β-Caryophyllene alleviates D-galactosamine and lipopolysaccharide-induced hepatic injury through suppression of the TLR4 and RAGE signaling pathways

β-caryophyllene inhibits heroin self-administration, but does not alter opioid-induced antinociception in rodents

A growing body of research indicates that β-caryophyllene (BCP), a constituent present in a large number of plants, possesses significant therapeutic properties against CNS disorders, including alcohol and psychostimulant use disorders. However, it is unknown whether BCP has similar therapeutic potential for opioid use disorders. In this study, we found that systemic administration of BCP dose-dependently reduced heroin self-administration in rats under an FR2 schedule of reinforcement and partially blocked heroin-enhanced brain stimulation reward in DAT-cre mice, maintained by optical stimulation of midbrain dopamine neurons at high frequencies. Acute administration of BCP failed to block heroin conditioned place preference (CPP) in male mice, but attenuated heroin-induced CPP in females. Furthermore, repeated dosing with BCP for 5 days facilitated the extinction of CPP in female but not male mice. In the hot plate assay, pretreatment with the same doses of BCP failed to enhance or prolong opioid antinociception. Lastly, in a substitution test, BCP replacement for heroin failed to maintain intravenous BCP self-administration, suggesting that BCP itself has no reinforcing properties. These findings suggest that BCP may have certain therapeutic effects against opioid use disorders with fewer unwanted side-effects by itself.

Integrating GC-MS and comparative transcriptome analysis reveals that TsERF66 promotes the biosynthesis of caryophyllene in Toona sinensis tender leaves

Introduction

The strong aromatic characteristics of the tender leaves of Toona sinensis determine their quality and economic value.

Methods and results

Here, GC-MS analysis revealed that caryophyllene is a key volatile compound in the tender leaves of two different T. sinensis varieties, however, the transcriptional mechanisms controlling its gene expression are unknown. Comparative transcriptome analysis revealed significant enrichment of terpenoid synthesis pathway genes, suggesting that the regulation of terpenoid synthesis-related gene expression is an important factor leading to differences in aroma between the two varieties. Further analysis of expression levels and genetic evolution revealed that TsTPS18 is a caryophyllene synthase, which was confirmed by transient overexpression in T. sinensis and Nicotiana benthamiana leaves. Furthermore, we screened an AP2/ERF transcriptional factor ERF-IX member, TsERF66, for the potential regulation of caryophyllene synthesis. The TsERF66 had a similar expression trend to that of TsTPS18 and was highly expressed in high-aroma varieties and tender leaves. Exogenous spraying of MeJA also induced the expression of TsERF66 and TsTPS18 and promoted the biosynthesis of caryophyllene. Transient overexpression of TsERF66 in T. sinensis significantly promoted TsTPS18 expression and caryophyllene biosynthesis.

Discussion

Our results showed that TsERF66 promoted the expression of TsTPS18 and the biosynthesis of caryophyllene in T. sinensis leaves, providing a strategy for improving the aroma of tender leaves.

Toll-like receptor signalling as a cannabinoid target

Toll-like receptors (TLRs) have become a focus in biomedicine and biomedical research given the roles of this unique family of innate immune proteins in immune activation, infection, and autoimmunity. It is evident that TLR dysregulation, and subsequent alterations in TLR-mediated inflammatory signalling, can contribute to disease pathogenesis, and TLR targeted therapies are in development. This review highlights evidence that cannabinoids are key regulators of TLR signalling. Cannabinoids include component of the plant Cannabis sativa L. (C. sativa), synthetic and endogenous ligands, and overall represent a class of compounds whose therapeutic potential and mechanism of action continues to be elucidated. Cannabinoid-based medicines are in the clinic, and are furthermore under intense investigation for broad clinical development to manage symptoms of a range of disorders. In this review, we present an overview of research evidence that signalling linked to a range of TLRs is targeted by cannabinoids, and such cannabinoid mediated effects represent therapeutic avenues for further investigation. First, we provide an overview of TLRs, adaptors and key signalling events, alongside a summary of evidence that TLRs are linked to disease pathologies. Next, we discuss the cannabinoids system and the development of cannabinoid-based therapeutics. Finally, for the bulk of this review, we systematically outline the evidence that cannabinoids (plant-derived cannabinoids, synthetic cannabinoids, and endogenous cannabinoid ligands) can cross-talk with innate immune signalling governed by TLRs, focusing specifically on each member of the TLR family. Cannabinoids should be considered as key regulators of signalling controlled by TLRs, and such regulation should be a major focus in terms of the anti-inflammatory propensity of the cannabinoid system.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

Agastache Species: A Comprehensive Review on Phytochemical Composition and Therapeutic Properties

The Agastache genus is part of the Lamiaceae family and is native to North America, while one species, Agastache rugosa (A. rugosa), is native to East Asia. A review on the phytochemistry and bioactivity of Agastache genus was last performed in 2014. Since then, a lot of progress has been made on the characterization of the phytochemical and pharmacological profiles of Agastache species. Thus, the purpose of this paper is to present a summary of the findings on the phytochemistry and biological effects of several Agastache species, including both extracts and essential oil characterization. We performed a comprehensive search using PubMed and Scopus databases, following PRISMA criteria regarding the study selection process. The available data is focused mainly on the description of the chemical composition and bioactivity of A. rugosa, with fewer reports referring to Agastache mexicana (A. mexicana) and Agastache foeniculum (A. foeniculum). Agastache species are characterized by the dominance of flavonoids and phenolic acids, as well as volatile compounds, particularly phenylpropanoids and monoterpenes. Moreover, a series of pharmacological effects, including antioxidant, cytotoxic, antimicrobial, anti-atherosclerotic, and cardioprotective properties, have been reported for species from the Agastache genus.

Knockdown of protein interacting with C α kinase 1 aggravates sepsis-induced acute liver injury by regulating the TLR4/NF-κB pathway

Acute liver injury (ALI) may manifest at any phase of sepsis, yet an explicit therapeutic approach remains elusive. In this study, LPS and cecum ligation and puncture (CLP) were utilized to establish an inflammatory cell model and a murine model of sepsis-induced liver injury, respectively, aiming to explore the potential protective effect of protein interacting with C α kinase 1 (PICK1) on sepsis-induced ALI and its underlying mechanisms. In both the cell supernatant and the murine whole blood, the concentrations of inflammatory factors were quantified by ELISA, while the protein and mRNA expressions of PICK1, cleaved-PARP-1, caspase1, TLR4, IκBα, and NF-κB were assessed via western blot and qRT-PCR. The outcomes revealed that the knockdown of PICK1 increased the levels of inflammatory factors and apoptosis, alongside activation of TLR4/NF-κB signaling pathway-related factors in both in vivo and in vitro models. Moreover, the murine liver samples were subjected to Hematoxylin-Eosin (HE) staining for assessment of histopathological morphology. The HE staining and liver injury scoring results manifested a markedly exacerbated hepatic damage in PICK1 knockout mice as compared to WT mice following CLP. Furthermore, the liver macrophages were isolated from murine livers, and the expression and activity of the factors associated with the TLR4/NF-κB signaling pathway were verified through RT-qPCR and western blot, and EMSA assay demonstrated an augmented NF-κB activity subsequent to PICK1 knockout. Finally, the expression and localization of PICK1 in macrophages were further scrutinized via immunofluorescence, and the interaction between PICK1 and TLR4 was identified through co-immunoprecipitation. In conclusion, the knockdown of PICK1 appeared to modulate inflammatory factors by activating the TLR4/NF-κB signaling pathway, thereby exacerbating hepatic damage induced by sepsis.

Combination of Taurine and Black Pepper Extract as a Treatment for Cardiovascular and Coronary Artery Diseases

The shift in modern dietary regimens to "Western style" and sedentary lifestyles are believed to be partly responsible for the increase in the global burden of cardiovascular diseases. Natural products have been used throughout human history as treatments for a plethora of pathological conditions. Taurine and, more recently, black pepper have gained attention for their beneficial health effects while remaining non-toxic even when ingested in excess. Taurine, black pepper, and the major terpene constituents found in black pepper (i.e., β-caryophyllene; α-pinene; β-pinene; α-humulene; limonene; and sabinene) that are present in PhytoCann BP^® have been shown to have cardioprotective effects based on anti-inflammatory, antioxidative, anti-hypertensive and anti-atherosclerotic mechanisms. This comprehensive review of the literature focuses on determining whether the combination of taurine and black pepper extract is an effective natural treatment for reducing cardiovascular diseases risk factors (i.e., hypertension and hyperhomocysteinemia) and for driving anti-inflammatory, antioxidative and anti-atherosclerotic mechanisms to combat coronary artery disease, heart failure, myocardial infarction, and atherosclerotic disease.

Chemical Composition of Essential Oils of Seven Polygonum Species from Turkey: A Chemotaxonomic Approach

Medicinal plants and herbal preparations are gaining attention in the scientific community today, as they are often used intermittently in the treatment of various diseases. The genus of Polygonum (Polygonaceae), known locally as “madimak”, is an aromatic plant widely used in world flavors. The chemical composition of the essential oils of dried aerial parts of seven of Polygonum was analyzed by GC-MS. These species are Polygonum lapathifolium L., Polygonum persicaria L., Polygonum arenastrum Bor., Polygonum bellardii All., Polygonum arenarium Waldst. Et Kit., Polygonum aviculare L., and Polygonum cognatum Meissn. Qualitative and quantitative differences were found in the essential oil analysis of the seven Polygonum species. The major compounds were determined as (E)-β-farnesene (19. 46%), dodecanal (15.92%), β-caryophyllene (12.95%), in P. aviculare; (E)-β-farnesene (25.00%), dodecanal (20.45%), β-caryophyllene (9.38%), and caryophyllene oxide (8. 26%) in P. persicaria; dodecanal (25.65%), caryophyllene oxide (13.35%), β-caryophyllene (7.95%), and (E)-β-farnesene (6.20%) in P. lapathifolium, and dodecanal (19.65%), (E)-β-farnesene (13.86%), β-caryophyllene (8.06%), and α-terpineol (7.2%) in P. arenarium, dodecanal (16.23%), β-caryophyllene (16.09%), (E)-β-farnesene (12.26%), caryophyllene oxide (7.94%) in P. bellardii, (E)-β-farnesene (20.75%), dodecanal (17.96%), β-caryophyllene (13.01%), α-terpineol (4.97%) in P. arenastrum, (E)-β-farnesene (9.49%), dodecanal (14.01%), β-caryophyllene (11.92%), geranyl acetate (9.49%), and undecanal (7.35%) in P. cognatum. This study is the most comprehensive study conducted to determine the essential oil components of Polygonum species. In addition, a literature review on the composition of the essential oils of these Polygonum taxa was performed. The essential oil components of the species in our study were revealed for the first time with this study.

circ-Katnal1 Enhances Inflammatory Pyroptosis in Sepsis-Induced Liver Injury through the miR-31-5p/GSDMD Axis

Background. Sepsis is a systemic inflammatory response that can elicit organ dysfunction as well as circulatory diseases in serious cases. When inflammatory responses are especially dysregulated, severe complications can arise, including sepsis-induced liver injury. Various microRNAs along with circular (circ) RNAs are involved in inflammatory responses; nevertheless, their functions in regulating sepsis-induced liver injury remain unknown. The cecal ligation and puncture (CLP) procedure can induce liver injury as well as polymicrobial sepsis. Methods. In this study, CLP was used to induce liver injury as well as polymicrobial sepsis. Then, liver function, inflammatory cytokine expression, and hepatic histopathology were evaluated. High-throughput sequencing was employed to investigate the abnormal hepatic circRNA expression after CLP. Raw264.7 cells were utilized to simulation an in vitro sepsis inflammation model with LPS induce. The relative mRNA as well as protein levels of TNF-α, IL-1β, and IL-6 was explored by quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays. We explored functional connections among circRNAs, miR-31-5p, and gasdermin D (GSDMD) using dual-luciferase reporter assays. Western blot was employed to test GSDMD, caspase-1, and NLRP3 expression in mice and cell models. Results. Our results showed that CLP-induced sepsis promoted liver injury via increasing inflammatory pyroptosis. The abnormal expression of circ-Katnal1 played an important role in CLP-induced sepsis. Downregulating circ-Katnal1 suppressed LPS-induced inflammatory pyroptosis in Raw264.7 cells. Bioinformatics and luciferase reporter results confirmed that miR-31-5p and GSDMD were downstream targets of circ-Katnal1. Inhibiting miR-31-5p or upregulating GSDMD reversed the protective effects of silencing circ-Katnal1. Conclusion. Taken together, circ-Katnal1 enhanced inflammatory pyroptosis in sepsis-induced liver injury through the miR-31-5p/GSDMD axis.

A mechanistic review on immunomodulatory effects of selective type two cannabinoid receptor β-caryophyllene

β-Caryophyllene (BCP) is a plant-derived compound and occurs naturally in various foods and spices, including cinnamon, citrus, fruits, clove, curry, and pepper. BCP showed different pharmacological effects, such as antioxidant and antimicrobial properties. This article tried to gather updated knowledge of the anti-inflammatory, antioxidant, and immunomodulatory effects of BCP and searched using various databases and appropriate keywords until April 2022. Several studies showed that the anti-inflammatory effects of BCP are mainly provided through cannabinoid receptor 2 (CB₂ ) receptor activation and the peroxisome proliferator-activated receptor (PPAR) γ pathway. It has also been demonstrated that BCP suppresses both protein and mRNA expression levels of interleukin (IL)-6 and reduces relevant proinflammatory cytokines but increases the anti-inflammatory cytokine IL-13. Previous results indicated that the antioxidant effects of β-caryophyllene were suggested through different pathways, including activation of nuclear factor erythroid 2-related factor-2 (Nrf2)/heme oxygenase-1 (HO-1)/antioxidant axis and inhibition of the HMG-CoA reductase activity, and oxidative stress biomarkers levels. Furthermore, various results showed immunomodulatory effects of BCP through inhibiting microglial cells, CD⁴⁺ and CD⁸⁺ T lymphocytes, modulated Th₁ /T_reg immune balance through the activation of the CB₂ receptor, and reducing mitogen-activated protein kinases (p38MAPK) and NF-kB activation and increased ionized calcium-binding adaptor molecule-1 (Iba-1) and IL-1β.

Multi-Target Effects of ß-Caryophyllene and Carnosic Acid at the Crossroads of Mitochondrial Dysfunction and Neurodegeneration: From Oxidative Stress to Microglia-Mediated Neuroinflammation

Inflammation and oxidative stress are interlinked and interdependent processes involved in many chronic diseases, including neurodegeneration, diabetes, cardiovascular diseases, and cancer. Therefore, targeting inflammatory pathways may represent a potential therapeutic strategy. Emerging evidence indicates that many phytochemicals extracted from edible plants have the potential to ameliorate the disease phenotypes. In this scenario, ß-caryophyllene (BCP), a bicyclic sesquiterpene, and carnosic acid (CA), an ortho-diphenolic diterpene, were demonstrated to exhibit anti-inflammatory, and antioxidant activities, as well as neuroprotective and mitoprotective effects in different in vitro and in vivo models. BCP essentially promotes its effects by acting as a selective agonist and allosteric modulator of cannabinoid type-2 receptor (CB2R). CA is a pro-electrophilic compound that, in response to oxidation, is converted to its electrophilic form. This can interact and activate the Keap1/Nrf2/ARE transcription pathway, triggering the synthesis of endogenous antioxidant “phase 2” enzymes. However, given the nature of its chemical structure, CA also exhibits direct antioxidant effects. BCP and CA can readily cross the BBB and accumulate in brain regions, giving rise to neuroprotective effects by preventing mitochondrial dysfunction and inhibiting activated microglia, substantially through the activation of pro-survival signalling pathways, including regulation of apoptosis and autophagy, and molecular mechanisms related to mitochondrial quality control. Findings from different in vitro/in vivo experimental models of Parkinson’s disease and Alzheimer’s disease reported the beneficial effects of both compounds, suggesting that their use in treatments may be a promising strategy in the management of neurodegenerative diseases aimed at maintaining mitochondrial homeostasis and ameliorating glia-mediated neuroinflammation.

Beta-caryophyllene as an antioxidant, anti-inflammatory and re-epithelialization activities in a rat skin wound excision model

The skin is a critical organ for the maintenance of the integrity and protection of the organism. When a wound occurs, a sequence of healing mechanisms is triggered to reconstruct the wounded area. β-caryophyllene is a sesquiterpene in Copaifera langsdorffii oleoresin with antioxidant and anti-inflammatory potential. On the basis of previous studies with C. langsdorffii, β-caryophyllene was selected to evaluate its wound healing potential and pharmacological mechanisms. The excision wound model was used with male Wistar rats and macroscopic, histological, immunohistochemical and biochemical analyses were performed with skin samples, comparing the β-caryophyllene-treated group with reference drugs. The results showed macroscopic retraction of the wounds treated with β-caryophyllene. Biochemical assays revealed the antioxidant and anti-inflammatory mechanisms of the β-caryophyllene-treated group with increasing levels of IL-10 and GPx and decreasing levels of pro-inflammatory molecules, including TNF-α, IFN-γ, IL-1β and IL-6. After β-caryophyllene treatment, immunohistochemical assays showed enhanced re-epithelialization, through the increase in laminin-γ2 and desmoglein-3 immunolabeling. β-caryophyllene also act in the remodeling mechanism, increasing the collagen content in the Masson’s trichrome staining. These findings indicated the wound-healing potential of β-caryophyllene topical formulation in rat skin wounds, mediated by antioxidant, anti-inflammatory and re-epithelialization mechanisms.

Network Pharmacology-Based Analysis of Pogostemon cablin (Blanco) Benth Beneficial Effects to Alleviate Nonalcoholic Fatty Liver Disease in Mice

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and is associated with high morbidity and mortality. Pogostemon cablin (Blanco) Benth/Huo Xiang (HX) is a perennial herb with unique anti-oxidant and anti-inflammatory properties, and thus, can positively affect liver function. In this study, we used network pharmacology to predict the potential mechanism of HX on NAFLD. Pharmacological experiments were used to verify the effect of HX on the functions of NAFLD. Network pharmacology identified nine components that interacted with 82 NAFLD-related targets, revealing four target genes: TNF, IL6, TP53, and AKT1. HX prevents the development and progression of NAFLD through different pathways and targets with quercetin-regulated lipid metabolism, anti-inflammatory, and anti-oxidant pathways playing an essential role in the treatment of NAFLD. Compared with feeding HFD, HX significantly attenuated lipid accumulation in vivo with mice and also in vitro with mouse liver cells. A high dose of HX decreased hepatocyte lipid accumulation and the abundance of SREBF1 and FASN. Validation experiments revealed that HX inhibited the activation of NF-κB/IκB signaling and decreased the release and levels of pro-inflammatory factors (TNF-α and IL-6). These data suggest that HX can attenuate abnormal lipid metabolic responses and enhance antioxidant mechanisms. Thus, the pharmacological effects from plants used in traditional Chinese medicine are achievde through a multi-level response.

Therapeutic potential of beta-caryophyllene against aflatoxin B1-Induced liver toxicity: biochemical and molecular insights in rats

Aflatoxin B1 (AFB1) is a mycotoxin highly toxic and carcinogenic to humans due to its potential to induce oxidative stress. The Beta-caryophyllene (BCP) have been highlighted for its broad spectrum of pharmacological effects. The present study aimed to investigate the beneficial effects of BCP against the susceptibility of hepatic and renal tissues to AFB1 toxicity, in biochemical parameters to assess organ function, tissue oxidation, and the immunocontent of oxidative and inflammatory proteins. Male Wistar rats was exposed to AFB1 (250 μg/kg, i.g.) and/or BCP (100 mg/kg, i.p.) for 14 successive days. It was found that exposure to AFB1 did not change the measured renal toxicity parameters. Also, AFB1 increased liver injury biomarkers (gamma glutamyl transferase and alkaline phosphatase) and reduced levels of non-enzymatic antioxidant defenses (ascorbic acid and non-protein thiol), however did not cause changes in the lipid peroxidation levels. Moreover, AFB1 interfered in oxidative pathway regulated by Kelch-like ECH-associated protein (Keap1)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2), overacting Glutathione-S-Transferase (GST) activity. Lastly, a main effect of AFB1 on the total interleukin 1 beta (IL-1β) was observed. Remarkably, the associated treatment of AFB1 + BCP improved altered liver parameters. In addition, BCP and AFB1 + BCP groups showed an increase in the levels of inhibitor of nuclear factor kappa-B kinase subunit beta (IKKβ). Thus, these results indicated that BCP has potential protective effect against AFB1 induced hepatotoxicity.

β-Caryophyllene, A Natural Dietary CB2 Receptor Selective Cannabinoid can be a Candidate to Target the Trinity of Infection, Immunity, and Inflammation in COVID-19

Coronavirus disease (COVID-19), caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing pandemic and presents a public health emergency. It has affected millions of people and continues to affect more, despite tremendous social preventive measures. Identifying candidate drugs for the prevention and treatment of COVID-19 is crucial. The pathogenesis and the complications with advanced infection mainly involve an immune-inflammatory cascade. Therefore, therapeutic strategy relies on suppressing infectivity and inflammation, along with immune modulation. One of the most promising therapeutic targets for the modulation of immune-inflammatory responses is the endocannabinoid system, particularly the activation of cannabinoid type 2 receptors (CB2R), a G-protein coupled receptor which mediates the anti-inflammatory properties by modulating numerous signaling pathways. To pharmacologically activate the CB2 receptors, a naturally occurring cannabinoid ligand, beta-caryophyllene (BCP), received attention due to its potent anti-inflammatory, antiviral, and immunomodulatory properties. BCP is recognized as a full selective functional agonist on CB2 receptors and produces therapeutic effects by activating CB2 and the nuclear receptors, peroxisome proliferator-activated receptors (PPARs). BCP is regarded as the first dietary cannabinoid with abundant presence across cannabis and non-cannabis plants, including spices and other edible plants. BCP showed tissue protective properties and favorably modulates numerous signaling pathways and inhibits inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. Based on its pharmacological properties, molecular mechanisms, and the therapeutic potential of BCP as an immunomodulator, anti-inflammatory, organ-protective, and antiviral, we hypothesize that BCP could be a promising therapeutic and/or preventive candidate to target the triad of infection, immunity, and inflammation in COVID-19. In line with numerous studies that proposed the potential of cannabinoids in COVID-19, BCP may be a novel candidate compound for pharmaceutical and nutraceutical development due to its unique functional receptor selectivity, wide availability and accessibility, dietary bioavailability, nonpsychoactivity, and negligible toxicity along with druggable properties, including favorable pharmacokinetic and physicochemical properties. Based on reasonable pharmacological mechanisms and therapeutic properties, we speculate that BCP has potential to be investigated against COVID-19 and will inspire further preclinical and clinical studies.

Beta-caryophyllene inhibits cocaine addiction-related behavior by activation of PPARα and PPARγ: repurposing a FDA-approved food additive for cocaine use disorder

Cocaine abuse continues to be a serious health problem worldwide. Despite intense research, there is still no FDA-approved medication to treat cocaine use disorder (CUD). In this report, we explored the potential utility of beta-caryophyllene (BCP), an FDA-approved food additive for the treatment of CUD. We found that BCP, when administered intraperitoneally or intragastrically, dose-dependently attenuated cocaine self-administration, cocaine-conditioned place preference, and cocaine-primed reinstatement of drug seeking in rats. In contrast, BCP failed to alter food self-administration or cocaine-induced hyperactivity. It also failed to maintain self-administration in a drug substitution test, suggesting that BCP has no abuse potential. BCP was previously reported to be a selective CB2 receptor agonist. Unexpectedly, pharmacological blockade or genetic deletion of CB1, CB2, or GPR55 receptors in gene-knockout mice failed to alter BCP's action against cocaine self-administration, suggesting the involvement of non-CB1, non-CB2, and non-GPR55 receptor mechanisms. Furthermore, pharmacological blockade of μ opioid receptor or Toll-like receptors complex failed to alter, while blockade of peroxisome proliferator-activated receptors (PPARα, PPARγ) reversed BCP-induced reduction in cocaine self-administration, suggesting the involvement of PPARα and PPARγ in BCP's action. Finally, we used electrical and optogenetic intracranial self-stimulation (eICSS, oICSS) paradigms to study the underlying neural substrate mechanisms. We found that BCP is more effective in attenuation of cocaine-enhanced oICSS than eICSS, the former driven by optical activation of midbrain dopamine neurons in DAT-cre mice. These findings indicate that BCP may be useful for the treatment of CUD, likely by stimulation of PPARα and PPARγ in the mesolimbic system.

Chemical and Bioinformatics Analyses of the Anti-Leishmanial and Anti-Oxidant Activities of Hemp Essential Oil

Industrial hemp is a multiuse crop that has been widely cultivated to produce fibers and nutrients. The capability of the essential oil (EO) from inflorescences as antimicrobial agent has been reported. However, literature data are still lacking about the hemp EO antiprotozoal efficacy in vivo. The present study aims to unravel this concern through the evaluation of the efficacy of hemp EOs (2.5 mL/kg, intraperitoneally) of three different cultivars, namely Futura 75, Carmagnola selezionata and Eletta campana, in mice intraperitoneally infected with Leishmania tropica. A detailed description of EO composition and targets-components analysis is reported. Myrcene, α-pinene and E-caryophyllene were the main components of the EOs, as indicated by the gas-chromatographic analysis. However, a prominent position in the scenario of the theoretical interactions underlying the bio-pharmacological activity was also occupied by selina-3,7(11)-diene, which displayed affinities in the micromolar range (5.4–28.9) towards proliferator-activated receptor α, cannabinoid CB2 receptor and acetylcholinesterase. The content of this compound was higher in Futura 75 and Eletta campana, in accordance with their higher scavenging/reducing properties and efficacy against the tissue wound, induced by L. tropica. Overall, the present study recommends hemp female inflorescences, as sources of biomolecules with potential pharmacological applications, especially towards infective diseases.

Susceptibility of Asialoglycoprotein Receptor-Deficient Mice to Lps/Galactosamine Liver Injury and Protection by Betaine Administration

BACKGROUND

Work from our laboratory has shown that the ethanol-induced increase in apoptotic hepatocellular death is closely related to the impairment in the ability of the asialoglycoprotein receptor (ASGP-R) to remove neighboring apoptotic cells. In this study, we assessed the role of ASGP-R in fulminant liver failure and investigated whether prior treatment with betaine (a naturally occurring tertiary amine) is protective.

METHODS

Lipopolysaccharide (LPS; 50 μg/kg BW) and galactosamine (GalN; 350 mg/kg BW) were injected together to wild-type and ASGP-R-deficient mice that were treated for two weeks prior with or without 2% betaine in drinking water. The mice were sacrificed 1.5, 3, or 4.5 h post-injection, and tissue samples were collected.

RESULTS

LPS/GalN injection generate distinct molecular processes, which includes increased production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), thus causing apoptosis as evident by increased caspase-3 activity. ASGP-R deficient animals showed increased liver caspase activities, serum TNF-α and IL-6 levels, as well as more pronounced liver damage compared with the wild-type control animals after intraperitoneal injection of LPS/GalN. In addition, prior administration of betaine was found to significantly attenuate the LPS/GalN-induced increases in liver injury parameters.

CONCLUSION

Our work underscores the importance of normal functioning of ASGP-R in preventing severe liver damage and signifies a therapeutic role of betaine in prevention of liver injuries from toxin-induced fulminant liver failure.

Chemopreventive Potential of Caryophyllane Sesquiterpenes: An Overview of Preliminary Evidence

Chemoprevention is referred to as a strategy to inhibit, suppress, or reverse tumor development and progression in healthy people along with high-risk subjects and oncologic patients through using pharmacological or natural substances. Numerous phytochemicals have been widely described in the literature to possess chemopreventive properties, although their clinical usefulness remains to be defined. Among them, caryophyllane sesquiterpenes are natural compounds widely occurring in nature kingdoms, especially in plants, fungi, and marine environments. Several structures, characterized by a common caryophyllane skeleton with further rearrangements, have been identified, but those isolated from plant essential oils, including β-caryophyllene, β-caryophyllene oxide, α-humulene, and isocaryophyllene, have attracted the greatest pharmacological attention. Emerging evidence has outlined a complex polypharmacological profile of caryophyllane sesquiterpenes characterized by blocking, suppressing, chemosensitizing, and cytoprotective properties, which suggests a possible usefulness of these natural substances in cancer chemoprevention for both preventive and adjuvant purposes. In the present review, the scientific knowledge about the chemopreventive properties of caryophyllane sesquiterpenes and the mechanisms involved have been collected and discussed; moreover, possible structure-activity relationships have been highlighted. Although further high-quality studies are required, the promising preclinical findings and the safe pharmacological profile encourage further studies to define a clinical usefulness of caryophyllane sesquiterpenes in primary, secondary, or tertiary chemoprevention.

Therapeutic Potential of β-Caryophyllene: A Dietary Cannabinoid in Diabetes and Associated Complications

Diabetes mellitus (DM), a metabolic disorder is one of the most prevalent chronic diseases worldwide across developed as well as developing nations. Hyperglycemia is the core feature of the type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), following insulin deficiency and impaired insulin secretion or sensitivity leads insulin resistance (IR), respectively. Genetic and environmental factors attributed to the pathogenesis of DM and various therapeutic strategies are available for the prevention and treatment of T2DM. Among the numerous therapeutic approaches, the health effects of dietary/nutraceutical approach due to the presence of bioactive constituents, popularly termed phytochemicals are receiving special interest for pharmacological effects and therapeutic benefits. The phytochemicals classes, in particular sesquiterpenes received attention because of potent antioxidant, anti-inflammatory, and antihyperglycemic effects and health benefits mediating modulation of enzymes, receptors, and signaling pathways deranged in DM and its complications. One of the terpene compounds, β-caryophyllene (BCP), received enormous attention because of its abundant occurrence, non-psychoactive nature, and dietary availability through consumption of edible plants including spices. BCP exhibit selective full agonism on cannabinoid receptor type 2 (CB2R), an important component of endocannabinoid system, and plays a role in glucose and lipid metabolism and represents the newest drug target for chronic inflammatory diseases. BCP also showed agonist action on peroxisome proliferated activated receptor subtypes, PPAR-α and PPAR-γ, the main target of currently used fibrates and imidazolidinones for dyslipidemia and IR, respectively. Many studies demonstrated its antioxidant, anti-inflammatory, organoprotective, and antihyperglycemic properties. In the present review, the plausible therapeutic potential of BCP in diabetes and associated complications has been comprehensively elaborated based on experimental and a few clinical studies available. Further, the pharmacological and molecular mechanisms of BCP in diabetes and its complications have been represented using synoptic tables and schemes. Given the safe status, abundant natural occurrence, oral bioavailability, dietary use and pleiotropic properties modulating receptors and enzymes, BCP appears as a promising molecule for diabetes and its complications.

Polygonum minus essential oil modulates cisplatin-induced hepatotoxicity through inflammatory and apoptotic pathways

Oxidative stress, inflammation and apoptosis are thought as primary mediators of cisplatin-induced hepatotoxicity. The objective of this study was to determine the protective effect of Polygonum minus essential oil in cisplatin-induced hepatotoxicity. A total of forty-two male rats were randomly divided into seven groups: control, cisplatin, β-caryophyllene 150 mg/kg (BCP), PmEO 100 mg/kg + cisplatin (PmEO100CP), PmEO 200 mg/kg + cisplatin (PmEO200CP), PmEO 400 mg/kg + cisplatin (PmEO400CP) and PmEO 400 mg/kg (PmEO400). Rats in the BCP, PmEO100CP, PmEO200CP, PmEO400CP and PmEO400 group received respective treatment orally for 14 consecutive days prior to cisplatin injection. All animals except for those in the control group and PmEO400 were administered with a single dose of cisplatin (10 mg/kg) intraperitoneally on day 15 and all animals were sacrificed on day 18. PmEO100CP pretreatment protected against cisplatin-induced hepatotoxicity by decreasing CYP2E1 and indicators of oxidative stress including malondialdehyde, 8-OHdG and protein carbonyl which was accompanied by increased antioxidant status (glutathione, glutathione peroxidase, superoxide dismutase and catalase) as compared to cisplatin group. PmEO100CP pretreatment also modulated changes in liver inflammatory markers (TNF-α, IL-1α, IL-1β, IL-6 and IL-10). PmEO100CP administration also notably reduced cisplatin-induced apoptosis significantly as compared to cisplatin group. In conclusion, our results suggested that P. minus essential oil at a dose of 100 mg/kg may protect against cisplatin-induced hepatotoxicity possibly via inhibition of oxidative stress, inflammation and apoptosis.

Terpenoids as Potential Geroprotectors

Terpenes and terpenoids are the largest groups of plant secondary metabolites. However, unlike polyphenols, they are rarely associated with geroprotective properties. Here we evaluated the conformity of the biological effects of terpenoids with the criteria of geroprotectors, including primary criteria (lifespan-extending effects in model organisms, improvement of aging biomarkers, low toxicity, minimal adverse effects, improvement of the quality of life) and secondary criteria (evolutionarily conserved mechanisms of action, reproducibility of the effects on different models, prevention of age-associated diseases, increasing of stress-resistance). The number of substances that demonstrate the greatest compliance with both primary and secondary criteria of geroprotectors were found among different classes of terpenoids. Thus, terpenoids are an underestimated source of potential geroprotectors that can effectively influence the mechanisms of aging and age-related diseases.

A Systematic Review of Essential Oils and the Endocannabinoid System: A Connection Worthy of Further Exploration

Aromatic compounds have a long history of use as medicines in most recorded cultures. An increasing interest in these therapeutic volatile molecules in both scientific and lay communities has led to the advancement of essential oils as phytomedicines. Recent discoveries suggest essential oils augment the endocannabinoid system in a positive manner to mitigate various pathologies. However, the exact mechanisms whereby essential oils influence endocannabinoid system activity are not fully known, these studies provide a glimpse into their involvement and warrant further evaluation. Additional study of the interaction between essential oils and the endocannabinoid system may lead to promising phytomedicines for the treatment of diseases and conditions involving dysregulation or activation of the endocannabinoid system.

Methane alleviates sepsis-induced injury by inhibiting pyroptosis and apoptosis: in vivo and in vitro experiments

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Methane has been reported to have anti-oxidative, anti-apoptotic and anti-inflammatory properties. We investigated the potential protective effects of methane on sepsis-induced injury and determined the related mechanisms. C57BL/6 mice received laparotomy with cecal ligation and puncture (CLP) to create a septic model, followed by methane-rich saline (MRS) treatment after CLP. MRS treatment improved the 5-day survival rate and organ functions and alleviated pathological damage of the mice, as well as reduced excessive inflammatory mediators, such as tumor necrosis factor-α and interleukin-6. MRS treatment also decreased the levels of oxidative stress index proteins, decreased the apoptosis of cells and inhibited nod-liker receptor protein (NLRP)3-mediated pyroptosis in the lung and intestine. In in vitro experiments, RAW264.7 and primary peritoneal macrophages were treated with lipopolysaccharide (LPS) plus adenosine-triphosphate (ATP) to induce inflammation and pyroptosis. Consistent with the in vivo results, methane-rich medium (MRM) treatment also reduced the levels of excessive inflammatory mediators, and decreased the levels of ROS, inhibited apoptosis and pyroptosis. Our results indicate that methane offers a protective effect for septic mice via its anti-inflammation, anti-oxidation, anti-pyroptosis and anti-apoptosis properties.

β-Caryophyllene protects against ischemic stroke by promoting polarization of microglia toward M2 phenotype via the TLR4 pathway

AIMS

The objective of the study was to determine whether β-caryophyllene (BCP) exerts a neuroprotective effect in cerebral ischemia-reperfusion (I/R) injury by inhibiting microglial activation and modulating their polarization via the TLR4 pathway.

MAIN METHODS

Wild-type (WT) and TLR4 knockout (KO) C57BL/6J mice were subjected to cerebral I/R injury and neurologic dysfunction, cerebral infarct volume, brain edema, microglia activation and polarization, and TLR4 expression were determined. In vitro, primary microglia were stimulated with LPS and IFN-γ or IL-4 to induce polarization of microglia toward M1 or M2 phenotypes.

KEY FINDINGS

BCP reduced cerebral infarct volume, brain edema, and neurologic deficits in WT mice after I/R. The optimal dose of BCP, 72 mg/kg body weight, inhibited microglial activation and reduced the secretion of proinflammatory cytokines interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 by microglia of WT mice. BCP inhibited the level of TLR4 in WT mice, and partially reduced neurologic deficits, infarct volume, and brain edema in TLR4 KO mice. Importantly, BCP reduced the number of activated M1-type microglia and increased the number of M2-type microglia in the ipsilateral cortex of both WT and TLR4 KO mice. In vitro, BCP decreased the secretion of proinflammatory cytokines induced by LPS plus IFN-γ, downregulated the level of TLR4 protein, and polarized microglia towards the M2 phenotype.

SIGNIFICANCES

The decrease in TLR4 activity mediated, at least in part, the anti-inflammatory effects of BCP and its ability to shift microglia polarization from the M1 to M2 phenotype.

Xiaochaihu Decoction reduces hepatic steatosis and improves D-GalN/LPS-induced liver injury in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

Excessive lipid accumulation and chemical abuse can induce fatty liver diseases in fish, but the underlying mechanism and therapies are unknown. The present study aims to evaluate the effects of Xiaochaihu Decoction (XCHD) on the growth performance, lipid metabolism and antioxidant function of hybrid grouper in vitro and in vivo, and provide evidence as to whether it can be potentially used as a medicine for liver diseases in aquaculture. In vitro, steatosis model of hybrid grouper primary hepatocytes were incubated for 48 h in control or lipid emulsion (LE)-containing medium with or without 24 h post-treatment with XCHD. XCHD treatment reversed the LE-induced intracellular lipid accumulation, cell viability and hepatocytes morphological structure. In vivo, a total of 300 hybrid grouper with an average initial weight of 25.43 ± 0.18 g were fed diets containing five graded levels of XCHD at 150-1200 mg/kg diet for 8 weeks. After that, a challenge trial was conducted by injection of D-GalN/LPS to induce liver injury. As a result, dietary supplementation with 150-300 mg/kg XCHD diets can significant improve growth performance and feed utilization (P < 0.05). Dietary XCHD down-regulated the expression of lipogenic-related genes (G6PD, DGAT2 and ME1) and up-regulated lipolysis-related genes (ATGL, PPARα and LPL) expression in the liver of hybrid grouper. Livers challenged with D-GalN/LPS exhibited extensive areas of vacuolization with the disappearance of nuclei and the loss of hepatic architecture. These pathological alterations were ameliorated by XCHD treatment. XCHD significantly down-regulated the D-GalN/LPS induced apoptosis-related genes caspase-3, caspase-9 and p53 mRNA expression and up-regulated the antioxidant-related genes CAT and MnSOD mRNA expression in dose dependent manner, respectively. XCHD potently reduced hepatic lipid accumulation and enhanced antioxidant capability in hybrid grouper and may be a potential fish-feed additive to prevent fatty liver diseases onset and progression.

β-Caryophyllene as a Potential Protective Agent Against Myocardial Injury: The Role of Toll-Like Receptors

Myocardial infarction (MI) remains one of the major causes of mortality around the world. A possible mechanism involved in myocardial infarction is the engagement of Toll-like receptors (TLRs). This study was intended to discover the prospective cardioprotective actions of β-caryophyllene, a natural sesquiterpene, to ameliorate isoproterenol (ISO)-induced myocardial infarction through HSP-60/TLR/MyD88/NFκB pathway. β-Caryophyllene (100 or 200 mg/kg/day orally) was administered for 21 days then MI was induced via ISO (85 mg/kg, subcutaneous) on 20th and 21st days. The results indicated that ISO induced a significant infarcted area associated with several alterations in the electrocardiogram (ECG) and blood pressure (BP) indices and caused an increase in numerous cardiac indicators such as creatine phosphokinase (CPK), creatine kinase-myocardial bound (CK-MB), lactate dehydrogenase (LDH), and cardiac tropinine T (cTnT). In addition, ISO significantly amplified heat shock protein 60 (HSP-60) and other inflammatory markers, such as TNF-α, IL-Iβ, and NFκB, and affected TLR2 and TLR4 expression and their adaptor proteins; Myeloid differentiation primary response 88 (MYD88), and TIR-domain-containing adapter-inducing interferon-β (TRIF). On the other hand, consumption of β-caryophyllene significantly reversed the infarcted size, ECG and BP alterations, ameliorated the ISO elevation in cardiac indicators; it also notably diminished HSP-60, and subsequently TLR2, TLR4, MYD88, and TRIF expression, with a substantial reduction in inflammatory mediator levels. This study revealed the cardioprotective effect of β-caryophyllene against MI through inhibiting HSP-60/TLR/MyD88/NFκB signaling pathways.

Necrostatin-1 Protects Against D-Galactosamine and Lipopolysaccharide-Induced Hepatic Injury by Preventing TLR4 and RAGE Signaling

Fulminant hepatic failure (FHF) is a life-threatening clinical syndrome results in massive inflammation and hepatocyte death. Necroptosis is a regulated form of necrotic cell death that is emerging as a crucial control point for inflammatory diseases. The kinases receptor interacting protein (RIP) 1 and RIP3 are known as key modulators of necroptosis. In this study, we investigated the impact of necroptosis in the pathogenesis of FHF and molecular mechanisms, particularly its linkage to damage-associated molecular pattern (DAMP)-mediated pattern recognition receptor (PRR) signaling pathways. Male C57BL/6 mice were given an intraperitoneal injection of necrostatin-1 (Nec-1, RIP1 inhibitor; 1.8 mg/kg; dissolved in 2% dimethyl sulfoxide in phosphate-buffered saline) 1 h before receiving D-galactosamine (GalN; 800 mg/kg)/lipopolysaccharide (LPS; 40 μg/kg). Hepatic RIP1, RIP3 protein expression, their phosphorylation, and RIP1/RIP3 complex formation upregulated in the GalN/LPS group were attenuated by Nec-1. Nec-1 markedly reduced the increases in mortality and serum alanine aminotransferase activity induced by GalN/LPS. Increased serum high mobility group box 1 (HMGB1) and interleukin (IL)-33 release, HMGB1-toll-like receptor 4 and HMGB1-receptor for advanced glycation end products (RAGE) interaction, and nuclear protein expressions of NF-κB and early growth response protein-1 (egr-1) were attenuated by Nec-1. Our finding suggests that necroptosis is responsible for GalN/LPS-induced liver injury through DAMP-activated PRR signaling.

Methyl-β-cyclodextrin Inclusion Complex with β-Caryophyllene: Preparation, Characterization, and Improvement of Pharmacological Activities

β-Caryophyllene (BCP) is a sesquiterpene that shows high potential in pharmacological applications. However, these have been drastically limited by the respective volatility and poor water solubility. The present study investigates the formation of inclusion complexes between BCP and methyl-β-cyclodextrin (MβCD) and shows that these complexes promote a significant improvement of the anti-inflammatory, gastric protection, and antioxidant activities relative to neat BCP. It is shown that the solubility of BCP is significantly increased through complexation in phase solubility studies. Inclusion complexes with MβCD in solid state were prepared by three different methods, kneading, rotary evaporation, and lyophilization, with the latter confirmed by differential scanning calorimetry, Fourier transformed infrared spectroscopy, scanning electron microscopy, ¹H NMR spectroscopy, and molecular dynamics studies. This study provides for the first time a full characterization of inclusion complexes between BCP and MβCD and highlights the impact of complex formation upon pharmacological activity.

Neuroprotective Effect of β-Caryophyllene on Cerebral Ischemia-Reperfusion Injury via Regulation of Necroptotic Neuronal Death and Inflammation: In Vivo and in Vitro

Necrotic cell death is a hallmark feature of ischemic stroke and it may facilitate inflammation by releasing intracellular components after cell-membrane rupture. Previous studies reported that β-caryophyllene (BCP) mitigates cerebral ischemia-reperfusion (I/R) injury, but the underlying mechanism remains unclear. We explored whether BCP exerts a neuroprotective effect in cerebral I/R injury through inhibiting necroptotic cell death and inflammation. Primary neurons with and without BCP (0.2, 1, 5, 25 μM) treatment were exposed to oxygen-glucose deprivation and re-oxygenation (OGD/R). Neuron damage, neuronal death type and mixed lineage kinase domain-like (MLKL) protein expression were assessed 48 h after OGD/R. Furthermore, mice underwent I/R procedures with or without BCP (8, 24, 72 mg/kg, ip.). Neurologic dysfunction, cerebral infarct volumes, cell death, cytokine levels, necroptosis core molecules, and HMGB1-TLR4 signaling were determined at 48 h after I/R. BCP (5 μM) significantly reduced necroptotic neurons and MLKL protein expression following OGD/R. BCP (24, 72 mg/kg, ip.) reduced infarct volumes, neuronal necrosis, receptor-interaction protein kinase-1 (RIPK1), receptor-interaction protein kinase-3 (RIPK3) expression, and MLKL phosphorylation after I/R injury. BCP also decreased high-mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) levels. Thus, BCP alleviates ischemic brain damage potentially by inhibiting necroptotic neuronal death and inflammatory response. This study suggests a novel application for BCP as a neuroprotective agent.

Hepatoprotective Effects of Kaempferol-3-O-α-l-Arabinopyranosyl-7-O-α-l-Rhamnopyranoside on d-Galactosamine and Lipopolysaccharide Caused Hepatic Failure in Mice

Fulminant hepatic failure (FHF), associated with high mortality, is characterized by extensive death of hepatocytes and hepatic dysfunction. There is no effective treatment for FHF. Several studies have indicated that flavonoids can protect the liver from different factor-induced injury. Previously, we found that the extracts of Elaeagnus mollis leaves had favorable protective effects on acute liver injury. However, the role and mechanisms behind that was elusive. This study examined the hepatoprotective mechanisms of kaempferol-3-O-α-l-arabinopyranosyl-7-O-α-l-rhamnopyra-noside (KAR), a major flavonol glycoside of E. mollis, against d-galactosamine (GalN) and lipopolysaccharide (LPS)-induced hepatic failure. KAR reduces the mouse mortality, protects the normal liver structure, inhibits the serum aspartate aminotransferase (AST) and alamine aminotransferase (ALT) activity and decreases the production of malondialdehyde (MDA) and reactive oxygen species (ROS) and inflammatory cytokines, TNF-α, IL-6, and IL-1β. Furthermore, KAR inhibits the apoptosis of hepatocytes and reduces the expression of TLR4 and NF-κB signaling pathway-related proteins induced by GalN/LPS treatment. These findings suggest that the anti-oxidative, anti-inflammatory, and anti-apoptotic effects of KAR on GalN/LPS-induced acute liver injury were performed through down-regulating the activity of the TLR4 and NF-κB signaling pathways.

Terpenes from Forests and Human Health

Forest bathing has beneficial effects on human health via showering of forest aerosols as well as physical relaxation. Terpenes that consist of multiple isoprene units are the largest class of organic compounds produced by various plants, and one of the major components of forest aerosols. Traditionally, terpene-containing plant oil has been used to treat various diseases without knowing the exact functions or the mechanisms of action of the individual bioactive compounds. This review categorizes various terpenes easily obtained from forests according to their anti-inflammatory, anti-tumorigenic, or neuroprotective activities. Moreover, potential action mechanisms of the individual terpenes and their effects on such processes, which are described in various in vivo and in vitro systems, are discussed. In conclusion, the studies that show the biological effectiveness of terpenes support the benefits of forest bathing and propose a potential use of terpenes as chemotherapeutic agents for treating various human diseases.

β-Caryophyllene protects against alcoholic steatohepatitis by attenuating inflammation and metabolic dysregulation in mice

BACKGROUND AND AIMS

β-Caryophyllene (BCP) is a plant-derived FDA approved food additive with anti-inflammatory properties. Some of its beneficial effects in vivo are reported to involve activation of cannabinoid CB₂ receptors that are predominantly expressed in immune cells. Here, we evaluated the translational potential of BCP using a well-established model of chronic and binge alcohol-induced liver injury.

METHODS

In this study, we investigated the effects of BCP on liver injury induced by chronic plus binge alcohol feeding in mice in vivo by using biochemical assays, real-time PCR and histology analyses. Serum and hepatic BCP levels were also determined by GC/MS.

RESULTS

Chronic treatment with BCP alleviated the chronic and binge alcohol-induced liver injury and inflammation by attenuating the pro-inflammatory phenotypic `M1` switch of Kupffer cells and by decreasing the expression of vascular adhesion molecules intercellular adhesion molecule 1, E-Selectin and P-Selectin, as well as the neutrophil infiltration. It also beneficially influenced hepatic metabolic dysregulation (steatosis, protein hyperacetylation and PPAR-α signalling). These protective effects of BCP against alcohol-induced liver injury were attenuated in CB₂ receptor knockout mice, indicating that the beneficial effects of this natural product in liver injury involve activation of these receptors. Following acute or chronic administration, BCP was detectable both in the serum and liver tissue homogenates but not in the brain.

CONCLUSIONS

Given the safety of BCP in humans, this food additive has a high translational potential in treating or preventing hepatic injury associated with oxidative stress, inflammation and steatosis.

LINKED ARTICLES

This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc.

Quantitative Determination of Stilbenoids and Dihydroisocoumarins in Shorea roxburghii and Evaluation of Their Hepatoprotective Activity

A simultaneous quantitative analytical method for 13 stilbenoids including (-)-hopeaphenol (1), (+)-isohopeaphenol (2), hemsleyanol D (3), (-)-ampelopsin H (4), vaticanols A (5), E (6), and G (7), (+)-α-viniferin (8), pauciflorol A (9), hopeafuran (10), (-)-balanocarpol (11), (-)-ampelopsin A (12), and trans-resveratrol 10-C-β-d-glucopyranoside (13), and two dihydroisocoumarins, phayomphenols A₁ (14) and A₂ (15) in the extract of Shorea roxburghii (dipterocarpaceae) was developed. According to the established protocol, distributions of these 15 polyphenols (1-15) in the bark and wood parts of S. roxburghii and a related plant Cotylelobium melanoxylon were evaluated. In addition, the principal polyphenols (1, 2, 8, 13-15) exhibited hepatoprotective effects against d-galactosamine (d-galN)/lipopolysaccharide (LPS)-induced liver injury in mice at a dose of 100 or 200 mg/kg, p.o. To characterize the mechanisms of action, the isolates were examined in in vitro studies assessing their effects on (i) d-GalN-induced cytotoxicity in primary cultured mouse hepatocytes; (ii) LPS-induced nitric oxide (NO) production in mouse peritoneal macrophages; and (iii) tumor necrosis factor-α (TNF-α)-induced cytotoxicity in L929 cells. The mechanisms of action of these polyphenols (1, 2, and 8) were suggested to be dependent on the inhibition of LPS-induced macrophage activation and reduction of sensitivity of hepatocytes to TNF-α. However, none of the isolates reduced the cytotoxicity caused by d-GalN.

Afzelin ameliorates D-galactosamine and lipopolysaccharide-induced fulminant hepatic failure by modulating mitochondrial quality control and dynamics

BACKGROUND AND PURPOSE

Fulminant hepatic failure (FHF) is a fatal clinical syndrome that results in excessive inflammation and hepatocyte death. Mitochondrial dysfunction is considered to be a possible mechanism of FHF. Afzelin, a flavonol glycoside found in Houttuynia cordata Thunberg, has anti-inflammatory and antioxidant properties. The present study elucidated the cytoprotective mechanisms of afzelin against D-galactosamine (GalN)/LPS induced FHF, particularly focusing on mitochondrial quality control and dynamics.

EXPERIMENTAL APPROACH

Mice were administered afzelin i.p. 1 h before receiving GalN (800 mg·kg^-1 )/LPS (40 μg·kg^-1 ), and they were then killed 5 h after GalN/LPS treatment.

KEY RESULTS

Afzelin improved the survival rate and reduced the serum levels of alanine aminotransferase and pro-inflammatory cytokines in GalN/LPS-treated mice. Afzelin attenuated the mitochondrial damage, as indicated by diminished mitochondrial swelling and mitochondrial glutamate dehydrogenase activity in GalN/LPS-treated mice. Afzelin enhanced mitochondrial biogenesis, as indicated by increased levels of PPAR-γ coactivator 1α, nuclear respiratory factor 1 and mitochondrial transcription factor A. Afzelin also decreased the level of mitophagy-related proteins, parkin and PTEN-induced putative kinase 1. Furthermore, while GalN/LPS significantly increased the level of fission-related protein, dynamin-related protein 1, and decreased the level of fusion-related protein, mitofusin 2; these effects were attenuated by afzelin.

CONCLUSIONS AND IMPLICATIONS

Our findings demonstrated that afzelin protects against GalN/LPS-induced liver injury by enhancing mitochondrial biogenesis, suppressing excessive mitophagy and balancing mitochondrial dynamics.

Protective effects of combined β-caryophyllene and silymarin against ketoprofen-induced hepatotoxicity in rats

Ketoprofen (Ket), widely utilized in treatment of many inflammatory disorders, is found to induce liver toxicity especially with overdose. This study aimed to evaluate the possible protective effects of concomitant β-caryophyllene (Cary) and silymarin (Sily) against Ket-induced hepatotoxicity in rats. Forty adult male albino rats were divided into 5 groups (each n = 8): the control group received distilled water for 6 weeks; the Ket-treated group received distilled water for 5 weeks and Ket in a dose of 8 mg·kg−1·day−1 p.o. for the 6th week; the Cary + Ket treated group received Cary in a dose of 200 mg·kg−1·day−1 orally for 6 weeks and Ket for the 6th week; the Sily + Ket treated group received Sily in the dose of 150 mg·kg−1·day−1 for 6 weeks and Ket for the 6th week; and the Cary + Sily + Ket treated group received Sily and Cary for 6 weeks and Ket for the 6th week. At end of the experiment, serum ALT, AST, and albumin and liver total antioxidant capacity (t.TAC) and malondialdehyde (t.MDA) were measured in all rats. Ket increased serum ALT and AST and t.MDA and decreased t.TAC. Cary and Sily improved these changes. Combined Cary and Sily restored these liver changes to nearly normal. Combined Cary and Sily is hepatoprotective, with the ability to scavenge oxidants against Ket-induced hepatotoxicity in rats.

Toxicological Evaluation of β-Caryophyllene Oil: Subchronic Toxicity in Rats

In a subchronic toxicity study, administration of β-caryophyllene (BCP) oil by oral gavage to Wistar rats at dosages of 0, 150, 450, or 700 mg/kg/d for 90 days, including a 21-day recovery period, did not produce any significant toxicologic manifestations. The study design also included a 28-day interim sacrifice in the control and high-dose groups. The BCP oil test article was well tolerated as evidenced by the absence of major treatment-related changes in the general condition and appearance of the rats, neurobehavioral end points, growth, feed and water intake, ophthalmoscopic examinations, routine hematology and clinical chemistry parameters, urinalysis, and necropsy findings. The no observed adverse effect level was the highest dosage level administered of 700 mg/kg body weight/d for both male and female rats. The study was conducted as part of an investigation to examine the safety of BCP oil for its proposed use in medical food products.

Hepatoprotective Limonoids from Andiroba (Carapa guianensis)

Three gedunin-type limonoids, gedunin (1), 6α-acetoxygedunin (2), and 7-deacetoxy-7-oxogedunin (3), which were isolated from the seed and flower oils of andiroba (Carapa guianensis Aublet, Meliaceae), exhibited hepatoprotective effects at doses of 25 mg/kg, p.o. against d-galactosamine (d-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. To characterize the mechanisms of action of 1-3 and clarify the structural requirements for their hepatoprotective effects, 17 related limonoids (1-17) isolated from the seed and/or flower oils of C. guianensis were examined in in vitro studies assessing their effects on (i) d-GalN-induced cytotoxicity in primary cultured mouse hepatocytes, (ii) LPS-induced nitric oxide (NO) production in mouse peritoneal macrophages, and (iii) tumor necrosis factor-α (TNF-α)-induced cytotoxicity in L929 cells. The mechanisms of action of 1-3 are likely to involve the inhibition of LPS-induced macrophage activation and reduced sensitivity of hepatocytes to TNF-α; however, these compounds did not decrease the cytotoxicity caused by d-GalN. In addition, the structural requirements of limonoids (1-17) for inhibition of LPS-induced NO production in mouse peritoneal macrophages and TNF-α-induced cytotoxicity in L929 cells were evaluated.