Dose- and time-dependent effects of luteolin on carbon tetrachloride-induced hepatotoxicity in mice

β-Cyclodextrin metal-organic framework as a green carrier to improve the dissolution, bioavailability, and liver protective effect of luteolin

The incidence of acetaminophen-induced liver injury has increased, but effective prevention methods are limited. Although luteolin has hepatoprotective activity, its low solubility and bioavailability limit its applications. Cyclodextrin metal-organic frameworks (CD-MOFs) possess 3D-network structures and large inner cavities, which make them excellent carriers of poorly soluble drugs. In this study, we used CD-MOFs as carriers to improve the dissolution of luteolin and assessed their antioxidant activity, bioavailability, and hepatoprotective effects. Luteolin was loaded into β-CD-MOF, γ-CD-MOF, β-CD, and γ-CD, and characterized by powder X-ray diffractometry (PXRD) and thermogravimetric analysis (TGA). Our results showed that luteolin-β-CD-MOF was the most stable. The main driving forces were hydrogen bonds and van der Waals forces, as determined by molecular simulation. The loading capacity of luteolin-β-CD-MOF was 14.67 wt%. Compared to raw luteolin, luteolin-β-CD-MOF exhibited a 4.50-fold increase in dissolution and increased antioxidant activity in vitro. Luteolin-β-CD-MOF increased the bioavailability of luteolin by approximately 4.04- and 11.07-fold in healthy rats and liver injured rats induced by acetaminophen in vivo, respectively. As determined by biochemical analysis, luteolin-β-CD-MOF exhibited a better hepatoprotective effect than raw luteolin in rats with acetaminophen-induced liver injury. This study provides a new approach for preventing acetaminophen-mediated liver damage.

Luteolin attenuates CCl4-induced hepatic injury by inhibiting ferroptosis via SLC7A11

BACKGROUND

Luteolin (3,4,5,7-tetrahydroxy flavone) is reported to strongly protect from acute carbon tetrachloride (CCl4) -induced liver injury or fibrosis. Ferroptosis can be induced by hepatic injury, and contributes to liver fibrosis development. The exact functional mechanism underlying luteolin inhibition of hepatic injury and whether ferroptosis is involved are unclear.

METHODS

Mice model and cell model of liver injury were constructed or induced to explore the effect and molecular mechanisms of Luteolin in the treatment of hepatic injury using CCl4. Cell Counting Kit-8 (CCK-8) and flow cytometry were used to evaluate HepG2 cell viability and apoptosis. The differential expressed genes involved in liver injury were scanned using RNA-seq and confirmed using functional study. Western blot was used to detect the indicators related to ferroptosis.

RESULTS

Luteolin attenuated hepatic injury by alleviating cell morphology and decreasing serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) levels in vivo mice models, and increasing cell viability, downregulating arachidonate 12-lipoxygenase (ALOX12), cyclooxygenase-2 (COX-2) and P21 protein expression, suppressing apoptosis in vitro cell models. Luteolin also inhibited ferroptosis by stimulating glutathione peroxidase 4 (GPX4) and mitochondrial ferritin (FTMT) protein expression, increasing glutathione (GSH) content, and minimizing Fe2+ and malondialdehyde (MDA) levels. Solute carrier family 7a member 11 (SLC7A11) was identified to be a key regulatory gene that participated in luteolin attenuation of CCl4-induced hepatic injuries in HepG2 cells using Microarray assay. Functional study showed that SLC7A11 can alleviate hepatic injury and ferroptosis.

CONCLUSION

Luteolin attenuated CCl4-induced hepatic injury by inhibiting ferroptosis via SLC7A11. SLC7A11 may serve as a novel alternative therapeutic target for hepatic injury.

Apolipoprotein E3 Containing Nanodiscs as Vehicles for Transport and Targeted Delivery of Flavonoid Luteolin

Luteolin is a flavonoid that possesses multiple beneficial biological properties, such as anticancer, antioxidant, and anti-inflammatory effects. The objective of this study is to test the hypothesis that luteolin can be transported across a cell via a nanodisc delivery system and delivered to intracellular sites. Luteolin was incorporated into reconstituted high-density lipoprotein complexes made up of apolipoprotein E3 (apoE3) N-terminal domain (apoE3NT) and 1,2-dimystrioyl-sn-glycero-3-phosphocholine. ApoE3NT confers the ability on nanodiscs to traverse the plasma membrane via low-density lipoprotein receptor or scavenger receptor-B1. Physicochemical characterization revealed that the nanodiscs were 17-22 nm in diameter as demonstrated by native polyacrylamide gel electrophoresis and dynamic lightering analysis and ∼660 kDa in size, with a luteolin content of ∼4 luteolin molecules/nanodisc. Luteolin appeared to be embedded in the nonpolar core of nanodiscs, as revealed by fluorescence quenching and polarization analysis and spectroscopic characterization. The presence of luteolin did not affect the ability of apoE3NT to mediate binding and cellular uptake of luteolin containing nanodiscs in macrophages, as inferred from immunofluorescence analysis that revealed apoE- and lipid-related fluorescence as punctate perinuclear vesicles and from flow cytometry studies. Lastly, luteolin appeared to be localized in the nucleus, having escaped the lysosomes following disassembly of the nanodiscs as suggested by fluorescence spectroscopy and microscopy analyses. Taken together, nanodiscs offer the potential to effectively transport luteolin and potentially therapeutic drugs into perinuclear sites in cells, where they can be available to enter the nucleus.

β-Cyfluthrin-Mediated Cytotoxicity of Cultured Rat Primary Hepatocytes Ameliorated by Cotreatment with Luteolin

The current study was designed to evaluate the possible protective effects of luteolin against β-cyfluthrin-mediated toxicity on the primary culture of rat hepatocytes (RHs). In the first step, the exposure of RHs to β-cyfluthrin (10, 20, 40, and 80 μM) was assessed by MTT. Second, redox condition was evaluated in cotreatment of cells with luteolin (20, 40, and 60 μM) and β-cyfluthrin (40 μM) at both medium and intra levels. In comparison to control, viability was lower in 40 and 80 μM β-cyfluthrin-treated groups at 24 h and all β-cyfluthrin-treated groups at 48 h (P < 0.05). Cotreatment with 20 or 40 μM luteolin + 40 μM β-cyfluthrin resulted in a higher viability value compared to β-cyfluthrin alone at 24 and 48 h of incubation (P < 0.05). Administration of 20 or 40 μM luteolin with β-cyfluthrin led to the decrease of malondialdehyde and total nitrate/nitrite and the increase of total antioxidant capacity (TAC) values in both medium and intrahepatocyte levels compared to the β-cyfluthrin-treated group at 48 h (P < 0.05). It seems that low and medium doses of luteolin possess the potential to reduce β-cyfluthrin-mediated hepatotoxicity via attenuation of peroxidative/nitrosative reactions and augmentation of TAC levels.

Protective effect of luteolin against chemical and natural toxicants by targeting NF-κB pathway

Humans are continuously exposed to environmental, occupational, consumer and household products, food, and pharmaceutical substances. Luteolin, a flavone from the flavonoids family of compounds, is found in different fruits and vegetables. LUT is a strong anti-inflammatory (via inhibition of NF-κB, ERK1/2, MAPK, JNK, IL-6, IL-8, and TNF-α) and antioxidant agent (reducing ROS and enhancement of endogenous antioxidants). LUT can chelate transition metal ions responsible for ROS generation and consequently repress lipoxygenase. It has been proven that NF-κB, as a commom cellular pathway plays a considerable role in the progression of inflammatory process and stimulates the expression of genes encoding inducible pro-inflammatory enzymes (iNOS and COX-2) and cytokines including IL-1β, IL-6, and TNF-α. This review summarizes the available literature discussing LUT and its potential protective role against pharmaceuticals-, metals-, and environmental compounds-induced toxicities. Furthermore, the review explains the involved protective mechanisms, especially inhibition of the NF-κB pathway.

NLRP3 inflammasome in rosmarinic acid-afforded attenuation of acute kidney injury in mice

Cisplatin (CP) is a well-known anticancer drug used to effectively treat various kinds of solid tumors. CP causes acute kidney injury (AKI) and unfortunately, there is no therapeutic approach in hand to prevent AKI. Several signaling pathways are responsible for inducing AKI which leads to inflammation in proximal convoluted tubule cells in the kidney. Furthermore, the nucleotide-binding oligomerization domain (NOD)-like receptor containing pyrin domain 3 (NLRP3) inflammasome is involved in the CP-induced AKI. In this study, we investigated therapeutic effects of rosmarinic acid (RA) against inflammation-induced AKI. RA was orally administered at the dose of 100 mg/kg for two consecutive days after 24 h of a single injection of CP at the dose of 20 mg/kg administered intraperitoneally in Swiss albino male mice. Treatment of RA inhibited the activation of NLRP3 signaling pathway by blocking the activated caspase-1 and downstream signal molecules such as IL-1β and IL18. CP activated HMGB1-TLR4/MyD88 axis was also found to be downregulated with the RA treatment. Activation of nuclear factor-κB and elevated protein expression of cyclooxygenase-2 (COX-2) were also found to be downregulated in RA-treated animals. Alteration of early tubular injury biomarker, kidney injury molecule-1 (KIM-1), was found to be subsided in RA-treated mice. RA has been earlier reported for antioxidant and anti-inflammatory properties. Our findings show that blocking a critical step of inflammasome signaling pathway by RA treatment can be a novel and beneficial approach to prevent the CP-induced AKI.

Medicinal plants used against hepatic disorders in Bangladesh: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Liver disease is a major cause of illness and death worldwide which accounts for approximately 2 million deaths per year worldwide, 1 million due to complications of cirrhosis and 1 million due to viral hepatitis and hepatocellular carcinoma. That's why it is seeking the researchers' attention to find out the effective treatment strategies. Phytochemicals from natural resources are the main leads for the development of noble hepatoprotective drugs. The majority of the natural sources whose active compounds are currently employed actually have an ethnomedical use. Ethnopharmacological research is essential for the development of these bioactive compounds. These studies not only provide scientific evidence on medicinal plants utilized for particular therapeutic purposes, but they also ensure cultural heritage preservation. Plenty of experimental studies have been well-documented that the ethnomedicinal plants are of therapeutics' interest for the advanced pharmacological intervention in terms of hepatic disorders.

AIM OF THE STUDY

This study summarizes the processes of hepatotoxicity induced by various toxins and explores identified hepatoprotective plants and their phytoconstituents, which can guide the extraction of novel phytochemical constituents from plants to treat liver injury. This review aimed to summarize the hepatoprotective activity of Bangladeshi medicinal plants where the bioactive compounds may be leads for the drug discovery in future.

MATERIALS AND METHODS

Literature searches in electronic databases, such as Web of Science, Science Direct, SpringerLink, PubMed, Google Scholar, Semantic Scholar, Scopus, BanglaJOL, and so on, were performed using the keywords 'Bangladesh', 'ethnomedicinal plants', 'Hepatoprotective agents' as for primary searches, and secondary search terms were used as follows, either alone or in combination: traditional medicine, medicinal plants, folk medicine, liver, hepatitis, therapeutic uses, and anti-inflammatory. Besides, several books, including the book entitled "Medicinal plants of Bangladesh: chemical constituents and uses" authored by Abdul Ghani, were carefully considered, which contained pharmacological properties and phytoconstituents of many medicinal plants growing and traditionally available in Bangladesh. Among them, the most promising plant species with their latest therapeutic effects against hepatic disorders were deeply considered in this review.

RESULTS

The results of this study revealed that in most cases, therapy using plant extracts stabilized altered hepatic biochemical markers induced by hepatotoxins. Initially, we investigated 32 plant species for hepatoprotective activity, however after extensive literature searching; we observed that 20 plants offer good pharmacological evidence of hepatoprotective function. Consequently, most bioactive compounds derived from the herbs including berberine, thymoquinone, andrographolide, ursolic acid, luteolin, naringenin, genistein, quercetin, troxerutin, morin, epigallocatechin-3-gallate, chlorogenic acid, emodin, curcumin, resveratrol, capsaicin, ellagic acid, etc. are appeared to be effective against hepatic disorders.

CONCLUSIONS

Flavonoids, phenolic acids, monoterpenoids, diterpenoids, triterpenoids, alkaloids, chromenes, capsaicinoids, curcuminoids, and anthraquinones are among the phytoconstituents were appraised to have hepatoprotective activities. All the actions displayed by these ethnomedicinal plants could make them serve as leads in the formulation of drugs with higher efficacy to treat hepatic disorders.

Hepatoprotective Potential of Pomegranate in Curbing the Incidence of Acute Liver Injury by Alleviating Oxidative Stress and Inflammatory Response

Hepatitis is an inflammatory disease of the liver and is considered one of the leading causes of death worldwide. Due to its scavenging activity, Punica granatum may be used for the treatment and prevention of liver diseases. The current study investigated the protective mechanism underlying the effects of pomegranate against a rat model of carbon tetrachloride–induced liver injury. Intraperitoneal injection of CCl₄ resulted in liver inflammation, oxidative stress, and accumulation of lipid in hepatocytes. CCl₄ induced a downregulation of superoxide dismutase (SOD), glutathione (GSH), and melonaldehyde (MDA). Pomegranate protection was assessed in terms of biochemical parameters, histopathology, and immunohistochemistry. Promegranate administration decreased inflammation, elevated serum enzymes and ROS production, and countered the debilitating effects caused by CCl₄. In addition, CCl₄-induced histological changes were absent in the crude pomegranate extract group, which also enhanced the scavenging activity of reactive oxygen species by enhancing the antioxidant defense mechanism as confirmed by detecting MDA, SOD, and GSH expressions. The migration of CD68⁺ macrophages was halted at the injured area of the central vein and the number of macrophages was reduced to the normal control by the crude extract compared to the positive control silymarin group. Likewise, protective effects of ethylacetate and the aqueous fraction of the crude extract were also observed. However, the butanol and n-hexane fractions displayed increased levels of ALT, AST, and ALP as compared to silymarin. About 25% damage to hepatocytes was observed in the butanol and n-hexane group by histopathological examination, which is a little better compared to the CCl₄-treated group. The crude extract and its ethyl acetate and aqueous fractions may be accountable for the hepatoprotective potential of Punica granatum, which was further confirmed by in vivo experiments. Together, these findings confirm that pomegranate exerts hepatoprotective activity against CCl₄-induced oxidative stress and liver damage.

Luteolin mitigates tamoxifen-associated fatty liver and cognitive impairment in rats by modulating beta-catenin

BACKGROUND AND AIM

Tamoxifen (TAM) therapy has been associated with fatty liver diseases. Recently, multiple reports have also shown that TAM is related to cognitive impairment in patients with breast cancer. Luteolin, a natural flavonoid, has been traditionally used to treat various inflammatory disorders, such as chronic liver diseases, cognitive impairments, and cancers. This study aimed to evaluate the potential protective effects of luteolin against the cognitive defects and liver steatosis induced by TAM in rats.

EXPERIMENTAL APPROACH

The diseased group was subcutaneously (s.c) injected with TAM at a dose of 1 mg/kg daily for 7 days. The cotreated groups were given luteolin via oral gavage at a dose of 20 or 40 mg/kg concomitantly with s.c injection of TAM at a dose of 1 mg/kg for 7 days. All the groups were subjected to behavioral tests 24 h after the last TAM injection. Then, the rats were sacrificed 3 days after the last TAM injection.

RESULTS

Luteolin cotreatment significantly alleviated the behavioral defects in rats with TAM-induced cognitive impairment. This finding was supported by the reversal of neurodegeneration in the cortex and in the hippocampal regions of the brain. Furthermore, luteolin attenuated hepatic steatosis and decreased the levels of serum aminotransferases and hypertriglyceridemia. As an anti-inflammatory agent, luteolin cotreatment similarly decreased the levels of hepatic inflammatory markers and increased the levels of hepatic β-catenin in TAM-induced fatty liver.

CONCLUSIONS

Luteolin improved the TAM-induced cognitive impairment and hepatic steatosis in rats by alleviating inflammation and modulating hepatic β-catenin levels.

Protective Effect of Luteolin on D-Galactosamine (D-Gal)/Lipopolysaccharide (LPS) Induced Hepatic Injury by in Mice

To observe the effects of luteolin on galactosamine (D-Gal)/lipopolysaccharide (LPS) induced liver injury in mice. Male C57BL/6 mice were randomly divided into 4 groups: normal control group, D-GaI/LPS group, D-GaI/LPS + luteolin (Lu, 20 mg/kg), and D-GaI/LPS + luteolin (Lu, 40 mg/kg). Mice in the normal control group and D-GaI/LPS group were given distilled water while other groups were given drugs in 7 days by gavage. 4 hours after the continuous administration, Gal (700 mg/kg) and LPS (10 mg/kg) were injected intraperitoneally. Mice in the normal control group were given the same volume of vegetable oil solution. 24 h after the establishment of the mice model, blood and liver samples were collected. Hematoxylin (HE) staining was used to observe the changes of hepatic histopathology. Alanine aminotransferase (ALT) and glutamic oxalacetic transaminase (AST) in serum, interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor (TNF-α) were measured by related kits. Western blotting was used to demonstrate the expression levels of related inflammation proteins. Lu significantly reduced levels of proinflammatory cytokines including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in serum and liver. Lu restored the pathological changes after galactosamine (D-Gal)/lipopolysaccharide (LPS) treatment. In addition, Lu regulated proteins levels of the NLRP3/NF-κB pathway in liver. Lu exhibited therapeutical effects on D-GaI/LPS induced liver injury in mice which might be related to the regulation of the NLRP3/NF-κB pathway.

Phenols fragment of Veronica ciliata Fisch. ameliorate free radical-induced nonalcoholic fatty liver disease by mediating PI3K/Akt signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Veronica ciliata Fisch. is used in numerous of Tibetan medicine prescriptions because of its hepatoprotective effect.

AIMS OF THIS STUDY

Here, we aimed to investigate the hepatoprotective effect and mechanism of phenolic fraction (PF) of V. ciliata Fisch. on liver injury induced by free radical.

MATERIALS AND METHODS

BRL 3A cells were pre-treated with PF and luteolin (Lut) following tert-butyl hydroperoxide (t-BHP) treatment. The cell viability, lactate dehydrogenase (LDH) levels, reactive oxygen species (ROS) generation, apoptosis, cell cycle and autophagy were analyzed. Apoptotic, inflammatory, and autophagy,- related proteins were analyzed using Western blotting. The combination of molecular docking and drug affinity targeting experiments (DARTS) were first utilized to analysis the target protein of Lut.

RESULTS

PF effectively suppressed t-BHP-induced apoptosis caused by mitochondrial dysfunction, which were associated with inhibiting ROS generation. Further investigation indicated that PF significantly suppressed apoptosis, inflammation, and autophagy by regulating the expression of related proteins. The results of molecular docking and drug affinity targeting experiments (DARTS) revealed that PI3K was the target protein of PF and Lut. Further studies have shown that PF relieved liver injury induced by t-BHP via suppressing phosphorylated expression of PI3K.

CONCLUSION

Our results indicate that PF effectively protect against hepatotoxicity induced by t-BHP through inhibiting the abnormal activation of PI3K-Akt signaling pathway and highlight the health benefits of PF regarding oxidative stress, proving it to be an important source of bioactive compounds associated with Nonalcoholic fatty liver disease (NAFLD).

Luteolin protects against lead acetate-induced nephrotoxicity through antioxidant, anti-inflammatory, anti-apoptotic, and Nrf2/HO-1 signaling pathways

Lead (Pb) is one of the most common heavy metal pollutants affecting living organisms. It induces nephrotoxicity with significant alterations in renal structure and function. Luteolin (LUT) a flavonoid present in various plant products is well known for exhibiting numerous pharmacological properties. We evaluated the protective efficacy of LUT against Pb-induced renal injury in male Wistar rats. Four experimental groups: control, LUT (50 mg/kg, orally), PbAc (20 mg/kg, i.p.), LUT + PbAc (at the aforementioned doses) were maintained for 7 days. PbAc administration significantly increased renal Pb accumulation, urea, and creatinine levels in serum, and induced renal histological alterations. Additionally, compared to the control rats, PbAc-treated rats exhibited significantly low levels of antioxidant enzyme activity and expression (SOD, CAT, GPx and GR), as well as high MDA levels. Moreover, PbAc exposure downregulated Nfe212 and Homx1 mRNA expression and significantly increased inflammatory marker (TNF-α, IL-1β and NO) levels in renal tissue. PbAc significantly upregulated the synthesis of apoptotic related proteins and downregulated antiapoptotic protein expression. Notably, LUT pretreatment of PbAc-treated rats provided significant nephroprotection and reversed the alterations in the abovementioned parameters. In conclusion, LUT provided significant protection against PbAc intoxication via antioxidant, anti-inflammatory, and anti-apoptotic activities by activating the Nrf2/ARE signaling pathway.

NAFLD Preclinical Models: More than a Handful, Less of a Concern?

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of liver diseases ranging from simple steatosis to non-alcoholic steatohepatitis, fibrosis, cirrhosis, and/or hepatocellular carcinoma. Due to its increasing prevalence, NAFLD is currently a major public health concern. Although a wide variety of preclinical models have contributed to better understanding the pathophysiology of NAFLD, it is not always obvious which model is best suitable for addressing a specific research question. This review provides insights into currently existing models, mainly focusing on murine models, which is of great importance to aid in the identification of novel therapeutic options for human NAFLD.

Antipyretic and hepatoprotective potential of Tinospora crispa and investigation of possible lead compounds through in silico approaches

This research describes an investigation of the antipyretic and hepatoprotective properties of both a crude organic extract and various subfractions of the ethnomedicinal plant Tinospora crispa, using appropriate animal models. In an attempt to identify potential lead hepatoprotective compounds, in silico experiments were utilized. Antipyretic activity was assessed via the Brewer's yeast-induced pyrexia method, while hepatoprotective effects were evaluated in a carbon tetrachloride (CCl4)-induced animal model. A computer-aided prediction of activity spectra for substances (PASS) model was applied to a selection of documented phytoconstituents, with the aim of identifying those compounds with most promising hepatoprotective effects. Results were analyzed using Molinspiration software. Our results showed that both the methanol extract (METC) and various subfractions (pet ether, PEFTC; n-hexane, NHFTC; and chloroform, CFTC) significantly (p < .05) reduced pyrexia in a dose-dependent manner. In CCl4-induced hepatotoxicity studies, METC ameliorated elevated hepatic markers including serum alanine amino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP), and total bilirubin. Malondialdehyde (MDA) levels were significantly reduced, while superoxide dismutase (SOD) levels were significantly increased. Among a selection of metabolites of T. crispa, genkwanin was found to be the most potent hepatoprotective constituent using PASS predictive models. These results demonstrate that both the methanolic extract of T. crispa and those fractions containing genkwanin may offer promise in reducing pyrexia and as a source of potential hepatoprotective agents.

Antagonistic Efficacy of Luteolin against Lead Acetate Exposure-Associated with Hepatotoxicity is Mediated via Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Activities

The abundant use of lead (Pb; toxic heavy metal) worldwide has increased occupational and ecosystem exposure, with subsequent negative health effects. The flavonoid luteolin (LUT) found in many natural foodstuffs possesses antioxidant and anti-inflammatory properties. Herein, we hypothesized that LUT could mitigate liver damage induced by exposure to lead acetate (PbAc). Male Wistar rats were allocated to four groups: control group received normal saline, LUT-treated group (50 mg/kg, oral, daily), PbAc-treated group (20 mg/kg, i.p., daily), and LUT+PbAc-treated group (received the aforementioned doses via the respective routes of administration); the rats were treated for 7 days. The results revealed that PbAc exposure significantly increased hepatic Pb residue and serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin value. Oxidative reactions were observed in the liver tissue following PbAc intoxication, characterized by the depletion and downregulation of antioxidant proteins (glutathione, glutathione reductase, glutathione peroxidase, superoxide dismutase, catalase, nuclear factor erythroid 2-related factor 2, and heme oxygenase-1), and an increase in oxidants (malondialdehyde and nitric oxide). Additionally, PbAc increased the release and expression of the pro-inflammatory cytokines (tumor necrosis factor alpha and interleukin-1 beta), inducible nitric oxide synthase, and nuclear factor kappa B. Moreover, PbAc enhanced hepatocyte loss by increasing the expression of pro-apoptotic proteins (Bax and caspase-3) and downregulating the anti-apoptotic protein (Bcl-2). The changes in the aforementioned parameters were further confirmed by noticeable histopathological lesions. LUT supplementation significantly reversed all of the tested parameters in comparison with the PbAc-exposed group. In conclusion, our findings describe the potential mechanisms involved in the alleviation of PbAc-induced liver injury by luteolin via its potent anti-inflammatory, antioxidant, and anti-apoptotic properties.

Biological activities, isolated compounds and HPLC profile of Verbascum nubicum

Context: Genus Verbascum (Scrophulariaceae) comprises about 360 species of flowering plants. Verbascum has been used in traditional medicine as an astringent, antitussive, analgesic and anti-inflammatory. Objective: Nothing was found in the available literature concerning Verbascum nubicum Murb; therefore, the study evaluates the biological activities, isolated compounds and HPLC profile. Materials and methods: Methanol extract (VME) and butanol fraction (VBF) of air-dried powdered V. nubicum were obtained. Four compounds were isolated from VBE and identified by 1H- and 13C-NMR. High-performance liquid chromatography (HPLC) profile was determined for (VME). LD50, in vitro antioxidant, in vivo antiulcerogenic and anti-inflammatory activities as well as hepatoprotective activity were assessed. Anti-ulcerogenic and hepatoprotective activities were supported by histopathological examinations. Results: HPLC analysis of VME revealed the presence of luteolin 7-glucoside (2215.43 mg/100 g), hesperidin (954.51 mg/100 g) and apigenin (233.15 mg/100 g) as major compounds. Four compounds were isolated and confirmed by NMR data, were identified as gentiopicroside, luteolin, aucubin and gallic acid. The LD50 of VME and VBF extracts were calculated to be 8200 and 4225 mg/kg b.w., respectively. IC50 values of VBE and VMF as measured by DPPH·method were 43.6 and 50 µg/mL, respectively. Also, anti-inflammatory effect of VME (400 mg/kg b.w.) and VBF (200 mg/kg b.w.) induced edema model after 120 min were 61.93 and 56.13%, respectively. Antiulcerogenic activity of VME (400 mg/kg b.w.) and VBF (200 mg/kg b.w.) in albino rats were 65.14 and 84.57%, respectively. Conclusions: The V. nubicum extracts displayed safe and promising antioxidant, anti-inflammatory and hepatoprotective properties. It can be also applied in the pharmacy industry, food industry and healthcare.

Recent advances in our understanding of mast cell activation - or should it be mast cell mediator disorders?

INTRODUCTION

An increasing number of patients present with multiple symptoms affecting many organs including the brain due to multiple mediators released by mast cells. These unique tissue immune cells are critical for allergic reactions triggered by immunoglobulin E (IgE), but are also stimulated (not activated) by immune, drug, environmental, food, infectious, and stress triggers, leading to secretion of multiple mediators often without histamine and tryptase. The presentation, diagnosis, and management of the spectrum of mast cell disorders are very confusing. As a result, neuropsychiatric symptoms have been left out, and diagnostic criteria made stricter excluding most patients. Areas covered: A literature search was performed on papers published between January 1990 and November 2018 using MEDLINE. Terms used were activation, antihistamines, atopy, autism, brain fog, heparin, KIT mutation, IgE, inflammation, IL-6, IL-31, IL-37, luteolin, mast cells, mastocytosis, mediators, mycotoxins, release, secretion, tetramethoxyluteolin, and tryptase. Expert opinion: Conditions associated with elevated serum or urine levels of any mast cell mediator, in the absence of comorbidities that could explain elevated levels, should be considered 'Mast Cell Mediator Disorders (MCMD).' Emphasis should be placed on the identification of unique mast cell mediators, and development of drugs or supplements that inhibit their release.

Extracts from Fermented Black Garlic Exhibit a Hepatoprotective Effect on Acute Hepatic Injury

The mechanism of hepatoprotective compounds is usually related to its antioxidant or anti-inflammatory effects. Black garlic is produced from garlic by heat treatment and its anti-inflammatory activity has been previously reported. Therefore, the aim of this study was to investigate the hepatoprotective effect of five different extracts of black garlic against carbon tetrachloride (CCl₄)-induced acute hepatic injury (AHI). In this study, mice in the control, CCl₄, silymarin, and black garlic groups were orally administered distilled water, silymarin, and different fraction extracts of black garlic, respectively, after CCl₄ was injected intraperitoneally to induce AHI. The results revealed that the n-butanol layer extract (BA) and water layer extract (WS) demonstrated a hepatoprotective effect by reducing the levels of alanine aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and hepatic malondialdehyde (MDA). Furthermore, the BA and WS fractions of black garlic extract increased the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd), tumor necrosis factor alpha (TNF-α), and the interleukin-1 (IL-1β) level in liver. It was concluded that black garlic exhibited significant protective effects on CCl₄-induced acute hepatic injury.

Protection against nonalcoholic steatohepatitis through targeting IL-18 and IL-1alpha by luteolin

BACKGROUND

The management of nonalcoholic steatohepatitis (NASH) is still a crosstalk so the current study was designed to evaluate the effect of different luteolin doses on an experimental model of NASH and to elucidate novel anti-inflammatory pathways underlying its effect.

METHODS

Adult male Wistar rats (200-220 g; n = 60) were used. Rats were fed a high carbohydrate/high fat diet (˜ 30% carbohydrate and 42% fat) daily for 12 weeks to induce NASH. Luteolin (10, 25, 50 or 100 mg/kg/day) was administered as a suspension (10% w/v in 0.9% NaCl) using an oral gavage. Histopathological changes (necrosis, inflammation and steatosis) were evaluated. Biomarkers for liver function, lipid peroxidation, extracellular matrix deposition and anti-oxidant activity were measured. Levels of IFN-γ, TNF-α and IL-1α and IL-18 were measured.

RESULTS

Obtained results showed ability of luteolin to reduce activity of ALT and AST and to decrease levels of bilirubin, hyaluronic acid and malondialdehyde significantly (p <  0.05). Also, luteolin showed an anti-oxidant activity as indicated by the significant (p <  0.05) increase in reduced glutathione. Finally, a significant (p <  0.05) decrease in IFN-γ, TNF-α, IL-1α and IL-18 levels was observed most notably in groups that received high doses of luteolin (50 and 100 mg/kg).

CONCLUSIONS

Luteolin can protect against non-alcoholic steatohepatitis through targeting the pro-inflammatory IL-1 and Il-18 pathways in addition to an antioxidant effect.

The Falconoid Luteolin Mitigates the Myocardial Inflammatory Response Induced by High-Carbohydrate/High-Fat Diet in Wistar Rats

Luteolin is a major component of many medicinal plants and traditional medicines. The current study aims at testing its protective effect against high-carbohydrate/high-fat (HCHF) diet-induced cardiac dysfunction in rats. Male Wistar rats were divided into six groups as follows: control group that received standard rat chow, group received HCHF diet (~ 30% carbohydrate and 42% fat) daily for 16 weeks, and four groups received HCHF diet concurrently with luteolin (10, 25, 50 or 100 mg/kg; 10% w/v suspension in 0.9% NaCl) daily from the first week by oral gavage. Body weight was measured weekly. At the end of the study, histopathological examinations of stained heart sections were carried out. Lipid profile, oxidative stress, and cardiac function biomarkers were measured. Furthermore, neurohumoral mediators and inflammatory cytokines (TNF-α, IL-18) were assigned. Results showed a significant improvement in cardiac function, tissue integrity, and a decrease in the compensatory neurohumoral mediators by luteolin 50 and 100 mg/kg. In addition, a significant (P < 0.05) decrease in collagen deposition, fibrosis percentage, lipid peroxidation, and inflammatory cells (macrophages and lymphocytes) infiltration was observed. Tested doses of luteolin decreased lipid peroxidation and elevated the endogenous antioxidant biomarkers (reduced glutathione and superoxide dismutase) significantly (P < 0.05). Finally, luteolin decreased TNF-α and IL-18 (P < 0.001) in a dose-dependent manner. It can be concluded that luteolin has a cardioprotective effect against HCHF diet-induced myocardial inflammation through antioxidant anti-inflammatory mechanisms.

Hepatoprotective activity of Macrothelypteris torresiana (Gaudich.) aerial parts against CCl4-induced hepatotoxicity in rodents and analysis of polyphenolic compounds by HPTLC

Macrothelypteris torresiana is a fern species belonging to family Thelypteridaceae. The present study was conducted to evaluate hepatoprotective potential of ethanol extract from M. torresiana aerial parts (EEMTAP) and detect the polyphenolic compounds present in the extract using high performance thin layer chromatography (HPTLC). Hepatoprotective potential of EEMTAP were tested at doses of 300 and 600 mg/kg, per os (p.o.), on Wistar albino rats. The extract and silymarin treated animal groups showed significant decrease in activities of different biochemical parameters like serum glutamic oxaloacetic transaminase (SGOT), serum glutamate-pyruvate transaminase (SGPT), alkaline phosphatase (ALP), which were elevated by carbon tetrachloride (CCl₄) intoxication. The levels of total bilirubin and total protein alongwith the liver weight were also restored to normalcy by EEMTAP and silymarin treatment. After CCl₄ administration the level of hepatic antioxidant enzymes such as Glutathione (GSH) and Catalase (CAT) were decreased whereas the level of hepatic lipid peroxidation (LPO) was elevated. The level of these hepatic antioxidant enzymes were also brought to normalcy by EEMTAP and silymarin treatment. Histological studies supported the biochemical findings and treatment with EEMTAP at doses 300 and 600 mg/kg, p.o. was found to be effective in restoring CCl₄-induced hepatotoxicity in rats. A simple HPTLC analysis was conducted for the detection of polyphenolic compounds in EEMTAP, and the result revealed the presence of caffeic acid as phenolic acid and quercetin as flavonoid. The proposed HPTLC method is simple, concise and provides a good resolution of caffeic acid and quercetin from other constituents present in EEMTAP.

Luteolin Treatment Protects against Renal Ischemia-Reperfusion Injury in Rats

Renal ischemia-reperfusion (I/R) injury is a common but severe scientific problem. Luteolin has great anti-inflammatory and antioxidant effects. In this study, we studied the effect of luteolin on renal I/R injury in rats. Intragastric administration of luteolin or saline was performed in Sprague-Dawley rats before (40 mg/kg for three days) and after (one day) renal I/R modeling. Kidney and blood samples were harvested to detect the severity of renal injury 24 hours after operation. The results showed that luteolin-treated rats exhibited milder histomorphological changes with lower scores of renal histological lesions; lower blood urea nitrogen and creatinine levels; lower renal malondialdehyde (MDA), 8-oxo-deoxyguanosine (8-OHdG), and myeloperoxidase (MPO) levels; and higher superoxide dismutase (SOD) and catalase (CAT) activities in the kidney. Luteolin attenuated the increased levels of serum and renal tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, renal high mobility group box-1 (HMGB1), and nuclear factor kappa β (NF-κB) expression levels in I/R rats. Furthermore, luteolin treatment significantly reduced renal cell apoptosis and endoplasmic reticulum (ER) stress caused by renal I/R injury. In conclusion, luteolin improved renal function in I/R rats by reducing oxidative stress, neutrophil infiltration, inflammation, renal cell apoptosis, and expression of HMGB1 and NF-κB, and ER stress.

Hepatoprotective effects of Vaccinium arctostaphylos against CCl4-induced acute liver injury in rats

BACKGROUND

This study was carried out to evaluate the antioxidant and hepatoprotective effects of Vaccinium arctostaphylos (V.a) methanolic extract on carbon tetrachloride (CCl4)-induced acute liver injury in Wistar rats.

METHODS

Total phenolic and total flavonoid contents as well as antioxidant activity of V.a were determined. Extracts of V.a at doses of 200 and 400 mg/kg were administered by oral gavage to rats once per day for 7 days and then were given an intraperitoneal injection of 1 mL/kg CCl4 (1:1 in olive oil) for 3 consecutive days. Serum biochemical markers of liver injury, oxidative markers, as well as hydroxyproline (HP) content and histopathology of liver were evaluated.

RESULTS

The obtained results showed that V.a had strong antioxidant activity. Treatment of rats with V.a blocked the CCl4-induced elevation of serum markers of liver function and enhanced albumin and total protein levels. The level of hepatic HP content was also reduced by the administration of V.a treatment. Histological examination of the liver section revealed that V.a prevented the occurrence of pathological changes in CCl4-treated rats.

CONCLUSIONS

These findings suggested that V.a may be useful in the treatment and prevention of hepatic injury induced by CCl4.

Protective effects of flavonoids isolated from Korean milk thistle Cirsium japonicum var. maackii (Maxim.) Matsum on tert-butyl hydroperoxide-induced hepatotoxicity in HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Milk thistle leaves and flowers have been traditionally used as herbal remedy to alleviate liver diseases for decades. Korean milk thistle, Cirsium japonicum var. maackii (Maxim.) Matsum has been employed in traditional folk medicine as diuretic, antiphlogistic, hemostatic, and detoxifying agents.

AIM OF THE STUDY

The aim of current investigation was to evaluate hepatoprotective properties of the MeOH extract of the roots, stems, leaves and flowers of Korean milk thistle as well as four isolated flavonoids, luteolin, luteolin 5-O-glucoside, apigenin and apigenin 7-O-glucuronide during t-BHP-induced oxidative stress in HepG2 cells.

MATERIALS AND METHODS

Hepatoprotective potential of the MeOH extracts and flavonoids derived from Korean milk thistle against t-BHP-induced oxidative stress in HepG2 cells were evaluated following MTT method. Incubating HepG2 cells with t-BHP markedly decreased the cell viability and increased the intracellular ROS generation accompanied by depleted GSH levels. Protein expression of heme oxygenase (HO-1) and nuclear factor-E2-related factor 2 (Nrf-2) was determined by Western blot.

RESULTS

Our findings revealed that pretreating HepG2 cells with MeOH extracts and bioactive flavonoids significantly attenuated the t-BHP-induced oxidative damage, followed by increased cell viability in a dose-dependent manner. The results illustrate that excess ROS generation was reduced and GSH levels increased dose-dependently when HepG2 cells were pretreated with four flavonoids. Moreover, Western blotting analysis demonstrated that protein expressions of Nrf-2 and HO-1 were also up-regulated by flavonoids treatment.

CONCLUSIONS

These results clearly demonstrate that the MeOH extracts and flavonoids from Korean milk thistle protected HepG2 cells against oxidative damage triggered by t-BHP principally by modulating ROS generation and restoring depleted GSH levels in addition to the increased Nrf-2/HO-1 signaling cascade. These flavonoids are potential natural antioxidative biomarkers against oxidative stress-induced hepatotoxicity.

Regulation of Sirt1/Nrf2/TNF-α signaling pathway by luteolin is critical to attenuate acute mercuric chloride exposure induced hepatotoxicity

Inorganic mercury, though a key component of pediatric vaccines, is an environmental toxicant threatening human health via accumulating oxidative stress in part. Luteolin has been of great interest because of its antiinflammatory, anticarcinogenic and antioxidative effects. Here we hypothesized that luteolin would attenuate hepatotoxicity induced by acute inorganic mercury exposure. Kunming mice were treated with luteolin (100 mg/kg) 24 h after administration of 4 mg/kg mercuric chloride (HgCl₂). The results showed that luteolin ameliorated HgCl₂ induced anemia and hepatotoxicity, regulating radical oxygen species (ROS) production and hepatocyte viability in vitro and oxidative stress and apoptosis in vivo. Furthermore, luteolin reversed the changes in levels of inflammation- and apoptosis-related proteins involving NF-κB, TNF-α, Sirt1, mTOR, Bax, p53, and Bcl-2, and inhibited p38 MAPK activation. Luteolin enhanced antioxidant defense system based on Keap1, Nrf2, HO-1, NQO1, and KLF9. Moreover, luteolin did not affect miRNA-146a expression. Collectively, our findings, for the first time, elucidate a precise mechanism for attenuation of HgCl₂-induced liver dysfunction by dietary luteolin via regulating Sirt1/Nrf2/TNF-α signaling pathway, and provide a foundation for further study of luteolin as a novel therapeutic agent against inorganic mercury poisoning.

Hepatoprotective activity of viscosine is mediated by attenuation of hepatic macrophages and iNOS expression in CCl4-intoxicated rats

This study investigated the molecular mechanism(s) of the protective effects of a C-alkylated flavonoid, viscosine on an animal model of CCl₄-induced hepatotoxicity. Viscosine at 20, 50 and 100 mg kg^-1 was orally administered in a dose dependent manner per day for 3 days before the CCl₄ (1 : 1 v/v in olive oil, 1 ml kg^-1) treatment and 2 days after the treatment. Hepatoprotection was assessed in terms of reduction in serum enzyme activities (ALT, AST, and ALP) that occur after CCl₄ injury, and by histopathology and immunohistochemistry. The rise in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in CCl₄-intoxicated rats was markedly suppressed by viscosine in a concentration dependent manner. The decrease in the activity of hepatic antioxidant enzyme, SOD, was significantly prevented by viscosine, likewise gradually the levels of MDA and GSH were also normalized compared to silymarin. Viscosine also reduced the CCl₄-induced damaged area from 2% to 0% as assessed by histopathology and prevented the mixed inflammatory infiltrate. Viscosine attenuated the inflammation in the liver around the injured central vein region by downregulating the CCl₄ induced activation of hepatic CD68+ macrophages, thereby reducing their number as well. The expression of inducible nitric oxide synthase (iNOS) was more potentially suppressed by viscosine compared to the FDA approved positive control silymarin. The results of this study indicate that viscosine could be effective in protecting the liver from acute CCl₄-induced injury. The hepatoprotective mechanisms of viscosine may be related to the free radical scavenging and attenuation of oxidative stress, as well as to the inhibition of inflammatory response in the liver. Here, we are proposing a novel mechanism of action of viscosine and suggesting that it may be a safe and better in vivo antioxidant.

Spectrum of mast cell activation disorders

Mast cell (MC) activation disorders present with multiple symptoms including flushing, pruritus, hypotension, gastrointestinal complaints, irritability, headaches, concentration/memory loss and neuropsychiatric issues. These disorders are classified as: cutaneous and systemic mastocytosis with a c-kit mutation and clonal MC activation disorder, allergies, urticarias and inflammatory disorders and mast cell activation syndrome (MCAS), idiopathic urticaria and angioedema. MCs are activated by IgE, but also by cytokines, environmental, food, infectious, drug and stress triggers, leading to secretion of multiple mediators. The symptom profile and comorbidities associated with these disorders, such as chronic fatigue syndrome and fibromyalgia, are confusing. We propose the use of the term 'spectrum' and highlight the main symptoms, useful diagnostic tests and treatment approaches.

Nephroprotective activities of rosmarinic acid against cisplatin-induced kidney injury in mice

Rosmarinic acid (RA) is a natural phenolic compound with a broad range of applications, from food preservatives to cosmetics. Increasing amounts of evidence suggests its beneficial effects against various pathological conditions. The aim of this study was to investigate the therapeutic activity of rosmarinic acid (RA) against cisplatin (CP)-induced nephrotoxicity. RA was administered by oral gavage at doses of 1, 2 and 5mg/kg for two successive days, 48 h after intraperitoneal CP injection (13 mg/kg). Twenty four hours later, mice were sacrificed. Treatment with RA significantly ameliorated histopathological changes and the increase in serum creatinine and blood urea nitrogen (BUN) induced by CP. Oxidative stress induced by CP, evidenced by increased renal 4-hydroxynonenal (4-HNE), cytochrome P450 2E1 (CYP2E1) and heme oxygenase (HO-1) expression, was significantly reduced by RA administration. Moreover, RA inhibited the expression of nuclear factor-kappaB (NF-κB) and tumor necrosis factor-α (TNF-α), indicating the inhibition of inflammation. Additionally, RA exhibited antiapoptotic activity through the reduction of p53, phosphorylated p53 and active caspase-3 expression in the kidneys. These findings show that RA ameliorates CP-induced oxidative stress, inflammation and apoptosis in the kidneys. The nephroprotective activity of RA could be, at least in part, attributed to reduced CYP2E1 expression.

Luteolin inhibits human keratinocyte activation and decreases NF-κB induction that is increased in psoriatic skin

Psoriasis (Ps) is an autoimmune disease characterized by keratinocyte hyperproliferation and chronic inflammation, with increased expression of tumor necrosis factor (TNF) and vascular endothelial growth factor (VEGF). Anti-TNF biologic agents are effective in treating Ps, but are associated with increased risk of infections and blood malignancies. Moreover, keratinocyte hyperproliferation and activation have yet to be addressed. Flavonoids, such as luteolin, are natural compounds with potent anti-inflammatory properties, but their actions on keratinocytes remain unknown. We show that TNF (50 ng/mL) triggers significant production of inflammatory mediators interleukin-6, interleukin-8 and VEGF from both human HaCaT and primary keratinocytes. Pretreatment with the flavonoid luteolin (10–100 µM) significantly inhibits mRNA expression and release of all three mediators in a concentration-dependent manner. More importantly, luteolin decreases TNF-induced phosphorylation, nuclear translocation and DNA binding of the nuclear factor-kappa B (NF-κB) typically involved in inflammatory mediator transcription. We also report that luteolin reduces TNF-induced mRNA expression of two genes (NFKB1 and RELA) encoding two NF-κB subunits (NF-κB p50 and NF-κB p65, respectively). Interestingly, we show that gene expression of RELA is increased in human psoriatic skin. Keratinocyte proliferation, which is a characteristic feature of psoriatic skin, is effectively reduced by luteolin in HaCaT cells, but not in primary keratinocytes. Finally, luteolin does not affect intracellular ATP production or viability. Appropriate formulations of luteolin and related flavones may be promising candidates to be developed into local and systemic treatments for Ps and other inflammatory skin diseases.

The time-dependent hormetic effects of 1-alkyl-3-methylimidazolium chloride and their mixtures on Vibrio qinghaiensis sp. -Q67

The hormetic effects of ionic liquids (ILs) were paid more ecological attentions. However, the time-dependent hormetic effects of ILs and their mixtures remained to be studied. In this paper, the time-dependent toxicities of five single ILs, 1-ethyl-, 1-butyl-, 1-hexyl-, 1-octyl-, and 1-dodecyl-3-methylimidazolium chlorides (named as [C2mim]Cl, [C4mim]Cl, [C6mim]Cl, [C8mim]Cl, and [C12mim]Cl, respectively), and their five-component mixtures to Vibrio qinghaiensis sp.-Q67 were determined at five exposure time points. For single ILs, [C2mim]Cl displayed significant hormetic effects at 2, 4, 8, and 12h; and [C4mim]Cl exhibited significant hormetic effects at 4, 8 and 12h; while [C6mim]Cl, [C8mim]Cl and [C12mim]Cl have not significant hormetic effects. At the same time point, the longer the side chain is, the larger the inhibition at high concentration is, and the less the stimulation at low concentration is. Meanwhile, the maximum stimulation effects were found between 4 and 8h. All six IL mixtures designed by uniform design ray showed significant hormetic effects at 8 and 12h. By means of the variable selection and modeling method based on the prediction (VSMP), it was found that the higher the concentration of [C2mim]Cl is, the stronger the mixture hormetic effect is and the higher the concentration of [C12mim]Cl is, the weaker the hormetic effect is.

Luteolin ameliorates cisplatin-induced nephrotoxicity in mice through inhibition of platinum accumulation, inflammation and apoptosis in the kidney

The aim of this study was to investigate the effects of flavone luteolin against cisplatin (CP)-induced kidney injury in mice. Luteolin at doses of 10mg/kg was administered intraperitoneally (ip) once daily for 3 days following single CP (10 or 20mg/kg) ip injection. Mice were sacrificed 24h after the last dose of luteolin. The CP treatment significantly increased serum creatinine and blood urea nitrogen and induced pathohistological changes in the kidneys. Renal oxidative/nitrosative stress was evidenced by decreased glutathione (GSH) levels and increased 3-nitrotyrosine (3-NT) and 4-hydroxynonenal (4-HNE) formation as well as cytochrome P450 2E1 (CYP2E1) expression. The CP administration triggered inflammatory response in mice kidneys through activation of nuclear factor-kappaB (NF-κB) and overexpression of tumor necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2). Simultaneously, the increase in renal p53 and caspase-3 expression indicated apoptosis of tubular cells. The administration of luteolin significantly reduced histological and biochemical changes induced by CP, decreased platinum (Pt) levels and suppressed oxidative/nitrosative stress, inflammation and apoptosis in the kidneys. These results suggest that luteolin is an effective nephroprotective agent, with potential to reduce Pt accumulation in the kidneys and ameliorate CP-induced nephrotoxicity.

Time-dependent hormetic effects of 1-alkyl-3-methylimidazolium bromide on Vibrio qinghaiensis sp.-Q67: luminescence, redox reactants and antioxidases

The green credentials of ionic liquids (ILs) are being challenged due to the increasing evidence of their toxicity. The hormetic effects further raised their ecological concern. However, it remained poorly studied on the time-dependent changes of the hormetic effects and the mechanisms. In this study, we investigated the time-dependent hormetic effects of four 1-alkyl-3-methylimidazolium bromide ([amim]Br), including 1-ethyl ([emim]Br), -butyl ([bmim]Br), -hexyl ([hmim]Br) and -octyl ([omim]Br), on the luminescence of Vibrio qinghaiensis sp.-Q67. The results showed that [amim]Br with shorter side chains, [emim]Br and [bmim]Br, caused obvious hormetic time-dependent toxicities. The effective concentration (EC) values for the hormetic effects of [emim]Br and [bmim]Br increased with time. [amim]Br with longer side chains, [hmim]Br and [omim]Br, produced sigmoid concentration-dependent inhibitions on the luminescence, and the EC50 values almost unchanged. To illustrate the mechanism, we subsequently examined the responses of redox reactants and antioxidases. [emim]Br and [bmim]Br significantly induced FMN (flavin mononucleotide), NADH (reduced nicotinamide adenine dinucleotide), SOD (superoxide dismutase) and CAT (catalase), and the inductions increased with time, which is similar to the time-dependent changes of their hormetic effects on Q67. Meanwhile, [hmim]Br and [omim]Br did not cause significant effects on the redox reactants and antioxidases. In conclusion, the hormetic effects of [amim]Br on the luminescence, redox reactants and antioxidases showed the dependence on both exposure time and side chains. Our findings provided insights into the time-dependent biological process of the hormetic effects of [emim]Br and [bmim]Br on the photobacterium and its biochemical indicators.

Hepatoprotective effect of 2,3-dehydrosilybin on carbon tetrachloride-induced liver injury in rats

The aim of this study was to investigate the protective effect of 2,3-dehydrosilybin (DHS) against carbon tetrachloride (CCl(4))-induced liver injury in rats. Administration of DHS significantly attenuated the levels of serum aspartate aminotransferase, alanine aminotransferase, and liver lipid peroxidation in CCl(4)-treated rats. Moreover, we showed that DHS prevented DNA damage and decreased the protein levels of γ-H2AX, which is a specific DNA damage marker, in CCl(4)-treated rat livers. DHS also markedly increased the activity of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase in CCl(4)-treated rat livers. Furthermore, we found that DHS significantly inhibited the production of serum nitric oxide as well as the levels of serum IL-6, IFN-γ, and TNF-α in CCl(4)-treated rats. Additionally, DHS significantly suppressed iNOS expression on the protein levels in CCl(4)-treated rat livers. Collectively, the present study suggests that DHS protects the liver from CCl(4)-induced hepatic damage via antioxidant and anti-inflammatory mechanisms.

Hepatoprotective and antioxidant activity of methanolic extract of flowers of Nerium oleander against CCl4-induced liver injury in rats

OBJECTIVE

To investigate the antioxidant and hepatoprotective activity of methanolic flower extract of Nerium oleander against CCl(4)-induced hepatotoxicity in rats.

METHODS

In vitro antioxidant activity of methanolic extract of flowers of Nerium oleander (MENO-F) was evaluated by various assays, including reducing power, lipid peroxidation, DPPH, ABTS, superoxide anion, hydroxyl radicals and metal chelation. The hepatoprotective and in vivo antioxidant activity of MENO-F were evaluated against CCl(4)-induced hepatic damage in rats. The MENO-F at dose of 100, 200 and 400 mg/kg were administered orally once daily for seven days. Serum enzymatic levels of serum glutamate oxaloacetate transaminase (AST), serum glutamate pyruvate transaminase (ALT), serum alkaline phosphatase (ALP) and total bilirubin were estimated along with estimation of superoxide dismutase (SOD) and malondialdehyde (MDA) levels in liver tissues. Further histopathological examination of the liver sections was carried out to support the induction of hepatotoxicity and hepatoprotective efficacy.

RESULTS

The extract showed potent activities on reducing power, lipid peroxide, DPPH, ABTS, superoxide anion, hydroxyl radical and metal chelation. The substantially elevated serum enzymatic levels of AST, ALT, ALP and total bilirubin were found to be restored towards normalization significantly by the MENO-F in a dose dependent manner with maximum hepatoprotection at 400 mg/kg dose level. The histopathological observations supported the biochemical evidences of hepatoprotection. Elevated level of SOD and decreased level of MDA further strengthen the hepatoprotective observations.

CONCLUSIONS

The results of the present study strongly reveal that MENO-F has potent antioxidant activity and hepatoprotective activity against CCl(4)-induced hepatic damage in experimental animals.

Effects of Luteolin on Liver, Kidney and Brain in Pentylentetrazol-Induced Seizures: Involvement of Metalloproteinases and NOS Activities

OBJECTIVE

Flavonoids are an important group of recognized antioxidants in plants. Luteolin (LUT) is a natural flavonoid in the plant kingdom. This study was aimed to investigate the effects of the LUT in the liver, kidney and brain of pentylentetrazol (PTZ)-induced seizure and the relationship between nitric oxide synthases (iNOS, eNOS) and matrix metalloproteinases (MMP2, MMP9).

MATERIALS AND METHODS

LUT (10 mg/kg) was given intraperitoneally during two weeks prior to seizure induction. A single dose PTZ 80 mg/kg i.p. was administered and seizures were observed and evaluated with regard to latency, frequency and stage for one hour.

RESULTS

Seizure frequen cy after PTZ administration was significantly decreased in LUT pretreated rats (p<0.05). An increase of immunhistochemical reactions of iNOS and MMP2, but a decrease of eNOS activity, were observed in rat hippocampus and peripheral tissues during the PTZ induced seizures. LUT pretreatment reversed the iNOS and MMP2 activity to the control levels and significantly increased the eNOS activity (p<0.001).

CONCLUSION

LUT seems to have an effective role in reducing the seizure frequency and a protective role on peripheral organ injury in animal models of seizure. The protective effect of LUT in seizures and the seizure induced peripheral tissue damage warrant further investigations.

Hepatoprotective effects of 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone on CCl4-induced acute liver injury in mice

In this paper, the hepatoprotective effects of 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) on CCl(4)-induced acute liver injury in Kunming mice were investigated. DMC was administered intraperitoneally (ip) (5, 10, or 20 mg/kg of body weight) for 7 days prior to the administration of CCl(4) (0.1%, ip). Pretreatment with DMC significantly decreased activities of serum hepatic enzymes, namely alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, γ-glutamyl transferase, and total bilirubin, and decreased the elevation of lipid peroxidation, malondialdehyde, reactive oxygen species, and protein carbonyl content. Pretreatment with DMC markedly increased activities of enzymatic antioxidants such as superoxide dismutase, catalase, glucose-6-phosphate dehydrogenase, glutathione peroxidase, glutathione S-transferase, and glutathione reductase and increased levels of nonenzymatic antioxidant markers such as reduced glutathione, total sulfhydryl groups, vitamin C, and vitamin E in liver. These results combined with liver histopathology demonstrate that DMC has potential hepatoprotective effects, which may be related to the attenuation of oxidative stress, accelerating the antioxidant cascade and inhibition of lipid peroxidation.

Hepatoprotective effect of Scoparia dulcis on carbon tetrachloride induced acute liver injury in mice

This study aims to investigate the hepatoprotective activity and active constituents of the ethanol extract of Scoparia dulcis (SDE). The hepatoprotective effect of SDE (0.1, 0.5 and 1 g/kg) was evaluated on the carbon tetrachloride (CCl(4))-induced acute liver injury. The active constituents were detected by high performance liquid chromatography (HPLC). Mice pretreated orally with SDE (0.5 and 1.0 g/kg) and silymarin (200 mg/kg) for five consecutive days before the administering of a single dose of 0.2% CCl(4) (10 ml/kg of bw, ip) showed a significant inhibition of the increase of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histological analyses also showed that SDE (0.5 and 1.0 g/kg) and silymarin reduced the extent of liver lesions induced by CCl(4), including vacuole formation, neutrophil infiltration and necrosis. Moreover, SDE decreased the malondialdehyde (MDA) level and elevated the content of reduced glutathione (GSH) in the liver as compared to those in the CCl(4) group. Furthermore, SDE (0.5 and 1.0 g/kg) enhanced the activities of anti-oxidative enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRd) and glutathione-S-transferase (GST). The quantities of active constituents in SDE were about 3.1 mg luteolin/g extract and 1.1 mg apigenin/g extract. The hepatoprotective mechanisms of SDE were likely associated to the decrease in MDA level and increase in GSH level by increasing the activities of antioxidant enzymes such as SOD, GPx, GRd and GST. These results demonstrated that SDE could alleviate CCl(4)-induced acute liver injury in mice.