Naturally derived micelles for rapid in vitro screening of potential cholesterol-lowering bioactives

Improved physicochemical and functional properties of dietary fiber from matcha fermented by Trichoderma viride

The low-grade matcha is rich in insoluble dietary fiber. Trichoderma viride was used to increase the soluble dietary fiber to improve its functional properties. The soluble dietary fiber content increased from 6.74% to 15.24%. Pectin, hemicellulose, maltose, d-xylose, and glucose contents increased by 63.35% and 11.54%, 2.18, 0.11, and 7.04 mg/g, respectively. Trichoderma viride fermentation disrupted the dense structure of insoluble dietary fiber, resulting in a honeycomb structure and improving crystallinity by 22.75%. These structural changes led to an improved cation exchange capacity from 1.69 to 4.22 mmol/g, an increase in the inhibitory effect of α-amylase from 47.38% to 72.04%, and a 2.13-fold in the ferrous ion scavenging ability, and the IC50 values of superoxide anion was reduced from 7.00 to 1.54 mg/mL, respectively. Therefore, Trichoderma viride fermentation is an excellent method for improving the quality of dietary fiber in matcha processing by-products.

Suppressive Effect of Coffee Leaves on Lipid Digestion and Absorption In Vitro

BACKGROUND

Coffee leaves are a major source of bioactive components and are used as ethnomedicine. However, despite their traditional medicinal use, information about their effects on antihyperlipidemia remains limited.

METHODS

The aims of this study were to evaluate the main components of leaf extracts from Arabica and Robusta coffees and to examine the potential of these coffee leaves in reducing lipid digestion and absorption in vitro.

RESULTS

Coffee leaf extracts from Arabica coffee contain a high amount of caffeine, whereas extracts from Robusta coffee contain high amounts of chlorogenic acid (CGA) and caffeine. Additionally, leaf extracts from Arabica and Robusta coffee demonstrated the inhibition of pancreatic lipase, decreased micellar cholesterol solubility, and reduced bile acid binding. Furthermore, these extracts resulted in a reduction in cholesterol uptake in Caco-2 cells. Molecular docking experiments supported this discovery, showing CGA and caffeine binding to Niemann-Pick C1-like 1 (NPC1L1), a key protein in cholesterol absorption. The results indicated that CGA and caffeine can competitively bind to NPC1L1 at the cholesterol binding pocket, reducing its cholesterol binding rate. These findings suggest that coffee leaves might help suppress lipid absorption and digestion, highlighting their potential use in preventing and treating hyperlipidemia.

Structural characterization of polysaccharide from the peel of Trichosanthes kirilowii Maxim and its anti-hyperlipidemia activity by regulating gut microbiota and inhibiting cholesterol absorption

The peel of Trichosanthes kirilowii Maxim, is considered one of the primary sources for Trichosanthis pericarpium in traditional Chinese medicine, exhibiting lipid-lowering properties. The impact on hyperlipidemia mice of the crude polysaccharide from the peel of T. Kirilowii (TRP) was investigated in this study. The findings revealed that TRP exhibited a significant improvement in hepatic lipid deposition. Moreover, it significantly decreased serum levels of TC, TG, and LDL-C, while concurrently increasing HDL-C. 16S rRNA amplicon sequencing technique revealed that TRP group exhibited an increased relative abundance of Actinobacteria, a down-regulated relative abundance of Ruminiclostridium, and an up-regulated relative abundance of Ileibacterium. Therefore, TRP might play a role in anti-hyperlipidemia through regulation of the intestinal milieu and enhancement of microbial equilibrium. Consequently, targeted fractionation of TRP resulted in the isolation of a homogeneous acidic polysaccharide termed TRP-1. The TRP-1 polysaccharide, with an average molecular weight of 1.00 × 104 Da, and was primarily composed of Rha, GlcA, GalA, Glc, Gal and Ara. TRP-1 possessed a backbone consisting of alternating connections between → 6)-α-Galp-(1 → 4)-α-Rhap-(1 → 6)-α-Galp-(2 → 6)-β-Galp-(1 → 6)-α-Galp-(2 → 6)-β-Galp-(1 → units and branched chain containing → 6)-α-Glcp-(1→, 2,4)-β-Glcp-(1, and → 4)-α-GlapA-(1→. Both TRP and TRP-1 exhibited significant disruption of cholesterol micelles, highlighting their potential as lipid-lowering agents that effectively inhibit cholesterol absorption pathways.

Organic Nanoparticles in Progressing Cardiovascular Disease Treatment and Diagnosis

Cardiovascular diseases (CVDs), the world's most prominent cause of mortality, continue to be challenging conditions for patients, physicians, and researchers alike. CVDs comprise a wide range of illnesses affecting the heart, blood vessels, and the blood that flows through and between them. Advances in nanomedicine, a discipline focused on improving patient outcomes through revolutionary treatments, imaging agents, and ex vivo diagnostics, have created enthusiasm for overcoming limitations in CVDs' therapeutic and diagnostic landscapes. Nanomedicine can be involved in clinical purposes for CVD through the augmentation of cardiac or heart-related biomaterials, which can be functionally, mechanically, immunologically, and electrically improved by incorporating nanomaterials; vasculature applications, which involve systemically injected nanotherapeutics and imaging nanodiagnostics, nano-enabled biomaterials, or tissue-nanoengineered solutions; and enhancement of sensitivity and/or specificity of ex vivo diagnostic devices for patient samples. Therefore, this review discusses the latest studies based on applying organic nanoparticles in cardiovascular illness, including drug-conjugated polymers, lipid nanoparticles, and micelles. Following the revised information, it can be concluded that organic nanoparticles may be the most appropriate type of treatment for cardiovascular diseases due to their biocompatibility and capacity to integrate various drugs.

Journey into tomorrow: cardiovascular wellbeing transformed by nano-scale innovations

Worldwide, cardiovascular diseases (CVDs) account for the vast majority of deaths and place enormous financial strains on healthcare systems. Gold nanoparticles, quantum dots, polymeric nanoparticles, carbon nanotubes, and lipids are innovative nanomaterials promising in tackling CVDs. In the setting of CVDs, these nanomaterials actively impact cellular responses due to their distinctive properties, including surface energy and topographies. Opportunities to more precisely target CVDs have arisen due to recent developments in nanomaterial science, which have introduced fresh approaches. An in-depth familiarity with the illness and its targeted mechanisms is necessary to use nanomaterials in CVDs effectively. We support the academic community's efforts to prioritize Nano-technological techniques in addressing risk factors linked with cardiovascular diseases, acknowledging the far-reaching effects of these conditions. The significant impact of nanotechnology on the early detection and treatment of cardiovascular diseases highlights the critical need for novel approaches to this pressing health problem, which is affecting people worldwide.

Fermented milks with specific Lactobacillus spp. with potential cardioprotective effects

In vitro and in vivo studies have reported the potential cardioprotective effects of fermented milks (FM). The aim of the present study was to evaluate the inhibitory activities of angiotensin converting enzyme (ACE), thrombin enzyme (TI) and micellar solubility of cholesterol of FM after 24 and 48 h of fermentation with Limosilactobacillus fermentum (J20, J23, J28 and J38), Lactiplantibacillus plantarum (J25) or Lactiplantibacillus pentosus (J34 and J37) exposed to simulated gastrointestinal digestion. Results showed that FM with J20 and J23 at 48 h of fermentation presented significantly (p < 0.05) higher degree of hydrolysis than other FM, and were not significantly different (p > 0.05) between them. Conversely, peptide relative abundance was significantly (p < 0.05) higher in FM with J20 than FM with J23. Moreover, IC₅₀ (protein concentration necessary to inhibit enzyme activity by 50%) for ACE inhibition were 0.33 and 0.5 mg/mL for FM with J20 and J23, respectively. For TI inhibition, the IC₅₀ were 0.3 and 0.24 mg/mL for FM with J20 and J23, respectively. Results exhibited 51 and 74% inhibition of micellar solubility cholesterol for FM with J20 and J23, respectively. Therefore, these results showed that not only peptide abundance, but also specific peptides might be responsible for these potential cardioprotective effects.

Cholesterol-lowering activity of adzuki bean (Vigna angularis) polyphenols

BACKGROUND

Adzuki beans (ABs; Vigna angularis) were reported to show potential for prevention of cholesterol absorption and lowering of the blood cholesterol level. However, the main active compounds and some cellular effects remain unknown. In this study, we evaluated the potential cholesterol-lowering effects of (+)-catechin 7-O-β-D-glucopyranoside (C7G) and (+)-epicatechin 7-O-β-D-glucopyranoside (E7G), identified as abundant polyphenols in ABs.

METHODS AND RESULTS

To investigate the cholesterol-lowering activity in vitro, cholesterol micelles, bile acids, and Caco-2 cells as an intestinal model were used in the study. C7G and E7G each inhibited micellar solubility in a dose-dependent manner, and their inhibitory activity was as strong as that of (+)-catechin (IC₅₀ values: C7G, 0.23 ± 0.03 mg/ml; E7G, 0.22 ± 0.02 mg/ml; (+)-catechin, 0.26 ± 0.11 mg/ml). The AB polyphenols showed binding activity toward bile acids and changed them into an insoluble form. When Caco-2 cells were treated with C7G or E7G, the amount of incorporated cholesterol was significantly decreased compared with vehicle-treated control cells, and no cytotoxicity was observed under the experimental conditions used. Meanwhile, quantitative real-time PCR revealed that the mRNA level of the cholesterol transporter NPC1L1 remained unchanged in the treated cells.

CONCLUSIONS

Taken together, the present findings suggest that C7G and E7G are the main active compounds in ABs, and have the ability to inhibit micellar solubility, bind to bile acids, and suppress cholesterol absorption. The present study supports the health benefits of ABs as a medicinal food and the application of AB polyphenols as medicinal supplements to suppress cholesterol elevation.

Anti-inflammatory, cytotoxicity and antilipidemic properties: novel bioactivities of true cinnamon (Cinnamomum zeylanicum Blume) leaf

Background

The leaf of Ceylon cinnamon (true cinnamon) is traditionally claimed for a variety of health benefits. However, reported scientific information is scanty and needs urgent attention for value addition.

Methods

Ethanolic (95%) and Dichloromethane:Methanol (DM, 1:1 v/v) leaf extracts of Ceylon cinnamon were evaluated for a range of medically important bioactivities namely anti-inflammatory [nitric oxide scavenging activity (NOSA), superoxide scavenging activity (SCA), COX1 and COX2 inhibition], growth inhibition & cytotoxicity against MCF7, HePG2 and AN3CA carcinoma cell lines, glutathionase-S-transferase (GST) inhibition and antilipidemic (anti-HMG-CoA reductase, anti-lipase, anti-cholesterol esterase, and cholesterol micellization inhibition) properties in vitro (n = 3). Further, a range of bioactive compounds in both leaf extracts was also quantified (n = 3).

Results

Both leaf extracts had all the investigated bioactive compounds and possessed moderately potent bioactivities compared to the reference drugs used in the study. Ethanolic leaf extract (ELE) exhibited the highest activities (IC_50: μg/mL) for NOSA (40.26 ± 0.52), SCA (696.24 ± 40.02), cholesterol esterase inhibition (110.19 ± 1.55), cholesterol micellization inhibition (616.69 ± 7.09), GST inhibition (403.78 ± 2.70) and growth inhibition (GI₅₀: 144.84 ± 1.59-269.00 ± 0.51) & cytotoxicity (LC₅₀: 355.44 ± 9.38-717.71 ± 23.69) against studied cancer cell lines. In contrast, COX1 & COX2 (IC_50: 6.62 ± 0.85 and 44.91 ± 3.06 μg/mL) and HMG-CoA reductase & lipase inhibitory activities (36.72 ± 4.74 and 19.71 ± 0.97% inhibition at 200 and 600 μg/mL) were highest in DM extract. ELE also showed the highest quantities (0.81 ± 0.06-104.38 ± 1.79) of tested compounds (mg/g extract) where eugenol was the highest and gallic acid was the lowest among quantified.

Conclusion

Both leaf extracts of Ceylon cinnamon had all the tested bioactive compounds and possess all the investigated bioactivities. This is the 1st study to report all the investigated bioactivities of the leaf of Ceylon Cinnamon.

Effect of oat β-glucan on in vitro digestion characteristics of set- type yogurt

The main objective of the study was to evaluate the effect of added 0.3% (w/w) oat β-glucan (OG) in set-type yogurt on its protein digestion using an in vitro gastrointestinal model. During gastric digestion phase, the amount of soluble proteins and peptides increased to 25% and 40% for control yogurt (yogurt without OG) and 0.3% OG yogurt, respectively. Buccal digestion has little effect on the structure of yogurts, while large spherical vesicles were formed for both control yogurt and 0.3% OG yogurt after gastric digestion. The presence of 0.3% OG promoted the hydrolysis of yogurt in the gastric digestion phase and caused higher antioxidant activity. Compared with that of control yogurt, the inhibition of cholesterol solubility of 0.3% OG yogurt showed no differences after buccal digestion but significantly higher after gastrointestinal digestion (21.3% for gastric and 22.7% for intestinal digestion). Overall, this study enhances the understanding of digestion characteristics of 0.3% OG-fortified set-type yogurt and provides a theoretical basis for the development of this kind of dairy products.

Effect of Roasting Degree, Extraction Time, and Temperature of Coffee Beans on Anti-Hyperglycaemic and Anti-Hyperlipidaemic Activities Using Ultrasound-Assisted Extraction

Coffee consumption has been linked to a low risk of metabolic syndrome. However, evidence supporting its anti-hyperglycaemic and anti-hyperlipidaemic activities remain poorly defined. The ultrasound-assisted extraction (UAE) technique has been shown to achieve high yields of bioactive compounds in coffee, with preserved functionality. The goal of the present study was to determine the effect of various coffee roasting extracts using UAE on their anti-hyperglycaemic and anti-hyperlipidaemic properties. We examined α-amylase and α-glucosidase, micelle size, micelle solubility, and pancreatic lipase activities. Coffee roasting degrees were classified as light coffee (LC), medium coffee (MC), and dark coffee (DC). We showed that DC at 80°C for 10 min, 40°C for 20 min, and 20°C for 20 min has a high potency to inhibit α-amylase, α-glucosidase, and pancreatic lipase activities by 33.79±3.25%, 19.68±1.43%, and 36.63±1.58%, respectively. LC enhanced cholesterol micelle size and suppressed cholesterol micelle solubility, which suggests that coffee roasting may enhance anti-hyperglycaemic and anti-hyperlipidaemic activities.

Nanodiagnosis and Nanotreatment of Cardiovascular Diseases: An Overview

Cardiovascular diseases (CVDs) are the world’s leading cause of mortality and represent a large contributor to the costs of medical care. Although tremendous progress has been made for the diagnosis of CVDs, there is an important need for more effective early diagnosis and the design of novel diagnostic methods. The diagnosis of CVDs generally relies on signs and symptoms depending on molecular imaging (MI) or on CVD-associated biomarkers. For early-stage CVDs, however, the reliability, specificity, and accuracy of the analysis is still problematic. Because of their unique chemical and physical properties, nanomaterial systems have been recognized as potential candidates to enhance the functional use of diagnostic instruments. Nanomaterials such as gold nanoparticles, carbon nanotubes, quantum dots, lipids, and polymeric nanoparticles represent novel sources to target CVDs. The special properties of nanomaterials including surface energy and topographies actively enhance the cellular response within CVDs. The availability of newly advanced techniques in nanomaterial science opens new avenues for the targeting of CVDs. The successful application of nanomaterials for CVDs needs a detailed understanding of both the disease and targeting moieties.

Catechin profile and hypolipidemic activity of Morinda citrifolia leaf water extract

Cardiovascular diseases (CVDs) are silent killers and hyperlipidemia is a high-risk factor. Morinda citrolia leaf (MCL), which is commonly consumed by many cultural groups and has high level of catechins, might exert antihyperlipidemic properties. In this study, the catechins profile of MCL water extract was determined via HPLC and ultraperformance liquid chromatography-traveling wave ion mobility-quadrupole time of flight mass spectrometry (UPLC-TWIMS-QTOF). The major catechin in MCL and the most widely studied catechin with hypolipidemic activity, epigallocatechin gallate (EGCG), was studied in a cytotoxicity test on HepG2 cells prior the in vitro anti-hyperlipidemic assay. The total catechins of MCL reached 141.88 ± 5.04 mg/g, with catechin gallate (CG) (75.27 ± 8.49 mg/g) as the major catechin. Catechin derivatives that were identified include epigallocatechin-3-O-gallate (EGCG) with m/z 459.0912 [M + H]+, epigallocatechin (EGC) with m/z 307.0818 [M + H]+, CG with m/z 443.0976 [M + H]+, epigallocatechin(4β→8)-gallocatechin with m/z 649.0951 [M + K]+, and gallocatechin(4α→8)-epicatechin with m/z 633.1 [M + K]+. Cell inhibitions of MCL, CG and EGCG were more than IC50 of 100 μg/ml. MCL increased LDL-c uptake up to 1.11 ± 0.03-fold, but this was insignificant relative to control. CG and EGCG significantly increased LDL-c uptake up to 1.37 ± 0.19-fold and 1.59 ± 0.19-fold, respectively. Thus, MCL with CG has shown potential for modulating hyperlipidemia.

In Vitro Antithrombotic and Hypocholesterolemic Activities of Milk Fermented with Specific Strains of Lactococcus lactis

Milk fermented with specific lactic acid bacteria (LAB) was reported to be a rich source of metabolites, such as peptides with different biological activities that may have a positive effect on cardiovascular health. Thus, in this study, the antithrombotic and hypocholesterolemic activities of fermented milk with specific strains of Lactococcus lactis were investigated before and after exposure to a simulated gastrointestinal digestion (SGD) model. The inhibition of thrombin-induced fibrin polymerization (IC₅₀ peptide concentration necessary to inhibit thrombin activity by 50%), anticoagulant activity, inhibition of micellar solubility of cholesterol and bile acid binding capacity of water soluble fractions (WSF) <3 kDa from fermented milk were evaluated. Results indicated that the WSF from fermented milk with Lc-572 showed antithrombotic (IC₅₀ = 0.049 mg/mL) and hypocholesterolemic (55% inhibition of micellar solubility of cholesterol and 27% bile acid binding capacity) activities. Meanwhile, fermented milk with Lc-571 showed mainly antithrombotic activity (IC₅₀ = 0.045 mg/mL). On the other hand, fermented milk with Lc-600 presented mainly hypocholesterolemic activity (31.4% inhibition of micellar solubility of and 70% bile acid binding capacity). Moreover, biological activities were not lost after simulated gastrointestinal digestion conditions. Thus, fermented milk with these specific L. lactis strains show potential for the development of functional foods.

Molecular Mechanism by Which Tea Catechins Decrease the Micellar Solubility of Cholesterol

Tea polyphenols lower the levels of cholesterol in the blood by decreasing the cholesterol micellar solubility. To clarify this mechanism, the interactions between taurocholic acid and (-)-epigallocatechin gallate (EGCg) and its derivatives were investigated. ¹³C NMR studies revealed remarkable chemical-shift changes for the carbonyl carbon atom and the 1″- and 4″-positions in the galloyl moiety. Furthermore, ¹H NMR studies using (-)-EGCg derivatives showed that the number of hydroxyl groups on the B ring did not affect these interactions, whereas the carbonyl carbon atom and the aromatic ring of the galloyl moiety had remarkable effects. The configuration at the 2- and 3-positions of the catechin also influenced these interactions, with the trans-configuration resulting in stronger inhibition activity than the cis-configuration. Additionally, a 1:1 component ratio for the catechin-taurocholic acid complex was determined by electrospray ionization-mass spectrometry. These molecular mechanisms contribute to the development of cholesterol-absorption inhibitors.

Siamese neem flower extract suppresses cholesterol absorption by interfering NPC1L1 and micellar property in vitro and in intestinal Caco-2 cells

Siamese neem (Azadirachta indica A. Juss var. siamensis Valeton) (A. indica) leaf extract, a traditional ayurvedic medicine, has been reported to exhibit antipyretic, antibacterial, antidyslipidemic, and antihyperglycemia effects. This study investigated the mechanism of hypocholesterolemic effect of methanolic extract of Siamese neem flowers in in vitro studies and in Caco-2 cells. Pancreatic cholesterol esterase and 3-hydroxy 3-methylglutaryl-CoA (HMG-CoA) reductase activities were assessed. Cholesterol micelle formation was prepared for in vitro cholesterol physicochemical property analyses, micelle size and solubility, and transport of cholesterol into the Caco-2 cells. The expression of niemann-pick C1 like 1 (NPC1L1), and its major regulator, peroxisome proliferator-activated receptor δ (PPARδ), were determined by western blot and real time polymerase chain reaction, respectively. A. indica flower extract inhibited pancreatic cholesterol esterase activity and increased cholesterol micelles size. Uptake of cholesterol into Caco-2 cells was inhibited by A. indica flower extract in a dose-dependent manner. In addition, A. indica extract inhibited HMG-CoA reductase activity, resulting in low level of intracellular cholesterol accumulation, together with increased cytosolic NPC1L1 protein expression and decreased PPARδ gene expression. In conclusion, A. indica flower extract has cholesterol-lowering effects by inhibiting intestinal cholesterol absorption, interfering micellar cholesterol formation, and attenuating cholesterol synthesis. As such, A. indica flower extract has potential for developing into nutraceutical product for prevention of hypocholesterolemia.

Lipid-lowering effects of Coffea arabica pulp aqueous extract in Caco-2 cells and hypercholesterolemic rats

BACKGROUND

Coffea arabica pulp (CP) is the first by-product obtained from coffee berries during coffee processing. The major constituents of CP, including chlorogenic acid, caffeine, and epicatechin exhibit anti-hyperlipidemic effects in in vitro and in vivo models. Whether Coffea arabica pulp aqueous extract (CPE) has a lipid-lowering effect remains unknown.

PURPOSE

This study examined the effect of CPE on cholesterol absorption, and identified the mechanisms involved in lowered cholesterol in in vitro and in vivo models.

METHODS

Uptake of [³H]-cholesterol micelles and the mode of CPE inhibition were determined using human intestinal Caco-2 cells, and subsequently, confirmed using isolated rat jejunal loops. In addition, the 12-week high-fat diet-induced hypercholesterolemic rats (HF) received either CPE (1000  mg/kg BW), a sole and high dose which was selected because it contained approximately 12  mg of CGA that was previously shown to have lipid-lowering effects, or ezetimibe (10  mg/kg BW), a cholesterol inhibitor. The rats were divided into HF, HF  ++ CPE, and HF  ++ ezetimibe groups for the next 12 weeks. Normal rats received a normal diet (ND) and CPE (ND  +  CPE). Body weights and lipid profiles were evaluated. Cholesterol transporter, Niemann-Pick C1-Like 1 (NPC1L1), protein expression and liver X receptor alpha (LXRα) mRNA expression were determined. In vitro micellar complex properties were also investigated.

RESULTS

CPE inhibited [³H]-cholesterol micelle transport in Caco-2 cells and rat jejunal loops in a dose-dependent, non-competitive manner partly by decreasing membrane NPC1L1 expression. Congruently, CPE and its major constituents activated LXRα which, in turn, down-regulated NPC1L1. Furthermore, CPE interfered with physicochemical characteristics of cholesterol mixed micelles. These data were consistent with decreased body weight and slowed body weight gain and improved lipid profiles by CPE in hypercholesterolemic rats while no change occurred in these parameters in normal rats. Down-regulated intestinal NPC1L1 expression mediated by increased LXRα mRNA were also observed in HF  ++ CPE and ND  +  CPE rats.

CONCLUSION

CPE has a cholesterol-lowering effect in in vitro and in vivo via inhibition of intestinal cholesterol absorption by down-regulating NPC1L1 mediated LXRα activation and interfering with micellar complex formation. Accordingly, CPE could be developed as nutraceutical product to prevent dyslipidemia-induced obesity and insulin resistance.

Inhibitory effects of Tiliacora triandra (Colebr.) Diels on cholesterol absorption

Background Natural supplements and herbal medicines have been attracted to use for managing elevated cholesterol levels. Tiliacora triandra (Colebr.) Diels (TT) or Yanang (in Thai) is commonly used as an ingredient in various types of Thai foods. In this study, we investigated the effect of methanolic TT leaf extract on cholesterol absorption by measuring the uptake and the efflux of cholesterol and cholesterol micellar solubility. In addition, we tested the effect of TT leaf extract on pancreatic lipase activity. Methods The uptake and efflux of cholesterol was determined by quantification of radioactivity in differentiated Caco-2 cells after treatment with radioactive cholesterol. Cholesterol mixed micelles were prepared for cholesterol uptake, efflux and solubility studies. The pancreatic lipase activity was determined using 4-methylumbelliferyl oleate as a substrate. Results Our finding showed that TT extract decreased the uptake of cholesterol by approximately 48% but did not affect the efflux of cholesterol. TT inhibited pancreatic lipase activity with the IC50 at 273.5 μg/mL and also decreased cholesterol micellar solubility. Conclusions These findings suggest that TT leaf extract seems to be a potential candidate as cholesterol-lowering agents.

Characterisation of an extract and fractions of Azadirachta indica flower on cholesterol lowering property and intestinal motility

Azadirachta indica has long been used in traditional medicine. This study focused on isolation and characterisation of active ingredients in the extract, its fractions (NF-EA, NF-AQ, NF-G) and its effect on the cholesterol absorption activity. The NF-EA fraction was identified by marker compounds by LC-ESI-QTOF/MS. Cholesterol absorption activity was performed by measuring the solubility and size of cholesterol micelles. The intestinal motility was also examined by isolated rat's ileum to test the contraction. The extract and its fractions consist of flavonoids and phenolic compounds, like quercetin, kaempferol and myricetin. We found that A. indica extract and NF-EA increase cholesterol micelles size, while the extract, NF-AQ, myricetin and quercetin, reduced the solubility of cholesterol in micelles. The extract and quercetin inhibited the contraction induced by KCl up to 29 and 18%, respectively, and also decreased CaCl₂-induced contraction. This finding is in support to traditional uses of A. indica as cholesterol-lowering agents and regulator of gastrointestinal motility.

Bark Extracts of Ceylon Cinnamon Possess Antilipidemic Activities and Bind Bile Acids In Vitro

Ethanol (95%) and dichloromethane : methanol (1 : 1) bark extracts of authenticated Ceylon cinnamon were investigated for range of antilipidemic activities (ALA): HMG-CoA reductase, lipase, cholesterol esterase, and cholesterol micellization inhibitory activities and bile acids binding in vitro. Individual compounds in bark extracts were also evaluated. Bark extracts showed ALA in all the assays studied. The IC₅₀ (μg/mL) values ranged within 153.07 ± 8.38–277.13 ± 32.18, 297.57 ± 11.78–301.09 ± 4.05, 30.61 ± 0.79–34.05 ± 0.41, and 231.96 ± 9.22–478.89 ± 9.27, respectively, for HMG-CoA reductase, lipase, cholesterol esterase, and cholesterol micellization inhibitory activities. The bile acids binding (3 mg/mL) for taurocholate, glycodeoxycholate, and chenodeoxycholate ranged within 19.74 ± 0.31–20.22 ± 0.31, 21.97 ± 2.21–26.97 ± 1.61, and 16.11 ± 1.42–19.11 ± 1.52%, respectively. The observed ALA were moderate compared to the reference drugs studied. Individual compounds in bark extracts ranged within 2.14 ± 0.28–101.91 ± 3.61 and 0.42 ± 0.03–49.12 ± 1.89 mg/g of extract. Cinnamaldehyde and gallic acid were the highest and the lowest among the tested compounds. The ethanol extract had highest quantity of individual compounds and ALA investigated. Properties observed indicate usefulness of Ceylon cinnamon bark in managing hyperlipidemia and obesity worldwide. Further, this study provides scientific evidence for the traditional claim that Ceylon cinnamon has antilipidemic activities.

Phyllanthus Niruri Standardized Extract Alleviates the Progression of Non-Alcoholic Fatty Liver Disease and Decreases Atherosclerotic Risk in Sprague-Dawley Rats

Non-alcoholic fatty liver disease (NAFLD) is one of the major global health issues, strongly correlated with insulin resistance, obesity and oxidative stress. The current study aimed to evaluate anti-NAFLD effects of three different extracts of Phyllanthus niruri (P. niruri). NAFLD was induced in male Sprague-Dawley rats using a special high-fat diet (HFD). A 50% methanolic extract (50% ME) exhibited the highest inhibitory effect against NAFLD progression. It significantly reduced hepatomegaly (16%) and visceral fat weight (22%), decreased NAFLD score, prevented fibrosis, and reduced serum total cholesterol (TC) (48%), low-density lipoprotein (LDL) (65%), free fatty acids (FFAs) (25%), alanine aminotransferase (ALT) (45%), alkaline phosphatase (ALP) (38%), insulin concentration (67%), homeostatic model assessment of insulin resistance (HOMA-IR) (73%), serum atherogenic ratios TC/high-density lipoprotein (HDL) (29%), LDL/HDL (66%) and (TC-HDL)/HDL (64%), hepatic content of cholesterol (43%), triglyceride (29%) and malondialdehyde (MDA) (40%) compared to a non-treated HFD group. In vitro, 50% ME of P. niruri inhibited α-glucosidase, pancreatic lipase enzymes and cholesterol micellization. It also had higher total phenolic and total flavonoid contents compared to other extracts. Ellagic acid and phyllanthin were identified as major compounds. These results suggest that P. niruri could be further developed as a novel natural hepatoprotective agent against NAFLD and atherosclerosis.

Comparative Pharmacokinetic Profiles of Three Protoberberine-type Alkaloids from Raw and Bile-processed Rhizoma coptidis in Heat Syndrome Rats

Background:

The Bile-processed Rhizoma coptidis (BRC), which has a colder drug property than Rhizoma coptidis (RC), is widely used for the treatment of heat syndrome. We compared the pharmacokinetics of the protoberberine-type alkaloids in BRC and RC in rats with heat syndrome to elucidate the bile-processing mechanism.

Material and Methods:

We established a rapid and sensitive method for simultaneously determining three alkaloids: berberine, palmatine, and jatrorrhizine, in rat plasma based on ultra-performance liquid chromatography/tandem mass spectrometry. The separation was carried out on a Waters ACQUITY BEA C₁₈ column. The mobile phase consisted of acetonitrile (containing 0.1% formic acid) and water (containing 0.1% formic acid and 10 mmol/L ammonium acetate) and carbamazepine was used as an internal standard. The detection was carried out in a multiple reaction monitoring mode (MRM) using electrospray ionization in the positive ion mode.

Results:

Pharmacokinetic profiles indicated that the C_max of berberine and palmatine increased two times and the T_max of the three alkaloids decreased three times after bile processing. AUC_0→∞ and AUC_0→t of the alkaloids were similar between RC and BRC.

Conclusion:

The results suggest that bile processing could increase the absorption rate of alkaloids. This study broadens our understanding of Chinese herbal medicine processing.

SUMMARY

Contents of berberine, palmatine and jatrorrhizine, in heat syndrome rats’ plasma between the raw and bile-processed Rhizoma coptidis (RC) were determined by UPLC-MS/MS.

The whole pharmacokinetic profiles of three alkaloids in the bile-processed Rhizoma coptidis (BRC) were similar to those of RC.

The shorter T_max and increased 2-fold C_max were obtained after RC bile-processing.

Bile-processing could promote the absorption rate of alkaloids in a certain degree.

Abbreviation Used: RC: Rhizoma coptidis, BRC: Bile-processed Rhizoma coptidis, HPLC: high-performance liquid chromatography, UPLC-MS/MS: ultra-performance liquid chromatography-mass spectrometry/ mass spectrometry, LC-MS: liquid chromatography-mass spectrometry, MRM: multiple reaction monitoring mode, QC: quality control, RE: relative error, RSD: relative standard deviation, C_max: maxium of drug concentration, T_max: time for maxium of drug concentration, AUC: area under concentration-time curve, LLOQ: Linearity and lower limits of quantification, t_1/2: half-life, Clz: body clearance

Hypocholesterolemic effect of sericin-derived oligopeptides in high-cholesterol fed rats

The beneficial effect of cholesterol-lowering proteins and/or peptides derived from various dietary sources is continuously reported. A non-dietary protein from silk cocoon, sericin, has also demonstrated cholesterol-lowering activity. A sericin hydrolysate prepared by enzymatic hydrolysis was also expected to posses this effect. The present study was aimed at investigating the cholesterol-lowering effect of sericin peptides, so called "sericin-derived oligopeptides" (SDO) both in vivo and in vitro. The results showed that SDO at all three doses tested (10 mg kg^-1 day^-1, 50 mg kg^-1 day^-1, and 200 mg kg^-1 day^-1) suppressed serum total and non-HDL cholesterol levels in rats fed a high-cholesterol diet. Triglyceride and HDL-cholesterol levels were not significantly changed among all groups. The fecal contents of bile acids and cholesterol did not differ among high-cholesterol fed rats. SDO dose-dependently reduced cholesterol solubility in lipid micelles, and inhibited cholesterol uptake in monolayer Caco-2 cells. SDO also effectively bound to all three types of bile salts including taurocholate, deoxytaurocholate, and glycodeoxycholate. Direct interaction with bile acids of SDO may disrupt micellar cholesterol solubility, and subsequently reduce the absorption of dietary cholesterol in intestines. Taking all data together, SDO or sericin peptides exhibit a beneficial effect on blood cholesterol levels and could be potentially used as a health-promoting dietary supplement or nutraceutical product.

Spirogyra neglecta inhibits the absorption and synthesis of cholesterol in vitro

Background

Spirogyra neglecta (SN) has many nutritional benefits and it is commonly used to ameliorate different human conditions including inflammation, gastric ulcer, hyperglycemia, and hyperlipidemia. However, the mechanism of the hypocholesterolemic effect of SN still remains unclear. Therefore, the present study was aimed to evaluate the effect of SN extract particularly on cholesterol absorption and synthesis mechanisms.

Methods

For cholesterol absorption, the uptake of cholesterol was measured by using tritium radiolabeling of cholesterol in Caco-2 cells. Bile acid binding, micelles size, and cholesterol solubility were analyzed in in vitro assays, while cholesterol synthesis was evaluated by using a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase assay kit.

Results

SN extract was found to decrease cholesterol uptake in Caco-2 cells and decreased the solubility of cholesterol in micelles. The SN extract bound to taurocholate, taurodeoxycholate, and glycodeoxycholate bile acids, and increased micelles size. SN has also demonstrated an inhibitory effect on HMG-CoA reductase (HMGR) enzymatic activity. For further experimentation, the treatment combination of SN and ezetimibe (0.04 mg/mL) showed a greater significant reduction in cholesterol uptake than the extract alone.

Conclusion

These observations suggested that inhibitory cholesterol absorption effects of SN could be mediated through the modulation of size and solubility of cholesterol micelles, resulting in interference of cholesterol uptake. In addition, SN inhibited the rate limiting step of cholesterol synthesis. This study provides supporting evidence for the potential usage of SN as a cholesterol lowering agent.

The hypolipidemic effect and antithrombotic activity of Mucuna pruriens protein hydrolysates

Hydrolysates and peptide fractions (PF) obtained fromM. pruriensprotein concentrates with commercial and digestive enzymatic systems were studied for their hypolipidemic and antithrombotic activities.

Simulated gastrointestinal digestion, intestinal permeation and plasma protein interaction of white, green, and black tea polyphenols

The gastrointestinal digestion, intestinal permeation, and plasma protein interaction of polyphenols from a single tea cultivar at different stages of processing (white, green, and black teas) were simulated. The salivary phase contained 74.8-99.5% of native polyphenols, suggesting potential bioavailability of significant amounts of antioxidants through the oral mucosal epithelium that might be gastric sensitive and/or poorly absorbed in the intestine. White tea had the highest content and provided the best intestinal bioaccessibility and bioavailability for catechins. Since most of native catechins were not absorbed, they were expected to accumulate in the intestinal lumen where a potential inhibition capacity of cellular glucose and cholesterol uptake was assumed. The permeated catechins (approximately, 2-15% of intestinal levels) significantly bound (about 37%) to plasma HDLs, suggesting a major role in cholesterol metabolism. White tea and its potential nutraceuticals could be effective in the regulation of plasma glucose and cholesterol levels.

In vivo efficacy of HDL-like nanolipid particles containing multivalent peptide mimetics of apolipoprotein A-I

We have observed that molecular constructs based on multiple apoA-I mimetic peptides attached to a branched scaffold display promising anti-atherosclerosis functions in vitro. Building on these promising results, we now describe chronic in vivo studies to assess anti-atherosclerotic efficacy of HDL-like nanoparticles assembled from a trimeric construct, administered over 10 weeks either ip or orally to LDL receptor-null mice. When dosed ip, the trimer-based nanolipids markedly reduced plasma LDL-cholesterol levels by 40%, unlike many other apoA-I mimetic peptides, and were substantially atheroprotective. Surprisingly, these nanoparticles were also effective when administered orally at a dose of 75 mg/kg, despite the peptide construct being composed of l-amino acids and being undetectable in the plasma. The orally administered nanoparticles reduced whole aorta lesion areas by 55% and aortic sinus lesion volumes by 71%. Reductions in plasma cholesterol were due to the loss of non-HDL lipoproteins, while plasma HDL-cholesterol levels were increased. At a 10-fold lower oral dose, the nanoparticles were marginally effective in reducing atherosclerotic lesions. Intriguingly, analogous results were obtained with nanolipids of the corresponding monomeric peptide. These nanolipid formulations provide an avenue for developing orally efficacious therapeutic agents to manage atherosclerosis.

Black rice and anthocyanins induce inhibition of cholesterol absorption in vitro

Black rice (Oryza sativa L.) is often associated with blood lipid control. This study systematically assessed the inhibition of cholesterol absorption in vitro by black rice and explored cholesterol-lowering compounds present in this rice. Our results indicated that black rice extracts (BRE), which were aqueous, ethanol extracts and a fraction of macroporous resin caused the reduction of cholesterol absorption by inhibiting pancreatic lipase, decreasing the micellar cholesterol solubility and suppressing cholesterol uptake in Caco-2 cells. The inhibitory activity was positively associated with anthocyanin (cyanidin-3-glucoside (Cy-3-G) and peonidin-3-glucoside (Pn-3-G)) contents of the extracts. Therefore, the cholesterol absorption inhibiting properties of anthocyanins were further explored. The IC50 values of Cy-3-G and Pn-3-G against pancreatic lipase were 42.53 ± 4.45 and 18.13 ± 4.22 μg mL(-1), respectively. Kinetic analysis suggested that the enzymatic inhibitory mode of Cy-3-G and Pn-3-G belonged to the competitive type. In mixed micelles, Cy-3-G and Pn-3-G dose dependently reduced the solubility of cholesterol. Meanwhile, a potential mechanism of cholesterol reduction by anthocyanins was investigated. Results showed that anthocyanins led to precipitation of cholesterol from micellar solution, which may induce the reduction of cholesterol. In Caco-2 cells, Cy-3-G and Pn-3-G (40 μg mL(-1)) exhibited a significant reduction in cholesterol uptake, and the degree of this reduction was almost the same as that observed in the group treated with Ezetimibe at the same concentration. These findings provide important evidence that anthocyanins may partly contribute to the inhibitory effects of black rice on cholesterol absorption, and thus may be applied for the prevention and treatment of hypercholesterolaemia.

In vitro hypoglycaemic and hypolipidemic potential of white tea polyphenols

The leaves at different processing stages of a single tea cultivar in order to obtain white (WT), green (GT) and black tea (BT) samples, were analysed. The capacities of tea polyphenolics to influence the glucose and lipid metabolism in HepG2 cell lines were evaluated. WT appeared the most active in reducing the glucose and cholesterol uptake (+17.7% and +32.4% in the glucose and cholesterol cell medium concentration, respectively). Incubation with WT enhanced LDL receptor binding activity by 40% (+20% for GT and +0% for BT) and led to an increase in HDL cell medium concentration of 33.3% (+20% for GT and +0% for BT). Finally, WT revealed the best inhibition capacity against lipase activity, and triglyceride levels in the cell medium increased by 400% (+382.6% for GT and +191.3% for BT). The present study intended to contribute to the little knowledge about the potential health benefits of white tea in individuals affected by metabolic syndrome.

Mechanisms and prospects of food protein hydrolysates and peptide-induced hypolipidaemia

Hyperlipidaemia is an important risk factor for developing cardiovascular disease, a leading global health issue. While pharmaceutical interventions have proved efficacious in acute conditions, many hypolipidaemic drugs are known to induce adverse side effects. Due to a strong positive link between functional food components and human health, emerging research has explored the application of natural food-based strategies in disease management. One of such strategies involves the use of food proteins as precursors of peptides with a wide variety of beneficial health functions. Some plant, animal and marine-derived protein hydrolysates and peptides have shown promising hypolipidaemic properties when evaluated in vitro, in cultured mammalian cells and animal models. The products exert their functions via bile acid-binding and disruption of cholesterol micelles in the gastrointestinal tract, and by altering hepatic and adipocytic enzyme activity and gene expression of lipogenic proteins, which can modulate aberrant physiological lipid profiles. The activity of the protein hydrolysates and peptides depends on their physicochemical properties including hydrophobicity of amino acid residues but there is knowledge gap on detailed structure-function relationships and efficacy in hyperlipidaemic human subjects. Based on the prospects, commercial functional food products containing hypolipidaemic peptides have been developed for enhancement of cardiovascular health.

Concentration-dependent displacement of cholesterol in micelles by hydrophobic rice bran protein hydrolysates

BACKGROUND

Rice bran, containing about 100-150 g kg(-1) protein, is a by-product of rice milling that has only become an available ingredient in recent years owing to the centralisation of rice milling. Rice bran, but not its protein fraction or hydrolysates, has been shown to have a hypocholesterolaemic effect. Peptides from soy, milk and other foods have been proposed to have hypocholesterolaemic effects based on their ability to lower cholesterol solubility in bile acid/phosphotidyl choline micelles.

RESULTS

Rice bran protein hydrolysates (RBPHs) were prepared and investigated for their potential to lower cholesterol concentration in micelles. The RBPHs were produced by digestion using four different peptidases, alcalase 2.4L(®), neutrase 0.8L(®), papaya latex papain and porcine pancreas trypsin, and then fractionated by hydrophobicity using styrene/divinylbeneze resins. Alcalase 2.4L(®) produced the highest degree of hydrolysis, and the resulting hydrolysates had the highest micellar cholesterol inhibition ability in an in vitro hypocholesterolaemic test. The adsorption dynamics of four different macroporous resins, DA201-C, Sepabeads SP207 and SP825 and Diaion HP20, were determined using the Langmuir isotherm model. DA201-C had the highest adsorption capacity with an equilibrium concentration of 220 mg g(-1). The hydrolysates eluted with 25, 50, 75 and 95% (v/v) ethanol lowered the micellar cholesterol concentration by 11.88, 14.76, 19.37 and 7.56% respectively.

CONCLUSION

A hydrophobic fraction of RBPH had the highest inhibitory activity on micellar cholesterol, which suggests that it may have hypocholesterolaemic properties.

Cholesterol-lowering activity of the major polyphenols in grape seed

The major polyphenols in grape seed have been shown to have beneficial health effects in the prevention of dyslipidemia and cardiovascular diseases. In this present study, we investigated the cholesterol-lowering activity of three major polyphenolic compounds found in grape seed. The results showed that gallic acid, catechin, and epicatechin significantly inhibited pancreatic cholesterol esterase in a concentration-dependent manner. Moreover, they bound to taurocholic acid, taurodeoxycholic acid, and glycodeoxycholic acid at levels ranging from 38.6% to 28.2%. At the concentration of 0.2 mg/mL, gallic acid, catechin, and epicatechin reduced the formation of cholesterol micelles 27.26 ± 2.17%, 11.88 ± 0.75%, and 19.49 ± 3.71%, respectively. These findings clearly demonstrate that three major polyphenolic compounds present in a particular grape seed have cholesterol-lowering activity by inhibiting pancreatic cholesterol esterase, binding of bile acids, and reducing solubility of cholesterol in micelles which may result in delayed cholesterol absorption.

When cholesterol is not cholesterol: a note on the enzymatic determination of its concentration in model systems containing vegetable extracts

BACKGROUND

Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts.

RESULTS

By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on cholesterol partition. Evidenced interferences were analyzed by studying specific and unspecific inhibitors of cholesterol oxidase-peroxidase coupled reaction. Cholesterol was also quantified by LC/MS. We found a significant interference of diverse (cocoa and tea-derived) extracts over this method. The interference was strongly dependent on model matrix: while as in phosphate buffered saline, the development of unspecific fluorescence was inhibitable by catalase (but not by heat denaturation), suggesting vegetable extract derived H(2)O(2) production, in bile-containing model systems, this interference also comprised cholesterol-oxidase inhibition. Several strategies, such as cholesterol standard addition and use of suitable blanks containing vegetable extracts were tested. When those failed, the use of a mass-spectrometry based chromatographic assay allowed quantification of cholesterol in models of duodenal contents in the presence of vegetable extracts.

CONCLUSIONS

We propose that the use of cholesterol-oxidase and/or peroxidase based systems for cholesterol analyses in foodstuffs should be accurately monitored, as important interferences in all the components of the enzymatic chain were evident. The use of adequate controls, standard addition and finally, chromatographic analyses solve these issues.

Insoluble fraction of buckwheat (Fagopyrum esculentum Moench) protein possessing cholesterol-binding properties that reduce micelle cholesterol solubility and uptake by Caco-2 cells

Buckwheat (Fagopyrum esculentum Moench) protein (BWP) exhibits hypocholesterolemic activity in several animal models by increasing fecal excretion of neutral and acidic sterols. In the current study, the ability of BWP to disrupt micelle cholesterol solubility by sequestration of cholesterol was investigated. When BWP (0.2%) was incubated with cholesterol and micelle lipid components prior to micelle formation, cholesterol solubility was reduced 40%. In contrast, cholesterol solubility was not decreased when BWP (0.2%) was incubated after micelle formation and incorporation of soluble cholesterol. Buckwheat flour, from which BWP was derived, had no significant effect on cholesterol solubility. Cholesterol uptake in Caco-2 cells from micelles made in the presence of BWP (0.2%) was reduced by 47, 36, 35, and 33% when compared with buckwheat flour, bovine serum albumin, casein, and gelatin, respectively. Reduction in cholesterol uptake in Caco-2 cells was dose-dependent, with maximum reductions at 0.1-0.4% BWP. In cholesterol-binding experiments, 83% of the cholesterol was associated with an insoluble BWP fraction, indicating strong cholesterol-binding capacity that disrupts solubility and uptake by Caco-2 cells.