Zeaxanthin dipalmitate from Lycium chinense fruit reduces experimentally induced hepatic fibrosis in rats

Lycium chinense Miller fruit extract lowers liver enzyme levels in subjects with mild hepatic dysfunction: a randomized, double-blind, placebo-controlled clinical trial

PURPOSE

In our previous study, we showed that Lycium chinense Miller fruit extract (LFE) exerted hepatoprotective effects in mice. In the current study, we examined the effect of LFE on liver enzyme levels in subjects with mild hepatic dysfunction.

METHODS

A total of 90 subjects, aged 19 to 70 years old, with abnormal alanine aminotransferase (ALT) levels, were randomly placed into either an LFE (n = 45) treatment group or a placebo group (n = 45). During the 12-week clinical trial, subjects in each group received either LFE or placebo capsules, and were instructed to take four tablets per day (1760 mg/day). The primary outcome of the study was the changes of ALT and γ-glutamyltransferase (GGT) levels in each subject. The safety of LFE supplementation was assessed and adverse events were recorded.

RESULTS

LFE supplementation for 12 weeks resulted in a significant reduction of ALT (P = 0.0498) and GGT (P = 0.0368) levels in comparison to the placebo. No clinically significant changes were observed in any safety parameters.

CONCLUSION

These results suggest that LFE can be applied to subjects with mild hepatic dysfunction with no possible side effects.

TRIAL REGISTRATION

This study was registered at the Clinical Research Information Service (CRIS) as no. KCT0003985.

L-carnitine ameliorates bile duct ligation induced liver fibrosis via reducing the nitrosative stress in experimental animals: preclinical evidences

Bile duct ligation (BDL) has been extensively used in studying the mechanisms of fibrogenesis and anti-fibrotic drugs. Considering the liver regenerative capacity and the diverse results from BDL, the present study aimed to evaluate the protective effect of L-carnitine on bile duct ligation-induced liver fibrosis in experimental rats. Rats were randomly divided into seven groups (n = 6). The bile duct was ligated and serum aspartate transaminase (AST), alanine transaminase (ALT), total bilirubin and albumin, hepatic hydroxyproline (HP), reduced glutathione (GSH), and malondialdehyde (MDA) and cytokines were measured. iNOS expression was measured by using Western blot and finally, liver tissue was processed for histopathological analysis (H&E staining)". The level of iNOS was increased in the control group, whereas a decrease in the level of iNOS was found in the L-carnitine treated group. In the present study, we found that bile duct ligation in rats showed an increase in body and liver weight, while treatment with carnitine showed normal body and liver weight. Serum AST, ALT, total bilirubin, HP, GSH, MDA, and cytokines were increased in bile duct ligated rats. In addition, L-carnitine treated rats showed a reduction in oxidative stress as well as inhibiting the release of cytokines in a dose-dependent manner and showed protection against bile duct ligation. The study concludes that L-carnitine has a protective effect against the liver fibrosis induced by bile duct ligation.

Formation mechanism of isoprene compounds degraded from carotenoids during fermentation of goji wine

Fermented goji wine as a functional wine is made from yeast fermentation. To our knowledge, fermented goji wine still has a problem with insufficient characteristic aroma. Research has shown that some isoprene compounds with characteristic aromas may improve the aroma of goji wine. Therefore, the present study aimed to investigate the mechanism of isoprene compound production by carotenoid degradation during the fermentation of goji wine. It was found that C1–C6, C5–C6, C6–C7, C7–C8, C8–C9 and C9–C10 were the most easily degraded sites in carotenoids under seven different pretreatment conditions (mechanical treatment, pectinase treatment, adjustment of pH, autoclave treatment, SO2 treatment, oxidation treatment and light treatment). Meanwhile, breaking different sites, different aroma contributions such as woody, rose, fruity and grassy aromas were found. Single-factor simulation experiments of goji wine during the fermentation showed that the metabolites in the fermentation process caused the degradation of carotenoids and most were volatile aroma compounds. These results may help improve the brewing process to enhance the aroma of goji wine.

Zeaxanthin Dipalmitate in the Treatment of Liver Disease

Goji berry, Lycium barbarum, has been widely used in traditional Chinese medicine (TCM), but its properties have not been studied until recently. The fruit is a major source of zeaxanthin dipalmitate (ZD), a xanthophyll carotenoid shown to benefit the liver. Liver disease is one of the most prevalent diseases in the world. Some conditions, such as chronic hepatitis B virus, liver cirrhosis, and hepatocellular carcinoma, remain incurable. Managing them can constitute an economic burden for patients and healthcare systems. Hence, development of more effective pharmacological drugs is warranted. Studies have shown the hepatoprotective, antifibrotic, antioxidant, anti-inflammatory, antiapoptotic, antitumor, and chemopreventive properties of ZD. These findings suggest that ZD-based drugs could hold promise for many liver disorders. In this paper, we reviewed the current literature regarding the therapeutic effects of ZD in the treatment of liver disease.

Comparison of Carotenoids for Their Antifibrogenic Effects in Hepatic Stellate Cells

Hepatic stellate cells (HSC) have an important role in the development of liver fibrosis by producing extracellular matrix proteins when they are activated upon liver injury. We previously demonstrated that astaxanthin (ASTX), a xanthophyll carotenoid, attenuates HSC activation. The objective of this study was to compare the anti-fibrogenic effects of ASTX with those of other common carotenoids. LX-2 cells, a human HSC cell line, were treated with ASTX, lycopene, lutein (LT), zeaxanthin, or canthaxanthin, to measure messenger RNA (mRNA) and protein expression of pro-fibrogenic genes. Pro-fibrogenic gene expressions were also measured in ASTX- or LT-treated primary mouse HSC. To determine the underlying mechanisms of the anti-fibrogenic effect of ASTX and LT, SMA-related and MAD-related protein 3 (SMAD3) pathways and the accumulation of reactive oxygen species (ROS) were measured in LX-2 cells. Among five carotenoids tested, ASTX and LT attenuated HSC activation in LX-2 cells by reducing the mRNA and protein levels of pro-fibrogenic genes, such as smooth muscle α actin and procollagen type I α1 (COL1A1). In addition, both ASTX and LT significantly decreased the expression of pro-fibrogenic genes, including COL1A1, COL3A1, and COL6A1, in activated primary mouse HSC, with ASTX being more potent than LT. The anti-fibrogenic effect of ASTX was mediated by inhibiting the phosphorylation of SMAD3 and cellular ROS accumulation, while LT only prevented the accumulation of ROS in LX-2 cells. In conclusion, ASTX showed the most potent anti-fibrogenic effect among the five carotenoids via inhibition of SMAD3 phosphorylation and cellular ROS accumulation while LT only prevented ROS levels in HSC.

Aquaporin 11-Dependent Inhibition of Proliferation by Deuterium Oxide in Activated Hepatic Stellate Cells

Deuterium oxide (D₂O) has been reported to be active toward various in vitro cell lines in combination with phytochemicals. Our objective was to describe, for the first time, the effect of D₂O on the proliferation of hepatic stellate cells (HSCs). After D₂O treatment, the p53-cyclin-dependent kinase (CDK) pathway was stimulated, leading to inhibition of the proliferation of HSCs and an increase in the [ATP]/[ADP] ratio. We also evaluated the role of aquaporin (AQP) 11 in activated HSCs. We found that D₂O treatment decreased AQP11 expression levels. Of note, AQP11 levels elevated by a genetic approach counteracted the D₂O-mediated inhibition of proliferation. In addition, the expression levels of AQP11 negatively correlated with those of p53. On the other hand, cells transfected with an AQP11-targeted small interfering RNA (siRNA) showed enhanced inhibition of proliferation. These findings suggest that the inhibition of cell proliferation by D₂O in activated HSCs could be AQP11 dependent. Our previous studies have documented that bisdemethoxycurcumin (BDMC) induces apoptosis by regulating heme oxygenase (HO)-1 protein expression in activated HSCs. In the current study, we tested whether cotreatment with BDMC and D₂O can modulate the AQP11-dependent inhibition of cell proliferation effectively. We observed that D₂O cotreatment with BDMC significantly decreased cell proliferation compared to treatment with D₂O alone, and this effect was accompanied by downregulation of HO-1 and an increase in p53 levels.

Zeaxanthin dipalmitate alleviates hepatic injury induced by superimposed chronic hepatitis B and non-alcoholic steatohepatitis in non-obese mice

A hepatitis B virus (HBV) transgenic mice model was used to establish the fatty liver superimposed model by feeding the methionine choline-deficient (MCD) diet for 8 weeks, with or without the gavage of 2 mg/kg zeaxanthin dipalmitate (ZD) three times per week. Both wild-type and HBV transgenic mice, with MCD diet, gained typical non-obese non-alcoholic steatohepatitis (NASH) and HBV symptoms. Coadministration with ZD exhibited evident therapeutic effects through alleviating those pathological events. Moreover, long-term vehicle-ZD treatment was found to be safe. Thus, ZD is a promising and safe hepato-protective agent against hepatic injury induced by superimposed HBV and NASH in non-obese mice.

Riboflavin accumulation and molecular characterization of cDNAs encoding bifunctional GTP cyclohydrolase II/3,4-dihydroxy-2-butanone 4-phosphate synthase, lumazine synthase, and riboflavin synthase in different organs of Lycium chinense plant

Riboflavin (vitamin B2) is the precursor of flavin mononucleotide and flavin adenine dinucleotide—essential cofactors for a wide variety of enzymes involving in numerous metabolic processes. In this study, a partial-length cDNA encoding bifunctional GTP cyclohydrolase II/3,4-dihydroxy-2-butanone-4-phosphate synthase (LcRIBA), 2 full-length cDNAs encoding lumazine synthase (LcLS1 and LcLS2), and a full-length cDNA encoding riboflavin synthase (LcRS) were isolated from Lycium chinense, an important traditional medicinal plant. Sequence analyses showed that these genes exhibited high identities with their orthologous genes as well as having the same common features related to plant riboflavin biosynthetic genes. LcRIBA, like other plant RIBAs, contained a DHBPS region in its N terminus and a GCHII region in its C-terminal part. LcLSs and LcRS carried an N-terminal extension found in plant riboflavin biosynthetic genes unlike the orthologous microbial genes. Quantitative real-time polymerase chain reaction analysis showed that 4 riboflavin biosynthetic genes were constitutively expressed in all organs examined of L. chinense plants with the highest expression levels found in the leaves or red fruits. LcRIBA, which catalyzes 2 initial reactions in riboflavin biosynthetic pathway, was the highest transcript in the leaves, and hence, the richest content of riboflavin was detected in this organ. Our study might provide the basis for investigating the contribution of riboflavin in diverse biological activities of L. chinense and may facilitate the metabolic engineering of vitamin B2 in crop plants.

Molecular characterization of carotenoid biosynthetic genes and carotenoid accumulation in Lycium chinense

Lycium chinense is a shrub that has health benefits and is used as a source of medicines in Asia. In this study, a full-length cDNA clone encoding β-ring carotene hydroxylase (LcCHXB) and partial-length cDNA clones encoding phytoene synthase (LcPSY), phytoene desaturase (LcPDS), ξ-carotene desaturase (LcZDS), lycopene β-cyclase (LcLCYB), lycopene ε-cyclase (LcLCYE), ε-ring carotene hydroxylase (LcCHXE), zeaxanthin epoxidase (LcZEP), carotenoid cleavage dioxygenase (LcCCD1), and 9-cis epoxycarotenoid dioxygenase (LcNCED) were identified in L. chinense. The transcripts were constitutively expressed at high levels in leaves, flowers and red fruits, where the carotenoids are mostly distributed. In contrast, most of the carotenoid biosynthetic genes were weakly expressed in the roots and stems, which contained only small amounts of carotenoids. The level of LcLCYE transcripts was very high in leaves and correlated with the abundance of lutein in this plant tissue. During maturation, the levels of lutein and zeaxanthin in L. chinense fruits dramatically increased, concomitant with a rise in the level of β-cryptoxanthin. LcPSY, LcPDS, LcZDS, LcLCYB, and LcCHXE were highly expressed in red fruits, leading to their substantially higher total carotenoid content compared to that in green fruits. Total carotenoid content was high in both the leaves and red fruits of L. chinense. Our findings on the biosynthesis of carotenoids in L. chinense provide insights into the molecular mechanisms involved in carotenoid biosynthesis and may facilitate the optimization of carotenoid production in L. chinense.

An Evidence-Based Systematic Review of Goji (Lycium spp.) by the Natural Standard Research Collaboration

An evidence-based systematic review of goji (Lycium spp.) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Zeaxanthin dipalmitate therapeutically improves hepatic functions in an alcoholic fatty liver disease model through modulating MAPK pathway

In the current study, the therapeutic effects of zeaxanthin dipalmitate (ZD) on a rat alcoholic fatty liver disease (AFLD) model were evaluated. After-treatment with ZD from the 5th week to the 10th week in a 10-week ethanol intragastric administration in rats significantly alleviated the typical AFLD symptoms, including reduction in rat body weight, accumulation of hepatic fat droplets, occurrence of oxidative stress, inflammation, chemoattractive responses and hepatic apoptosis in the liver. The reduction of liver function abnormalities by ZD was partly through lower expression level of cytochrome P450 2E1 (CYP2E1), diminished activity of nuclear factor kappa B (NF-κB) through the restoration of its inhibitor kappa B alpha (IκBα), and the modulation of MAPK pathways including p38 MAPK, JNK and ERK. ZD treatment alone did not pose obvious adverse effect on the healthy rat. In the cellular AFLD model, we also confirmed the inhibition of p38 MAPK and ERK abolished the beneficial effects of ZD. These results provide a scientific rationale for the use of zeaxanthin and its derivatives as new complementary agents for the prevention and treatment of alcoholic liver diseases.

Effects of Lycium barbarum aqueous and ethanol extracts on high-fat-diet induced oxidative stress in rat liver tissue

This study evaluated the protective effects of aqueous extract of Lycium barbarum (LBAE) and ethanol extract of Lycium barbarum (LBEE) on blood lipid levels, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activities and liver tissue antioxidant enzyme activities in rats fed a high fat diet (HF). The rats were randomly divided into seven groups of ten rats each and fed a different diet for eight weeks as follows: One group (NC group) was fed a standard diet, one group was fed a high-fat diet (HF group), one group was fed a high-fat diet and orally fed with 20 mg/kg b.w. simvastatin (HF + simvastatin group), and the other group was fed the high fat diet and orally fed with 50 mg/kg b.w. or 100 mg/kg b.w. LBAE (HF + LBAE), or 50 mg/kg b.w. or 100 mg/kg b.w. LBEE (HF + LBEE), respectively. After eight weeks, the HF diet caused deleterious metabolic effects. Rats fed the HF diet alone showed increased hepatocellular enzyme activities in plasma, a significant decline in antioxidant enzyme activities, and elevated liver lipid peroxidation indices. LBAE and LBEE administration significantly reduced liver damage and oxidative changes, and brought back the antioxidants and lipids towards normal levels. These data suggest that these antioxidants protect against toxicity parameters in HF rats.

Plasma carotenoids are related to intima--media thickness of the carotid artery wall in men from eastern Finland

BACKGROUND

Several previous epidemiological studies have suggested that high plasma concentrations of carotenoids may slow the development of early atherosclerosis, but results have been inconclusive.

METHODS

We examined the effect of carotenoids on early atherosclerosis in a population-based study. The association between plasma carotenoid concentrations and intima-media thickness of the common carotid artery (CCA-IMT) was investigated in 1212 elderly men (aged 61-80 years) in Eastern Finland. They were examined by B-mode ultrasound to detect early signs of carotid atherosclerosis, and plasma concentrations of carotenoids were measured by high-performance liquid chromatography.

RESULTS

Men in the lowest quartile of CCA-IMT had significantly higher concentrations of plasma β-cryptoxanthin, lycopene and α-carotene than men in the highest quartile (P for the differences: 0.043, 0.045 and 0.046, respectively), after adjustment for age, examination year, body mass index, smoking, alcohol intake, years of education, symptomatic coronary heart disease (CHD) or CHD history, diabetes, low-density lipoprotein cholesterol, medications and season. The concentrations of plasma β-cryptoxanthin, lycopene and α-carotene decreased linearly with increasing CCA-IMT.

CONCLUSIONS

The results of this study suggest that high plasma concentrations of β-cryptoxanthin, lycopene and α-carotene may be associated with decreased carotid atherosclerosis in elderly men from eastern Finland.

Cytoprotective effect of the fruits of Lycium chinense Miller against oxidative stress-induced hepatotoxicity

AIM OF THE STUDY

Fruits of Lycium chinense Miller (Solanaceae), distributed in northeast Asia, have gained attraction for their hepatoprotective role in traditional oriental medicine. The excessive production of reactive oxygen species (ROS) is hazardous for living organisms and damage major cellular constituents such as DNA, lipid, and protein. The cytoprotective effect of Lycium chinense fruits (Lycium extract) was assessed against H(2)O(2)-induced Chang liver cell damage.

MATERIALS AND METHODS

The effect of Lycium extract against H(2)O(2)-induced cell death was determined by the MTT assay. Radical scavenging activity was determined through the assessments of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, intracellular ROS, hydroxyl radicals, and superoxide. The inductions of antioxidant enzymes were determined via their protein expressions and activities. DNA damage was measured using comet assay and expression of phospho-histone H2A.X. Lipid peroxidation was measured using 8-isoprostane level and fluorescent probe. Protein modification was measured using protein carbonyl moiety.

RESULTS AND CONCLUSION

Lycium extract scavenged the DPPH free radicals, intracellular ROS, hydroxyl radicals, and superoxide. Lycium extract recovered activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) decreased by H(2)O(2). Lycium extract decreased DNA damage, lipid peroxidation and protein carbonyl values increased by H(2)O(2) exposure. In addition, Lycium extract increased the cell viability of Chang liver cells exposed to H(2)O(2) via inhibition of apoptosis. These results show that Lycium extract protected Chang liver cells against oxidative stressed cell damage by H(2)O(2) via scavenging ROS and enhancing antioxidant enzyme activity.

Protective effects of the carotenoid zeaxanthin in experimental nonalcoholic steatohepatitis

Fat infiltration and inflammation cause liver injury and fibrosis and may progress to nonalcoholic steatohepatitis (NASH) and end-stage liver disease. Currently, there are no effective treatments for NASH. Zeaxanthin is a carotenoid which has been shown to be preferentially accumulated in the adipose tissue and liver. We hypothesized that treatment with zeaxanthin may decrease oxidative stress in the liver and, possibly, halt the inflammation and fibrosis associated with NASH. Here we tested zeaxanthin effects in preventing progression of liver injury in a model of NASH. Mongolian gerbils, fed a methionine-choline-deficient diet, were treated with different doses of zeaxanthin. We assessed histopathological changes by hematoxylin-eosin and Masson trichrome staining and determined oxidative stress by measuring lipid peroxidation. The obtained results show that zeaxanthin significantly prevented NASH progression by decreasing oxidative stress and liver fibrosis, thus suggesting a potential therapeutic application for this carotenoid in the management of NASH.

Quantification of zeaxanthin dipalmitate and total carotenoids in Lycium fruits (Fructus Lycii)

An HPLC-DAD method has been developed to quantitatively analyze for the content of zeaxanthin dipalmitate, a major carotenoid in Fructus Lycii, in different species of the genus Lycium. Determination was performed using an Alltima C18 column with the mobile phase consisting of acetonitrile and dichloromethane (42:58). The total contents of carotenoids in these samples were also determined by using UV spectrophotometric assay. Total carotenoid concentrations of different Fructus Lycii are within the range of 0.03-0.5%. Zeaxanthin dipalmitate is a predominant carotenoid, comprising 31-56% of the total carotenoids in Fructus Lycii. This study is the first systematic quantification of the carotenoids in the fruits of different Lycium species. The results demonstrated that these methods are reliable and facile techniques for rapid analysis of carotenoids for crude drug and plant-derived food supplements.