by spring leaves (stages of 2WAB, 4WAB and 6WAB) were significantly lower than other growth stages. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of the VBTL and VBTL juice samples showed distinct classifications. Further variable importance in projection (VIP) plot in PLS-DA model demonstrated the discriminatory potential biomarkers between VBTL and VBTL juice samples. Some of the identified biomarkers were tentatively identified as the precursor compounds of the iridoid-derived pigments.

Sedative and hypnotic effects of Vaccinium bracteatum Thunb. through the regulation of serotonegic and GABAA-ergic systems: Involvement of 5-HT1A receptor agonistic activity

The present study was conducted to investigate the sedative and hypnotic activities of Vaccinium bracteatum Thunb. fruit (VBFW) in an animal model and to identify the underlying mechanisms of its action.VBFW exhibited sedative effects through a reduction in the locomotor activity in the open field test (OFT). In addition, VBFW significantly reduced the sleep latency and increased total sleep duration in pentobarbital-induced sleeping behaviors in mice. The effects of 4-Chloro-DL-phenylalanine methyl ester hydrochloride (PCPA) were studied in normal and serotonin-depleted mice. Additionally, the changes in the related serum corticosterone (CORT) and neurotransmitter levels were evaluated. Pretreatment with VBFW (50, and 100 mg/kg) produced a significant decrease in the immobility time in the forced swim test (FST), while VBFW 100 plus PCPA treatment attenuated the change in immobility time observed following administration of VBFW alone. However, VBFW plus PCPA treatments did not significantly influence the changes in the locomotor activity that were induced by VBFW alone. The results suggest that VBFW leads to a decrease in the levels of serum CORT and norepinephrine in the hippocampus (HC) region (P < 0.01). Furthermore, PCPA treatment alone decreased serotonin (5-HT) levels in the HC (P < 0.05) and the prefrontal cortex (PFC; P < 0.05), while VBFW plus PCPA significantly increased the 5-HT levels in both the HC and the PFC (P < 0.05). In addition, we also found that VBFW showed a strong agonistic effect at the 5-HT1A receptor by activating 5-HT1A receptor-mediated intracellular Ca2+ and ERK1/2 phosphorylation. Similarly, VBFW (30 and 100 μg/mL) significantly increased the intracellular Cl− influx through its effects on the γ-aminobutyric acid type A receptor (GABAA receptor) subunits (α5, β1, and β2) in primary rat cerebellar granule cells. Moreover, the glutamate decarboxylase (GAD)65/67 protein was upregulated following VBFW treatment (30 and 100 μg/mL). The results of our study indicate that VBFW induces sedative and hypnotic effects by regulating the serotonergic and GABAA-ergic systems, which is possibly associated with 5-HT1A receptor agonistic activity. Additionally, this data suggests that VBFW up-regulates intracellular Cl− and GABAA receptor subunits as well as GAD65/67 protein levels.

Experimental and modeling analysis of flavones extraction from Vaccinium bracteatum Thunb. leaves by ultrasound and microwave assisted simultaneously

Ultrasound and microwave-assisted extraction (UMAE) technique was used to extract flavones from Vaccinium bracteatum Thunb. leaves (VBTL). Mathematical model based on Fick’s law was established to investigate the extraction process. In order to validate the model developed under various operating conditions, effect of microwave power, temperature and solid–solvent ratio on model and yield was investigated. Values of effective diffusion coefficient were calculated based on the mathematical model. Moreover, Biot number (Bi) was employed to validate the assumptions in mathematical modeling and understand the mechanism of extraction. The results indicated that the values of effective diffusion coefficient were in the range from 3.474 × 10−11 to 10.019 × 10−11 m2/s, and the activation energy (Ea) was obtained as 47.74 kJ/mol. Values of Bi suggested the extraction process was controlled by diffusion. Our developed mathematical model gave a good approximation of experimental data under various operating conditions and could be used for further process design and investigation on extraction of flavones from VBTL.

Vaccinium bracteatum Leaf Extract Reverses Chronic Restraint Stress-Induced Depression-Like Behavior in Mice: Regulation of Hypothalamic-Pituitary-Adrenal Axis, Serotonin Turnover Systems, and ERK/Akt Phosphorylation.

The leaves of Vaccinium bracteatum Thunb. are a source of traditional herbal medicines found in East Asia. The present study aimed to evaluate the mechanisms underlying the antidepressant-like effects of water extract of V. bracteatum Thunb. leaves (VBLW) in a mouse model of chronic restraint stress (CRS) and to identify the possible molecular in vitro mechanisms of the neuroprotective effects. The CRS-exposed mice were orally administered VBLW (100 and 200 mg/kg) daily for 21 days consecutively. The behavioral effects of VBLW were assessed through the forced swim test (FST) and the open field test (OFT). The levels of serum corticosterone (CORT), corticotropin releasing hormone (CRH), and adrenocorticotropin hormone (ACTH), brain monoamines, such as serotonin, dopamine, and norepinephrine, and serotonin turnover by tryptophan hydroxylase 2 (TPH2), serotonin reuptake (SERT), and monoamine oxidase A (MAO-A) were evaluated, in addition to the extracellular signal-regulated kinases (ERKs)/protein kinase B (Akt) signaling pathway. CRS-exposed mice treated with VBLW (100 and 200 mg/kg) showed significantly reduced immobility time and increased swimming and climbing times in the FST, and increased locomotor activity in the OFT. Moreover, CRS mice treated with VBLW exhibited significantly decreased CORT and ACTH, but enhanced brain monoamine neurotransmitters. In addition, CRS mice treated with VBLW had dramatically decreased protein levels of MAO-A and SERT, but increased TPH2 protein levels in the hippocampus and the PFC. Similarly, VBLW significantly upregulated the ERKs/Akt signaling pathway in the hippocampus and the PFC. Furthermore, VBLW showed neuroprotective effects via increased CREB phosphorylation in CORT-induced cell injury that were mediated through the ERK/Akt/mTOR signaling pathways. These results suggested that the antidepressant-like effects of VBLW might be mediated by the regulation of the HPA axis, glucocorticoids, and serotonin turnover, such as TPH2, SERT, and MAO-A, as well as the concentration of monoamine neurotransmitters, and the activities of ERK and Akt phosphorylation, which were possibly associated with neuroprotective effects.