The phytochemical and pharmacological profile of dandelion

Dandelion (Taraxacum genus), a perennial herb belonging to the Asteraceae family is widely distributed in hillside grasslands, roadsides, fields, and river beaches in middle and low-altitude areas. It has a long history of traditional Chinese medicine usage as a heat-clearing and detoxifying agent, often consumed as tea or vegetable. Multiple pharmacological studies have demonstrated the antiviral, antibacterial, anti-inflammatory, immune-regulating, antioxidant, anti-tumor, and other effects of the Taraxacum genus. Bioactive compounds associated with these effects include triterpenes and their saponins, phenolic acids, sterols and their glycosides, flavonoids, organic acids, volatile oils, and saccharides.

Protective Effects of the Third Generation Vasodilatory Βeta - Blocker Nebivolol against D-Galactosamine - Induced Hepatorenal Syndrome in Rats

BACKGROUND:

Renal dysfunction is very common in patients with advanced liver cirrhosis and portal hypertension. The development of renal failure in the absence of clinical, anatomical or pathological causes renal of failure is termed hepatorenal syndrome (HRS).

AIM:

The present study was constructed to investigate the possible protective effects of nebivolol (Nebi) against D-galactosamine (Gal)-induced HRS in rats.

MATERIAL AND METHODS:

Rats were treated with Nebi for ten successive days. On the 8th day of the experiment, they received a single dose of Gal. Serum levels of Cr, BUN, Na+ and K+ as well as AST, ALT, total bilirubin (TB), NH3 and endothelin-1 (ET-1) were determined following Gal administration. Moreover, renal and liver contents of MDA, GSH, F2-isoprostanes (F2-IPs), tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-B (NF-κB), total nitric oxide (NO), in addition to activities of caspase-3 (Cas-3), heme oxygenase-1 (HO-1), inducible and endothelial NO synthase (iNOS and eNOS) enzymes were also assessed. Finally, histopathological examination was performed.

RESULTS:

Nebi attenuated Gal-induced renal and hepatic dysfunction. It also decreased the Gal-induced oxidative stress and inflammatory recruitment.

CONCLUSION:

Results demonstrated both nephroprotective and hepatoprotective effects of Nebi against HRS and suggested a role of its antioxidant, anti-inflammatory, anti-apoptotic and NO-releasing properties.

Review of the Pharmacological Effects of Vitis vinifera (Grape) and its Bioactive Constituents: An Update

Vitis vinifera fruit (grape) contains various phenolic compounds, flavonoids and stilbenes. In recent years, active constituents found in the fruits, seeds, stems, skin and pomaces of grapes have been identified and some have been studied. In this review, we summarize the active constituents of different parts of V. vinifera and their pharmacological effects including skin protection, antioxidant, antibacterial, anticancer, antiinflammatory and antidiabetic activities, as well as hepatoprotective, cardioprotective and neuroprotective effects in experimental studies published after our 2009 review. Clinical and toxicity studies have also been examined. Copyright © 2016 John Wiley & Sons, Ltd.

Taraxacum officinale and related species-An ethnopharmacological review and its potential as a commercial medicinal plant

ETHNOPHARMACOLOGICAL RELEVANCE

Dandelion (Taraxacum spec) is a wild plant that has been used for centuries as a traditional medicine in the relief and treatment of several diseases. This use is due to the presence of sesquiterpenes, saponins, phenolic compounds, flavonoids, and sugars, among others, found in the organs of the plant.

AIM OF THE STUDY

The aim of this work is to provide a current review of developments and trends in research on the Taraxacum genus, with a focus on traditional uses and pharmacological properties. This should shed light on the potential of this plant as an attractive commercial herbal medicine.

MATERIALS AND METHODS

Documents were collected, analyzed, and classified for information regarding medical, agronomic, genetic, and biological aspects of the Taraxacum species. This process was based on a thorough search of documents indexed by scientific search engines.

RESULTS

Two important periods of research on Taraxacum have been identified: the first, between 1930 and 1950; and the second, from 1990 to today. During the former, agricultural and genetics research on this plant were, due to the shortage of natural rubber, the focus. In contrast, the main drive in Taraxacum research is now the recovery of bioactives and/or applications in medicine. Pharmacology is the main area in which these plants have been tested, thanks in part to its widely known traditional uses; however, there is less than enthusiastic interest in further human clinical trials. In other areas, Taraxacum sports an enormous list of compounds of industrial interest; and while it is true that only a small amount of these compounds is immediately available in Taraxacum organs and makes it relatively commercially unattractive, only scarce efforts have been made to improve yields. Compounding this issue, most studies of its growth and cultivation have been focused mainly on controlling it as a weed detrimental to certain industrial crops. To wit, in spite of all the research carried out, less than 1% of all the species identified so far (>2500) have been studied (including Taraxacum officinale, Taraxacum coreanum, Taraxacum mongolicum and Taraxacum platycarpum). This is a indication of the little knowledge that we have about this genus so far. Biotechnology (involving genetics, agriculture, and biology) is the most powerful means by which to take advantage of all the medicinal potential of Taraxacum. Great strides have been made in identifying metabolic pathways for synthesizing terpenes, one of the most important compound families in clinical applications. In order to improve yield and performance of the plant in the field, greenhouse cultivation is another aspect taken into account, deriving an increase in recovery of bioactives from Taraxacum organs. Even while considering that only a few species have been studied, their different biochemical and cultivation profiles indicate huge potential for qualitative improvements in composition through genetic engineering, thus directly impacting pharmacological properties.

CONCLUSIONS

Taraxacum is has been traditionally considered a natural remedy, well-inserted into popular knowledge, but with low commercial applicability. Only once the recovery of pure and highly reactive compounds can be pursued at (a qualitatively and quantitatively attractive) economical scale, human clinical trials would be of interest in order to prove their efficacy and safety, positioning Taraxacum as an important commercial source of natural drugs.

Protective effect of wild ginseng cambial meristematic cells on d-galactosamine-induced hepatotoxicity in rats

Background

Panax ginseng has a wide range of biological activities including anti-inflammatory, antioxidant, and immunomodulatory functions. Wild ginseng cambial meristematic cells (CMCs) were obtained from P. ginseng cambium. This study examined the protective mechanism of wild ginseng CMCs against d-galactosamine (GalN)-induced liver injury. GalN, a well-known hepatotoxicant, causes severe hepatocellular inflammatory damage and clinical features similar to those of human viral hepatitis in experimental animals.

Methods

Hepatotoxicity was induced in rats using GalN (700 mg/kg, i.p.). Wild ginseng CMCs was administered orally once a day for 2 wks, and then 2 h prior to and 6 h after GalN injection.

Results

Wild ginseng CMCs attenuated the increase in serum aminotransferase activity that occurs 24 h after GalN injection. Wild ginseng CMCs also attenuated the GalN-induced increase in serum tumor necrosis factor-α, interleukin-6 level, and hepatic cyclooxygenase-2 protein and mRNA expression. Wild ginseng CMCs augmented the increase in serum interleukin -10 and hepatic heme oxygenase-1 protein and mRNA expression that was induced by GalN, inhibited the increase in the nuclear level of nuclear factor-kappa B, and enhanced the increase in NF-E2-related factor 2.

Conclusion

Our findings suggest that wild ginseng CMCs protects liver against GalN-induced inflammation by suppressing proinflammatory mediators and enhancing production of anti-inflammatory mediators.

Schisandra chinensis regulates drug metabolizing enzymes and drug transporters via activation of Nrf2-mediated signaling pathway

Drug metabolizing enzymes (DMEs) and drug transporters are regulated via epigenetic, transcriptional, posttranscriptional, and translational and posttranslational modifications. Phase I and II DMEs and drug transporters play an important role in the disposition and detoxification of a large number of endogenous and exogenous compounds. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a critical regulator of a variety of important cytoprotective genes that are involved in disposition and detoxification of xenobiotics. Schisandra chinensis (SC) is a commonly used traditional Chinese herbal medicine that has been primarily used to protect the liver because of its potent antioxidative and anti-inflammatory activities. SC can modulate some DMEs and drug transporters, but the underlying mechanisms are unclear. In this study, we aimed to explore the role of Nrf2 in the regulatory effect of SC extract (SCE) on selected DMEs and drug transporters in human hepatocellular liver carcinoma cell line (HepG2) cells. The results showed that SCE, schisandrin A, and schisandrin B significantly increased the expression of NAD(P)H: Nicotinamide Adenine Dinucleotide Phosphate-oxidase or:quinone oxidoreductase 1, heme oxygenase-1, glutamate–cysteine ligase, and glutathione S-transferase A4 at both transcriptional and posttranscriptional levels. Incubation of HepG2 cells with SCE resulted in a significant increase in the intracellular level of glutathione and total glutathione S-transferase content. SCE significantly elevated the messenger ribonucleic acid and protein levels of P-glycoprotein and multidrug resistance-associated protein 2 and 4, whereas the expression of organic anion transporting peptide 1A2 and 1B1 was significantly downregulated by SCE. Knockdown of Nrf2 by small interfering ribonucleic acid attenuated the regulatory effect of SCE on these DMEs and drug transporters. SCE significantly upregulated Nrf2 and promoted the translocation of Nrf2 from cytoplasm to the nuclei. Additionally, SCE significantly suppressed the expression of cytosolic Kelch-like ECH-associated protein 1 (the repressor of Nrf2) and remarkably increased Nrf2 stability in HepG2 cells. Taken together, our findings suggest that the hepatoprotective effects of SCE may be partially ascribed to the modulation of DMEs and drug transporters via Nrf2-mediated signaling pathway. SCE may alter the pharmacokinetics of other coadministered drugs that are substrates of these DMEs and transporters and thus cause unfavorable herb–drug interactions.

Induction of Nrf2 and metallothionein as a common mechanism of hepatoprotective medicinal herbs

Many Chinese medicines have the potential to be hepatoprotective and therefore can be used to treat acute and chronic liver diseases. The challenge is to identify the molecular target for their protective mechanism. This study investigated the induction of nuclear factor-erythroid 2(NF-E2)-related factor 2 (Nrf2) antioxidant genes and metallothionein as a common mechanism of hepatoprotective effects of Chinese medicines such as Piper puberulum. Mice were pretreated with Piper puberulum extract (PPE, 500 mg/kg, po) or vehicles for seven days, followed by intoxication with CCl 4 (25 μl/kg, ip for 16 h), D-galactosamine (800 mg/kg, ip for 8 h), or acetaminophen (400 mg/kg, ip for 8 h). Hepatotoprotection was evaluated by serum enzyme activities and histopathology. To determine the mechanism of protection, mice were given PPE (250-1000 mg/kg, po for seven days) and livers were collected to quantify the expression of Nrf2-targeted genes and metallothionein. Nrf2-null mice were also used to determine the role of Nrf2 in PPE-mediated hepatoprotection.PPE pretreatment protected against the hepatotoxicity produced by CCl 4, D-galactosamine, and acetaminophen, as evidenced by decreased serum enzyme activities and ameliorated liver lesions. PPE treatment increased the expression of hepatic Nrf2, NAD(P)H:quinone oxidoreductase1 (Nqo1), heme oxygenase-1 (Ho-1), glutamate-cysteine ligases (Gclc), and metallothionein (MT), at both transcripts and protein levels. PPE protected wild-type mice from CCl 4 and acetaminophen hepatotoxicity, but not Nrf2-null mice, fortifying the Nrf2-dependent protection. In conclusion, induction of the Nrf2 antioxidant pathways and metallothionein appears to be a common mechanism for hepatoprotective herbs such as PPE.

The effects of high-dose qinggan huoxue recipe on acute liver failure induced by d-galactosamine in rats

Qinggan Huoxue Recipe is a traditional Chinese medicine, which has been usually used to improve liver function in hepatitis. In order to investigate the effects of high-dose Qinggan Huoxue Recipe on acute liver failure and explore the potential mechanism, we had built acute liver failure models in rats by intraperitoneal injection of D-galactosamine (D-GalN). High-dose Qinggan Huoxue Recipe was delivered by gavage. After treatment, the blood alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), albumin (ALB), cholinesterase (CHE), and prothrombin time (PT) were determined. The pathological score of liver tissue was recorded. Proliferating cell nuclear antigen (PCNA) immunohistochemistry staining and fluorescence quantitative reverse transcription polymerase chain reaction (qRT-PCR) of high mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF- κ B), and Caspase-3 were performed. The survival curve was also depicted. Our results demonstrated that high-dose Qinggan Huoxue Recipe could significantly improve liver function and increase survival rates in rats with acute liver failure. These effects were supposed to be mediated by suppressing inflammatory reaction and apoptosis.