Naringin prevents carbon tetrachloride-induced acute liver injury in mice

Flavonoids for treating pulmonary fibrosis: Present status and future prospects

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with an unknown underlying cause. There is no complete cure for IPF; however, two anti-fibrotic agents (Nintedanib and pirfenidone) are approved by the USFDA to extend the patient's life span. Therefore, alternative therapies supporting the survival of fibrotic patients have been studied in recent literature. The abundance of phenolic compounds, particularly flavonoids, has gathered attention due to their potential health benefits. Various flavonoids, like naringin, quercetin, baicalin, baicalein, puerarin, silymarin, and kaempferol, exhibit anti-inflammatory and anti-oxidant properties, which help decrease lung fibrosis. Various databases, including PubMed, EBSCO, ProQuest, and Scopus, as well as particular websites, such as the World Health Organisation and the National Institutes of Health, were used to conduct a literature search. Several mechanisms of action of flavonoids are reported with the help of in vivo and cell line studies emphasizing their ability to modulate oxidative stress, inflammation, and fibrotic processes in the lungs. They are reported for the restoration of biomarkers like hydroxyproline, cytokines, superoxide dismutase, malondialdehyde and others associated with IPF and for modulating various pathways responsible for the progression of pulmonary fibrosis. Yet, flavonoids have some drawbacks, such as poor solubility, challenging drug loading, stability issues, and scarce bioavailability. Therefore, novel formulations of flavonoids are explored, including liposomes, solid lipid microparticles, polymeric nanoparticles, nanogels, and nanocrystals, to enhance the therapeutic efficacy of flavonoids in pulmonary fibrosis. This review focuses on the role of flavonoids in mitigating idiopathic pulmonary fibrosis, their mode of action and novel formulations.

Hepatoprotective effects of natural drugs: Current trends, scope, relevance and future perspectives

BACKGROUND

The liver is a well-known player in the metabolism and removal of drugs. Drug metabolizing enzymes in the liver detoxify drugs and xenobiotics, ultimately leading to the acquisition of homeostasis. However, liver toxicity and cell damage are not only related to the nature and dosage of a particular drug but are also influenced by other factors such as aging, immune status, environmental contaminants, microbial metabolites, gender, obesity, and expression of individual genes Furthermore, factors such as drugs, alcohol, and environmental contaminants could induce oxidative stress, thereby impairing the regenerative potential of the liver and causing several diseases. Persons suffering from other ailments and those with comorbidities are found to be more prone to drug-induced toxicities. Moreover, drug composition and drug-drug interactions could further aggravate the risk of drug-induced hepatotoxicity. A plethora of mechanisms are responsible for initiating liver cell damage and further aggravating liver cell injury, followed by impairment of homeostasis, ultimately leading to the generation of reactive oxygen species, immune-suppression, and oxidative stress.

OBJECTIVE

To summarize the potential of phytochemicals and natural bioactive compounds to treat hepatotoxicity and other liver diseases.

STUDY DESIGN

A deductive qualitative content analysis approach was employed to assess the overall outcomes of the research and review articles pertaining to hepatoprotection induced by natural drugs, along with analysis of the interventions.

METHODS

An extensive literature search of bibliographic databases, including Web of Science, PUBMED, SCOPUS, GOOGLE SCHOLAR, etc., was carried out to understand the role of hepatoprotective effects of natural drugs.

RESULTS

Bioactive natural products, including curcumin, resveratrol, etc., have been seen as neutralizing agents against the side effects induced by the drugs. Moreover, these natural products are dietary and are readily available; thus, could be supplemented along with drugs to reduce toxicity to cells. Probiotics, prebiotics, and synbiotics have shown promise of improving overall liver functioning, and these should be evaluated more extensively for their hepatoprotective potential. Therefore, selecting an appropriate natural product or a bioactive compound that is free of toxicity and offers a reliable solution for drug-induced liver toxicity is quintessential.

CONCLUSIONS

The current review highlights the role of natural bioactive products in neutralizing drug-induced hepatotoxicity. Efforts have been made to delineate the possible underlying mechanism associated with the neutralization process.

Integrated network analysis and metabolomics reveal the molecular mechanism of Yinchen Sini decoction in CCl4-induced acute liver injury

Objective: Yinchen Sini decoction (YCSND), a traditional Chinese medicine (TCM) formula, plays a crucial role in the treatment of liver disease. However, the bioactive constituents and pharmacological mechanisms of action remain unclear. The present study aimed to reveal the molecular mechanism of YCSND in the treatment of acute liver injury (ALI) using integrated network analysis and metabolomics. Methods: Ultra-high-performance liquid chromatography coupled with Q-Exactive focus mass spectrum (UHPLC-QE-MS) was utilized to identify metabolites in YCSND, and high-performance liquid chromatography (HPLC) was applied to evaluate the quality of four botanical drugs in YCSND. Cell damage and ALI models in mice were established using CCl4. 1H-NMR metabolomics approach, along with histopathological observation using hematoxylin and eosin (H&E), biochemical measurements, and reverse transcription quantitative real-time PCR (RT-qPCR), was applied to evaluate the effect of YCSND on CCl4- induced ALI. Network analysis was conducted to predict the potential targets of YCSND in ALI. Result: Our results showed that 89 metabolites in YCSND were identified using UHPLC-QE-MS. YCSND protected against ALI by reducing the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malondialdehyde (MDA) contents and increasing those of superoxide dismutase (SOD), and glutathione (GSH) both in vivo and in vitro. The 1H-NMRmetabolic pattern revealed that YCSND reversed CCl4-induced metabolic abnormalities in the liver. Additionally, the Kyoto Encyclopedia of Genes and Genome (KEGG) pathway enrichment analysis identified five pathways related to liver injury, including the PI3K-AKT, MAPK, HIF-1, apoptosis, and TNF signaling pathways. Moreover, RT-qPCR showed YCSND regulated the inflammatory response (Tlr4, Il6, Tnfα, Nfκb1, Ptgs2, and Mmp9) and apoptosis (Bcl2, Caspase3, Bax, and Mapk3), and inhibited PI3K-AKT signaling pathway (Pi3k and Akt1). Combined network analysis and metabolomics showed a link between the key targets (Tlr4, Ptgs2, and Mmp9) and vital metabolites (choline, xanthine, lactate, and 3-hydroxybutyric acid) of YCSND in ALI. Conclusion: Overall, the results contribute to the understanding of the therapeutic effects of YCSND on ALI, and indicate that the integrated network analysis and metabolomics could be a powerful strategy to reveal the pharmacological effects of TCM.

Polysaccharides from Oudemansiella radicata residues attenuate carbon tetrachloride-induced liver injury

In addition to fruiting bodies and mycelia, the mushroom residues have also been demonstrated to be rich in polysaccharides which have attracted academic attentions owing to their extensive bioactivities. Therefore, the present work aimed to investigate the potential hepatoprotective effects of Oudemansiella radicata residues polysaccharides (RPS). Our results demonstrated that RPS showed significantly protective effects against carbon tetrachloride (CCl₄)-induced liver injury, and the possible mechanisms may be related with the predominant bioactivities of RPS containing anti-oxidation by activating the Nrf2 signal pathways, anti-inflammation by inhibiting NF-κB signal pathways and reducing the release of inflammatory cytokines, anti-apoptosis by regulating Bcl-2/Bax pathway, and anti-fibrosis by inhibiting the expressions of TGF-β1, Hyp and α-SMA, respectively. These findings suggested that RPS, a typical β-type glycosidic pyranose-polysaccharides, could be used as promising diet supplement or medication for the adjunctive treatment of hepatic diseases, and also contributed to promoting the recyclable utilization of mushroom residues.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

Protective Effects of Naringin-Dextrin Nanoformula against Chemically Induced Hepatocellular Carcinoma in Wistar Rats: Roles of Oxidative Stress, Inflammation, Cell Apoptosis, and Proliferation

Nanotechnology holds great promise for the development of treatments for deadly human diseases, such as hepatocellular carcinoma (HCC). In the current study, we compared the hepatoprotective effects of naringin-dextrin nanoparticles (NDNPs) against HCC in male Wistar rats with those of pure naringin and investigated the underlying cellular and molecular mechanisms. HCC was induced by intraperitoneal injection of diethylnitrosamine (DEN, 150 mg/kg body weight (b.w.) per week) for two weeks, followed by oral administration of 2-acetylaminofluorene (2AAF, 20 mg/kg b.w.) four times per week for three weeks. DEN/2AAF-administered rats were divided into three groups that respectively received 1% carboxymethyl cellulose (as vehicle), 10 mg/kg b.w. naringin, or 10 mg/kg b.w. NDNP every other day by oral gavage for 24 weeks. Both naringin and NDNP significantly attenuated the harmful effects of DEN on liver function. Both compounds also suppressed tumorigenesis as indicated by the reduced serum concentrations of liver tumor markers, and this antitumor effect was confirmed by histopathological evaluation. Additionally, naringin and NDNP prevented DEN-induced changes in hepatic oxidative stress and antioxidant activities. In addition, naringin and NDNP suppressed inflammation induced by DEN. Moreover, naringin and NDNP significantly reduced the hepatic expression of Bcl-2 and increased Bax, p53, and PDCD5 expressions. Naringin and NDNP also reduced expression of IQGAP1, IQGAP3, Ras signaling, and Ki-67 while increasing expression of IQGAP2. Notably, NDNP more effectively mitigated oxidative stress and inflammatory signaling than free naringin and demonstrated improved antitumor efficacy, suggesting that this nanoformulation improves bioavailability within nascent tumor sites.

Protective Effects of Naringenin from Citrus sinensis (var. Valencia) Peels against CCl4-Induced Hepatic and Renal Injuries in Rats Assessed by Metabolomics, Histological and Biochemical Analyses

Citrus fruits are grown worldwide for their special nutritive and several health benefits. Among citrus bioactives, naringenin, a major flavanone, exhibits a potential hepatoprotective effect that is not fully elucidated. Herein, serum biochemical parameters and histopathological assays were used to estimate the hepatoprotective activity of naringenin, isolated from Citrus sinensis (var. Valencia) peels, in CCl4-induced injury in a rat model. Further, GC-MS-based untargeted metabolomics was used to characterize the potential metabolite biomarkers associated with its activity. Present results revealed that naringenin could ameliorate the increases in liver enzymes (ALT and AST) induced by CCl4 and attenuate the pathological changes in liver tissue. Naringenin decreased urea, creatinine and uric acid levels and improved the kidney tissue architecture, suggesting its role in treating renal disorders. In addition, naringenin increased the expression of the antiapoptoic cell marker, Bcl-2. Significant changes in serum metabolic profiling were noticed in the naringenin-treated group compared to the CCl4 group, exemplified by increases in palmitic acid, stearic acid, myristic acid and lauric acids and decrease levels of alanine, tryptophan, lactic acid, glucosamine and glucose in CCl4 model rats. The results suggested that naringenin's potential hepato- and renoprotective effects could be related to its ability to regulate fatty acids (FAs), amino acids and energy metabolism, which may become effective targets for liver and kidney toxicity management. In conclusion, the current study presents new insights into the hepato- and renoprotective mechanisms of naringenin against CCl4-induced toxicity.

Plant-Derived Chinese Medicine Monomers on Ovarian Cancer via the Wnt/β-Catenin Signaling Pathway: Review of Mechanisms and Prospects

Ovarian cancer (OC) is a common malignant tumor of the female reproductive system and has a high morbidity and mortality rate. The progression and metastasis of OC are complex and involve multiple signaling pathways. The Wnt/β-catenin signaling pathway is closely related to OC, and therefore blocking the activation of the Wnt/β-catenin signaling directly or inhibiting related genes, and molecular targets is of great value in treating OC. Toxicities such as myelotoxicity, cardiotoxicity, genotoxicity, and vasospasm are the major side effects for common anticancer drugs and are well documented. There is, therefore, a need to develop new, effective, safer, and more affordable anticancer drugs from alternative sources. In recent years, plant-derived Chinese medicine monomers have drawn increasing attention due to their high safety, low toxicity, minimal side effects, and antitumor effects. Plant-derived Chinese medicine monomers are effective against multiple targets and can regulate the growth, proliferation, apoptosis, invasion, and migration of OC as well as reverse drug resistance by regulating the Wnt/β-catenin signaling pathway. In this review, we summarize and provide mechanisms and prospects for the use of plant-derived Chinese medicines for the prevention and treatment of OC.

Preventive Effect of Flavonoid Extract from the Peel of Gonggan (Citrus reticulata Blanco Var. Gonggan) on CCl4-Induced Acute Liver Injury in Mice

Objective

Citrus peel, a waste product of citrus consumption and processing, is rich in flavonoids. This study aimed to study the protective effect of flavonoid extract from the peel of gonggan (Citrus reticulata Blanco var. gonggan) on acute chemical liver injury.

Materials and Methods

We established a chemical liver injury model induced by carbon tetrachloride (CCl₄) in mice. The flavonoid composition in gonggan (Citrus reticulata Blanco var. gonggan) peel was detected by HPLC. The histopathological sections of liver, related biochemical indicators in serum and liver, and related genes were examined to evaluate the protective effect of gonggan peel flavonoid extract (GPFE).

Results

The results showed that GPFE contained narirutin, hesperidin, nobiletin, tangeretin, and 5-demethylnobiletin. After 14 days of intragastric administration of GPFE, the result showed GPFE could reduce the increase in liver index, serum alanine aminotransferase (ALT), and aspartate transaminase (AST) levels caused by CCl₄. At the same time, pathological sections of liver confirmed that GPFE alleviated the damage to liver tissue. Moreover, biochemical indicator results showed that GPFE increased the activities of superoxide dismutase (SOD) and catalase (CAT) in liver tissue and reduced the content of malondialdehyde (MDA). Also, it reduced the levels of inflammation factors: tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin (IL)-1β, and IL-6. In addition, q-PCR results showed that GPFE upregulated mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), glutathione peroxidase (GSH-Px), γ-glutamylcysteine synthetase (γ-GCS), CAT, and downregulated IL-6 and TNF-α mRNA expression levels. The mechanism of GPFE may be related to the inhibition of oxidative stress and inflammation.

Conclusion

The experiment indicates GPFE has a good protective effect on acute chemical liver injury in mice induced by CCl₄ via antioxidant and anti-inflammatory pathways.

Purified anthocyanins from Zea mays L. cob ameliorates chronic liver injury in mice via modulating of oxidative stress and apoptosis

BACKGROUND

Purple corn (Zea mays L.) is one of the main economic crops in China and has been used in the treatment of cystitis, urinary infections and obesity. However, purple corncobs, the by-product remaining after processing and having an intense purple-black color, are normally disposed of as waste or used as animal feed. Therefore, to further expand the medicinal value of purple corncob, its content was analyzed and, after purification, the effect and mechanism of purified purple corncob anthocyanins (PPCCA) on CCl₄ -induced chronic liver injury in mice were investigated.

RESULTS

It was observed that the total anthocyanin content (TAC) from PPCCA (317.51 ± 9.30 mg cyanidin 3-O-glucoside (C-3-G) g^-1 dry weight) was significantly higher than that from the purified purple corn seed anthocyanin (266.73 ± 3.67 mg C-3-G g^-1 dry weight), of which C-3-G accounted for 90.6% and 90.4% of the TAC, respectively. Furthermore, compared with the CCl₄ group, PPCCA treatment significantly reduced liver index, serum total bilirubin, alanine transaminase, aspartate transaminase and liver malondialdehyde levels, but increased liver superoxide dismutase activity. The pathological changes were also improved, such as more regular arrangement of hepatocytes, less swelling, and fewer vacuoles and apoptotic cells. Additionally, mechanistic studies showed that PPCCA downregulated the expression of Caspase-3, Bax and cytochrome P450 2E1 proteins in the liver and upregulated the expression of Bcl-2.

CONCLUSION

These results demonstrated that PPCCA could ameliorate CCl₄ -induced chronic liver injury by regulating oxidative stress and hepatocyte apoptosis pathways. © 2021 Society of Chemical Industry.

Morchella importuna Polysaccharides Alleviate Carbon Tetrachloride-Induced Hepatic Oxidative Injury in Mice

This study aimed to investigate the effects of Morchella importuna polysaccharides (MIPs) on carbon tetrachloride (CCl4)-induced hepatic damage in mice. A total of 144 female mice were randomly assigned to four treatment groups, namely, control, CCl4, low-dose MIP (LMIP) group, and high-dose MIP (HMIP) group. After the 10-day experiment, serum and liver were sampled for biochemical and metabolomic analyses. The HMIPs markedly decreased the liver weight under CCl4 intoxication. Furthermore, the significantly elevated concentrations of five serum biochemical parameters, including alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, and total bile acid under CCl4 treatment were subverted by MIP administration in a dose-dependent manner. Moreover, MIPs relieved the increased hepatic malonaldehyde and protein carbonyl content and the decreased superoxide dismutase and catalase contents caused by CCl4 intoxication. There was also a dose-dependent decrease in the CCl4-induced inflammatory indices, such as the levels of interleukin-1, interleukin-6, tumor necrosis factor-alpha, and myeloperoxidase, with MIP administration. Subsequent ultra-high performance liquid chromatography-tandem mass spectrometry-based serum metabolomics identified nine metabolites between the control and CCl4 groups and 10 metabolites between the HMIP and CCl4 groups, including some critical metabolites involved in flavonoid biosynthesis, amino acid metabolism, energy metabolism, and toxicant degradation. These novel findings indicate that MIPs may be of therapeutic value in alleviating the oxidative stress and inflammation caused by CCl4. Liquid chromatography-mass spectrometry-based metabolomics provides a valuable opportunity for identifying potential biomarkers and elucidating the protective mechanisms of medicinal mushrooms against hepatic oxidative injury.

Betulin ameliorates 7,12-dimethylbenz(a)anthracene-induced rat mammary cancer by modulating MAPK and AhR/Nrf-2 signaling pathway

The aim of the present study is to explore the preventive efficacy of betulin (BE) in 7,12-dimethylbenz(a)anthracene (DMBA)-administered mammary cancer by modulating Ahr/Nrf2 signaling in experimental models. The mammary cancer was stimulated by the addition of DMBA (25 mg/kg/b.Wt) mixed in 1 ml of vehicle solution (sunflower oil and saline 1:1) through subcutaneous injection. The DMBA-exposed mammary tumor models showed low bodyweight, elevated quantities of lipid peroxidation molecules (TBARS and LOOH), and low enzymatic (GPx, SOD, and CAT), and nonenzymatic (GSH, vitamin C, and vitamin E) antioxidant activities in plasma and mammary tissues. Moreover, histopathological studies confirmed that invasive ductal carcinoma was observed in DMBA-induced mammary tissue of the experimental model. Dietary oral supplementation of BE prevents the loss of bodyweight, overproduces lipid peroxidation, and restores the antioxidant activities in DMBA-exposed experimental animals. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a crucial antioxidant protein that involves preventing numerous cancers. Therefore, Nrf2-associated signaling concern is a significant target for preventing mammary cancer. This study observed an increased expression of MAPKs, Keap1, ARNT, AhR, and CYP1A1, whereas decreased expression of HO-1 and Nrf2 in DMBA-induced cancer-bearing experimental animals. The oral supplementation of BE effectively modulates the expression of MAPKs, AhR/Nrf2-associated protein expressions in DMBA-exposed experimental animals. This current study concluded that BE is a strong antioxidant, which triggers the MAPKs-mediated oxidative stress and inhibits proliferative markers by restoring the activity of Nrf2 signaling.

5-O-Demethylnobiletin Alleviates CCl4-Induced Acute Liver Injury by Equilibrating ROS-Mediated Apoptosis and Autophagy Induction

Polymethoxyflavanoids (PMFs) have exhibited a vast array of therapeutic biological properties. 5-O-Demethylnobiletin (5-DN) is one such PMF having anti-inflammatory activity, yet its role in hepatoprotection has not been studied before. Results from in vitro study revealed that 5-DN did not exert a high level of cytotoxicity on HepG2 cells at 40 μM, and it was able to rescue HepG2 cell death induced by carbon tetrachloride (CCl₄). Subsequently, we investigated acute liver injury on BALB/c mice induced by CCl₄ through the intraperitoneal injection of 1 mL/kg CCl₄ and co-administration of 5-DN at (1 and 2 mg/kg) by oral gavage for 15 days. The results illustrated that treatment with 5-DN attenuated CCl₄-induced elevated serum aminotransferase (AST)/alanine aminotransferase (ALT) ratio and significantly ameliorated severe hepatic damage such as inflammation and fibrosis evidenced through lesser aberrations in the liver histology of 5-DN dose groups. Additionally, 5-DN efficiently counteracted and equilibrated the production of ROS accelerated by CCl₄ and dramatically downregulated the expression of CYP2E1 vitally involved in converting CCl₄ to toxic free radicals and also enhanced the antioxidant enzymes. 5-DN treatment also inhibited cell proliferation and inflammatory pathway abnormally regulated by CCl₄ treatment. Furthermore, the apoptotic response induced by CCl₄ treatment was remarkably reduced by enhanced Bcl-2 expression and noticeable reduction in Bax, Bid, cleaved caspase 3, caspase 9, and apaf-1 expression. 5-DN treatment also induced the conversion of LC3 and promoted the autophagic flux. Conclusively, 5-DN exhibited hepatoprotective effects in vitro and in vivo and prevented liver fibrosis induced by CCl₄.

Standardized Olea europaea L. leaf extract exhibits protective activity in carbon tetrachloride-induced acute liver injury in rats: the insight into potential mechanisms

The protective activity of dry olive leaf extract (DOLE) in carbon tetrachloride (CCl₄)-induced liver damage and possible mechanisms involved in this protection were investigated in rats. Acute CCl₄ intoxication resulted in a massive hepatic necrosis, in increased serum transaminases, and in a perturbation of oxidative stress parameters in liver tissue [malondyaldehide, glutathione (GSH), catalase]. CCl₄ did not affect the expression of caspase-3 and cytochrome c as markers of apoptosis; however, CCl₄ increased the AMP-activated protein kinase (AMPK) activity and the expression of autophagy-related protein LC3II and decreased the expression of p62 protein. The pre-treatment with DOLE significantly improved serum markers of liver damage, liver catalase activity, and GSH concentration, suggesting that antioxidative mechanism is responsible for hepatoprotection. Oral administration of DOLE did not influence LC3II conversion and p62 degradation in liver, but AMPK activity was significantly decreased, suggesting the energy balance perturbation as an additional potential mechanism of DOLE hepatoprotective effect.

Flavonoids from Aurantii Fructus Immaturus and Aurantii Fructus: promising phytomedicines for the treatment of liver diseases

Background

Liver diseases and related complications are major sources of morbidity and mortality, which places a huge financial burden on patients and lead to nonnegligible social problems. Therefore, the discovery of novel therapeutic drugs for the treatment of liver diseases is urgently required. Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF) are frequently used herbal medicines in traditional Chinese medicine (TCM) formulas for the treatment of diverse ailments. A variety of bioactive ingredients have been isolated and identified from AFI and AF, including alkaloids, flavonoids, coumarins and volatile oils.

Main body

Emerging evidence suggests that flavonoids, especially hesperidin (HD), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangeretin (TN), hesperetin (HT) and eriodictyol (ED) are major representative bioactive ingredients that alleviate diseases through multi-targeting mechanisms, including anti-oxidative stress, anti-cytotoxicity, anti-inflammation, anti-fibrosis and anti-tumor mechanisms. In the current review, we summarize the recent progress in the research of hepatoprotective effects of HD, NIN, NOB, NRG, TN, HT and ED and highlight the potential underlying molecular mechanisms. We also point out the limitations of the current studies and shed light on further in-depth pharmacological and pharmacokinetic studies of these bioactive flavonoids.

Conclusion

This review outlines the recent advances in the literature and highlights the potential of these flavonoids isolated from AFI and AF as therapeutic agents for the treatment of liver diseases. Further pharmacological studies will accelerate the development of natural products in AFI and AF and their derivatives as medicines with tantalizing prospects in the clinical application.

DNA polymerase-γ hypothesis in nucleoside reverse transcriptase-induced mitochondrial toxicity revisited: A potentially protective role for citrus fruit-derived naringenin?

Nucleoside reverse transcriptase inhibitors (NRTIs) form the backbone in combination antiretroviral therapy (cARVs). They halt chain elongation of the viral cDNA by acting as false substrates in counterfeit incorporation mechanism to viral RNA-dependent DNA polymerase. In the process genomic DNA polymerase as well as mitochondrial DNA (mtDNA) polymerase-γ (which has a much higher affinity for these drugs at therapeutic doses) are also impaired. This leads to mitochondrial toxicity that manifests clinically as mitochondrial myopathy, peripheral neuropathy, hyperlactatemia or lactic acidosis and lipoatrophy. This has led to the revision of clinical guidelines by World Health Organization to remove stavudine from first-line listing in the treatment of HIV infections. Recent reports have implicated oxidative stress besides mtDNA polymerase-γ hypothesis in NRTI-induced metabolic complications. Reduced plasma antioxidant concentrations have been reported in HIV positive patients on cARVs but clinical intervention with antioxidant supplements have not been successful either due to low efficacy or poor experimental designs. Citrus fruit-derived naringenin has previously been demonstrated to possess antioxidant and free radical scavenging properties which could prevent mitochondrial toxicity associated with these drugs. This review revisits the controversy surrounding mtDNA polymerase-γ hypothesis and evaluates the potential benefits of naringenin as a potent anti-oxidant and free radical scavenger which as a nutritional supplement or therapeutic adjunct could mitigate the development of mitochondrial toxicity associated with these drugs.

Effect of Sechium edule var. nigrum spinosum (Chayote) on Oxidative Stress and Pro-Inflammatory Markers in Older Adults with Metabolic Syndrome: An Exploratory Study

Metabolic syndrome (MetS) is a risk factor for cognitive deterioration and frailty in older adults. In this regard it has been shown that oxidative stress (OxS) and chronic inflammation are involved in the pathophysiology of these alterations. Harmless antioxidant and anti-inflammatory therapeutic alternatives have been proposed, such as the consumption of Sechium edule (chayote), but the evidence is inconclusive. For this reason, an exploratory study of a single group chosen by convenience sampling, including 12 older adults, with an average age of 71 ± 6 years (10 women and 2 men) with a diagnosis of MetS according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP III) criteria. This exploratory study aimed to determine the effect of the consumption of the dried fruit powder supplement of Sechium edule var. nigrum spinosum (500 mg, 3 times per day) for six weeks on the markers of OxS in elderly adults with MetS. All participants' OxS markers were measured before and after treatment. There was a statistically significant decrease in the concentration of lipoperoxides (baseline, 0.289 ± 0.04 vs. post-treatment, 0.234 ± 0.06 μmol/L, p < 0.05), together with a significant increase in total antioxidant status (baseline, 0.97 ± 0.18 vs. post-treatment, 1.2 ± 0.12 mmol/L, p < 0.05). In this sense, the oxidative stress index showed a statistically significant decrease (baseline, 1.7 ± 0.78 vs. post-treatment, 0.75 ± 0.87, p < 0.05). A statistically significant decrease in the concentration of TNF-α after treatment was also found (baseline, 5.3 ± 1.4 vs. post-treatment, 3.5 ± 1.3, p < 0.05).Our findings suggest that the consumption of the dry fruit of Sechium edule has an antioxidant and anti-inflammatory effect in older adults with metabolic syndrome.

Naringin protects against perfluorooctane sulfonate-induced liver injury by modulating NRF2 and NF-κB in mice

Perfluorooctane sulfonate (PFOS), a persistent organic pollutant, has been demonstrated to cause multiple toxicities. In this study, we explored the role of naringin (Nar) in alleviating PFOS-caused mouse liver injury and its potential mechanisms. Male mice were intragastrically administered PFOS (10 mg/kg/day) alone or with Nar (100 mg/kg/day) for 3 weeks. Nar supplementation led to resumption of elevated serum hepatic enzyme activities and increased relative liver weight in PFOS-challenged mice. Moreover, Nar treatment increased hepatic expression of transcription factor NRF2 protein and its regulated antioxidative enzyme genes heme oxygenase‑1, superoxide dismutase and catalase, with an inhibition of malondialdehyde and hydrogen peroxide production. Furthermore, simultaneous administration of Nar suppressed PFOS-induced elevation in NF-κB activity and generation of inflammatory cytokines TNF-α and IL-6 in the liver. In addition, Nar enhanced anti-apoptotic Bcl-2 expression, decreased pro-apoptotic Bax expression and inhibited caspase‑3 activation in liver tissue in mice exposed to PFOS. Our results indicate that Nar protects against PFOS-induced hepatotoxicity in mice via modulating oxidative, inflammatory and apoptotic pathways.

Preparation, characterization and in vitro and in vivo evaluation of a solid dispersion of Naringin

Naringin (NA) is one of typical flavanone glycosides widely distributed in nature and possesses several biological activities including antioxidant, anti-inflammatory, and antiapoptotic. The aim of this study was to develop solid dispersion (SD) and to improve the dissolution rate and oral bioavailability of NA. NA-SD was prepared by the traditional preparation methods using PEG6000, F68, or PVP K30 as carrier at different drug to carrier ratios. According to the results of solubility and in vitro dissolution test, the NA-PEG6000 (1:3) SD was considered as an optimal formulation to characterize by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry and powder X-ray diffraction. Furthermore, oral bioavailabilities of NA-PEG6000 (1:3) SD and NA-suspension with the same dosage were investigated in SD rats. The results confirmed the formation of SD and the pharmacokinetic parameters of NA-PEG6000 (1:3) SD (C_max = 0.645 ± 0.262 µg/ml, AUC_0-t = 0.471 ± 0.084 µg/ml h) were higher than that of NA-suspension (C_max = 0.328 ± 0.183 µg/ml, AUC_0-t  = 0.361 ± 0.093 µg/ml h). Based on the results, the SD is considered as a promising approach to enhance the dissolution rate and oral bioavailability of NA.

Naringin protects against cyclophosphamide-induced hepatotoxicity and nephrotoxicity through modulation of oxidative stress, inflammation, apoptosis, autophagy, and DNA damage

Cyclophosphamide (CP) is a common chemotherapeutic agent that is effective against a wide variety of tumors. The associated hepatotoxicity and nephrotoxicity, however, limit its therapeutic use. Naringin (NG) is a natural flavanone glycoside that has pharmacological and therapeutic activities, such as anti-inflammation, anti-apoptotic, and antioxidant properties. Therefore, the present study was undertaken to evaluate the protective effect of NG against CP-induced hepatotoxicity and nephrotoxicity in rats. Rats were pre-treated with NG (50 and 100 mg/kg b.w.) for 7 days before administering a single dose of CP (200 mg/kg b.w.) on the seventh day. CP-induced hepatotoxicity and nephrotoxicity were associated with an increase in serum toxicity markers and a decrease in antioxidant enzyme activities. CP also induced inflammatory responses by increasing the levels of tumor necrosis factor-α (TNF-α), nuclear factor kappa B (NF-κB), interleukin-6 (IL-6), and interleukin-1β (IL-1β), and activities of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, it activated the apoptotic and autophagic pathway by increasing cysteine aspartate-specific protease-3 (caspase-3) expression and light chain 3B (LC3B) level and also increased the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), which is the marker of oxidative DNA damage. Pre-treatment with NG (50 and 100 mg/kg), however, significantly decreased serum toxicity markers, increased antioxidant enzyme activities, and regulated inflammation, apoptosis, autophagy, and oxidative DNA damage in hepatic and renal tissues. These results indicated that NG was an effective protectant against CP-induced hepatotoxicity and nephrotoxicity.

Beneficial effects of naringenin in liver diseases: Molecular mechanisms

Liver diseases are caused by different etiological agents, mainly alcohol consumption, viruses, drug intoxication or malnutrition. Frequently, liver diseases are initiated by oxidative stress and inflammation that lead to the excessive production of extracellular matrix (ECM), followed by a progression to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). It has been reported that some natural products display hepatoprotective properties. Naringenin is a flavonoid with antioxidant, antifibrogenic, anti-inflammatory and anticancer properties that is capable of preventing liver damage caused by different agents. The main protective effects of naringenin in liver diseases are the inhibition of oxidative stress, transforming growth factor (TGF-β) pathway and the prevention of the transdifferentiation of hepatic stellate cells (HSC), leading to decreased collagen synthesis. Other effects include the inhibition of the mitogen activated protein kinase (MAPK), toll-like receptor (TLR) and TGF-β non-canonical pathways, the inhibition of which further results in a strong reduction in ECM synthesis and deposition. In addition, naringenin has shown beneficial effects on nonalcoholic fatty liver disease (NAFLD) through the regulation of lipid metabolism, modulating the synthesis and oxidation of lipids and cholesterol. Moreover, naringenin protects from HCC, since it inhibits growth factors such as TGF-β and vascular endothelial growth factor (VEGF), inducing apoptosis and regulating MAPK pathways. Naringenin is safe and acts by targeting multiple proteins. However, it possesses low bioavailability and high intestinal metabolism. In this regard, formulations, such as nanoparticles or liposomes, have been developed to improve naringenin bioavailability. We conclude that naringenin should be considered in the future as an important candidate in the treatment of different liver diseases.

Protective effects of stigmasterol against ketamine-induced psychotic symptoms: Possible behavioral, biochemical and histopathological changes in mice

BACKGROUND

Stigmasterol, a naturally occurring phytoestrogen has been reported to possess many pharmacological activities. The aim of the present study was to screen the effect of stigmasterol against ketamine-induced mice model of psychosis.

METHODS

The behavioural studies included an assessment of locomotor activity, stereotypic behaviours, immobility duration, step down latency and effects on catalepsy. Biochemical estimations involved the estimations of GABA, dopamine, GSH, MDA, TNF-α, total protein content and AChE activity. Histopathological changes and effect on androgenic parameters were also evaluated.

RESULTS

Stigmasterol treated animals showed significant decrease in locomotor activity, stereotypic behaviours, immobility duration and increased step down latency. Biochemical estimations revealed increased GABA, GSH levels and decreased dopamine, MDA, TNF-α levels and AChE activity. These findings were confirmed by histopathological changes in the cortex part of the brain. Further, stigmasterol was not found to cause catalepsy and any adverse effect on the reproductive system.

CONCLUSION

This study concluded that stigmasterol could ameliorate ketamine-induced behavioral, biochemical and histopathological alterations in mice showing its potential effects in the management of psychotic symptoms.

Naringin attenuates thioacetamide-induced liver fibrosis in rats through modulation of the PI3K/Akt pathway

AIMS

Naringin (NR) is a flavanone glycoside extracted from grapefruits and citrus fruits. The aim of this study is to investigate the antifibrotic efficacy of NR in thioacetamide (TAA)-induced hepatic fibrosis in rats through evaluating NR effect on the PI3K/Akt pathway.

MAIN METHODS

Hepatic fibrosis was induced in rats by intraperitoneal injection of TAA (200mg/kg) twice per week for 6weeks. Simultaneously, NR (40mg/kg/day, p.o.) was given along with TAA injection. The ratio of P-Akt/Akt was assessed in hepatic homogenate as well as antioxidant enzymes (catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx)) and lipid peroxidation marker, malondialdehyde (MDA). Serum level of interleukin (IL)-6 were measured using ELISA. Hepatic tissues were examined histopathologically using hematoxylin and eosin (H&E) and Masson trichome staining. Tissue expression of alpha smooth muscle actin (α-SMA), transforming growth factor β1 (TGF-β1), caspase-3 and fibronectin were scored immunohistochemically. Finally, the mRNA level of cytokine genes (IL-1β, IL-6, IL-10, interferon gamma (IFN-γ)), caspase-3, TGF-β1 and fibronectin were quantified using qPCR.

KEY FINDINGS

NR significantly suppressed Akt phosphorylation associated with increased number of caspase-3 positive cells especially in the fibrotic areas. Liver tissues of treated rats showed restoration of normal liver histology and decrease in collagen and fibronectin deposition. Furthermore, NR treatment ameliorated oxidative stress and inflammatory cytokine production.

SIGNIFICANCE

NR alleviated experimental liver fibrosis through inhibition of PI3K/Akt pathway beside its anti-inflammatory and antioxidant effects. Therefore, NR is a promising therapeutic candidate for hepatic fibrosis.

Naringenin prevents experimental liver fibrosis by blocking TGFβ-Smad3 and JNK-Smad3 pathways

AIM

To study the molecular mechanisms involved in the hepatoprotective effects of naringenin (NAR) on carbon tetrachloride (CCl₄)-induced liver fibrosis.

METHODS

Thirty-two male Wistar rats (120-150 g) were randomly divided into four groups: (1) a control group (n = 8) that received 0.7% carboxy methyl-cellulose (NAR vehicle) 1 mL/daily p.o.; (2) a CCl₄ group (n = 8) that received 400 mg of CCl₄/kg body weight i.p. 3 times a week for 8 wk; (3) a CCl₄ + NAR (n = 8) group that received 400 mg of CCl₄/kg body weight i.p. 3 times a week for 8 wk and 100 mg of NAR/kg body weight daily for 8 wk p.o.; and (4) an NAR group (n = 8) that received 100 mg of NAR/kg body weight daily for 8 wk p.o. After the experimental period, animals were sacrificed under ketamine and xylazine anesthesia. Liver damage markers such as alanine aminotransferase (ALT), alkaline phosphatase (AP), γ-glutamyl transpeptidase (γ-GTP), reduced glutathione (GSH), glycogen content, lipid peroxidation (LPO) and collagen content were measured. The enzymatic activity of glutathione peroxidase (GPx) was assessed. Liver histopathology was performed utilizing Masson’s trichrome and hematoxylin-eosin stains. Zymography assays for MMP-9 and MMP-2 were carried out. Hepatic TGF-β, α-SMA, CTGF, Col-I, MMP-13, NF-κB, IL-1, IL-10, Smad7, Smad3, pSmad3 and pJNK proteins were detected via western blot.

RESULTS

NAR administration prevented increases in ALT, AP, γ-GTP, and GPx enzymatic activity; depletion of GSH and glycogen; and increases in LPO and collagen produced by chronic CCl₄ intoxication (P < 0.05). Liver histopathology showed a decrease in collagen deposition when rats received NAR in addition to CCl₄. Although zymography assays showed that CCl₄ produced an increase in MMP-9 and MMP-2 gelatinase activity; interestingly, NAR administration was associated with normal MMP-9 and MMP-2 activity (P < 0.05). The anti-inflammatory, antinecrotic and antifibrotic effects of NAR may be attributed to its ability to prevent NF-κB activation and the subsequent production of IL-1 and IL-10 (P < 0.05). NAR completely prevented the increase in TGF-β, α-SMA, CTGF, Col-1, and MMP-13 proteins compared with the CCl₄-treated group (P < 0.05). NAR prevented Smad3 phosphorylation in the linker region by JNK since this flavonoid blocked this kinase (P < 0.05).

CONCLUSION

NAR prevents CCl₄ induced liver inflammation, necrosis and fibrosis, due to its antioxidant capacity as a free radical inhibitor and by inhibiting the NF-κB, TGF-β-Smad3 and JNK-Smad3 pathways.

Protective effect of a polysaccharide from Anoectochilus roxburghii against carbon tetrachloride-induced acute liver injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Anoectochilus roxburghii (Wall.) Lindl. is traditionally used for the treatment of various types of chronic and acute hepatitis in China. Considering that Anoectochilus roxburghii polysaccharide (ARPT) is the main constituent of Anoectochilus roxburghii, the present study was designed to investigate the hepatoprotective effect of ARPT and its possible mechanism in carbon tetrachloride (CCl₄)-induced mice.

MATERIAL AND METHODS

The hepatoprotective activity of ARPT (150, 300 and 500mg/kg) were investigated on CCl₄-induced acute liver damage in mice. The activities of alanine transaminase (ALT), aspartate transaminase (AST) were determined in serum. The hepatic levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were measured in liver homogenates. The levels of cytochrome P450 sub family 2E1 (CYP2E1), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), KC (Murine IL-8 ortholog), transforming growth factor-beta1 (TGF-β1), Bcl-2 and Bax were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The expressions of CYP2E1, nuclear factor-kappa B (NF-κB) p65 and caspase-3 were evaluated by western blot assays. The hepatic levels of TNF-α, IL-6, MIP-2 and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA). Furthermore, histopathological observation and terminal-deoxynucleoitidyl transferase mediated nick end labeling assay (TUNEL) were carried out on the separated livers of mice.

RESULTS

ARPT significantly decreased serum ALT and AST activities, hepatic MDA level, and markedly enhanced antioxidant enzyme (SOD, CAT and GSH-Px) activities and GSH level in hepatic tissue, in a dose-dependent manner, when compared to the model group. Histopathological observation revealed the hepatoprotective effect of ARPT against the damage. Furthermore, ARPT remarkably inhibited CYP2E1 mRNA expression, decreased NF-κB p65 expression and therefore to prevent the secretion of pro-inflammatory cytokines (TNF-α and IL-6) and chemokines (MCP-1, MIP-2 and KC), suppressed TGF-β1 expression and hepatocytes apoptosis. Moreover, ARPT could prevent DNA fragmentation based on TUNEL assay results.

CONCLUSION

These findings suggested that ARPT possessed hepatoprotective effect against CCl₄-induced hepatotoxicity in mice and the action might in part be through reducing oxidative stress, inflammation and apoptosis.

Protective effect of naringin against the LPS-induced apoptosis of PC12 cells: Implications for the treatment of neurodegenerative disorders

Several studies have demonstrated that increased apoptosis plays an essential role in neurodegenerative disorders. It has been demonstrated that lipopolysaccharide (LPS) induces apoptosis largely through the production of intracellular reactive oxygen species (ROS) and inflammatory mediators. In this study, we investigated the potential protective mechanisms of naringin (Nar), a pummelo peel extract, on LPS-induced PC12 cell apoptosis. Nar pre-conditioning prior to stimulation with LPS for 18 h was a prerequisite for evaluating PC12 cell viability and the protective mechanisms of Nar. Nar significantly improved cell survival in a time- and concentration-dependent manner. On the one hand, Nar downregulated cytochrome P450 2E1 (CYP2E1), inhibited the release of ROS, mitigated the stimulation of oxidative stress, and rectified the antioxidant protein contents of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), superoxide dismutase (SOD)2 and glutathione synthetase (GSS). On the other hand, Nar down-regulated inflammatory gene and protein expression, including interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, HMGB1, high mobility group box 1 protein (HMGB1), cyclo-oxygenase-2 (COX-2), the Toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-TNF receptor-associated factor 6 (TRAF6) path way and downstream mitogen activated protein kinase (MAPK) phosphorylation, activator protein transcription factor-1 (AP-1) and nuclear factor (NF)-κB. Moroever, Nar markedly attenuated the cytochrome c shift from the mitochondria to the cytosol and regulated caspase-3-related protein expression. To the best of our knowledge, this is the first study to report the antioxidant, anti-inflammatory and anti-apoptotic effects of Nar in neuronal-like PC12 cells. These results suggest that Nar can be utilized as a potential drug for the treatment of neurodegenerative disorders.

Inulin-type fructan and infusion of Artemisia vulgaris protect the liver against carbon tetrachloride-induced liver injury

BACKGROUND

Infusions of aerial parts of Artemisia vulgaris L. (Asteraceae) are used in herbal medicine to treat several disorders, including hepatosis.

PURPOSE

Evaluation of in vivo hepatoprotective effects of A. vulgaris infusion (VI) and inulin (VPI; i.e., the major polysaccharide of VI).

STUDY DESIGN

The hepatoprotective effect of A. vulgaris extracts on carbon tetrachloride (CCl₄)-induced hepatotoxicity and the probable mechanism involved in this protection were investigated in mice.

METHODS

A. vulgaris infusion (VI) was prepared according to folk medicine using the aerial parts of the plant. Carbohydrate, protein, and total phenolic content was determined in VI, and its phenolic profile was determined by high-performance liquid chromatography (HPLC). Male Swiss mice were orally pretreated for 7 days with VI or VPI (once per day). On days 6 and 7 of treatment, the mice were intraperitoneally challenged with CCl₄. Liver and blood were collected and markers of hepatic damage in plasma and oxidative stress in the liver were analyzed. Hepatic histology and inflammatory parameters were also studied in the liver. The scavenging activity of VI and VPI were evaluated in vitro using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.

RESULTS

VI contained 40% carbohydrates, 2.9% proteins and 9.8% phenolic compounds. The HPLC fingerprint analysis of VI revealed chlorogenic, caffeic and dicaffeoylquinic acids as major low-molar-mass constituents. Oral pretreatment with VI and VPI significantly attenuated CCl₄-induced liver damage, reduced the activity of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) in plasma, and prevented reactive oxygen species accumulation and lipid peroxidation in the liver. Comparisons with the CCl₄-treated group showed that VI and VPI completely prevented necrosis, increased the levels of reduced glutathione (GSH), and reduced tumor necrosis factor alpha (TNF-α) level in the liver. VI and VPI also exhibited high radical scavenging activity in vitro.

CONCLUSION

VI and VPI had remarkable hepatoprotective effects in vivo, which were likely attributable to antioxidant and immunomodulatory properties. The present findings support the traditional use of A. vulgaris infusion for the treatment of hepatic disorders.

Protective effects of theasinensin A against carbon tetrachloride-induced liver injury in mice

TSA markedly reduced the CCl₄-induced liver injury in mice.

Shugan Xiaozhi Decoction Attenuates Nonalcoholic Steatohepatitis by Enhancing PPAR and L-FABP Expressions in High-Fat-Fed Rats

This study aimed to investigate the effects of Shugan Xiaozhi decoction (SX) on nonalcoholic steatohepatitis (NASH) induced by high-fat diet in rats. The rats were randomly divided into 6 groups, namely, control, model, fenofibrate, and three different dosage of SX (10, 20, and 40 g/kg/day, p.o.). After establishing the NASH model, at 8 weeks of the experiment, treatments were administrated intragastrically to the fenofibrate and SX groups. All rats were killed after 4 weeks of treatment. Compared with the model group, alanine aminotransferase (ALT), aspartate aminotransferase (AST), free fatty acid (FFA), total cholesterol (TC), triacylglycerol (TG), and low-density lipoprotein cholesterol (LDL) serum in the serum were significantly reduced in all SX treatment groups in a dose-dependent manner. Evidence showed that SX could protect the liver by upregulating the gene and protein expressions of peroxisome proliferator-activated receptor alpha (PPARα) and liver fatty acid binding protein (L-FABP) in a dose-dependent manner. Chemical constituents of SX were further analyzed by ultraperformance liquid chromatography coupled with electrospray ionization mass spectrometry (UPLC-ESI-MS) and 30 chemicals in the ethanolic extract were tentatively identified. To conclude, our results clearly indicated that SX could protect liver functions and relieve hepatic steatosis and inflammation.

Endogenous n-3 Fatty Acids Alleviate Carbon-Tetrachloride-Induced Acute Liver Injury in Fat-1 Transgenic Mice

n-3 polyunsaturated fatty acids (PUFAs) are beneficial for numerous models of liver diseases. The probable protective effects of n-3 PUFA against carbon-tetrachloride- (CCl₄-) induced acute liver injury were evaluated in a fat-1 transgenic mouse that synthesizes endogenous n-3 from n-6 PUFA. Fat-1 mice and their WT littermates were fed a modified AIN93 diet containing 10% corn oil and were injected intraperitoneally with a single dose of CCl₄ or vehicle. CCl₄ challenge caused severe liver injury in WT mice, as indicated by serum parameters and histopathological changes, which were remarkably ameliorated in fat-1 mice. Endogenous n-3 PUFA decreased the elevation of oxidative stress induced by CCl₄ challenge, which might be attributed to the activation of Nrf2/keap1 pathway. Additionally, endogenous n-3 PUFA reduces hepatocyte apoptosis via suppressing MAPK pathway. These findings indicate that n-3 PUFA has potent protective effects against acute liver injury induced by CCl₄ in mice, suggesting that n-3 PUFA can be used for the prevention and treatment of liver injury.

Protective Effects of Genistein and Puerarin against Chronic Alcohol-Induced Liver Injury in Mice via Antioxidant, Anti-inflammatory, and Anti-apoptotic Mechanisms

This study aimed to investigate the protective effect of genistein or puerarin on chronic alcohol-induced liver injury in vivo and to explore the underlying mechanisms of hepatoprotective effects. Mice were administered genistein or puerarin (0.3 mmol kg(-1) body weight) and gastrically infused with 50% alcohol once per day for 5 weeks. Levels of serum transaminases, serum and hepatic lipids, hepatic antioxidant capacities, inflammation, apoptosis, and histopathological sections were analyzed. Results showed that genistein and puerarin exhibited similar effects in ameliorating alcohol-induced liver injury. However, genistein is more effective than puerarin in decreasing levels of malondialdehyde (1.05 ± 0.0947 vs 1.28 ± 0.213 nmol/mg pro, p < 0.05), tumor necrosis factor α (3.12 ± 0.498 vs 3.82 ± 0.277 pg/mg pro, p < 0.05), interleukin-6 (1.46 ± 0.223 vs 1.88 ± 0.309 pg/mg pro, p < 0.05), whereas puerarin is more effective than genistein in ameliorating serum activities or levels of alanine transaminase (35.8 ± 3.95 vs 42.6 ± 6.56 U/L, p < 0.05) and low-density lipoprotein cholesterol (1.12 ± 0.160 vs 1.55 ± 0.150 mmol/L, p < 0.05). In conclusion, both genistein and puerarin effectively alleviate hepatic damage induced by chronic alcohol administration through potential antioxidant, anti-inflammatory, or anti-apoptotic mechanisms.

Pequi (Caryocar brasiliense Camb.) almond oil attenuates carbon tetrachloride-induced acute hepatic injury in rats: Antioxidant and anti-inflammatory effects

Carbon tetrachloride (CCl₄) is a potent hepatotoxin, capable of generating free radicals that lead to oxidative stress and the inflammation process. Pequi almond oil (PAO) has been reported to possess unsaturated fatty acid and antioxidant compounds related to beneficial effects on oxidation and inflammatory conditions. The present study was undertaken to evaluate the hepatoprotective effects of handmade and coldpressed PAO on CCl₄-induced acute liver injury. The possible mechanisms underlying the effect on liver injury enzymes, histopathological parameters, lipid profile, lipid peroxidation, and antioxidant and detoxification defense systems, as well as inflammatory parameters, were determined. Rats treated with PAO (3 or 6 mL/kg) for 21 days before CCl₄ induction (3 mL/kg, 70%) showed significantly decreased levels of alanine aminotransferase and aspartate aminotransferase, milder hepatic lesions and higher levels of serum high-density lipoprotein compared to CCl₄ group. Moreover, PAO enhanced antioxidant capacity by increasing hepatic glutathione peroxidase and glutathione reductase enzyme activities, as well as reducing circulating concentrations of leptin and inflammatory mediators such as interleukin-6, leukotrienes -4 and -5 and the tumor necrosis factor receptor. In summary, PAO, especially cold-pressed oil, attenuated the CCl₄-induced alterations in serum and hepatic tissue in rats due to its antioxidant and anti-inflammatory properties.

Simultaneous Quantification of Seven Bioactive Flavonoids in Citri Reticulatae Pericarpium by Ultra-Fast Liquid Chromatography Coupled with Tandem Mass Spectrometry

INTRODUCTION

Citri Reticulatae Pericarpium (CRP) is a commonly-used traditional Chinese medicine with flavonoids as the major bioactive components. Nevertheless, the contents of the flavonoids in CRP of different sources may significantly vary affecting their therapeutic effects. Thus, the setting up of a reliable and comprehensive quality assessment method for flavonoids in CRP is necessary.

OBJECTIVE

To set up a rapid and sensitive ultra-fast liquid chromatography coupled with tandem mass spectrometry (UFLC-MS/MS) method for simultaneous quantification of seven bioactive flavonoids in CRP.

METHODS

A UFLC-MS/MS method coupled to ultrasound-assisted extraction was developed for simultaneous separation and quantification of seven flavonoids including hesperidin, neohesperidin, naringin, narirutin, tangeretin, nobiletin and sinensetin in 16 batches of CRP samples from different sources in China.

RESULTS

The established method showed good linearity for all analytes with correlation coefficient (R) over 0.9980, together with satisfactory accuracy, precision and reproducibility. Furthermore, the recoveries at the three spiked levels were higher than 89.71% with relative standard deviations (RSDs) lower than 5.19%. The results indicated that the contents of seven bioactive flavonoids in CRP varied significantly among different sources. Among the samples under study, hesperidin showed the highest contents in 16 samples ranged from 27.50 to 86.30 mg/g, the contents of hesperidin in CRP-15 and CRP-9 were 27.50 and 86.30 mg/g, respectively, while, the amount of narirutin was too low to be measured in some samples.

CONCLUSION

This study revealed that the developed UFLC-MS/MS method was simple, sensitive and reliable for simultaneous quantification of multi-components in CRP with potential perspective for quality control of complex matrices. Copyright © 2016 John Wiley & Sons, Ltd.

Liver Injury Assessment by Vetscan VS2 Analyzer and Most Frequently Used ALT/GTP Reagent

BACKGROUND AND AIM

Liver injury is estimated by serum alanine aminotransferases (ALT) levels in experimental animal models. Laboratories use various techniques to measure ALT levels including assay reagents and chemistry analyzers. VetScan VS2 (VS2) is widely used in veterinary clinics and research laboratories for highly reproducible, convenient and effective testing. Alternatively, ALT liquid reagent is used by laboratories to estimate liver injury in animal studies. The aim of this study was to perform comparative analyses of data obtained from these two assays in two different animal models.

METHODS

In this study, we used two different mouse models and compared the ALT levels measured using VetScan VS2 chemistry analyzer and ALT liquid reagent. Immunohistochemical analysis of hepatic tissue was also performed to document liver pathology. The first model is a high fat diet feeding model that results in a mild hepatic steatosis (fat accumulation in the liver) without elevation of ALT levels. For a severe liver injury model, we employed a hepatotoxin-induced liver injury model (carbon tetrachloride, CCl4), which leads to the development of hepatic fibrosis and very high ALT levels.

RESULTS

VetScan VS2 and ALT reagent gave different values of ALT for all animal groups. However, linear regression analysis showed a significantly high association between ALT levels obtained by VS2 and ALT liquid reagent in a high-fat feeding model with no liver injury. For the CCl₄ induced liver injury model, serum dilution (5 and 10 times) was performed to obtain accurate results with ALT reagent. ALT levels acquired from both techniques showed a close association. Interestingly, this correlation was closer when serum was diluted 5 fold.

CONCLUSION

This study demonstrates that both methods give similar results when evaluating liver injury in animal studies. However, the serum dilution factor is critical for severe liver injury assessment when using ALT reagent and requires some optimization. In this regard, VetScan VS2 is easier to use and gives comparable results.

Effects of Rhus tripartitum fruit extract on CCl4-induced hepatotoxicity and cisplatin-induced nephrotoxicity in rats

Rhus tripartitum D.C., Anacardiaceae, has traditionally been used in Tunisia against many illnesses. The present study investigates, for the first time, the protective effects of the methanol extract of Rhus tripartitum fruit (MERT) against CCl4-induced hepatotoxicity and cisplatin-induced nephrotoxicty in Wistar rats. ALT, AST, LDH, GGT, creatinin, urea, and uric acid levels were studied. The changes in antioxidant parameters such as malondialdehyde (MDA) and protein carbonyl contents were also determined. The increased levels of MDA (30.97 and 11.50 nmol MDA/mg protein in liver and kidney, respectively) and protein carbonyls (13.4 and 17.95 nmol/mg protein in liver and kidney, respectively) were attenuated by MERT pretreatment (19.35 and 6.1 nmol MDA/mg protein and 9.15 and 12 nmol/mg protein in liver and kidney, respectively). The MERT pretreatment significantly reduced the increased biochemical parameters of liver and kidney caused by CCl4 and cisplatin treatment. The histopathologic observation showed that MERT pretreatment restores the altered tissues. The observed results could be due to the high phenolic content and to MERT's important antioxidant potential. This study supports the hepatoprotective and nephroprotective effects of R. tripartitum.

Pharmacokinetics in Vitro and in Vivo of Two Novel Prodrugs of Oleanolic Acid in Rats and Its Hepatoprotective Effects against Liver Injury Induced by CCl4

Oleanolic acid (OA) is a well-known pentacyclic triterpenoid compound, which has been used as a dietary supplement and is supplied as an over-the-counter drug for the treatment of human liver diseases. These are reasons for the low bioavailability of OA which have restricted its wider application. In this study, two OA prodrugs (1,3-cyclic propanyl phosphate esters of OA) were designed and synthesized. The hepatoprotective effects of these prodrugs were evaluated against carbon tetrachloride (CCl4) induced liver injury in mice; the levels of alanine aminotransferase (ALT), lactic dehydrogenase (LDH), and aspartate aminotransferase (AST) were significantly increased, and the level of the hepatic malondialdehyde (MDA) was increased. The metabolism, in vitro, of the prodrugs was studied by incubation in rat liver microsome; the plasma pharmacokinetics and the biodistribution in vivo after intravenous (iv) injection to six rats were investigated, respectively. The prodrugs diminished gradually with time; most of the parent drugs were released within 30 min in vitro, and the presumed mechanism of the in vitro metabolism was confirmed. The plasma-concentration data in vivo was analyzed by a compartmental method: both the prodrugs and the corresponding released parent drugs existed at up to 48 h in rats. The t1/2 improved after intravenous administration in rats compared with direct injection of the parent drugs. All analyte concentrations were highest in the liver, and most of the prodrugs were excreted in feces (>47.11%). Therefore, 1,3-cyclic propanyl phosphate esters of OA can serve as a promising lead candidate for drugs.

Naringin inhibits lipopolysaccharide-induced damage in human umbilical vein endothelial cells via attenuation of inflammation, apoptosis and MAPK pathways

Endothelial cell activation, injury and dysfunction have been regarded as one of the initial key events in the pathogenesis of atherosclerosis. Lipopolysaccharide (LPS), an important mediator of inflammation, can cause endothelial cell damage and apoptosis. Naringin (Nar), one major flavanone glycoside from citrus fruits, shows various pharmacological actions, but the effect of Nar on LPS-induced damage in human umbilical vein endothelial cells (HUVECs) remains unknown. The present results showed that Nar significantly improved the survival rate of HUVECs, and decreased reactive oxygen species and intracellular Ca(2+) levels caused by LPS compared with model group. In addition, Nar obviously decreased cytochrome c release from mitochondria into cytosol. Moreover, Nar significantly down-regulated the protein or mRNA levels of IL-1, IL-6, TNF-α, VCAM-1, ICAM-1, NF-κB, AP-1, cleaved-3,-7,-9, p53, Bak and Bax, and up-regulated the expressions of Bcl-xl, Bcl-2 to suppress inflammation and apoptosis. Furthermore, Nar obviously inhibited phosphorylation levels of JNK, ERK and p38 MAPK. In conclusion, Nar exhibited potent effects against LPS-induced damage in HUVECs through the modulation of oxidative stress, inflammation, apoptosis and MAPK pathways, which should be developed as a potent candidate for the treatment of atherosclerosis in the future.

Cytoprotective mechanism of ferulic acid against high glucose-induced oxidative stress in cardiomyocytes and hepatocytes

Background

Ferulic acid (FA), a phenolic acid, is a potential therapy for diabetes mellitus. FA has been shown to protect against hepatic and myocardial injury and oxidative stress in obese rats with late-stage diabetes, but the mechanism of the antioxidative activity of FA is still unclear.

Objective

The aim of this study was to elucidate whether FA can prevent damage to cardiomyocytes and hepatocytes caused by high glucose (HG)-induced oxidative stress and whether the protection effects of FA on these cells are related to the Keap1-Nrf2-ARE signaling pathways.

Design

Cells were divided into four groups: a control group (cultured with normal medium), an HG group (medium containing 80 mmol/L glucose), an FA+HG group (medium containing 80 mmol/L glucose and 1, 5, or 10 µg/mL FA), and a dimethylbiguanide (DMBG)+HG group (medium containing 80 mmol/L glucose and 50 µg/mL DMBG).

Results

FA treatment significantly increased cell viability and significantly decreased cell apoptosis compared with the HG-treated group. Moreover, FA down-regulated the expression of Keap1 protein and up-regulated the expression of Nrf2 protein and gene transcription of HO-1 and glutathione S-transferase (GST) in a dose-dependent manner.

Conclusion

FA alleviated the HG-induced oxidative stress and decreased cell apoptosis in hepatocytes and cardiomyocytes. These effects were associated with the Keap1-Nrf2-ARE signaling pathway.