A plant kavalactone desmethoxyyangonin prevents inflammation and fulminant hepatitis in mice

Opportunities and Challenges of Kava in Lung Cancer Prevention

Lung cancer is the leading cause of cancer-related deaths due to its high incidence, late diagnosis, and limited success in clinical treatment. Prevention therefore is critical to help improve lung cancer management. Although tobacco control and tobacco cessation are effective strategies for lung cancer prevention, the numbers of current and former smokers in the USA and globally are not expected to decrease significantly in the near future. Chemoprevention and interception are needed to help high-risk individuals reduce their lung cancer risk or delay lung cancer development. This article will review the epidemiological data, pre-clinical animal data, and limited clinical data that support the potential of kava in reducing human lung cancer risk via its holistic polypharmacological effects. To facilitate its future clinical translation, advanced knowledge is needed with respect to its mechanisms of action and the development of mechanism-based non-invasive biomarkers in addition to safety and efficacy in more clinically relevant animal models.

[Dihydromyricetin reduces lipid accumulation in LO2 cells via AMPK/mTOR-mediated lipophagy pathway and inhibits HepG2 cell proliferation in vitro]

OBJECTIVE

To explore the mechanism underlying the hepatoprotective effect of dihydromyricetin (DMY) against lipid accumulation in light of the lipophagy pathway and the inhibitory effect of DMY on HepG2 cell proliferation.

METHODS

LO2 cells were cultured in the presence of 10% FBS for 24 h and treated with 100 μg/mL DMY, or exposed to 50% FBS for 24 h followed by treatment with 50, 100, or 200 μg/mL DMY; the cells in recovery group were cultured in 50% FBS for 24 h and then in 10% FBS for another 24 h. Oil red O staining was used to observe the accumulation of lipid droplets in the cells, and the levels of TC, TG, and LDL and activities of AST, ALT and LDH were measured. The expression of LC3 protein was detected using Western blotting. AO staining and transmission electron microscopy were used to determine the numbers of autophagolysosomes and autophagosomes, respectively. The formation of autophagosomes was observed with MDC staining, and the mRNA expression levels of LC3, ATG7, AMPK, mTOR, p62 and Beclin1 were determined with q-PCR. Flow cytometry was performed to analyze the effect of 50, 100, and 200 μg/mL DMY on cell cycle and apoptosis of HepG2 cells; DNA integrity in the treated cells was examined with cell DNA fragmentation test.

RESULTS

DMY treatment and pretreatment obviously inhibited lipid accumulation and reduced the levels of TC, TG, LDL and enzyme activities of AST, ALT and LDH in LO2 cells (P < 0.05). In routinely cultured LO2 cells, DMY significantly promoted the formation of autophagosomes and autophagolysosomes and upregulated the expression of LC3 protein. DMY obviously attenuated high FBS-induced inhibition of autophagosome formation in LO2 cells, up- regulated the mRNA levels of LC3, ATG7, Beclin1 and AMPK, and downregulated p62 and mTOR mRNA levels (P < 0.05 or 0.01). In HepG2 cells, DMY caused obvious cell cycle arrest, inhibited cell proliferation, and induced late apoptosis and DNA fragmentation.

CONCLUSION

DMY reduces lipid accumulation in LO2 cells by regulating the AMPK/ mTOR-mediated lipophagy pathway and inhibits the proliferation of HepG2 by causing cell cycle arrest and promoting apoptosis.

Identification of Novel Cannabinoid CB2 Receptor Agonists from Botanical Compounds and Preliminary Evaluation of Their Anti-Osteoporotic Effects

As cannabinoid CB2 receptors (CB2R) possess various pharmacological effects—including anti-epilepsy, analgesia, anti-inflammation, anti-fibrosis, and regulation of bone metabolism—without the psychoactive side effects induced by cannabinoid CB1R activation, they have become the focus of research and development of new target drugs in recent years. The present study was intended to (1) establish a double luciferase screening system for a CB2R modulator; (2) validate the agonistic activities of the screened compounds on CB2R by determining cAMP accumulation using HEK293 cells that are stably expressing CB2R; (3) predict the binding affinity between ligands and CB2 receptors and characterize the binding modes using molecular docking; (4) analyze the CB2 receptors–ligand complex stability, conformational behavior, and interaction using molecular dynamics; and (5) evaluate the regulatory effects of the screened compounds on bone metabolism in osteoblasts and osteoclasts. The results demonstrated that the screening system had good stability and was able to screen cannabinoid CB2R modulators from botanical compounds. Altogether, nine CB2R agonists were identified by screening from 69 botanical compounds, and these CB2R agonists exhibited remarkable inhibitory effects on cAMP accumulation and good affinity to CB2R, as evidenced by the molecular docking and molecular dynamics. Five of the nine CB2R agonists could stimulate osteoblastic bone formation and inhibit osteoclastic bone resorption. All these findings may provide useful clues for the development of novel anti-osteoporotic drugs and help elucidate the mechanism underlying the biological activities of CB2R agonists identified from the botanical materials.

Kava as a Clinical Nutrient: Promises and Challenges

Kava beverages are typically prepared from the root of Piper methysticum. They have been consumed among Pacific Islanders for centuries. Kava extract preparations were once used as herbal drugs to treat anxiety in Europe. Kava is also marketed as a dietary supplement in the U.S. and is gaining popularity as a recreational drink in Western countries. Recent studies suggest that kava and its key phytochemicals have anti-inflammatory and anticancer effects, in addition to the well-documented neurological benefits. While its beneficial effects are widely recognized, rare hepatotoxicity had been associated with use of certain kava preparations, but there are no validations nor consistent mechanisms. Major challenges lie in the diversity of kava products and the lack of standardization, which has produced an unmet need for quality initiatives. This review aims to provide the scientific community and consumers, as well as regulatory agencies, with a broad overview on kava use and its related research. We first provide a historical background for its different uses and then discuss the current state of the research, including its chemical composition, possible mechanisms of action, and its therapeutic potential in treating inflammatory and neurological conditions, as well as cancer. We then discuss the challenges associated with kava use and research, focusing on the need for the detailed characterization of kava components and associated risks such as its reported hepatotoxicity. Lastly, given its growing popularity in clinical and recreational use, we emphasize the urgent need for quality control and quality assurance of kava products, pharmacokinetics, absorption, distribution, metabolism, excretion, and foundational pharmacology. These are essential in order to inform research into the molecular targets, cellular mechanisms, and creative use of early stage human clinical trials for designer kava modalities to inform and guide the design and execution of future randomized placebo controlled trials to maximize kava's clinical efficacy and to minimize its risks.

Effects of Alpinia pricei on the Neuropharmacological Activities in Mice

Alpinia pricei Hayata (Zingiberaceae) is a spicy plant endemic to Taiwan. In this study, several behavioral analyses were used to evaluate the neuropharmacological activity of A. pricei in mice. Oral administration of 100, 300, and 500 mg/kg of A. pricei extract (APE) significantly prolonged pentobarbital-induced sleeping time in mice by 24.5%, 74.7%, and 79.0%, respectively. Also, the antidepressant effect of APE was evaluated using suspended tail and forced swimming tests. The immobility periods of mice in the suspended tail and forced swimming tests were reduced after the administration of APE. Further, an elevated plus-maze test was used to study the anxiolytic activity of APE. After treatment with 500 mg/kg of APE the time the mice spent in the open arms (31.55 ± 13.65 seconds) and the number of times they entered the open arms (51.75 ± 16.51 times) ( P < 0.05) of the plus-maze increased significantly compared to a saline-treated group. Our results also revealed that APE showed potent analgesic activity in the tail-flick test; all dosages of APE prolonged the tail-flick time for up to 90 minutes. In conclusion, APE had a potent effect on the neuropharmacological activities of mice. Finally, the main compounds of APE were separated, and spectral analysis was conducted. The major constituents of APE were characterized as 5,7-dimethoxyflavanone (1), desmethoxyyangonin (2), 2′,4′,6′-trimethoxychalcone (3), cardamonin (4), trans/ cis-3,5-dimethoxystilbene (5), and flavokawain B (6).

Antimicrobial substances from Amazonian Aniba (Lauraceae) species

Extracts and six isolated substances from Aniba (Lauraceae) Amazonian species A. parviflora, A. panurensis and A. rosaeodora were analysed in vitro to their antibacterial, antiparasitic and antiplasmodial activities. NMR and MS experiments led to the identification of three styrylpyrones (5,6-dihydrokawain [I], 4-methoxy-11,12-methylenedioxy-6-trans-styryl-pyran-2-one [II] and rel-(6R,7S,8S,5'S)-4'-methoxy-8-(11,12-dimethoxyphenyl-7-[6-(4-methoxy-2-pyranyl)]-6-(E)-styryl-1'-oxabicyclo[4,2,0]oct-4'-en-2'-one [III]), a pyridine alkaloid (anibine [IV]) and two kavalactones (tetrahydroyangonin [V] and dihydromethysticin [VI]). The best antibacterial result was observed at the hexane fraction of A. panurensis (MIC 7.8 μg/mL against the three bacteria). Equal MIC were observed by the extract and dichloromethane fraction of A. panurensis against S. simulans and S. aureus; and 15.62 μg/mL against MRSA. Similarly, only A. panurensis extracts showed in vitro activities against Tripanossoma cruzi and Leishmania amazonensis parasites. In Plasmodium falciparum assay, 5,6-dihydrokawain was considered an active antimalarial (14.03 μM), and substances II (132.94 μM) and III (41.84 μM) presented moderate activities.

Phyto-sesquiterpene lactone deoxyelephantopin and cisplatin synergistically suppress lung metastasis of B16 melanoma in mice with reduced nephrotoxicity

BACKGROUND

Cisplatin (CP) is a chemotherapeutic drug for treating melanoma that also causes adverse side effects in cancer patients.

PURPOSE

This study investigated the bioefficacy of a phytoagent deoxyelephantopin (DET) in inhibiting B16 melanoma cell activity, its synergism with CP against metastatic melanoma, and its capability to attenuate CP side effects in animals.

METHODS

DET and CP bioactivities were assessed by MTT assay, isobologram analysis, time-lapse microscopy, migration and invasion assays, flow cytometry and western blotting. In vivo bioluminescence imaging was used to detect lung metastasis of B16 cells carrying COX-2 reporter gene in syngeneic mice. H&E staining and immunohistochemistry were used to evaluate the compound/drug efficacy and CP side effects. Nephrotoxicity caused by CP treatment in mice was evaluated by UPLC/ESI-QTOF MS - based metabolomics and haematometry.

RESULT

DET, alone or in combination with cisplatin, inhibited B16 cell proliferation, migration, and invasion, and induced cell-cycle arrested at the G₂/M phase and de-regulated cell-cycle mediators in cancer cells. In a murine B16^COX-Luc metastatic allograft model, CP2 (2  mg/kg) treatment inhibited B16 lung metastasis accompanied by severe body weight loss, renal damage and inflammation, and haematological toxicity. DET10 and CP cotreatment (DET10 + CP1) or sequential treatment (CP2→DET10) significantly inhibited formation of pulmonary melanoma foci and reduced renal damage. DET pretreatment (Pre-DET10) or CP2→DET10 treatment had the longest survival (52  vs. 37 days for tumor control mice). CP treatment caused abnormally accumulated urea cycle metabolites and serotonin metabolite hippuric acid in renal tissues that were not seen with DET alone or in combination with CP.

CONCLUSION

The CP and DET combination may be an effective intervention for melanoma with reduced side effects.

Astaxanthin alleviated ethanol-induced liver injury by inhibition of oxidative stress and inflammatory responses via blocking of STAT3 activity

Astaxanthin (AXT) is classified as a xanthophyll carotenoid compound which have broader functions including potent antioxidant, anti-inflammatory and neuroprotective properties. Considerable researches have demonstrated that AXT shows preventive and therapeutic properties against for Diabetes, Osteoarthritis and Rheumatoid Arthritis. However, the protective effect of AXT on liver disease has not yet been reported. In this study, we investigated effects of AXT on ethanol-induced liver injury in chronic plus binge alcohol feeding model. The hepatic steatosis and inflammation induced by ethanol administration were alleviated by AXT. Serum levels of aspartate transaminase and alanine transaminase were decreased in the livers of AXT administrated group. The ethanol-induced expression of cytochrome P450 2E1 (CYP2E1), pro-inflammatory proteins, cytokines, chemokines and reactive oxygen species (ROS) levels were also reduced in the livers of AXT administrated group. Moreover, ethanol-induced infiltration of neutrophils was decreased in the livers of AXT administrated group. Docking model and pull-down assay showed that AXT directly binds to the DNA binding site of STAT3. Moreover, AXT decreased STAT3 phosphorylation in the liver of AXT administration group. Therefore, these results suggest that AXT could prevent ethanol-induced hepatic injury via inhibition of oxidant and inflammatory responses via blocking of STAT3 activity.

Metabolic regulations of a decoction of Hedyotis diffusa in acute liver injury of mouse models

Background

Dysfunctional metabolisms are contributed to LPS/GALN-induced hepatitis. However, whether Hedyotis diffusa (HD) employs metabolic strategies against hepatitis is unknown.

Methods

We use the cytokines expression, levels of serum alanine transaminase and aspartate transaminase, survival and histological analysis to measure the effect of decoction of HD on acute severe hepatitis of mouse induced by LPS/GALN. Meanwhile, we utilize GC/MS-based metabolomics to characterize the variation of metabolomes.

Results

The present study shows the relieving liver damage in HD decoction-treated mice. Metabolic category using differential metabolites indicates the lower percentage of carbohydrates in LPS/GALN + HD group than LPS/GALN group, revealing the value of carbohydrate metabolism in HD decoction-administrated mouse liver. Further pathway enrichment analysis proposes that citrate cycle, galactose metabolism, and starch and sucrose metabolism are three important carbohydrate metabolisms that involve in the protective effect of decoction of HD during acute hepatitis. Furthermore, other important enrichment pathways are biosynthesis of unsaturated fatty acids, alanine, aspartate and glutamate metabolism, and arginine and proline metabolism. Fatty acids or amino acids involved in above-mentioned pathways are also detected in high loading distribution on IC01 and IC02, thereby manifesting the significance of these metabolites. Other key metabolites detect in ICA analysis were cholesterol, lactic acid and tryptophan.

Conclusions

The variation tendency of above-mentioned metabolites is totally consistent with the protective nature of decoction of HD. These findings give a viewpoint that HD decoction-effected metabolic strategies are linked to underlying mechanisms of decoction of HD and highlight the importance of metabolic mechanisms against hepatitis.

Electronic supplementary material

The online version of this article (10.1186/s13020-017-0159-4) contains supplementary material, which is available to authorized users.

Interactions of Desmethoxyyangonin, a Secondary Metabolite from Renealmia alpinia, with Human Monoamine Oxidase-A and Oxidase-B

Renealmia alpinia (Zingiberaceae), a medicinal plant of tropical rainforests, is used to treat snakebites and other injuries and also as a febrifuge, analgesic, antiemetic, antiulcer, and anticonvulsant. The dichloromethane extract of R. alpinia leaves showed potent inhibition of human monoamine oxidases- (MAOs-) A and B. Phytochemical studies yielded six known compounds, including pinostrobin 1, 4′-methyl ether sakuranetin 2, sakuranetin 3, pinostrobin chalcone 4, yashabushidiol A 5, and desmethoxyyangonin 6. Compound 6 displayed about 30-fold higher affinity for MAO-B than MAO-A, with Ki values of 31 and 922 nM, respectively. Kinetic analysis of inhibition and equilibrium-dialysis dissociation assay of the enzyme-inhibitor complex showed reversible binding of desmethoxyyangonin 6 with MAO-A and MAO-B. The binding interactions of compound 6 in the active site of the MAO-A and MAO-B isoenzymes, investigated through molecular modeling algorithms, confirmed preferential binding of desmethoxyyangonin 6 with MAO-B compared to MAO-A. Selective reversible inhibitors of MAO-B, like desmethoxyyangonin 6, may have important therapeutic significance for the treatment of neurodegenerative disorders, such as Parkinson's disease and Alzheimer's disease.

CQMUH-011, a novel adamantane sulfonamide compound, inhibits lipopolysaccharide- and D-galactosamine-induced fulminant hepatic failure in mice

CQMUH-011, a novel adamantane sulfonamide compound, was shown to suppress macrophage activation and proliferation in our previous study. However, it is unknown whether CQMUH-011 has anti-inflammatory and hepatoprotective properties. In this study, we investigated the potential effects and mechanisms of CQMUH-011 on lipopolysaccharide (LPS)-induced RAW264.7 cell activation in vitro and LPS- and D-galactosamine (D-GalN)-induced fulminant hepatic failure (FHF) in vivo. The results showed that in RAW264.7 cells challenged by LPS, CQMUH-011 inhibited cell proliferation and induced cell cycle arrest and apoptosis. Furthermore, CQMUH-011 reduced tumor necrosis factor (TNF)-α and interleukin (IL)-1β production and down-regulated the overexpression of toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB induced by LPS in RAW264.7 cells. In vivo, CQMUH-011 reduced serum levels of aspartic aminotransferase and alanine transaminase and improved the mortality and hepatic pathological damage induced by LPS/D-GalN in mice. Moreover, CQMUH-011 significantly inhibited the serum levels of proinflammatory mediators, including TNF-α, IL-6, IL-1β, nitric oxide (NO), and prostaglandin E2 (PGE₂), and down-regulated the protein expression of TLR4, p38 mitogen-activated protein kinases, NF-κB, NF-κB inhibitor α (IκBα), IκB kinase β (IKKβ), cyclooxygenase-2 (COX-2) and inducible NO synthases (iNOS) induced by LPS/D-GalN in mice. In conclusion, these results demonstrated that CQMUH-011 has a notable anti-inflammatory effect and protects mice from LPS/D-GalN-induced FHF and that the molecular mechanisms might be related to the inhibition of the TLR4/NF-κB signaling pathway activation, the subsequent decrease in proinflammatory mediator production, and the inhibition of macrophage activation.