White tea and its active polyphenols lower cholesterol through reduction of very-low-density lipoprotein production and induction of LDLR expression

Immature carob pods extract and its fractions prevent lipid metabolism disorders and lipoprotein-rich plasma oxidation in mice: A phytochemical and pharmacological study

ETHNOPHARMACOLOGICAL RELEVANCE

In Morocco carob fruits are used traditionally to treat hypercholesterolemia, diabetes and related diseases.

AIMS

This study was designed to evaluate the hypolipidemic activity of Ceratonia siliqua green pods extract and its fractions in Triton WR-1339 and high fat/cholesterol diet (HFCD) induced hyperlipidemia mice, as well as their ability to prevent lipoproteins oxidation in vitro.

MATERIALS AND METHODS

High performance liquid chromatography (HPLC) analysis was used to determine the phenolic composition of the immature carob pods extract (HWCE). Antioxidant activities were evaluated using the DPPH radical scavenging test as well as MDA measurement in oxidized lipoprotein rich plasma. Plasma lipids, glucose and biliary total cholesterol, as well as lipids level in liver and feces, were analyzed. The acute oral toxicity was performed in mice single dosed with the HWCE at 2000 and 5000 mg/kg body weight.

RESULTS

HPLC analysis shows that gallic acid is the main phenolic compound in the HWCE. The acute oral toxicity assessment revealed that the HWCE is not toxic (LD50 is greater than 5000 mg/kg body weight). In the acute hypolipidemic study, mice treated with the HWCE and its fractions exhibited a significant (P < 0.001) reduction in plasma total cholesterol (TC), triglycerides (TG) and low density lipoprotein-cholesterol (LDL-C) levels. Importantly, immature carob aqueous extract was more effective in lowering mice hypercholesterolemia than its fractions. Indeed, mice fed the HFCD for 12 weeks showed a significant raise in plasma TC, TG and LDL-C, as well as in hepatic and fecal TC and TG levels. The HWCE at 100 and 200 mg/kg body weight significantly (P < 0.001) reversed the plasmatic levels of these lipid parameters, increased plasma HDL-C level, reduced hepatic lipids accumulation, but increased cholesterol level in the bile and fecal lipids excretion. The HWCE decreased also the atherogenic index, the LDL-C/HDL-C ratio and plasma glucose level after 12 weeks' experiment. On the other hand, the HWCE was more effective in preventing mice lipoprotein-rich plasma oxidation than its fractions, with a concentration-dependent manner.

CONCLUSION

C. siliqua green fruits extract could be effective in preventing atherosclerosis and related cardiovascular complications through the inhibition of lipoprotein oxidation and cholesterol clearance.

Tea's anti-obesity properties, cardiometabolic health-promoting potentials, bioactive compounds, and adverse effects: A review focusing on white and green teas

Tea is one of the most commonly consumed beverages in the world. Morocco, Japan, and China have consumed green tea for centuries. White tea, which is a variety of green teas, is very popular in China and is highly revered for its taste. Presently, both teas are consumed in other countries around the world, even as functional ingredients, and novel research is constantly being conducted in these areas. We provide an update on the health benefits of white and green teas in this review, based on recent research done to present. After a general introduction, we focused on tea's anti-obesity and human health-promoting potential, adverse effects, and new approaches to tea and its bioactive compounds. It has been found that the health benefits of tea are due to its bioactive components, mainly phenolic compounds. Of these, catechins are the most abundant. This beverage (or its extracts) has potential anti-inflammatory and antioxidant properties, which could contribute to body weight control and the improvement of several chronic diseases. However, some studies have mentioned the possibility of toxic effects; therefore, reducing tea consumption is a good idea, especially during the last trimester of pregnancy. Additionally, new evidence will provide insight into the possible effects of tea on the human gut microbiota, and even on the viruses responsible for SARS-CoV-2. A beverage such as this may favor beneficial gut microbes, which may have important implications due to the influence of gut microbiota on human health.

Hypolipidemic and Anti-Inflammatory Effects of Curcuma longa-Derived Bisacurone in High-Fat Diet-Fed Mice

Turmeric (Curcuma longa) contains various compounds that potentially improve health. Bisacurone is a turmeric-derived compound but has been less studied compared to other compounds, such as curcumin. In this study, we aimed to evaluate the anti-inflammatory and lipid-lowering effects of bisacurone in high-fat diet (HFD)-fed mice. Mice were fed HFD to induce lipidemia and orally administered bisacurone daily for two weeks. Bisacurone reduced liver weight, serum cholesterol and triglyceride levels, and blood viscosity in mice. Splenocytes from bisacurone-treated mice produced lower levels of the pro-inflammatory cytokines IL-6 and TNF-α upon stimulation with a toll-like receptor (TLR) 4 ligand, lipopolysaccharide (LPS), and TLR1/2 ligand, Pam3CSK4, than those from untreated mice. Bisacurone also inhibited LPS-induced IL-6 and TNF-α production in the murine macrophage cell line, RAW264.7. Western blot analysis revealed that bisacurone inhibited the phosphorylation of IKKα/β and NF-κB p65 subunit, but not of the mitogen-activated protein kinases, p38 kinase and p42/44 kinases, and c-Jun N-terminal kinase in the cells. Collectively, these results suggest that bisacurone has the potential to reduce serum lipid levels and blood viscosity in mice with high-fat diet-induced lipidemia and modulate inflammation via inhibition of NF-κB-mediated pathways.

Fresh and Browned Lotus Root Extracts Promote Cholesterol Metabolism in FFA-Induced HepG2 Cells through Different Pathways

Browning of fresh-cut plants is mainly attributed to the enzymatic browning of phenolic compounds induced by polyphenol oxidase (PPO), producing browning products such as anthraquinones, flavanol oxides, and glycosides, which are usually considered to be non-toxic. Could browning bring any benefits on behalf of their bioactivity? Our previous study found that browned lotus root extracts (BLREs) could reduce the cholesterol level in obese mice as fresh lotus root extracts (FLREs) did. This study aimed to compare the mechanisms of FLRE and BLRE on cholesterol metabolism and verify whether the main component's monomer regulates cholesterol metabolism like the extracts do through in vitro experiments. Extracts and monomeric compounds are applied to HepG2 cells induced by free fatty acids (FFA). Extracellular total cholesterol (TC) and triglyceride (TG) levels were also detected. In addition, RT-PCR and Western blot were used to observe cholesterol metabolism-related gene and protein expression. The in vitro results showed that BLRE and FLRE could reduce TC and TG levels in HepG2 cells. In addition, BLRE suppressed the synthesis of cholesterol. Meanwhile, FLRE promoted the synthesis of bile acid (BA) as well as the clearance and efflux of cholesterol. Furthermore, the main monomers of BLRE also decreased cholesterol synthesis, which is the same as BLRE. In addition, the main monomers of FLRE promoted the synthesis of BAs, similar to FLRE. BLRE and FLRE promote cholesterol metabolism by different pathways.

White tea alleviates non-alcoholic fatty liver disease by regulating energy expenditure and lipid metabolism

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of liver disease, which lacks effective treatments. Abnormal lipid metabolism and inflammation are the most prominent pathological manifestations of NAFLD. Recently, it has been reported that white tea extract (WTE) can regulate lipid metabolism in human adipocytes and liver cancer cells in vitro. However, its beneficial effects on NAFLD and the underlying mechanisms remain largely unknown. Here, we showed that WTE alleviated obesity, lipid accumulation, hepatic steatosis, and liver injury in a mouse model of NAFLD. Mechanistically, we demonstrated that WTE exerted the anti-NAFLD effect by decreasing the expression of genes involved in lipid transport and synthesis processes while activating genes associated with energy expenditure. In addition, a comparison of the transcriptional responses of WTE with that of green tea extract (GTE) revealed that WTE can not only regulate lipid metabolism and stress response like GTE but also regulate antioxidant and inflammatory pathways more effectively. Taken together, our findings demonstrate that WTE inhibits the progression of NAFLD in a mouse model and indicate that WTE can be a potential dietary intervention for NAFLD.

Epigallocatechin gallate: Phytochemistry, bioavailability, utilization challenges, and strategies

Epigallocatechin gallate (EGCG), a green tea catechin, has gained the attention of current study due to its excellent health-promoting effects. It possesses anti-obesity, antimicrobial, anticancer, anti-inflammatory activities, and is under extensive investigation in functional foods for improvement. It is susceptible to lower stability, lesser bioavailability, and lower absorption rate due to various environmental, processing, formulations, and gastrointestinal conditions of the human body. Therefore, it is the foremost concern for the researchers to enhance its bioactivity and make it the most suitable therapeutic compound for its clinical applications. In the current review, factors affecting the bioavailability of EGCG and the possible strategies to overcome these issues are reviewed and discussed. This review summarizes structural modifications and delivery through nanoparticle-based approaches including nano-emulsions, encapsulations, and silica-based nanoparticles for effective use of EGCG in functional foods. Moreover, recent advances to enhance EGCG therapeutic efficacy by specifically targeting its molecules to increase its bioavailability and stability are also described. PRACTICAL APPLICATIONS: The main green tea constituent EGCG possesses several health-promoting effects making EGCG a potential therapeutic compound to cure ailments. However, its low stability and bioavailability render its uses in many disorders. Synthesizing EGCG prodrugs by structural modifications helps against its low bioavailability and stability by overcoming premature degradation and lower absorption rate. This review paper summarizes various strategies that benefit EGCG under different physiological conditions. The esterification, nanoparticle approaches, silica-based EGCG-NPs, and EGCG formulations serve as ideal EGCG modification strategies to deliver superior concentrations with lesser toxicity for its efficient penetration and absorption across cells both in vitro and in vivo. As a result of EGCG modifications, its bioactivities would be highly improved at lower doses. The protected or modified EGCG molecule would have enhanced potential effects and stability that would contribute to the clinical applications and expand its use in various food and cosmetic industries.

Perchlorate contamination of tea leaves and a corresponding probabilistic dietary risk assessment using Monte Carlo simulation

Perchlorate is known as a thyroid disrupter. Its contamination in various tea samples was monitored, and 286 samples belonging to four types of tea leaves were analysed. The detection rate of perchlorate in tea was 99.3%. The mean concentration in different tea types decreased in order from green tea, oolong tea, white tea to black tea. A probabilistic approach was performed to evaluate the dietary exposure of perchlorate for six different subpopulations. The daily intakes (EDIs) for consumers over the age of 41 were higher than that of other subpopulations. The hazard quotient for six groups was lower than 1 even at the extreme percentile (P99). It indicates that the risk of dietary exposure to perchlorate from tea consumption for Fujian people is acceptable without considering other foodstuffs. However, the high occurrence of perchlorate in tea samples suggested that the actual source of this contaminant should be further investigated.

Effects of Nigella sativa, Camellia sinensis, and Allium sativum as Food Additives on Metabolic Disorders, a Literature Review

Objective: Metabolic disorders (MD) can disturb intracellular metabolic processes. A metabolic disorder can be resulted from enzyme deficits or disturbances in function of various organs including the liver, kidneys, pancreas, cardiovascular system, and endocrine system. Some herbs were used traditionally for spices, food additives, dietary, and medicinal purposes. Medicinal plants possess biological active compounds that enhance human health. We aimed to provide evidence about therapeutic effects of some medicinal herbs on MD.

Data Sources: PubMed, Scopus, and Google Scholar were explored for publications linked to MD until February 2021. The most literature reports that were published in the last 10 years were used. All types of studies such as animal studies, clinical trials, and in vitro studies were included. The keywords included “Metabolic disorders,” “Nigella sativa L.,” “Thymoquinone,” “White tea”OR “Camellia sinensis L.” “catechin,” and “Allium sativum L.” OR “garlic” were searched.

Results: Based on the results of scientific studies, the considered medicinal plants and their active components in this review have been able to exert the beneficial therapeutic effects on obesity, diabetes mellitus and non-alcoholic fatty liver disease.

Conclusions: These effects are obvious by inhibition of lipid peroxidation, suppression of inflammatory reactions, adjustment of lipid profile, reduction of adipogenesis and regulation of blood glucose level.

Chemical Composition, Protective Effects, and Mechanisms of Volatile Oil from Fructus Gleditsiae Abnormalis with Nasal Administration against Ischemic Injury in HFD and MCAO-Induced Rats

Fructus Gleditsiae Abnormalis (FGA) has been used as a traditional Chinese medicine (TCM) for the treatment of stroke caused by phlegm and blood stasis. However, its substance basis and mechanism of action are currently unknown. This study is aimed to analyze the constituents of the volatile oil in FGA (VOFGA) using gas chromatography coupled with mass spectrometry (GC-MS) and explore the underlying effects and mechanisms of VOFGA in the prevention and treatment of ischemia stroke. An in vivo ischemia model was constructed by combination treatment of high-fat diet (HFD) and middle cerebral artery occlusion (MCAO) method. After administration, the cerebral infarction volume, the brain water content, hemorheology, blood lipids, inflammatory factors, oxidative stress indicators, Bax, Bcl-2, and cleaved caspase-3 and histological examination (HE) were determined and observed to explore the underlying effects and mechanisms of VOFGA against ischemia stroke. The results showed that forty components were determined after analyzed by GC-MS, and the percentage content of palmitate, paeonol, violetone, linalool, salpinol, citral, and methyleugenol were 4.69%, 5.2%, 3.56%, 3.31%, 2.42%, 2.65%, and 1.67%, respectively. The high dose of VOFGA could inhibit neurological damage; reduce the cerebral infarction volume and brain water content; improve whole blood viscosity and red blood cell aggregation index at various shear rates; reduce the levels of TG, TC, LDL-C, TNF-α, IL-1β, MDA, and NO; increase the contents of HDL-C, IL-10, and SOD; downregulate the expressions of Bax and cleaved caspase-3 in the ischemic regions; and upregulate the expressions of Bcl-2. These effects implied that VOFGA may exert neuroprotective effects via inhibiting ischemia-triggered oxidative damage-regulating blood lipid factors and reducing the production of proinflammatory mediators against cerebral I/R injury and neuronal apoptosis. The VOFGA presents a potential treatment value for cerebral ischemic stroke, and it may offer insights into discovering new active compounds for the treatment of ischemic stroke.

Targeting Wnt signaling pathway by polyphenols: implication for aging and age-related diseases

Age is an important risk factor for different diseases. The same mechanisms that promote aging are involved in the development and progression of age-associated diseases. Polyphenols are organic compounds found in fruits and vegetables. Due to their beneficial properties (e.g. antioxidant and anti-inflammatory), polyphenols have been extensively used for treating chronic diseases. To exert their functions, polyphenols target various molecular mechanisms and signaling pathways, such as mTOR, NF-κB, and Wnt/β-catenin. Wnt signaling is a critical pathway for developmental processes. Besides, dysregulation of this signaling pathway has been observed in various diseases. Several investigations have been conducted on Wnt inhibitors at pre-clinical stages, showing promising results. Herein, we review the studies dealing with the role of polyphenols in targeting the Wnt signaling pathways in aging processes and age-associated diseases, including cancer, diabetes, Alzheimer's disease, osteoporosis, and Parkinson's disease.

The role of the intestinal microbiota in the pathogenesis of host depression and mechanism of TPs relieving depression

Depression is a prevalent neuropsychiatric disease with a high recurrence rate, affecting over 350 million people worldwide. Intestinal flora disorders and gut-brain-axis (GBA) dysfunction may cause mental disorders. Alterations in the intestinal flora composition could increase the permeability of the gut barrier, activate systemic inflammation and immune responses, regulate the release and efficacy of monoamine neurotransmitters, alter the activity and function of the hypothalamic-pituitary-adrenal (HPA) axis, and modify the abundance of the brain-derived neurotrophic factor (BDNF); all of these showed a close correlation with the occurrence of depression. In addition, the disturbance of the intestinal flora is related to circadian rhythm disorders, which aggravate the symptoms of depression. Tea polyphenols (TPs) have been found to have antidepressant effects. Therefore, the close reciprocity between the intestinal flora and circadian rhythm provides a new opportunity for TPs to regulate depression relying on the intestinal flora. In this review, we discussed the relationship between intestinal flora dysbiosis and the pathogenesis of depression and the mechanism of TPs relieving depression via the GBA.

Occurrence of pesticides in white tea and a corresponding risk exposure assessment for the different residents in Fujian, China

White tea has been of increasing public interest worldwide owing to its health benefits. Based on 2 years of surveillance, the long-term and cumulative chronic exposure risks of pesticide residues through white tea drinking were assessed for different subpopulations in Fujian, China. Twenty-five different pesticides were found, and 74.8% of samples contained at least one pesticide residue. The most frequently detected pesticide was bifenthrin with detection rates of 61.6%. Risk assessment was performed using both the deterministic approach and semiprobabilistic model under the best-case and the worst-case scenarios. The results demonstrated that the dietary risks were extremely low for six different subpopulations in which the risks for adults over the age of 41 were relatively higher. The risk ranking scheme indicated that isocarbophos and triazophos were considered to be of medium risk. The different use suggestions for the 25 positive pesticides are proposed to further minimize the exposure risk to consumer health. PRACTICAL APPLICATION: Tea is the second most popular nonalcoholic beverage throughout the world. Pesticides are used to improve the yield of tea. Pesticide residues in tea could be one of the exposure pathways for consumers. Monitoring residual levels and assessing the health risk assessment in tea are thus in an urge.

Widely targeted metabolomics analysis of white peony teas with different storage time and association with sensory attributes

The sensory features of white peony teas (WPTs) significantly change with storage age; however, their comprehensive associations with composition are still unclear. This study aimed to clarify the sensory quality-related chemical changes in WPTs during storage. Liquid chromatography-tandem mass spectrometry based on widely targeted metabolomics analysis was performed on WPTs of 1-13 years storage ages. Weighted gene co-expression network analysis (WGCNA) was used to correlate metabolites with sensory traits including color difference values and taste attributes. 323 sensory trait-related metabolites were obtained from six key modules via WGCNA, verified by multiple factor analysis. The decline and transformation of abundant flavonoids, tannins and amino acids were related to the reduced astringency, umami and increased browning of tea infusions. In contrast, the total contents of phenolic acids and organic acids increased with storage. This study provides a high-throughput method for the association of chemical compounds with various sensory traits of foods.

Green and white teas as health-promoting foods

Tea is one of the most consumed beverages around the world and as such, it is constantly the object of novel research. This review focuses on the research performed during the last five years to provide an updated view of the current position of tea regarding human health. According to most authors, tea health benefits can be traced back to its bioactive components, mostly phenolic compounds. Among them, catechins are the most abundant. Tea has an important antioxidant capacity and anti-inflammatory properties, which make this beverage (or its extracts) a potential aid in the fight against several chronic diseases. On the other hand, some studies report the possibility of toxic effects and it is advisable to reduce tea consumption, such as in the last trimester of pregnancy. Additionally, new technologies are increasing researchers' possibilities to study the effect of tea on human gut microbiota and even against SARS CoV-2. This beverage favours some beneficial gut microbes, which could have important repercussions due to the influence of gut microbiota on human health.