Effect of Cistus laurifolius L. leaf extracts and flavonoids on acetaminophen-induced hepatotoxicity in mice

Fabrication of wound dressings: Herbal extract-loaded nanoliposomes embedded in fungal chitosan/polycaprolactone electrospun nanofibers for tissue regeneration

Wound healing is a complex process and one of the major therapeutic and economic subjects in the pharmaceutical area. In recent years, the fabrication of nano-sized wound dressing models has attracted great attention for tissue regeneration. Plant extracts loaded nanoparticles are environmentally friendly and non-toxic and the release of the bioactive substance will be controlled to the wound area. This study aims to fabricate wound dressing models that contain bioactive components for tissue regeneration. Fungal chitosan/polycaprolactone nanofiber was fabricated by electrospinning and it has been characterized. Plant extracts loaded nanoliposomes were prepared, characterized, and embedded in nanofiber structures. The effectiveness of wound dressing models for tissue regeneration was evaluated by in vitro and in vivo studies. It was observed that all wound dressing models positively affect the cell viability of human dermal fibroblast cells. It was determined that plant extracts loaded nanoparticles embedded in nanofibers increased in cell viability than nanoparticles that were non-embedded in nanofiber structures. Histological analysis showed that plant extract-loaded nanoliposomes embedded in chitosan/PCL nanofibers were used for tissue regeneration. The most effective nanofibers were determined as Wd-ClNL nanofibers. RESEARCH HIGHLIGHTS: Hypericum perforatum L. and Cistus laurifolius L. were prepared by modified ultrasonic extraction method. Fungal chitosan/polycaprolactone nanofiber was fabricated by electrospinning and it has been characterized. Plant extract-loaded nanoliposomes were prepared, and characterized. They were embedded in chitosan/polycaprolactone nanofiber. Effects of the wound dressing model were analyzed by in vitro and in vivo assays for tissue regeneration.

Identification of bioactive components on antihemorrhoidal activity of Cistus laurifolius L. using RP-HPLC and LC-QTOF-MS

ETHNOPHARMACOLOGICAL RELEVANCE

Cistus laurifolius is widely used in folk medicine in Anatolia for the treatment of many ailments. The leaves of the plant are used in the form of tea in the treatment of hemorrhoids in the Western Black Sea Region and Central Anatolia.

AIMS OF THE STUDY

It was aimed at evaluating the anti-hemorrhoidal effects of C. laurifolus leaves in croton oil-induced hemorrhoid model in rats.

MATERIALS AND METHODS

The methanolic and aqueous extracts of C. laurifolius were tested for in vivo anti-hemorrhoidal efficacy using an experimental hemorrhoid model, followed by histological and biochemical analysis. Hemorrhoid was created by using croton oil on the anal region of the rats. TNF-α and VEGF mRNA expression levels were assessed using real-time PCR detections. The extract was also tested for anti-inflammatory properties, which are based on the suppression of an increase in capillary permeability caused by acetic acid. LC-QTOF-MS and RP-HPLC were used for the phytochemical analysis.

RESULTS

In comparison to the control, histological and biochemical assessment showed that the methanolic extract of C. laurifolius is particularly effective against hemorrhoids. The same extract group's TNF-α mRNA expression was found to be the lowest. Additionally, the methanolic extract showed a strong inhibitory effect on the increase in capillary permeability resulted on by acetic acid. Three phenolic compounds were discovered in the extracts by phytochemical analyses, while more than eighteen compounds were found by LC-QTOF-MS analysis. Five of these compounds are phenolic acid derivatives, and flavonoids constitute the majority of the group.

CONCLUSION

This is the first evidence from the research that C. laurifolius possesses strong anti-inflammatory and anti-hemorrhoidal properties.

Ionomic analysis, polyphenols characterization, analgesic, antiinflammatory and antioxidant capacities of Cistus laurifolius leaves: in vitro, in vivo, and in silico investigations

This study aims to investigate the chemical and mineral composition, antioxidant, analgesic, and anti-inflammatory effects of the aqueous extract of Cistus laurifolius var. atlanticus Pit. (Cistaceae). Additionally, molecular docking interactions of various ligands with antioxidant protein target urate oxidase (1R4U) and anti-inflammatory protein target cyclooxygenase-2 (3LN1), revealing potential dual activities and highlighting specific residue interactions. The chemical characterization focused at first glance on the mineral composition which showed that C. laurifolius extract is a mineral-rich source of potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), and zinc (Zn). We next performed, ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis, the latter showed various polyphenols in C. laurifolius extract including Gallic acid as the predominant polyphenol. Isoquercetin, Taxifolin and Astragalin were also among the major flavonoids detected. The antioxidant capacity of C. laurifolius leaves was tested using 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1- picrylhydrazyl (DPPH) and reducing power (RP) assays. In vitro analysis of the anti-inflammatory property of C. laurifolius leaves was conducted by the albumin denaturation test and the in vivo was assessed in the sequel by carrageenan-induced paw edema test. The analgesic activity was evaluated in vivo using tail flick, acetic acid-induced contortion, and plantar tests. The findings showed that the leave extract had a powerful antioxidant activity with an IC50 values of 2.92 ± 0.03 µg/mL (DPPH) and 2.59 ± 0.09 µg/mL (in RP test). The studied extract strongly abolished the induced inflammation (82%). Albumin denaturation test recorded an IC50 value of 210 µg/mL. Importantly, the oral administration of C. laurifolius extract considerably reduced the nociceptive effect of acetic acid in rats, showing a significant analgesic effect in a dose-related manner. Altogether, our results showed that C. laurifolius can be a promising source of phytochemicals for drug development potential.

Interaction of low-level dietary supplementation of Chlorella vulgaris Beijerinck, 1890, and feeding duration on growth hormone, growth performance and serum biochemistry of red hybrid tilapia (Oreochromis mossambicus × Oreochromis niloticus)

Chlorella is one of the most widely accepted Chlorophyta used by many as livestock and aquaculture feed. Nonetheless, different studies on the overall performances of fish reported the unfavourable effect of high-level supplementations of Chlorella vulgaris. The current study determined the impact of low-level dietary supplementation of C. vulgaris alongside the different feeding durations and their interactions on the growth hormone (GH), growth performances, serum-biochemical indices, hepatic function and some immunological parameters of red hybrid tilapia. The fingerlings (mean weight: 14.25 ± 0.01 g, length: 13.5 ± 0.49 cm) were fed diets containing 0, 0.99%, 2.91% and 4.76% of C. vulgaris powder per kilogram dry diet for 90 days. GH, growth performance, serum-biochemical indices (total serum protein, albumin, globulin, glucose, aspartate aminotransferase and alanine aminotransferase) and some immunological (respiratory burst and lysozyme activities) parameters of the fish were examined after 30, 60 and 90 days of feeding. The results demonstrated that tilapia fed C. vulgaris-supplemented diets showed increased levels of respiratory burst, lysozyme, albumin and total protein, GH and growth performances (P < 0.05), and the effects were duration dependent. After the 90 days of feeding, there was no adverse effect on the hepatic function of the fish. Besides, low survivability was observed in the control group than in the group fed the experimental diets. The group fed the diet supplemented with 4.76% C. vulgaris had significantly higher (P < 0.05) lysozyme activity throughout the duration of the feeding experiment. These results indicate that C. vulgaris enhanced growth performances, GH concentration, serum-biochemistry and some immunological parameters of red hybrid tilapia.

Lipid-lowering, anti-inflammatory, and hepatoprotective effects of isorhamnetin on acetaminophen-induced hepatotoxicity in mice

Isorhamnetin is a hepatoprotective flavonoid molecule derived from the leaves and fruits of Hippophae rhamnoides L. However, the protective effect of isorhamnetin on acetaminophen (APAP) induced hepatotoxicity is still unknown. Thus, we aimed to investigate the lipid-lowering, anti-inflammatory, and hepatoprotective effects of isorhamnetin on APAP-induced hepatotoxicity in mice. Hepatotoxicity was induced by a single injection of APAP (300 mg/kg, intraperitoneally). Isorhamnetin (50 or 100 mg/kg, orally) and N-acetylcysteine (NAC) (200 mg/kg, orally), or vehicle control, were administered 1 h before the administration of APAP. Total antioxidant status (TAS) and total oxidative status (TOS) of liver tissue and levels of inflammatory factors (TNF-α, IL-1β, and IL-6) were analyzed by ELISA. Lipid profiles and liver function parameters were measured using an autoanalyzer. In addition, liver tissue was examined histopathologically. Isorhamnetin treatment significantly reduced the APAP-induced increase in the liver weight and liver index; it also reduced the APAP-induced increase in serum liver parameters (ALT, AST, ALP, and LDH) (p < 0.05). Isorhamnetin significantly reduced APAP-induced oxidative stress and inflammation by increasing TAS levels and decreasing TOS, TNF-α, IL-1β, and IL-6 levels (p < 0.05). Moreover, isorhamnetin treatment significantly regulated lipid profiles (TG, T-C, LDL-C, and HDL-C levels) that changed in response to APAP administration (p < 0.05). In histopathological examination, liver degeneration observed in the APAP group was significantly reduced in the NAC and isorhamnetin-treated groups (p < 0.05). This study suggests that isorhamnetin has a significant protective effect on APAP-induced hepatotoxicity in mice through its lipid-lowering, antioxidant, and anti-inflammatory effects.

Essential Oils Derived from Cistus Species Activate Mitochondria by Inducing SIRT1 Expression in Human Keratinocytes, Leading to Senescence Inhibition

Cistus L. is a genus of dicotyledonous perennial herbaceous plants. Cistus species have been commonly used in folk medicine in the Mediterranean region. In the present study, the biological activities of essential oils derived from Cistus species (Cistus laurifolius, C. monspeliensis, C. creticus, and C. salviifolius) were evaluated. Essential oils derived from C. laurifolius and C. monspeliensis were found to augment the expression of SIRT1, an anti-aging gene, in the normal culture of HaCaT cells. Furthermore, these essential oils increased the number and size of mitochondria and augmented their activity. These effects were thought to be caused by the up- and downregulated expression of MITOL and Drp1 in HaCaT cells, respectively, in response to the essential oil treatment. In addition, these essential oils were found to attenuate ultraviolet-B-induced mitochondrial damage and cellular senescence in HaCaT cells. These findings indicate that essential oils derived from C. laurifolius and C. monspeliensis may inhibit skin aging through mitochondrial regulation via SIRT1 activation.

Modulatory effects of laurel-leaf cistus (Cistus laurifolius) ethanolic extract on innate immune responses and disease resistance in common carp (Cyprinus carpio)

Medicinal herbs are used for growth promotion, disease control and other health benefits in aquaculture industry. Here, we examined the effect of dietary laurel-leaf cistus (Cistus laurifolius) ethanolic extract on growth performance, digestive enzyme activity, haematological profile and nonspecific immune responses in common carp (Cyprinus carpio). In addition, resistance against Aeromonas hydrophila infection was examined. Common carp was fed diets containing 0 (Control), 0.1 (CL0.1), 0.5 (CL0.5) and 1 (CL1) g kg^-1 laurel-leaf cistus extract for 45 days. After 30 days, superoxide anion production (SAP) increased in CL0.1 and CL0.5 fish groups and at the end of the study all experimental fish groups had higher SAP compared to that of the control (P ˂ 0.05). Lysozyme activity (LA) was elevated in CL0.5 and CL1 treated groups on 30th day (P < 0.05), and this increase was only observed in C0.1 fish group at the end of study compared to control (P ˂ 0.05). Myeloperoxidase activity was significantly increased in CL0.5 and CL1 fish groups at the end of study. IL-1βgene expression was significantly increased in treated fish in a dose-depended manner. Similar results were observed for transcription of IL-6 and IL-8 (P < 0.05). Anti-inflammatory cytokines, IL-10 and TGF-β were highly up-regulated in the intestine and head kidney of CL treated fish groups compared to control (P < 0.05). At the end of experiment, significantly higher final body weight, weight gain, and specific growth rate were obtained in CL0.1 treated fish group compared to control. However, growth was negatively affected in CL1 fish group (P < 0.05). CL1 fish group had also a significantly higher FCR. Amylase activity was significantly increased in all experimental fish groups compared to control (P ˂ 0.05). Trypsin activity was decreased in CL0.1 and CL1 fish groups (P ˂ 0.05). WBC and RBC were significantly increased (P ˂ 0.05) in CL0.5 and CL1 fish groups, whereas haemoglobin, haematocrit, mean cell, mean cell haemoglobin contents were no significantly changed among control and treatment groups. Result of challenge test with A. hydrophila exhibited that survival rate in all treatment groups was significantly higher than that of control. These findings demonstrated that laurel-leaf cistus at 0.1 g kg^-1 can be a suitable candidate for growth promotion, immune system induction and infection control in fish.

Hepatoprotective effect of kaempferol glycosides isolated from Cedrela odorata L. leaves in albino mice: involvement of Raf/MAPK pathway

Background and purpose:

Paracetamol is the most implicated xenobiotic in inducing hepatotoxicity. Our study aimed to determine the impact of some kaempferol glycosides isolated from the leaves of Cedrela odorata L. on paracetamol hepatotoxicity.

Experimental approach:

The methanolic extract of dried leaves of C. odorata L. was subjected to the combination of spectroscopic methods (¹H and ¹³CNMR). Six kaempferol glycosides were isolated: kaempferol-3-O-β-D-glycopyranoside (astragalin), kaempferol-3-O-β-L-rhamnopyranoside, kaempferol-3-O-β-D-rutinoside, kaempferide-3-O-β-D-rutinoside, kaempferide-3-O-β-Drutinosyl-7-O-β-D-rhamnopyranoside, and kaempferol-3-O-β-D- rutinosyl-7-O-a-D-arabinopyranoside. Fifty-four female Swiss Albino mice were divided randomly into 9 groups including (1) control negative (1 mL/kg saline; IP), (2) control positive (paracetamol 300 mg/kg; IP), (3) silymarin 50 mg/kg (IP). Animals of groups 4-9 were injected with 6 different samples of isolated compounds at 100 mg/kg (IP). One h later, groups 3-9 were injected with paracetamol (300 mg/kg IP). Two h later, tissue samples were taken from all animals to assess nitrotyrosine, c-Jun N-terminal protein kinase (c-JNK), Raf -1kinase, and oxidative stress biomarkers viz. reduced glutathione (GSH) and malondialdehyde (MDA).

Findings/Results:

Isolated glycosides had a prominent anti-apoptotic effect via inhibition of c-JNK and Raf-1 kinase. They also exerted a powerful antioxidant effect by modulating the oxidative stress induced by paracetamol via increasing GSH, reducing MDA and nitrotyrosine concentrations compared to positive control. The glycoside (1) showed a better effect than silymarin (standard) in ameliorating the formation of nitrotyrosine, Raf-1 kinase, c-JNK, and GSH.

Conclusion and implication:

Kaempferol glycosides isolated for the first time from C. odorata L. leaves exerted antioxidant and antiapoptotic effects via amelioration of oxidative stress and inhibition of Raf/MAPK pathway.

A Review on Cistus sp.: Phytochemical and Antimicrobial Activities

Resistance to drugs is reaching alarming levels and is placing human health at risk. With the lack of new antimicrobials drugs, infectious diseases are becoming harder to treat. Hence, there is an increasing awareness of active phytochemicals with therapeutic functions. The tremendous research interest on the Cistus L. genus includes numerous plants used in traditional medicine by people living around the Mediterranean Sea, also resulted in some interesting discoveries and written literature. This review aimed at gathering scientific literature about Cistus species, describing phytochemical profiles and the various pharmacological activities. We also extensively reviewed the antimicrobial activities, including antiviral, antiparasitic, antifungal, and antibacterial potentials of Essential Oils (EO), raw extracts as well as isolated compounds. Mechanisms of action along with methods used are also investigated in this review. Considering the findings of the Cistus species extracts, this genus offers an adequate reserve of active phytochemicals since many have been used to create drugs. Therefore, this review work can serve society by providing a global view on Cistus L. sp. regarding pharmacological potentials and their chemical profiles.

Assessment of compliance level of ICH guidelines for organic volatile impurities in common ayurvedic hepatic formulations

Background Herbal medicines have been used in the treatment of liver diseases for a long time. In recent years, the use of herbal medicines for protection from other strong antibiotics as well as drugs that can damage the liver during their metabolism in liver and for treatment of liver diseases has increased all over the world. It is important to mention that a number of organic solvents are used at different stages of extraction/formulation development for these traditional preparations in industries/pharmacies. In addition, some of these solvents possess established carcinogenic properties and may enter the formulation as residual solvents. Hence as per ICH guidelines it is mandatory to keep the level of these solvents up to permissible limits. There has been a lot of hue and cry that ayurvedic formulations available in the market are not properly standardized for their quality due to lack of stringent regulations and standards from regulatory authorities. Therefore the aim of present work was to assess the compliance of ICH guidelines for level of organic volatile impurities in common marketed ayurvedic hepatic formulations. Methods In this study, 25 ayurvedic herbal formulations available as OTC product have been assessed for presence of residual solvents using gas chromatography with flame ionization detector. Results This study on 25 fast moving hepatic formulations in the market reflects that no residual solvents were detected in any of the formulations however if present were within prescribed permissible limits of ICH guidelines. The data was also subjected to statistical analysis (F-test and t-test at 95% confidence level). Conclusions Results indicate the safety of these hepatic formulations with respect to residual solvents. In addition presents a simple, linear, specific, accurate, precise and rugged gas chromatographic method for estimation of residual solvents.

Therapeutic Potential of Plants and Plant Derived Phytochemicals against Acetaminophen-Induced Liver Injury

Acetaminophen (APAP), which is also known as paracetamol or N-acetyl-p-aminophenol is a safe and potent drug for fever, pain and inflammation when used at its normal therapeutic doses. It is available as over-the-counter drug and used by all the age groups. The overdose results in acute liver failure that often requires liver transplantation. Current clinical therapy for APAP-induced liver toxicity is the administration of N-acetyl-cysteine (NAC), a sulphydryl compound an approved drug which acts by replenishing cellular glutathione (GSH) stores in the liver. Over the past five decades, several studies indicate that the safety and efficacy of herbal extracts or plant derived compounds that are used either as monotherapy or as an adjunct therapy along with conventional medicines for hepatotoxicity have shown favorable responses. Phytochemicals mitigate necrotic cell death and protect against APAP-induced liver toxicityby restoring cellular antioxidant defense system, limiting oxidative stress and subsequently protecting mitochondrial dysfunction and inflammation. Recent experimental evidences indicat that these phytochemicals also regulate differential gene expression to modulate various cellular pathways that are implicated in cellular protection. Therefore, in this review, we highlight the role of the phytochemicals, which are shown to be efficacious in clinically relevant APAP-induced hepatotoxicity experimental models. In this review, we have made comprehensive attempt to delineate the molecular mechanism and the cellular targets that are modulated by the phytochemicals to mediate the cytoprotective effect against APAP-induced hepatotoxicity. In this review, we have also defined the challenges and scope of phytochemicals to be developed as drugs to target APAP-induced hepatotoxicity.

Oxidative stress during acetaminophen hepatotoxicity: Sources, pathophysiological role and therapeutic potential

Acetaminophen (APAP) hepatotoxicity is characterized by an extensive oxidative stress. However, its source, pathophysiological role and possible therapeutic potential if targeted, have been controversially described. Earlier studies argued for cytochrome P450-generated reactive oxygen species (ROS) during APAP metabolism, which resulted in massive lipid peroxidation and subsequent liver injury. However, subsequent studies convincingly challenged this assumption and the current paradigm suggests that mitochondria are the main source of ROS, which impair mitochondrial function and are responsible for cell signaling resulting in cell death. Although immune cells can be a source of ROS in other models, no reliable evidence exists to support a role for immune cell-derived ROS in APAP hepatotoxicity. Recent studies suggest that mitochondrial targeted antioxidants can be viable therapeutic agents against hepatotoxicity induced by APAP overdose, and re-purposing existing drugs to target oxidative stress and other concurrent signaling events can be a promising strategy to increase its potential application in patients with APAP overdose.

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Oxidative stress plays a critical role in acetaminophen hepatotoxicity.

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Mitochondria are the main source of ROS and RNS that are responsible for the toxicity.

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Cytochrome P450 and inflammatory cells are probably not relevant sources of ROS for the toxicity.

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Mitochondrial oxidative stress is a promising therapeutic target against APAP overdose.

Quantitative Variation of Flavonoids and Diterpenes in Leaves and Stems of Cistus ladanifer L. at Different Ages

The compounds derived from secondary metabolism in plants perform a variety of ecological functions, providing the plant with resistance to biotic and abiotic factors. The basal levels of these metabolites for each organ, tissue or cell type depend on the development stage of the plant and they may be modified as a response to biotic and/or abiotic stress. As a consequence, the resistance state of a plant may vary in space and time. The secondary metabolites of Cistus ladanifer have been quantified in leaves and stems throughout autumn, winter, spring and summer, and at different ages of the plant. This study shows that there are significant differences between young leaves, mature leaves and stems, and between individuals of different ages. Young leaves show significantly greater synthesis of flavonoids and diterpenes than mature leaves and stems, with a clear seasonal variation, and the differences between leaves at different growth stages and stems is maintained during the quantified seasons. With respect to age, specimens under one year of age secreted significantly lower amounts of compounds. The variation in the composition of secondary metabolites between different parts of the plant, the season and the variations in age may determine the interactions of Cistus ladanifer with the biotic and abiotic factors to which it is exposed.

A Review on Hepatoprotective and Immunomodulatory Herbal Plants

The liver is the most important organ that plays an important role in maintaining various physiological processes in the body. Hepatitis is an inflammation of the liver and is characterized by the presence of inflammatory cells in the tissue of the organ. There are five main viruses, referred to as types A, B, C, D, and E. These five types are of the greatest concern because of the burden of illness and death. Liver injury or liver dysfunction is a major health problem that challenges not only health care professionals but also the drug regulatory agencies and the pharmaceutical industry. Herbal medicines have been used in the treatment of liver disease for a long time. The immune system is the part of body that diagnoses the pathogen by using a specific receptor to reveal immediate response by the activation of immune components cells, chemokines, and cytokines, and also the release of the inflammatory mediator. They potentiate and modulate the immune system. The plant-derived phytoconstituents (polysaccharides, proteins and flavanoids, lignans, rotenoids, etc.) stimulate the immune system and maintained hepatic diseases. There are a number of hepatoprotective and immunomodulatory herbs that have been reported. The present review is aimed at compiling data on promising phytochemicals from hepatoprotective and immunomodulatory herbs.

Sulforaphane protects against acetaminophen-induced hepatotoxicity

Oxidative stress is closely associated with acetaminophen (APAP)-induced toxicity. Heme oxygenase-1 (HO-1), an antioxidant defense enzyme, has been shown to protect against oxidant-induced tissue injury. This study investigated whether sulforaphane (SFN), as a HO-1 inducer, plays a protective role against APAP hepatotoxicity in vitro and in vivo. Pretreatment of primary hepatocyte with SFN induced nuclear factor E2-factor related factor (Nrf2) target gene expression, especially HO-1 mRNA and protein expression, and suppressed APAP-induced glutathione (GSH) depletion and lipid peroxidation, which eventually leads to hepatocyte cell death. A comparable effect was observed in mice treated with APAP. Mice were treated with 300 mg/kg APAP 30 min after SFN (5 mg/kg) administration and were then sacrificed after 6 h. APAP alone caused severe liver injuries as characterized by increased plasma AST and ALT levels, GSH depletion, apoptosis, and 4-hydroxynonenal (4-HNE) formations. This APAP-induced liver damage was significantly attenuated by pretreatment with SFN. Furthermore, while hepatic reactive oxygen species (ROS) levels were increased by APAP exposure, pretreatment with SFN completely blocked ROS formation. These results suggest that SFN plays a protective role against APAP-mediated hepatotoxicity through antioxidant effects mediated by HO-1 induction. SFN has preventive action in oxidative stress-mediated liver injury.

Genus Cistus: a model for exploring labdane-type diterpenes' biosynthesis and a natural source of high value products with biological, aromatic, and pharmacological properties

The family Cistaceae (Angiosperm, Malvales) consists of 8 genera and 180 species, with 5 genera native to the Mediterranean area (Cistus, Fumara, Halimium, Helianthemum, and Tuberaria). Traditionally, a number of Cistus species have been used in Mediterranean folk medicine as herbal tea infusions for healing digestive problems and colds, as extracts for the treatment of diseases, and as fragrances. The resin, ladano, secreted by the glandular trichomes of certain Cistus species contains a number of phytochemicals with antioxidant, antibacterial, antifungal, and anticancer properties. Furthermore, total leaf aqueous extracts possess anti-influenza virus activity. All these properties have been attributed to phytochemicals such as terpenoids, including diterpenes, labdane-type diterpenes and clerodanes, phenylpropanoids, including flavonoids and ellagitannins, several groups of alkaloids and other types of secondary metabolites. In the past 20 years, research on Cistus involved chemical, biological and phylogenetic analyses but recent investigations have involved genomic and molecular approaches. Our lab is exploring the biosynthetic machinery that generates terpenoids and phenylpropanoids, with a goal to harness their numerous properties that have applications in the pharmaceutical, chemical and aromatic industries. This review focuses on the systematics, botanical characteristics, geographic distribution, chemical analyses, biological function and biosynthesis of major compounds, as well as genomic analyses and biotechnological approaches of the main Cistus species found in the Mediterranean basin, namely C. albidus, C. creticus, C. crispus, C. parviflorus, C. monspeliensis, C. populifolius, C. salviifolius, C. ladanifer, C. laurifolius, and C. clusii.

In vivo and in vitro antidiabetic effect of Cistus laurifolius L. and detection of major phenolic compounds by UPLC-TOF-MS analysis

ETHNOPHARMACOLOGICAL RELEVANCE

In Turkish folk medicine, various parts of Cistus laurifolius L. are used to treat gastric ulcer and various types of pains. Additionally the tea prepared from the leaves is used to decrease symptoms of diabetes.

MATERIALS AND METHODS

In the present study, the hypoglycemic effects of aqueous and ethanol extracts of Cistus laurifolius were investigated in normal, glucose loaded hyperglycemic and streptozocin (STZ)-induced diabetic rats. α-Glucosidase and α-amylase enzyme inhibitory effects were determined to evaluate the mechanism of action. Total phenolic content of the extracts were determined by using Folin-Ciocalteu reagent and Ultra Performance Liquid Chromatography-Time of Flight Mass Spectrometer (UPLC-TOF-MS) was used to detect the major phenolic compounds in the extract.

RESULTS

Results indicated that blood glucose levels of the STZ-induced diabetic rats were decreased by ethanol extract at of 250 and 500mg/kg doses as compared to control group (16%-34%). In glucose loaded animals, extracts have shown a weak hypoglycemic effect (11%-20%). Additionally, the ethanol extract of Cistus laurifolius is found to be a potent inhibitor of α-glucosidase and α-amylase, possibly due to several polyphenolic compounds present within the extract. Twelve major flavonoids (apigenin, quercetin, kaempferol, naringenin, quercitrin and their derivatives), gallic, ellagic and chlorogenic acid in chromatographic fingerprint were analyzed by the on-line UPLC-TOF-MS system.

CONCLUSIONS

Due to having inhibitory effect on blood glucose level and carbohydrate digesting enzymes (α-glucosidase and α-amylase), Cistus laurifolius leaves might be beneficial for diabetic patients.

Davallialactone protects against acetaminophen overdose-induced liver injuries in mice

Oxidative stress is closely associated with acetaminophen (APAP)-induced toxicity. Davallialactone (DAVA), a hispidin analog derived from the mushroom Inonotus xeranticus, has antioxidant properties. This study evaluated whether DAVA plays protective roles against APAP hepatotoxicity in mice. Pretreatments with DAVA (10 mg/kg) prior to exposures of mice to a hepatotoxic dose of 600 mg/kg APAP significantly increased survival rate compared to APAP alone. To verify this effect, mice were treated with 400 mg/kg APAP 30 min after DAVA administration and were then sacrificed after 0.5, 1, 3, and 6 h. APAP alone caused severe liver injuries as characterized by increased plasma GOT and GPT levels, ATP and GSH depletion, and peroxynitrite and 4-HNE formations. These liver damages induced by APAP were significantly attenuated by DAVA pretreatments. The GSH/GSSG ratio nearly recovered to the levels observed in non-APAP-treated mice at 6h after APAP treatment in DAVA-pretreated mice. Furthermore, while hepatic ROS levels were increased by APAP exposures, pretreatments with DAVA completely blocked ROS formation. In addition, APAP-induced sustained activations of JNK and ERK were remarkably reduced by DAVA pretreatment. In conclusion, these results suggest that DAVA plays protective roles against APAP-mediated hepatotoxicity through function as ROS scavenger.

Models of drug-induced liver injury for evaluation of phytotherapeutics and other natural products

Extracts from medicinal plants, many of which have been used for centuries, are increasingly tested in models of hepatotoxicity. One of the most popular models to evaluate the hepatoprotective potential of natural products is acetaminophen (APAP)-induced liver injury, although other hepatotoxicity models such as carbon tetrachloride, thioacetamide, ethanol and endotoxin are occasionally used. APAP overdose is a clinically relevant model of drug-induced liver injury. Critical mechanisms and signaling pathways, which trigger necrotic cell death and sterile inflammation, are discussed. Although there is increasing understanding of the pathophysiology of APAP-induced liver injury, the mechanism is complex and prone to misinterpretation, especially when unknown chemicals such as plant extracts are tested. This review discusses the fundamental aspects that need to be considered when using this model, such as selection of the animal species or in vitro system, timing and dose-responses of signaling events, metabolic activation and protein adduct formation, the role of lipid peroxidation and apoptotic versus necrotic cell death, and the impact of the ensuing sterile inflammatory response. The goal is to enable researchers to select the appropriate model and experimental conditions for testing of natural products that will yield clinically relevant results and allow valid interpretations of the pharmacological mechanisms.

Inhibition and induction of glutathione S-transferases by flavonoids: possible pharmacological and toxicological consequences

Many studies reviewed herein demonstrated the potency of some flavonoids to modulate the activity and/or expression of glutathione S-transferases (GSTs). Because GSTs play a crucial role in the detoxification of xenobiotics, their inhibition or induction may significantly affect metabolism and biological effects of many drugs, industrials, and environmental contaminants. The effect of flavonoids on GSTs strongly depends on flavonoid structure, concentration, period of administration, as well as on GST isoform and origin. Moreover, the results obtained in vitro are often contrary to the vivo results. Based on these facts, the revelation of important flavonoid-drug or flavonoid-pollutant interaction has been complicated. However, it should be borne in mind that ingestion of certain flavonoids in combination with drugs or pollutants (e.g., acetaminophen, simvastatin, cyclophosphamide, cisplatine, polycyclic aromatic hydrocarbons, chlorpyrifos, acrylamide, and isocyanates), which are GST substrates, could have significant pharmacological and toxicological consequences. Although reasonable consumptions of a flavonoids-rich diet (that may lead to GST induction) are mostly beneficial, the uncontrolled intake of high concentrations of certain flavonoids (e.g., quercetin and catechins) in dietary supplements (that may cause GST inhibition) may threaten human health.

Oxidant stress, mitochondria, and cell death mechanisms in drug-induced liver injury: lessons learned from acetaminophen hepatotoxicity

Hepatotoxicity is a serious problem during drug development and for the use of many established drugs. For example, acetaminophen overdose is currently the most frequent cause of acute liver failure in the United States and Great Britain. Evaluation of the mechanisms of drug-induced liver injury indicates that mitochondria are critical targets for drug toxicity, either directly or indirectly through the formation of reactive metabolites. The consequence of these modifications is generally a mitochondrial oxidant stress and peroxynitrite formation, which leads to structural alterations of proteins and mitochondrial DNA and, eventually, to the opening of mitochondrial membrane permeability transition (MPT) pores. MPT pore formation results in a collapse of mitochondrial membrane potential and cessation of adenosine triphosphate synthesis. In addition, the release of intermembrane proteins, such as apoptosis-inducing factor and endonuclease G, and their translocation to the nucleus, leads to nuclear DNA fragmentation. Together, these events trigger necrotic cell death. Alternatively, the release of cytochrome c and other proapoptotic factors from mitochondria can promote caspase activation and apoptotic cell death. Drug toxicity can also induce an inflammatory response with the formation of reactive oxygen species by Kupffer cells and neutrophils. If not properly detoxified, these extracellularly generated oxidants can diffuse into hepatocytes and trigger mitochondrial dysfunction and oxidant stress, which then induces MPT and necrotic cell death. This review addresses the formation of oxidants and the defense mechanisms available for cells and applies this knowledge to better understand mechanisms of drug hepatotoxicity, especially acetaminophen-induced liver injury.

Hepatoprotective activity of a vinylic telluride against acute exposure to acetaminophen

Acetaminophen (APAP) hepatotoxicity has been related with several cases of cirrhosis, hepatitis and suicides attempts. Notably, oxidative stress plays a central role in the hepatic damage caused by APAP and antioxidants have been tested as alternative treatment against APAP toxicity. In the present study, we observed the hepatoprotector activity of the diethyl-2-phenyl-2-tellurophenyl vinylphosphonate (DPTVP), an organotellurium compound with low toxicity and high antioxidant potential. When the dose of 200 mg/kg of APAP was used, we observed that all used doses of DPTVP were able to restore the -SH levels that were depleted by APAP. Furthermore, the increase in thiobarbituric acid reactive substances levels and in the seric alanine aminotransferase (ALT) activity and the histopathological alterations caused by APAP were restored to control levels by DPTVP (30, 50 and 100 μmol/kg). On the other hand, when the 300 mg/kg dose of APAP was used, DPTVP restored the non-proteic -SH levels and repaired the normal liver morphology of the intoxicated mice only at 50 μmol/kg. Our in vitro results point out to a scavenging activity of DPTVP against several reactive species, action that is attributed to its chemical structure. Taken together, our results demonstrate that the pharmacological action of DPTVP as a hepatoprotector is probably due to its scavenging activity related to its chemical structure.

Current issues with acetaminophen hepatotoxicity--a clinically relevant model to test the efficacy of natural products

There is a significant need to evaluate the therapeutic potential of natural products and other compounds purported to be hepatoprotective. Acetaminophen-induced liver injury, especially in mice, is an attractive and widely used model for this purpose because it is both clinically relevant and experimentally convenient. However, the pathophysiology of liver injury after acetaminophen overdose is complex. This review describes the multiple steps and signaling pathways involved in acetaminophen-mediated cell death. The toxicity is initiated by the formation of a reactive metabolite, which depletes glutathione and binds to cellular proteins, especially in mitochondria. The resulting mitochondrial oxidant stress and peroxynitrite formation, in part through amplification by c-jun-N-terminal kinase activation, leads to mitochondrial DNA damage and opening of the mitochondrial permeability transition pore. Endonucleases from the mitochondrial intermembrane space and lysosomes are responsible for nuclear DNA fragmentation. Despite the oxidant stress, lipid peroxidation is not a relevant mechanism of injury. The mitochondrial dysfunction and nuclear DNA damage ultimately cause oncotic necrotic cell death with release of damage-associated molecular patterns that trigger a sterile inflammatory response. Current evidence supports the hypothesis that innate immune cells do not contribute to injury but are involved in cell debris removal and regeneration. This review discusses the latest mechanistic aspects of acetaminophen hepatotoxicity and demonstrates ways to assess the mechanisms of drug action and design experiments needed to avoid pitfalls and incorrect conclusions. This review should assist investigators in the optimal use of this model to test the efficacy of natural compounds and obtain reliable mechanistic information.

Effect of Chlorella vulgaris on lipid metabolism in Wistar rats fed high fat diet

This study was performed to investigate effects of Chlorella vulgaris on lipid metabolism in rats fed high fat diet. Sixty 6-week-old male Wistar rats were divided into two groups; normal diet group and high fat diet group, then the rats in each group were further divided into three subgroups and fed 0%, 5% and 10% (w/w) chlorella-containing diets, respectively, and raised for 9 weeks. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity and total protein and albumin concentration were not different among groups. Serum total lipids and liver TG concentration were significantly lower in 5% and 10% chlorella groups than 0% chlorella group in high fat diet groups (p<0.05). Serum TG, serum total cholesterol, liver total lipid and liver total cholesterol concentrations were significantly lower in 10% chlorella groups than 0% chlorella group in high fat diet groups (p<0.05). Fecal total lipid, TG and total cholesterol excretions were significantly higher in 5% and 10% chlorella groups than 0% chlorella groups in normal diet and high fat diet groups, respectively (p<0.05). These results suggest that Chlorella vulgaris is effective for prevention of dyslipidemia which may be due to the modulation of lipid metabolism and increased fecal excretion of lipid.

The effects of royal jelly on liver damage induced by paracetamol in mice

The present study was undertaken to investigate the protective effect of royal jelly against paracetamol-induced liver damage. The study was conducted in 90 female Swiss Albino mice, and six groups were established. While the first group was maintained as control, Groups 2-6 were administered 200mg/kg RJ for 1 day, 200mg/kg RJ for 7 days, 400mg/kg PAR for 1 day, 200mg/kg RJ plus 400mg/kg PAR for 1 day and 200mg/kg RJ for 7 days and then second 400mg/kg PAR on the 7th day, orally, respectively. It was shown that PAR significantly increased serum ALT, AST, ALP, liver MDA levels and significantly decreased liver GSH-Px activity, when compared to the control group (Group 1). On the other hand, meaningful changes were observed in the biochemical parameters of the group which was administered long-term RJ (Group 6). The aforementioned parameters which were statistically significant were determined to have drawn closer to values of the control group, and among these, the existing statistical differences for MDA level and GSH-Px activity between the trial group (Group 6) and the control group disappeared (Group 1). Compared to the pathological changes observed in the liver parenchyma, remark cords, sinusoids and hepatocytes in the group which was administered paracetamol alone (Group 4), lesions were determined to be less severe particularly in the group (Group 6) which received royal jelly for 7 days prior to paracetamol. In conclusion, the administration of royal jelly as a hepatoprotective agent for 7 days against paracetamol-induced liver damage was determined to exhibit marked protective effect on liver tissue.

Hepatoprotective effect of Hypericum japonicum extract and its fractions

OBJECTIVE

To investigate the hepatoprotective activity of different parts of Hypericum japonicum against carbon tetrachloride(CCl(4))-induced hepatitis and alpha-naphthyl-isothiocyanate (ANIT)-induced cholestasis.

MATERIALS AND METHODS

Mice were divided into groups and then administrated orally with solutions extracted from herbs before they were modeled in the experiments. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (T-BIL) in serum were evaluated. HPLC fingerprint was used for phytochemical analysis of the extracts.

RESULTS

The total aqueous extract of Hypericum japonicum had an obvious effect on the decreasing of AST, ALT and T-BIL levels in serum. The isolated fraction IV (F4) exhibited a preferable activity of ameliorating cholestasis, while Fraction V (F5) was more efficacious in protecting liver from injury. Chemical fingerprint indicated that F5 contained several flavonoids which might be the active chemicals against hepatotoxicity.

CONCLUSION

Different fractions of Hypericum japonicum manifest different effect, indicating their different potentials as candidacies of new drugs.

Flavonoids with anti-inflammatory and antinociceptive activity from Cistus laurifolius L. leaves through bioassay-guided procedures

Extracts obtained from the leaves and branches of various Cistus species have been used worldwide as folk remedy for the treatment of various inflammatory ailments including rheumatism and renal inflammations. Effects of the extracts and fractions from the leaves with non-woody branches of Cistus laurifolius L. (Cistaceae) were studied using two in vivo models of inflammation in mice. Model one was based on observed potent inhibitory activity against carrageenan-induced hind paw oedema and the second model used was acetic acid-induced, increased vascular permeability model. Through bioassay-guided fractionation and isolation procedures three flavonoids; 3-O-methylquercetin (1), 3,7-O-dimethylquercetin (2) and 3,7-O-dimethylkaempferol (3) were isolated as the main active ingredients from the ethanol extract. Later on, these flavonoids were shown to possess potent antinociceptive activity, which was assessed through inhibition of p-benzoquinone-induced writhing reflex. Results of the present study have clearly supported the utilization of Cistus laurifolius in Turkish traditional medicine. Subsequently, three flavonoids were shown to have strong antinociceptive and anti-inflammatory activities, per os without inducing any apparent acute toxicity as well as gastric damage.