Characterization of the intestinal transport mechanism of polystyrene microplastics (MPs) and the potential inhibitory effect of green tea extracts on MPs intestinal absorption

The aims of the current study included characterizing the intestinal transport mechanism of polystyrene microplastics (MPs) with different charges and sizes in the intestinal epithelial cell model and determining the inhibitory effect of green tea extracts (GTEs) on the intestinal absorption of MPs in Caco-2 cells. The smaller sizes, which included diameters of 0.2 μm, of amine-modified MPs compared to either larger size (1 μm diameter, or carboxylate-MPs (0.2 and 1 μm diameter) significantly lowered the cell viability of caco-2 cells that were measured by MTT assay (p < 0.05). The transported amount (particles/mL of the cell media) of amine-modified MPs by the Caco-2 cell, was not dependent according to the concentrations, energy, or temperature, but it was higher than the carboxylate-modified MPs. The co-treatment of GTEs with the amine-modified MPs inhibited Caco-2 cell cytotoxicity as well as reduced the production of intracellular reactive oxygen species (ROS) in HepG2 generated by the exposure of amine-modified MPs. The GTEs co-treatment also increased trans-epithelial electrical resistances (TEER) and reduced the transportation of Lucifer Yellow via the Caco-2 monolayer compared to only the amine-modified MPs exposure. The GTEs treatment led to a decrease in the number of amine-modified MPs transported to the basal side of the Caco-2 monolayer. The results from our study suggest that the consumption of GTEs could enhance the intestinal barrier function by recovering intestinal epithelial cell damage induced by MPs, which resulted in a decrease of the intestinal absorption of MPs.

Kinetic conversion of BIOGF1K enriched in compound K from in vitro 3-D human tissue model

The purposes of current study were to investigate the effect of ginsenosides from BIOGF1K enriched in compound K (CK) and compound Y (CY) on the skin barrier function, the deposition in in vitro 3-D human tissue model (EpiDermFT™ Full Thickness 400), and to identify and quantify kinetic bioconversion of the ginsenosides in artificial skin by utilizing the Fourier transform infrared spectroscopy (FT-IR) and liquid chromatography mass spectrometry (LC-MS), respectively. Epidermal barrier integrity evaluated using transepithelial electrical resistance (TEER) was significantly higher in the BIOGF1K treatment than the CY or CK individual treatment throughout incubation (p < 0.05). Skin deposition (%) of CY and CK from BIOGF1K treatment was approximately 4 and 2 times higher than the CY and CK single component treatment, respectively. Total amount of CK found in human skin by deposition and bioconversion was approximately 1087.3, 528.82, and 867.76 μM after topical treatment of BIOGF1K, CK, and CY. Results from the current study reveal that topical treatment of BIOGF1K more effectively induced CK deposition as well as bioconversion of CY to CK than that of a single treatment of CY or CK, suggesting that BIOGF1K could be a useful cosmetic preparation for enhancing skin function.

Bioconversion of BIOGF1K, a compound-K-rich fraction from ginseng root and its effect on epidermal barrier function

BIOGF1K, the ginseng root-based and hydrolyzed ginsenoside-rich fraction, is known to improve skin damage, but there are rare studies on the kinetic of ginsenosides in the epidermis and their effects on epidermal barrier function. The current study investigated the effect of BIOGF1K on epidermal barrier function and its kinetics on epidermal transport. HPLC and LC/MS were used to verify the ginsenosides and the metabolites of BIOGF1K. Human immortalized keratinocytes (HaCaT) and epidermis-dermis artificial skin were treated with BIOGF1K and their metabolites were analyzed by HPLC and LC/MS. The epidermal barrier function was evaluated by transepithelial electrical resistance (TEER). In BIOGF1K, ginsenoside Rg1, Rd, F1, F2, compound Mc, compound Y (CY), and compound K (CK) were detected and CK and CY were the most and second abundant ginsenosides. TEER of HaCaT with 100 and 200 μg/mL BIOGF1K treatment was significantly higher than the control during 600 min of incubation. CK was permeated to the epidermis in a time-dependent manner and its maximum transported rate was observed at 600 min. In the case of artificial skin, CY and CK were permeated to the epidermis-dermis skin as time-dependent. Also, 24 h after treatment of CY, CK was detected as 19.59% of CY. It was proposed that CY was hydrolyzed into CK while permeating the epidermis. Results from the current study suggest that bioconversion of BIOGF1K rich in CK effectively enhances epidermal barrier function and it could be a useful cosmeceutical to exhibit its functionality to the skin.

Safety evaluation of kaempferol glycosides-rich standardized roasted goji berry leaf extract

Goji berry leaf (GL) has been used for medicinal foods for its pharmacological effects, including anti-oxidative and anti-obesity activities. Nevertheless, toxicological information on GL is limited for developing health functional ingredient. The aim of the research was to evaluate the single dose acute, 14-day repeated oral toxicity, and genotoxicity of standardized roasted GL extract (rGL) rich in kaempferol-3-O-sophoroside-7-O-glucoside. Tested rGL was found to be stable as kaempferol-3-O-sophoroside-7-O-glucoside, showing 0.7-2.1% of analytical standard variance. According to the single dose toxicity for 14 days, the lethal dose of rGL was determined to be ≥ 2000 mg/kg. Repeated doses of 0-1000 mg/kg of rGL per day for 14 days did not show any toxicity signs or gross pathological abnormalities. No genotoxic signs for the rGL treatment appeared via bacterial reverse mutation up to 5000 μg/plate. There was no significant increase in chromosomal aberration of rGL irrespective of metabolic activation by using CHO-K1 cells (p > 0.05). Regarding carcinogenic toxicity, chromosomal aberrations were not induced at 2000 mg of rGL/kg by using the in vivo bone marrow micronucleus test (p > 0.05). Results from the current study suggest that rGL could be used as a functional ingredient to provide various effects with safety assurance.

Bioconversion of retinol and its cell barrier function in human immortalized keratinocytes cells and artificial epidermis-dermis skin

The current study aimed to characterize cellular uptake and bioconversion of retinol in fully differentiated human immortalized keratinocytes cells (HaCaT) and artificial skin by measuring the cell integrity of skin barriers, time-dependent transport of retinol, and bioconversion to its metabolites. The expression of epidermal differentiation related genes including Keratin 1 (KRT1), Keratin 10 (KRT10), and Involucrin (IVL) significantly increased in differentiated HaCaT. TEER of HaCaT did not decrease after incubating retinol compared to control (p > 0.05), indicating that retinol tends to maintain strength and integrity of epidermal barrier. TEER of artificial skin decreased treatment of retinol for 2 h, but it was recovered after 4 h. During retinol transport, metabolite was eluted at 13.37 and 13.82 min of basal medium of both keratinocytes and artificial skin, which was identified as retinoic acid by product ion of m/z 283.47. Retinol appeared to be accumulated in keratinocytes, but its uptake tends to be reduced in a time-dependent manner. Retinoic acid converted from retinol in keratinocytes was time dependently transported. In case of artificial skin, retinol was mostly found in apical at initial incubation time, but it was reduced during incubation for 24 h. Retinoic acid was time-dependently found in a basal, which was converted via epidermis-dermis. Results from the current study suggest that topical application of retinol to human skin optimal concentration and time exposure could maintain epidermal barrier function and promote skin function due to its remarkable bioconversion to retinoic acid in the epidermis-dermis.

Blue honeysuckle rich in cyanidin-3-O-glucoside inhibited adipogenic differentiation by modulation of the adipogenesis pathway in 3T3-L1 adipocytes

Background: Blue honeysuckle (BH; Lonicera caerulea L.), which is a traditional medicinal plant, is known to be a rich source of anthocyanins and phenolic acids due to its strong antioxidant and anti-inflammatory activities. Its anti-obesity effects, which are a result of attenuating abnormal lipid and glucose metabolisms, have also been reported. Aim: The purpose of this study is to investigate the effect of BH on genes and proteins that are involved in the adipocyte differentiation using 3T3-L1 cells. Methods: The effects of the water extracts of the BH were examined on adipogenesis and lipolysis using a biochemical and molecular analysis of the 3T3-L1 cells. Results: Cyanidin-3-O-glucoside (C3G) from the BH extract was determined in order to contain 1.67 mg/g by the high-performance liquid chromatography analysis. The lipid accumulation in the adipocytes was reduced, which ranged from 58 to 26% in the BH (500 and 1,000 µg/mL) compared to the control group. The lipolysis that was measured by the glycerol content was not affected by the BH at 1,000 μg/mL. The BH downregulated the expression of the main transcription factors of the adipogenesis pathway, such as peroxisome proliferator-activated receptor γ, 1, 2, adipose differentiation-related protein, CCAAT/enhancer binding protein α, and acetyl CoA carboxylase, while increasing the expression of the Adenosine monophosphate (AMP)-activated protein kinase α. Conclusion: These findings suggest that the BH is a good source of C3G, and it could be effective in regard to inhibiting the adipogenesis as opposed to the lipolysis, which indicates the potential for natural anti-obesity ingredients.

A pilot study on the effect of formulation and individual muscle mass on vitamin C absorption in randomized clinical study

The current study investigated that the vitamin C absorption in plasma depends on the individual muscle mass and the formulation including drinks (Vita 500), capsules, and tablets by using a randomized and double-blind clinical study. The volunteers were divided into two groups that depended on their muscle mass, including those whose muscle mass was greater than 40% ( ≥ $ \ge $ 40%) and less than 40% muscle mass (<40%). Levels of vitamin C in blood plasma was analyzed by high-performance liquid chromatography by ultraviolet detection (HPLC-UV). The existing HPLC method was modified according to lab conditions but maintained a constantly low pH sample reduction procedure. The analytical method validated stability, linearity, recovery, reliability, and accuracy. The vitamin C absorption was the highest at 120 min after ingesting Vita 500 (21.47 ± 15.99 µmol/L). It was higher in the group that has more than 40% muscle mass compared to other formulations, such as tablets and capsules. The results from the current study indicate that vitamin C formulations differently affect the vitamin C absorption, and its effect depends on the muscle mass. As the results, liquid type vitamin C formulations could enhance vitamin C absorption, which resulted in an improvement of vitamin C absorption according to muscle mass. PRACTICAL APPLICATION: The results of this study may recommend using vitamin C supplementation as liquid type. It may also provide evidence that people with higher muscle mass can absorb vitamin C more efficiently.

Impact of flavonol extracts derived from green tea or targeted flavonols as secondary ingredients on intestinal glucose transport

The purpose of the current study was to examine the effect of adding secondary ingredients such as green tea derived water-soluble polysaccharides (GTP) and flavonol aglycone rich fractions derived from cellulase treated green tea extract (FVN) into catechin rich green tea extracts (GTE) on wheat starch digestion and intestinal glucose transport using in vitro digestion with Caco-2 cells. Co-digestion of wheat starch with GTE (16.88 g L^-1) or GTE + GTP + FVN (16.69 g L^-1) appeared to promote starch hydrolysis compared to control (15.49 g L^-1). In case of major flavonoids, addition of epigallocatechin gallate (EGCG), EGCG + myricetin (M) into wheat starch significantly increased the digestion of starch into glucose. Glucose transport rate decreased by 22.35% in wheat starch + GTE + GTP + FVN (1.39%), while the least amount of glucose (1.70%) was transported in EGCG mixed with M (1% of EGCG) as secondary ingredients among individual flavonoids formulation. It indicated that inhibitory effect on glucose transport was higher in addition of GTE, GTP, and FVN as excipients ingredients rather than targeted major flavonoids. Results from the current study suggest that whole green tea including flavonoid rich fractions could enhance hypoglycemic potential of GTE.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05140-2.

Effect of Characterized Green Tea Extraction Methods and Formulations on Enzymatic Starch Hydrolysis and Intestinal Glucose Transport

The purpose of the current study was to investigate the effect of various characterized green tea extracts (GTEs) according to extraction methods on enzymatic starch hydrolysis and intestinal glucose transport. Codigestion of wheat starch with water extract (WGT) or ethanol extract formulated with green tea polysaccharides and flavonols (CATEPLUS) produced 3.4-3.5 times higher resistant starch (RS) than wheat starch only. Its microstructures were changed to spherical shapes and smooth surfaces as shown by scanning electron microscopy (SEM) results. According to Fourier transform infrared (FT-IR) spectra, the absorption peak of O-H stretching was red-shifted in WGT or CATEPLUS. The results confirmed that hydrogen bonds were formed between starch granules and polysaccharides in WGT or CATEPLUS. Intestinal glucose transport subsequently measured after in vitro digestion was mostly suppressed in CATEPLUS. Gene expression of the glucose transporter protein, particularly SGLT1, was significantly inhibited by addition of CATEPLUS (p < 0.05). Results from the current study suggest that co-intake of green tea extracts formulated with green tea polysaccharides and flavonols could be a potentially useful means to delay blood glucose absorption when consuming starchy foods.

Characterized Polysaccharides from Green Tea Inhibited Starch Hydrolysis and Glucose Intestinal Uptake by Inducing Microstructural Changes of Wheat Starch

The purpose of the current study was to investigate the effect of green tea ethanol extract (GTE) and polysaccharide fractions from green tea (PFGs) on the hydrolysis of wheat starch, microstructural changes, and intestinal transport of glucose. The amount of resistant starch (RS) was significantly lowered in the water-soluble polysaccharide (WSP), water-soluble polysaccharide-pectinase (WSP-P), and water-insoluble polysaccharide-alkali soluble (WISP-Alk-Soluble; p < 0.05). The microstructures of gelatinized wheat starch granules with WSP, WSP-P, and WISP-Alk-Soluble were spherical with small cracks. The amount of intestinal transported glucose from digested wheat starch was 2.12-3.50 times lower than the control group. The results from the current study suggest that water- and alkali-soluble PFGs could be potential ingredients to lower starch hydrolysis as well as to control the postprandial blood glucose level when foods that contain starch are consumed.

Impact of soy lecithin, zinc oxide, and methylsulfonylmethane, as excipient ingredients, on the bioaccessibility and intestinal transport of branched-chain amino acids from animal and plant protein mixtures

To maximize the biological activity of branched-chain amino acids (BCAAs), it is necessary to find a new excipient agent to increase the bioavailability of BCAAs in protein mixtures. The aim of the current study was to investigate the effects of soy lecithin (SLC), zinc oxide (ZnO), and methylsulfonylmethane (MSM) on the bioaccessibility and intestinal transport of BCAAs from animal and plant protein mixtures (PMs) via an in vitro digestion model with human intestinal epithelial (Caco-2) cells. The bioaccessibility of total BCAAs in PMs considerably increased by 107.51 ± 1.50% with the addition of SLC, and the combined effects of SLC, ZnO, and MSM on enhancing the bioaccessibility of total BCAAs was observed (107.14 ± 0.18%). Interestingly, SLC showed a major role in binding bile acid, showing 65.78 ± 1.66% of binding capacity. Intestinal transport of BCAAs was measured to be at 100.48, 110.86, and 130.29 μg mL^-1 for leucine, isoleucine, and valine, respectively, in PMs with SLC + ZnO + MSM, and it eventually amplified the amount of the total transported BCAAs (341.63 ± 6.34 μg mL^-1), which was about 8.72 times higher than that of PM only. The cellular integrity of digesta-treated Caco-2 cells tended to decrease according to the incubation time, but it was recovered in the treatment of PM + SLC + ZnO + MSM, and nearly reached the control levels with 92.82 ± 0.53%. Results from the current study suggest that the co-consumption of proteins equally consisting of plant and animal sources with SLC, ZnO, and MSM could improve the bioavailability of total BCAAs, resulting in the improvement of health benefits.

Curcumin Attenuates Sarcopenia in Chronic Forced Exercise Executed Aged Mice by Regulating Muscle Degradation and Protein Synthesis with Antioxidant and Anti-inflammatory Effects

The aim of the current study is to investigate the effects of spray dry powders of Curcuma longa containing 40% curcumin (CM-SD), as a new aqueous curcumin formula, on sarcopenia in chronic forced exercise executed 10 month old ICR mice. CM-SD (80 and 40 mg/kg) increased calf thicknesses and strengths, total body and calf protein amounts, and muscle weights in both gastrocnemius and soleus muscles. mRNA expressions regarding muscle growth and protein synthesis were induced, while those of muscle degradation significantly declined in CM-SD treatment. CM-SD decreased serum biochemical markers, lipid peroxidation, and reactive oxygen species and increased endogenous antioxidants and enzyme activities. It also reduced immunoreactive myofibers for apoptosis and oxidative stress markers but increased ATPase in myofibers. These results suggest that CM-SD can be an adjunct therapy to exercise-based remedy that prevents muscle disorders including sarcopenia by anti-apoptosis, anti-inflammation, and antioxidation-mediated modulation of gene expressions related to muscle degradation and protein synthesis.

Curcumin Ameliorated Oxidative Stress and Inflammation-Related Muscle Disorders in C2C12 Myoblast Cells

The purpose of the current study was to investigate antioxidant and anti-inflammatory effects of spray dry powder containing 40% curcumin (CM-SD) in C2C12 myoblast cells. CM-SD increased DPPH radical scavenging activity in a dose-dependent manner, and up to 30 μg/mL of CM-SD did not express cytotoxicity in C2C12 cells. Exposure to hydrogen peroxide (H₂O₂) drastically decreased the viability of C2C12 cells, but pre-treatment of CM-SD significantly increased the cell viability (p < 0.01). CM-SD significantly transactivated the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent luciferase activity in a dose-dependent manner and enhanced the levels of heme oxygenase (HO)-1, glutamate cysteine ligase catalytic subunit (GCLC), and NAD(P)H-dependent quinone oxidoreductase (NQO)-1. CM-SD also significantly reduced reactive oxygen species (ROS) production and lipid peroxidation and restored glutathione (GSH) depletion in H₂O₂-treated C2C12 cells. Moreover, CM-SD significantly reduced lipopolysaccharides (LPS)-mediated interleukin (IL)-6 production in the conditioned medium. Results from the current study suggest that CM-SD could be a useful candidate against oxidative stress and inflammation-related muscle disorders.

Addition of flavonols and polysaccharides as excipient ingredients into epicatechin rich green tea extract inhibited free radical formation and glucose uptake

It was revealed that excipient ingredients such as flavonols (FVN) or polysaccharides (GTP) which could be derived from green tea enhanced catechin absorption. We hypothesized that the addition of FVN or GTP as excipient ingredients into epicatechin rich green tea extracts (GTE) may improve the health benefits that accompany its consumption. When FVN8.7 (8.7% of GTE, w/w) was added to the GTE (20 mg) as an excipient ingredient, the bioaccessibility and intestinal absorption of total epicatechins was 1.2 and 1.5 times higher than that of only GTE, respectively. This was due to the free radical scavenging capacity of flavonols, showing 114.23 ± 3.07 μmol TE per g for GTE 100 + FVN8.7 and 113.64 ± 1.61 μmol TE per g for GTE 100 + FVN2, respectively. This was significantly higher than the GTE or GTE 100 + OW2 (onion peel and whangchil extracts, 2% of GTE, w/w) which have the same amount of total flavonols. Regarding potential hypoglycemic effects, co-digestion of GTE (20 mg) + green tea polysaccharides (2 mg) + FVN (5 mg) with wheat starch significantly reduced glucose intestinal absorption by 41.85 ± 1.75% compared to only the wheat starch. The results from the current study suggest that whole green tea components rich in flavonols and polysaccharides could be potential hypoglycemic excipient ingredients for green tea catechins.

Impact of acidity regulator and excipient nutrients on digestive solubility and intestinal transport of calcium from calcium phosphate and carbonate

The aim of the current study was to investigate the effect of an acidity regulator (SPORIX®), lactose, and vitamin D₃ as excipient ingredients on digestive solubility and intestinal transport of calcium from four different calcium materials (tricalcium phosphate (TCP), fish bone (FB), nano-fish bone (NFB), and algae calcium (AC)) through an in vitro digestion model system combined with Caco-2 cells. The concentration of ionized calcium (Ca²⁺) in an aqueous fraction after in vitro digestion increased with the addition of SPORIX®, and it was further enhanced by adding SPORIX® + lactose + vitamin D₃ into TCP, FB, NFB, and AC, respectively. In particular, FB with SPORIX® + lactose + vitamin D₃ enhanced calcium ionization to 33.89 ± 0.69 mg g^-1, which was about 11.76 times higher than that of FB only. In the case of intestinal cellular uptake of calcium, there was no significant difference in all the tested calcium materials with SPORIX® + lactose + vitamin D₃. However, the absolute amount of intestinal transport of calcium in FB (43.95 ± 3.29 μg) was significantly higher than other calcium materials with the addition of SPORIX® + lactose + vitamin D₃ (p < 0.05). This study suggests that the co-consumption of SPORIX®, lactose, and vitamin D₃ with FB could enhance the calcium bioavailability by lowering pH as well as improving calcium intestinal transport by modulating the paracellular and transcellular uptake mechanism.

Hypoglycemic effect of soluble polysaccharide and catechins from green tea on inhibiting intestinal transport of glucose

BACKGROUND

Water soluble polysaccharide derived from green tea (WSP) is produced as byproducts when catechins were extracted from green tea. Although inhibitory effect of green tea catechins on the glucose transport in small intestine has been studied, the hypoglycemic efficacy of the WSP or its combinational effect has not been studied. In order to investigate hypoglycemic efficacy of the WSP or its combinational effect with green tea extract (GTE), co-consumption of GTE and WSP with wheat starch was investigated using in vitro digestion coupled with Caco-2 cells. The mechanism of the intestinal glucose transport was elucidated throughout the gene expression of the intestinal glucose transporters, which included sodium dependent glucose transporter (SGLT1) and glucose transporter 2 (GLUT2), using quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The co-digestion of wheat starch with GTE during the small intestinal phase was the most rapidly digested into reducing sugar (73.96 g L^-1 ) compared to itself (48.44 g L^-1 ), WSP (60.35 g L^-1 ), and GTE + WSP (61.81 g L^-1 ). Intestinal glucose transport was 11.82, 7.59, 4.49, and 2.40% for wheat starch, wheat starch with GTE, WSP, and GTE + WSP, respectively. The highest decreased expression pattern in SGLT1 was observed when cells treated with wheat starch + GTE + WSP (0.66-fold) compared to GTE or WSP treatment.

CONCLUSION

The results suggested that co-consumption of green tea derived products with wheat starch could delay the intestinal absorption of glucose. Results from the current study suggested that GTE and WSP could be the useful supplements of dietary therapy for hyperglycemia to delay glucose absorption. © 2020 Society of Chemical Industry.

Inhibition of sphingosine 1-phosphate lyase activates human keratinocyte differentiation and attenuates psoriasis in mice

Sphingosine 1-phosphate (S1P) lyase is an intracellular enzyme that catalyzes the irreversible degradation of S1P and has been suggested as a therapeutic target for the treatment of psoriasis vulgaris. Because S1P induces differentiation of keratinocytes, we examined whether modulation of S1P lyase and altered intracellular S1P levels regulate proliferation and differentiation of human neonatal epidermal keratinocyte (HEKn) cells. To identify the physiological functions of S1P lyase in skin, we inhibited S1P lyase in HEKn cells with an S1P lyase-specific inhibitor (SLI) and with S1P lyase 1 (SGPL1)-specific siRNA (siSGPL1). In HEKn cells, pharmacological treatment with the SLI caused G1 arrest by upregulation of p21 and p27 and induced keratin 1, an early differentiation marker. Similarly, genetic suppression by siSGPL1 arrested the cell cycle at the G1 phase and activated differentiation. In addition, enzyme suppression by siSGPL1 upregulated keratin 1 and differentiation markers including involucrin and loricrin. When hyperproliferation of HEKn cells was induced by interleukin (IL)-17 and IL-22, pharmacologic inhibition of S1P lyase by SLI decreased proliferation and activated differentiation of HEKn cells simultaneously. In addition, SLI administration ameliorated imiquimod-induced psoriatic symptoms including erythema, scaling, and epidermal thickness in vivo. We thus demonstrated that S1P lyase inhibition reduces cell proliferation and induces keratinocyte differentiation, and that inhibition may attenuate psoriasiform changes. Collectively, these findings suggest that S1P lyase is a modulating factor for proliferation and differentiation, and support its potential as a therapeutic target for psoriasis in human keratinocytes.

Changes in the profiling of bioactive components with the roasting process in Lycium chinense leaves and the anti-obesity effect of its bioaccessible fractions

BACKGROUND

This study aimed to investigate the profiles of bioactive components in roasted Lycium chinense leaves (LCLs) and its in vitro anti-obesity activity after digestion processes.

RESULTS

Chlorogenic acid, kaempferol-3-sophoroside-7-glucoside, kaempferol-3-sophoroside, and kaempferol-3-glucoside were discovered as bioactive components in various ratios of ethanol (EtOH) extract in LCLs by using ultra-performance liquid chromatography-electrospray ionization-mass spectrophotometry (UPLC-ESI-MS). The roasting process followed by a 30% EtOH extraction tended to decrease the content of chlorogenic acid and kaempferol-3-glucoside, and enhanced the content of kaempferol-3-sophoroside-7-glucoside. It effectively inhibited pancreatic lipase activity by 62.50 ± 4.81%, which was approximately 1.71 percentage points higher than that of the dried-nonroasted LCL extract (60.79 ± 3.75%). Its bioaccessible fraction obtained from in vitro digestion significantly and dose dependently reduced intracellular lipid accumulation by adipocyte 3T3-L1 compared with a 30% EtOH extraction. At a concentration of 200 μg mL^-1 , it inhibited lipid accumulation up to 29.55% in 3T3-L1 cells, which indicated that human digestive enzymes converted kaempferol-3-sophoroside-7-glucoside to kaempferol metabolites that have anti-obesity effects.

CONCLUSION

This study suggests that the profiling of bioactive components by processing methods and a bioaccessible fraction could be crucial to improve the bioactivity of LCLs, and potentially be a natural anti-obesity ingredient after oral intake. © 2019 Society of Chemical Industry.

Hypoglycemic potential of whole green tea: water-soluble green tea polysaccharides combined with green tea extract delays digestibility and intestinal glucose transport of rice starch

Green tea is being studied extensively for its postprandial hypoglycemic effect due to its abundant catechins. Along with catechins, water-soluble green tea polysaccharides are also currently gaining attention due to their natural hypoglycemic properties. The current study investigated the combinational effect of green tea extract (GTE) and crude green tea polysaccharides (CTP) in inhibiting glucose transport after digestion of rice starch, using an in vitro digestion model with a Caco-2 cell. Co-digestion of rice starch with GTE (16.09 ± 1.02 g L-1), CTP (16.83 ± 0.81 g L-1), or GTE + CTP (17.79 ± 0.80 g L-1) hydrolyzed less starch into glucose compared with the control (18.24 ± 0.45 g L-1). Glucose transport from digesta to the Caco-2 cell after 120 min incubation was significantly inhibited with GTE + CTP (53.26 ± 4.34%). Gene expression of intestinal glucose transporters, which included sodium-dependent glucose transporter (SGLT1) and glucose transporter 2 (GLUT2), was not altered by GTE, CTP or GTE + CTP, except for the GTE-mediated upregulation of GLUT2. It is concluded that GTE + CTP lowered digestibility of rice starch with glucose and also delayed glucose uptake to the intestinal epithelium. This finding suggests a potential for green tea polysaccharides as a natural postprandial hypoglycemic substance.

Increased Intestinal Absorption of Vitamin U in Steamed Graviola Leaf Extract Activates Nicotine Detoxification

Graviola leaves contain much vitamin U (vit U), but their sensory quality is not good enough for them to be developed as food ingredients. Addition of excipient natural ingredients formulated alongside vit U as active ingredients could enhance not only its sensory quality but also its bioavailability. The objectives of this study were to measure the bioaccessibility and intestinal cellular uptake of bioactive components, including rutin, kaempferol-rutinoside, and vit U, from steamed extract of graviola leaves (SGV) and SGV enriched with kale extract (SGK), and to examine how much they can detoxify nicotine in HepG2 cells. The bioaccessibility of vit U from SGV and SGK was 82.40% and 68.03%, respectively. The cellular uptake of vit U in SGK by Caco-2 cells was higher than that in SGV. Cotinine content converted from nicotine in HepG2 cells for 120 min was 0.22 and 0.25 μg/mg protein in 50 μg/mL of SGV and SGK, respectively, which were 2.86 and 3.57 times higher than the no-treatment control. SGK treatment of HepG2 cells upregulated CYP2A6 three times as much as did that of SGV. Our results suggest that graviola leaf extract enriched with excipient ingredients such as kale could improve vit U absorption and provide a natural therapy for detoxifying nicotine.

Catechins Controlled Bioavailability of Benzo[a]pyrene (B[α]P) from the Gastrointestinal Tract to the Brain towards Reducing Brain Toxicity Using the In Vitro Bio-Mimic System Coupled with Sequential Co-Cultures

The aim of the current study was to examine the preventive effect of green tea catechins on the transport of Benzo[a]pyrene (B[α]P) into the brain using an in vitro bio-mimic system coupled with sequential co-cultures. When 72 μM of catechins was pre-treated, cellular cytotoxicity induced by IC₅₀ of B[α]P in human liver hepatocellular carcinoma (HepG2) and human brain microvascular endothelial cells (HBMECs) was reduced by 27% and 26%, respectively. The cellular integrity measured in HBMECs, which was exposed to IC₅₀ of B[α]P, slowly decreased. However, the pre-treatment of catechins retained cellular integrity that was 1.14 times higher than with the absence of catechins. Co-consumption of catechins reduced not only the bio-accessibility of B[α]P in digestive fluid, but it also decreased absorption of B[α]P in human intestinal epithelial cells (Caco-2) with a HepG2 co-culture system. It was found that approximately a two times lower amount of B[α]P was transported via the blood-brain barrier (BBB) compared to only the B[α]P intake. These results are taken in conjunction with each other support that catechins could be able to prevent brain toxicity induced by B[α]P in the human body by limiting the bio-availability of B[α]P.

Impact of Bioconversion of Gallated Catechins and Flavonol Glycosides on Bioaccessibility and Intestinal Cellular Uptake of Catechins

Two bioconversions were applied to green tea extracts (GTE) and flavonol glycoside rich fraction (FVNg) derived from insoluble green tea extract by tannase and cellulase treatment in order to obtain gallated catechins (EnzGTE) and flavonol aglycone rich fraction (FVNa), respectively. The bioaccessibility of epicatechins from GTE increased with the addition of FVNg, FVNa, and flavonol aglycone rich fraction of commercial production (FVNap). Epigallocatechin-gallate (EGCG) and epicatechin-gallate (ECG) were highly recovered 4- and 125-fold, respectively, by adding FVNap. They were mostly affected by the radical scavenging activity provided from FVNap, showing remarkable 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (10769.3 μg/g) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (8341.5 μg/g) values. The intestinal cellular uptake of epicatechins in GTE increased with the FVNap addition as follows: EGCG (332.46 ± 136.18%) > ECG (273.92 ± 97.92%) > epicatechin (EC) (150.22 ± 12.59%) > epigallocatechin (EGC) (131.21 ± 8.51%). EnzGTE and EnzGTE + FVNa were revealed to have a significant downregulation on the expression of P-glycoprotein (P-gp), up to 0.06- and 0.6-fold, respectively. The gene expression of multidrug resistance associated proteins 2 (MRP2) was reduced in EnzGTE + FVNap. The results suggest that coconsumption GTE or EnzGTE with GTE-derived flavonols could improve the bioavailability of epicatechins.

Inhibition of lactate dehydrogenase A suppresses inflammatory response in RAW 264.7 macrophages

Lactate is an important metabolite in cellular metabolism and fluctuates in certain disease conditions including cancer and immune diseases. It was hypothesized that a decrease in lactate would modulate the inflammatory response elicited by lipopolysaccharides (LPS) in macrophages. When RAW 264.7 macrophages were treated with FX11, a specific lactate dehydrogenase (LDHA) inhibitor, the expression of the cytokines, inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX‑2) was downregulated due to reduced cellular lactate levels. Genetic suppression of LDHA by small interfering RNA (siRNA) downregulated the LPS‑activated expression of interleukin (IL)‑6, iNOS, and COX‑2, and reduced the production of IL‑6 and nitrites. Pharmacological and genetic suppression of LDHA inhibited the phosphorylation of p38 mitogen‑activated protein kinase. Microarray gene expression profile demonstrated that the genes involved in cell proliferation and inflammation were mainly altered by siRNA‑mediated LDHA suppression. Collectively, the present observations suggest that lactate may be an important metabolite and implicated in regulation of inflammatory response.

Effect of catechins and high-temperature-processed green tea extract on scavenging reactive oxygen species and preventing Aβ1-42 fibrils' formation in brain microvascular endothelium

The present study investigated the effect of high-temperature-processed green tea extract (HTP_GTE) and its bioactive components on the reduction of reactive oxygen species (ROS) and amyloid-beta (Aβ) protein in human microvascular endothelial cells. Compared to Aβ_1-42-only treatment, pretreatment of HTP_GTE was revealed to effectively inhibit ROS generation (P<0.05). HTP_GTE and catechins not only inhibit Aβ_1-42 fibril formation but also destabilize preformed Aβ_1-42 fibrils. The presence of HTP_GTE, Aβ_1-42 fibril formation was significantly inhibited in a dose-dependent manner at 12.5-100 μg/ml of HTP_GTE, showing 86-56%, respectively. Treatment of various concentrations of HTP_GTE and catechins steadily destabilized the preformed Aβ_1-42 fibrils for 24 h in a dose-dependent manner. It was observed that the gallated groups such as epigallocatechin gallate, epicatechin gallate, gallocatechin gallate, and catechin gallate more effectively disturbed Aβ_1-42 fibril formation and destabilized the preformed Aβ_1-42 fibrils than the non-gallated group. Taken together, these findings supported that sterilized green tea could be promising natural anti-amyloidogenic agents associated with therapeutic approaches in Alzheimer's disease by scavenging ROS generation and Aβ fibril in the brain tissue.

Quercetin and fisetin enhanced the small intestine cellular uptake and plasma levels of epi-catechins in in vitro and in vivo models

Quercetin and fisetin, known as catechol-containing flavonoids, could positively affect the absorption of catechins due to their strong affinity for catechol-O-methyl transferase (COMT), which can methylate and cause the excretion of catechins. The current study examined the effect of quercetin and fisetin on the absorption of epi-catechins (ECs) by using a Caco-2 cell line and an in vivo model. The intestinal transport of total catechins by Caco-2 cells was enhanced from 1.3- to 1.6-fold and 1.4- to 1.7-fold by adding quercetin and fisetin, respectively, compared to the control. It was even higher in the treatment with a mixture of quercetin and fisetin. While EC had the highest value of intestinal transport (169% of the control) in 10% quercetin treatment, EGC (235%), EGCG (244%), and ECG (242%) were significantly transported in the treatment with a 5% mixture of quercetin and fisetin (p < 0.05). In an in vivo pharmacokinetic study, the values of the area under the plasma concentration-time curve (AUC, ng h mL^-1) were also higher in rats orally administered EGCG with 10% quercetin (365.5 ± 25.5) or 10% fisetin (825.3 ± 46.7) than in those administered EGCG only (111.3 ± 13.1). Methylated quercetin and methylated fisetin were determined to be m/z 317.24 and m/z 301.25 [M + H]⁺ with their own product ions, respectively. The results indicate that quercetin or fisetin is superior to ECs for methylation by COMT.

Influence of flavonol-rich excipient food (onion peel and Dendropanax morbifera) on the bioavailability of green tea epicatechins in vitro and in vivo

The impacts of onion peel (OP) and Dendropanax morbifera (DM), as excipient foods rich in flavonols, on the digestive recovery, intestinal absorption, and pharmacokinetics of GT epicatechins were studied via an in vitro digestion model system with Caco-2 cells and an in vivo study. The digestive stability of total epicatechins recovered from GT upon the addition of 2% DM was up to 1.12 times higher than that observed with OP. The combined effects of OP and DM, which were observed with 2% OP + DM in a ratio of 1 : 4 (w : w), significantly increased (by a factor of 1.31) the digestive recovery of total epicatechins (p < 0.05). Remarkable cellular uptakes of EC (185.36%) and ECG (188.08%) were found with 4% OP + DM (4 : 1, w : w), and those of EGC (112.30%) and EGCG (136.27%) were obtained with 2% OP + DM (4 : 1, w : w) and 1% OP + DM (1 : 1, w : w), respectively. The peak plasma concentrations of total epicatechins from GT, GT + 5% OP, GT + 5% DM, and GT + 2% OP + 2% DM were 1044.78 ± 609.10, 2267.18 ± 3734.38, 1270.35 ± 547.59, and 714.53 ± 499.27 ng mL^-1, respectively. The C_max value of total epicatechins in rats orally administrated with GT with 5% OP was found to be approximately twice of that obtained with GT alone. The co-ingestion of GT with flavonol-rich excipient foods possibly enhances the absorption of epicatechins because flavonols act as not only enhancers of digestive stability but also modulators of the biotransformation of epicatechins. The results obtained from the current study suggest that the absorption of GT catechins can vary depending upon the kinds and doses of excipient foods co-ingested.

Systematic Investigation of the Reduction of Inorganic Arsenic and Bioactive Nutrients in Rice with Various Cooking Techniques

The objectives of this study were to investigate the effect of polishing, stirring and rinsing, soaking, or pressure-steam cooking on total organic and inorganic arsenic content and to measure daily inorganic arsenic exposure and nutrient values from consumption of rice prepared under the optimal process. With increasing numbers of rinses and times stirred per rinse, the total arsenic content significantly decreased by 27.6% in brown rice and 39.0% in white rice with 10% degree of polishing (10DOP%). The increase in ratio of water to rice from 1.5:1 to 6:1 reduced total arsenic by 4.4 to 7.5%, depending on soaking time. The total arsenic concentrations found in samples prepared using the optimal process for cooked brown rice and for white rice with 5DOP%, 7DOP%, and 10DOP% were 56.1, 49.6, 52.0, and 42.0%, respectively, compared with those after bran residues were removed. The concentration of total dietary fiber in 10DOP% white and brown rice was 0.34 mg/100 g (54.7% reduction) and 2.52 mg/100 g (24.8% reduction) after the cooking process, respectively. Results from the current study suggest that the optimal cooking process could maximize the reduction of arsenic contents and, at the same time, minimize the loss of nutrients from rice.

Adipocyte-Specific Deficiency of De Novo Sphingolipid Biosynthesis Leads to Lipodystrophy and Insulin Resistance

Sphingolipids have been implicated in the etiology of chronic metabolic diseases. Here, we investigated whether sphingolipid biosynthesis is associated with the development of adipose tissues and metabolic diseases. SPTLC2, a subunit of serine palmitoyltransferase, was transcriptionally upregulated in the adipose tissues of obese mice and in differentiating adipocytes. Adipocyte-specific SPTLC2-deficient (aSPTLC2 KO) mice had markedly reduced adipose tissue mass. Fatty acids that were destined for the adipose tissue were instead shunted to liver and caused hepatosteatosis. This impaired fat distribution caused systemic insulin resistance and hyperglycemia, indicating severe lipodystrophy. Mechanistically, sphingosine 1-phosphate (S1P) was reduced in the adipose tissues of aSPTLC2 KO mice, and this inhibited adipocyte proliferation and differentiation via the downregulation of S1P receptor 1 and decreased activity of the peroxisome proliferator-activator receptor γ. In addition, downregulation of SREBP (sterol regulatory element-binding protein)-1c prevented adipogenesis of aSPTLC2 KO adipocytes. Collectively, our observations suggest that the tight regulation of de novo sphingolipid biosynthesis and S1P signaling plays an important role in adipogenesis and hepatosteatosis.

Impact of commercial cigarette smoke condensate on brain tissue co-cultured with astrocytes and blood-brain barrier endothelial cells

The purpose of the current study was to investigate the effect of two commercial cigarette smoke condensates (CCSC) on oxidative stress and cell cytotoxicity in human brain (T98G) or astrocytes (U-373 MG) in the presence of human brain microvascular endothelial cells (HBMEC). Cell viability of mono-culture of T98G or U-373 MG was markedly decreased in a concentration-dependent manner, and T98G was more susceptible than U-373 MG to CCSC exposure. Cytotoxicity was less prominent when T98G was co-cultured with HBMEC than when T98G was co-cultured with U-373 MG. Significant reduction in trans-epithelial electric resistance (TEER), a biomarker of cellular integrity was noted in HBMEC co-cultured with T98G (HBMEC-T98G co-culture) and U-373 MG co-cultured with T98G (U-373 MG-T98G co-culture) after 24 or 48 hr CCSC exposure, respectively. TEER value of U-373 MG co-cultured with T98G (79-84%) was higher than HBMEC co-cultured with T98G (62-63%) within 120-hr incubation with CCSC. Reactive oxygen species (ROS) generated by CCSC in mono-culture of T98G and U-373 MG reached highest levels at 4 and 16 mg/ml, respectively. ROS production by T98G fell when co-cultured with HBMEC or U-373MG. These findings suggest that adverse consequences of CCSC treatment on brain cells may be protected by blood-brain barrier or astrocytes, but with chronic exposure toxicity may be worsened due to destruction of cellular integrity.

The effect of tobacco smoke exposure on the generation of reactive oxygen species and cellular membrane damage using co-culture model of blood brain barrier with astrocytes

Brain tissue is known to be vulnerable to the exposure by tobacco smoke. Tobacco smoke can induce generation of reactive oxygen species (ROS), causing inflammatory activity and blood-brain barrier (BBB) impairment. The aim of the present study was to investigate the effect of tobacco smoke on cell cytotoxicity, generation of ROS, and cellular membrane damage in astrocytes and BBB using a co-culture system. Cell viability of U373MG cells was reduced in a dose-dependent manner, ranging from 96.7% to 40.3% by tobacco smoke condensate (TSC). Cell viability of U373MG co-cultured with human brain microvascular endothelial cells (HBMECs) was 104.9% at the IC50 value of TSC. Trans-epithelial electric resistance values drastically decreased 80% following 12-h incubation. The value was maintained until 48 h and then increased at 72-h incubation (85%). It then decreased to 75% at 120 h. Generation of ROS increased in a dose-dependent manner, ranging from 102.7% to 107.9%, when various concentrations of TSC (4-16 mg/mL) were administered to the U373MG monoculture. When TSC was added into U373MG co-cultured with HBMECs, production of ROS ranged from 101.7% to 102.6%, slightly increasing over 12 h. Maximum exposure-generated ROS of 104.8% was reached at 24 h. Cell cytotoxicity and oxidative stress levels in the U373MG co-culture model system with HBMECs were lower than U373MG monoculture. HBMECs effectively acted as a barrier to protect the astrocytes (U373MG) from toxicity of TSC.

Determination of total arsenic content and arsenic speciation in different types of rice

The objectives of this study was to examine the amount of total arsenic and arsenic speciation in different types of rice from two areas in Korea using inductively coupled plasma/mass spectrometer (ICP-MS) and high performance liquid chromatography-ICP/MS (HPLC-ICP/MS) and estimate the potential health risk from rice consumption. Brown rice (0% of degree of polishing, DOP%) contained the highest amount of total arsenic followed by 5, 7 and 10 DOP% white rice. Among the arsenic species, As(III) was predominantly detected in brown (0 DOP%) and white rice (10 DOP%), with concentrations ranging from 28.51±0.71 to 51.91±1.13 μg/kg in region A and from 62.1 to 130.4 μg/kg in region B. While estimating the daily arsenic exposure from consumption of polished rice, the expected daily exposure of inorganic arsenic from brown and 10 DOP% white rice was found to be below benchmark dose modeling value for a 0.5% increased incidence of lung cancer (BMDL0.5) (3.0 μg/kg bw per day). Therefore, arsenic in rice, particularly, As(III), tends to accumulate in the outer layer of rice.

Bioefficacy of Graviola leaf extracts in scavenging free radicals and upregulating antioxidant genes

The aims of this study were to determine bioactive components of Graviola leaf extracts and to examine the radical scavenging capacity, gene expression and transcription factors of antioxidant enzymes. Rutin, kaempferol-rutinoside, and vitamin U were identified from the steaming and 50% EtOH extracts of Graviola leaves. Graviola leaf extracts effectively scavenged peroxy and nitrogen radicals. 50% EtOH of Graviola leaves provided a 1-2.9 times higher trolox equivalent than the steaming extract. It also had a higher VCEAC. Graviola leaf extracts reduced the generation of reactive oxygen species (ROS) induced by H2O2 in a dose-dependent manner. The 50% EtOH extract of Graviola leaves upregulated SOD1 and Nrf2, but catalase and HMOX1 were not altered by the 50% EtOH extract of Graviola leaves.

Determination of S-methyl-L-methionine (SMM) from Brassicaceae Family Vegetables and Characterization of the Intestinal Transport of SMM by Caco-2 Cells

The objectives of the current study were to determine S-methyl-L-methionine (SMM) from various Brassicaceae family vegetables by using validated analytical method and to characterize the intestinal transport mechanism of SMM by the Caco-2 cells. The SMM is well known to provide therapeutic activity in peptic ulcers. The amount of SMM from various Brassicaceae family vegetables ranged from 89.08 ± 1.68 μg/g to 535.98 ± 4.85 μg/g of dry weight by using validated ultra-performance liquid chromatography-electrospray ionization-mass spectrometry method. For elucidating intestinal transport mechanism, the cells were incubated with or without transport inhibitors, energy source, or a metabolic inhibitor. Phloridzin and verapamil as inhibitors of sodium glucose transport protein (SGLT1) and P-glycoprotein, respectively, were not responsible for cellular uptake of SMM. Glucose and sodium azide were not affected by the cellular accumulation of SMM. The efflux ratio of SMM was 0.26, implying that it is not effluxed through Caco-2 cells. The apparent coefficient permeability (P_app ) of SMM was 4.69 × 10^-5 cm/s, indicating that it will show good oral absorption in in vivo.

Pharmacokinetics and Plasma Cellular Antioxidative Effects of Flavanols After Oral Intake of Green Tea Formulated with Vitamin C and Xylitol in Healthy Subjects

This study aimed to test whether green tea formulated with vitamin C and xylitol (GTVX) could improve absorption of flavanols and total antioxidant activity (TAC) of plasma compared with green tea only (GT) in healthy subjects. The total radical-trapping antioxidant parameter method was used to measure the TAC of plasma. Cmax, Tmax, and area under the curve (AUC) of flavanols in plasma after consumption of GTVX were 5980.58 μg/mL, 2.14 h, and 18,915.56 h·μg/mL, respectively, indicating that GTVX showed significantly higher AUC than GT (13,855.43 μg/mL). The peak TACs occurred at 3 and 0.5 h after intake of GT and GTVX, respectively. The TAC of plasma was found to be significantly higher in GTVX than in GT at each time point. This study suggests that formulating green tea with vitamin C and xylitol could increase the absorption of flavanols in green tea, enhancing cellular antioxidative effects.

Cigarette Smoking Condensate Disrupts Endoplasmic Reticulum-Golgi Network Homeostasis Through GOLPH3 Expression in Normal Lung Epithelial Cells

INTRODUCTION

Cigarette smoke (CS) is associated with a broad range of diseases including lung cancer. Many researchers have suggested that cigarette smoke condensate (CSC) may be more toxic compared to cigarette smoke extract (CSE) because CSC contains the lipid-soluble faction of smoke while CSE contains the hydrophilic or gas phase. The aim of this research is to investigate the effects of CSC on the disruption of endoplasmic reticulum (ER)-Golgi homeostasis in normal lung epithelial cells.

METHODS

CS was generated according to the ISO 3308 method. To ascertain the mechanistic effects of CSC on lung toxicity, normal lung epithelial cells of the cell line 16HBE14o- were treated with CSC (0.1mg/mL) for 48 hours. The toxic effects of CSC on ER-Golgi homeostasis and GOLPH3 expression were observed through diverse molecular tools including transmission electron microscope analysis.

RESULTS

Our results demonstrated that CSC treatment increased reactive oxygen species generation in lung cells and led to the alteration of ER-Golgi homeostasis in conjunction with increased autophagy. In particular, GOLPH3, known as an oncogene and a marker protein for the trans-Golgi network, was upregulated in CSC-treated cells. GOLPH3 protein overexpression was also confirmed in the lungs of human lung cancer patients as well as NNK-treated mice.

CONCLUSION

Our study revealed that CSC caused lung damage through the disruption of ER-Golgi homeostasis and autophagy induction. The expression level of the trans-Golgi marker protein GOLPH3 could serve as a reliable bio-indicator for CS-related lung cancer.

IMPLICATIONS

CS is a harmful factor in the development of many diseases including cancer. In this research, we demonstrated that CSC treatment led to malfunction of the ER-Golgi network, with the disrupted ER and Golgi causing GOLPH3 overexpression and abnormal autophagy accumulation. In addition, although the value of GOLPH3 as a predictor remains to be fully elucidated, our data suggest that GOLPH3 levels may be a novel prognostic biomarker of tobacco related lung disease.

Combinational enhancing effects of formulation and encapsulation on digestive stability and intestinal transport of green tea catechins

The hypothesis was that green tea catechins (GTCs) formulated with vitamin C and xylitol followed by enteric coating with hydroxypropyl methyl cellulose phthalate (HPMCP) or encapsulated into γ-cyclodextrin (γ-CD) could enhance intestinal absorption of GTCs. Surface morphology and size obtained by SEM were different. Digestive stability of GTCs encapsulated into γ-CD or coated with HPMCP was enhanced up to 65.56% or 57.63%, respectively. When GTCs were formulated, the digestive stability was greater than the one not formulated. Formulated GTCs followed by encapsulation into γ-CD significantly increased intestinal transport. Absorption of GTCs was 2.8%, 9.64%, 11.97%, 8.41% and 14.36% for only GTCs, GTCs encapsulated into γ-CD, formulated GTCs encapsulated into γ-CD, GTCs coated with HPMCP and formulated GTCs coated with HPMCP, respectively. This study suggests that GTCs, formulated with vitamin C and xylitol followed by γ-CD encapsulation or HPMCP enteric coating, provide combinational effect to increase bioavailability of GTCs.

Microbial bioconversion and processing methods enhance the phenolic acid and flavonoids and the radical scavenging capacity of Smilax china L. leaf

BACKGROUND

It has been reported that Smilax china L. leaf (SCL) provided various biological functions owing to polyphenols. The objective of the current study was to assess the enhancing effect of processing methods and microbial conversions on phenolic acid and flavonoid content and radical scavenging capacity of SCL for potential applications of diverse food products.

RESULTS

Targeted phenolic acid (chlorogenic acid) and flavonoids (piceid and quercetin) were identified in fresh SCL using liquid chromatography-mass spectrometry. The total amount of identified phenolic acid and flavonoids was highest in steamed SCL (12.70 ± 0.12 mg g(-1) on a dry matter basis, dmb). A substantial amount of chlorogenic acid (5.81 ± 0.16 mg g(-1) dmb), piceid (3.96 ± 0.04 mg g(-1) dmb) and quercetin (6.06 ± 0.12 mg g(-1) dmb) were quantified in SCL fermented by Bacillus species, roasted and steamed, respectively (P < 0.05). The oxygen radical absorbance capacity (ORAC) value was greater in microbial fermented SCL than in others, with the exception of Saccharomyces cerevisiae and Aspergillus oryzae. However, vitamin C equivalent antioxidant capacity (VCEAC) was highest in SCL fermented by Aspergillus oryzae.

CONCLUSION

Results from our study suggest that the microbial fermentation processing method could improve accessibility to extraction of phenolic acids and flavonoid content and radical scavenging capacity.

Activation of sphingosine kinase 2 by endoplasmic reticulum stress ameliorates hepatic steatosis and insulin resistance in mice

The endoplasmic reticulum (ER) is the principal organelle in the cell for protein folding and trafficking, lipid synthesis, and cellular calcium homeostasis. Perturbation of ER function results in activation of the unfolded protein response (UPR) and is implicated in abnormal lipid biosynthesis and development of insulin resistance. In this study, we investigated whether transcription of sphingosine kinase (Sphk)2 is regulated by ER stress-mediated UPR pathways. Sphk2, a major isotype of sphingosine kinase in the liver, was transcriptionally up-regulated by tunicamycin and lipopolysaccharides. Transcriptional regulation of Sphk2 was mediated by activation of activating transcription factor (ATF)4 as demonstrated by promoter assays, immunoblotting, and small interfering RNA analyses. In primary hepatocytes, adenoviral Sphk2 expression elevated cellular sphingosine 1 phosphate (S1P) and activated protein kinase B phosphorylation, with no alteration of insulin receptor substrate phosphorylation. Hepatic overexpression of Sphk2 in mice fed a high-fat diet (HFD) led to elevated S1P and reduced ceramide, sphingomyelin, and glucosylceramide in plasma and liver. Hepatic accumulation of lipid droplets by HFD feeding was reduced by Sphk2-mediated up-regulation of fatty acid (FA) oxidizing genes and increased FA oxidation in liver. In addition, glucose intolerance and insulin resistance were ameliorated by improved hepatic insulin signaling through Sphk2 up-regulation.

CONCLUSION

Sphk2 is transcriptionally up-regulated by acute ER stress through activation of ATF4 and improves perturbed hepatic glucose and FA metabolism.

Houttuynia cordata Extract Improves Physical Endurance Performance by Regulating Endothelial Production of Nitric Oxide

Vascular function is mediated by various regulatory molecules, including endothelial nitric oxide (NO), which regulates the vasodilation of smooth muscle cells. We investigated whether standardized Houttuynia cordata extract (SHCE) could improve physical endurance performance by regulating the endothelial production of NO. For the standardization of Houttuynia cordata (HC) extract, its bioactive components were identified and quantified using ultraperformance liquid chromatography-mass spectrometry. Bioaccessibility and biological activity were measured by the in vitro digestion model system and free radical scavenging capacity, respectively. The vascular function in the endothelium was assessed by the phosphorylation of endothelial nitric oxide synthase (eNOS). A preliminary clinical trial was carried out to assess the physical endurance performance. HC extract was standardized to bioactive components, including chlorogenic acid, rutin, and quercitrin, with the concentration of 5.53, 6.09, and 16.15 mg from 1 g of dry weight, respectively. Bioaccessibility was 33.17%, 31.67%, and 11.18% for chlorogenic acid, rutin, and quercitrin, respectively. Antioxidant activities of SHCE were expressed as vitamin C equivalent antioxidant capacity in 55.81 and 17.23 mg/g of HC extract using ABTS and DPPH scavenging assay, respectively. In human aortic endothelial cells, insulin-mediated phosphorylation of eNOS was increased by SHCE in the presence of palmitate. However, the expression of blood pressure-regulating genes was not altered. The level of blood lactate concentration and the heart rate of subjects who drank SHCE were lower than those of subjects who drank plain water. Oxygen uptake from subjects drinking SHCE was slightly higher than that from those who drank plain water. This study demonstrated that SHCE decreased heart rate and blood lactate, increased oxygen uptake, and improved physical performance, presumably due to the increased NO production.

Growth and migration of LNCaP prostate cancer cells are promoted by triclosan and benzophenone-1 via an androgen receptor signaling pathway

Prostate cancer (PCa) is a global health concern in human males. Recently, it has been known that endocrine-disrupting chemicals (EDCs) may act as an exogenous factor to enhance cancer progression. Triclosan (TCS) and 2,4-dihydroxybenzophenone (BP-1) were reported to bioaccumulate in human bodies through the skin absorption. However, there has been insufficient evidence on the findings that the intervention of EDCs may promote the cancer progression in PCa. In the present study, to verify the risk of TCS and BP-1 to a PCa progression, cancer cell proliferation and migration were investigated in LNCaP PCa cells. TCS and BP-1 increased LNCaP cell proliferative activity and migration as did dihydrotestosterone (DHT). This phenomenon was reversed by the treatment with bicalutamide, a well known AR antagonist, suggesting that TCS and BP-1 acted as a xenoandrogen in LNCaP cells via AR signaling pathway by mimicking the action of DHT. A Western blot assay was performed to identify the alterations in the translational levels of cell growth- and metastasis-related markers, i.e., c-fos, cyclin E, p21, and cathepsin D genes. The expressions of genes related with G1/S transition of cell cycle and metastasis were increased by DHT, TCS, and BP-1, while the expression of p21 protein responsible for cell cycle arrest was reduced by DHT, TCS, and BP-1. Taken together, these results indicated that TCS and BP-1 may enhance the progression of PCa by regulating cell cycle and metastasis-related genes via AR signaling pathway.

Crassaostrea gigas Oyster Shell Extract Inhibits Lipogenesis via Suppression of Serine Palmitoyltransferase

Oysters are widely consumed seafood, but their shells impose a serious environmental problem. To extend the utilization of oyster shell waste, we investigated the biological role of oyster shell extract. In this study, we verified that the ethanol extract of oyster shell (EOS) contains taurine and betaine, the major components of oyster body. EOS downregulated transcription of Sptlc1 and Sptlc2 mRNA, the subunits of serine palmitoyltransferase (SPT). Suppression of SPT subunits reduced sphinganine and sphingomyelin by inhibiting de novo sphingolipid biosynthesis. Inhibition of sphingomyelin biosynthesis resulted in downregulation of lipogenic gene expression such as ACC, FAS, SCD1, and DGAT2. Consistent with inhibition of lipogenesis, cellular triglyceride levels were diminished by EOS, but cholesterol levels were not altered. Taken together, these results suggest that EOS has a lipid-lowering effect and could be applied as either a therapeutic or preventive measure for metabolic dysfunction.

Crassaostrea gigas oyster shell extract inhibits lipogenesis via suppression of serine palmitoyltransferase

Oysters are widely consumed seafood, but their shells impose a serious environmental problem. To extend the utilization of oyster shell waste, we investigated the biological role of oyster shell extract. In this study, we verified that the ethanol extract of oyster shell (EOS) contains taurine and betaine, the major components of oyster body. EOS downregulated transcription of Sptlc1 and Sptlc2 mRNA, the subunits of serine palmitoyltransferase (SPT). Suppression of SPT subunits reduced sphinganine and sphingomyelin by inhibiting de novo sphingolipid biosynthesis. Inhibition of sphingomyelin biosynthesis resulted in downregulation of lipogenic gene expression such as ACC, FAS, SCD1, and DGAT2. Consistent with inhibition of lipogenesis, cellular triglyceride levels were diminished by EOS, but cholesterol levels were not altered. Taken together, these results suggest that EOS has a lipid-lowering effect and could be applied as either a therapeutic or preventive measure for metabolic dysfunction.

Oxidative Stress Induced by Cigarette Smoke Extracts in Human Brain Cells (T98G) and Human Brain Microvascular Endothelial Cells (HBMEC) in Mono- and Co-Culture

The objective of the current study was to examine oxidative stress induced by cigarette smoke extract (CSE) or cigarette smoke condensate (CSC) in human brain cells (T98G) and human brain microvascular endothelial cells (HBMEC) in mono- and co-culture systems. Cell viability of T98G cells exposed to CSC (0.05-4 mg/ml) was significantly decreased compared to CSE (0.025-20%). There were no marked differences between quantities of reactive oxygen species (ROS) generation by either CSE (2, 4, and 10%) or CSC (0.2, 0.4, and 0.8 mg/ml) treatment compared to control. However, a significant effect was noted in ROS generation following CSC incubation at 4mg/ml. Cellular integrity of HBMEC decreased to 74 and 64% within 120 h of exposure at the IC50 value of CSE and CSC, respectively. This study suggests that chronic exposure to cigarette smoking might initiate damage to the blood-brain barrier.