The inhibitory effects of β-caryophyllene, β-caryophyllene oxide and α-humulene on the activities of the main drug-metabolizing enzymes in rat and human liver in vitro

In Vitro Interaction of Binuclear Copper Complexes with Liver Drug-Metabolizing Cytochromes P450

Two copper(II) mixed ligand complexes with dicarboxylate bridges were prepared and studied, namely [Cu2(μ-fu)(pmdien)2(H2O)2](ClO4)2 (complex No. 5) and [Cu2(μ-dtdp)(pmdien)2(H2O)2](ClO4)2 (complex No. 6), where H2fu = fumaric acid, pmdien = N,N,N',N″,N″ pentamethyldiethylenetriamine, and H2dtdp = 3,3'-dithiodipropionic acid. The copper atoms are coordinated in the same mode by the tridentate pmdien ligand and oxygen of water molecules, and they only differ in the dicarboxylate bridge. This work is focused on the study of the inhibitory effect of these potential antimicrobial drugs on the activity of the most important human liver drug-metabolizing enzymes, cytochromes P450 (CYP), especially their forms CYP2C8, CYP2C19, and CYP3A4. The obtained results allow us to estimate the probability of potential drug interactions with simultaneously administrated drugs that are metabolized by these CYP enzymes. In conclusion, the presence of adverse effects due to drug-drug interactions with concomitantly used drugs cannot be excluded, and hence, topical application may be recommended as a relatively safe approach.

Effect of Essential Oil Components on the Activity of Steroidogenic Cytochrome P450

Endocrine-disrupting chemicals (EDCs) may impact the development of prostate cancer (PCa) by altering the steroid metabolism. Although their exact mechanism of action in controlling tumor growth is not known, EDCs may inhibit steroidogenic enzymes such as CYP17A1 or CYP19A1 which are involved in the production of androgens or estrogens. High levels of circulating androgens are linked to PCa in men and Polycystic Ovary Syndrome (PCOS) in women. Essential oils or their metabolites, like lavender oil and tea tree oil, have been reported to act as potential EDCs and contribute towards sex steroid imbalance in cases of prepubertal gynecomastia in boys and premature thelarche in girls due to the exposure to lavender-based fragrances. We screened a range of EO components to determine their effects on CYP17A1 and CYP19A1. Computational docking was performed to predict the binding of essential oils with CYP17A1 and CYP19A1. Functional assays were performed using the radiolabeled substrates or Liquid Chromatography-High-Resolution Mass Spectrometry and cell viability assays were carried out in LNCaP cells. Many of the tested compounds bind close to the active site of CYP17A1, and (+)-Cedrol had the best binding with CYP17A1 and CYP19A1. Eucalyptol, Dihydro-β-Ionone, and (-)-α-pinene showed 20% to 40% inhibition of dehydroepiandrosterone production; and some compounds also effected CYP19A1. Extensive use of these essential oils in various beauty and hygiene products is common, but only limited knowledge about their potential detrimental side effects exists. Our results suggest that prolonged exposure to some of these essential oils may result in steroid imbalances. On the other hand, due to their effect on lowering androgen output and ability to bind at the active site of steroidogenic cytochrome P450s, these compounds may provide design ideas for novel compounds against hyperandrogenic disorders such as PCa and PCOS.

Chemical Evaluation, Phytotoxic Potential, and In Silico Study of Essential Oils from Leaves of Guatteria schomburgkiana Mart. and Xylopia frutescens Aubl. (Annonaceae) from the Brazilian Amazon

The essential oils (EOs) of Guatteria schomburgkiana (Gsch) and Xylopia frutescens (Xfru) (Annonaceae) were obtained by hydrodistillation, and their chemical composition was evaluated by gas chromatography-mass spectrometry (GC/MS). Herbicide activity was measured by analyzing the seed germination percentage and root and hypocotyl elongation of two invasive species: Mimosa pudica and Senna obtusifolia. The highest yield was obtained for the EO of Xfru (1.06%). The chemical composition of Gsch was characterized by the presence of the oxygenated sesquiterpenes spathulenol (22.40%) and caryophyllene oxide (14.70%). Regarding the EO of Xfru, the hydrocarbon monoterpenes α-pinene (35.73%) and β-pinene (18.90%) were the components identified with the highest concentrations. The germination of seeds of S. obtusifolia (13.33 ± 5.77%) showed higher resistance than that of seeds of M. pudica (86.67 ± 5.77%). S. obtusifolia was also more sensitive to the EO of Xfru in terms of radicle (55.22 ± 2.72%) and hypocotyl (71.12 ± 3.80%) elongation, while M. pudica showed greater sensitivity to the EO of Gsch. To screen the herbicidal activity, the molecular docking study of the major and potent compounds was performed against 4-hydroxyphenylpyruvate dioxygenase (HPPD) protein. Results showed good binding affinities and attributed the strongest inhibitory activity to δ-cadinene for the target protein. This work contributes to the study of the herbicidal properties of the EOs of species of Annonaceae from the Amazon region.

Salvia sclarea Essential Oil Chemical Composition and Biological Activities

Salvia sclarea essential oil (SSEO) has a long tradition in the food, cosmetic, and perfume industries. The present study aimed to analyze the chemical composition of SSEO, its antioxidant activity, antimicrobial activity in vitro and in situ, antibiofilm, and insecticidal activity. Besides that, in this study, we have evaluated the antimicrobial activity of SSEO constituent (E)-caryophyllene and standard antibiotic meropenem. Identification of volatile constituents was performed by using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) techniques. Results obtained indicated that the main constituents of SSEO were linalool acetate (49.1%) and linalool (20.6%), followed by (E)-caryophyllene (5.1%), p-cimene (4.9%), a-terpineol (4.9%), and geranyl acetate (4.4%). Antioxidant activity was determined as low by the means of neutralization of the DDPH radical and ABTS radical cation. The SSEO was able to neutralize the DPPH radical to an extent of 11.76 ± 1.34%, while its ability to decolorize the ABTS radical cation was determined at 29.70 ± 1.45%. Preliminary results of antimicrobial activity were obtained with the disc diffusion method, while further results were obtained by broth microdilution and the vapor phase method. Overall, the results of antimicrobial testing of SSEO, (E)-caryophyllene, and meropenem, were moderate. However, the lowest MIC values, determined in the range of 0.22–0.75 µg/mL for MIC50 and 0.39–0.89 µg/mL for MIC90, were observed for (E)-caryophyllene. The antimicrobial activity of the vapor phase of SSEO (towards microorganisms growing on potato) was significantly stronger than that of the contact application. Biofilm analysis using the MALDI TOF MS Biotyper showed changes in the protein profile of Pseudomonas fluorescens that showed the efficiency of SSEO in inhibiting biofilm formation on stainless-steel and plastic surfaces. The insecticidal potential of SSEO against Oxycarenus lavatera was also demonstrated, and results show that the highest concentration was the most effective, showing insecticidal activity of 66.66%. The results obtained in this study indicate the potential application of SSEO as a biofilm control agent, in the shelf-life extension and storage of potatoes, and as an insecticidal agent.

Development of a GC/Q-ToF-MS Method Coupled with Headspace Solid-Phase Microextraction to Evaluate the In Vitro Metabolism of β-Caryophyllene

Sample preparation remains both a challenging and time-consuming process in the field of bioanalytical chemistry. Many traditional techniques often require multi-step processes, which can introduce additional errors to the analytical method. Given the complexity of many biological matrices, thorough analyte extraction presents a major challenge to researchers. In the present study, a headspace solid-phase microextraction (HS-SPME) coupled with a GC/Q-ToF-MS method, was developed to quantify in vitro metabolism of β-caryophyllene by both human liver microsome (HLM) and S9 liver fractions. Validation of the method was demonstrated both in terms of linearity (R2 = 0.9948) and sensitivity with a limit of detection of 3 ng/mL and a limit of quantitation of 10 ng/mL. In addition, the method also demonstrated both inter- and intra-day precision with the relative standard deviation (RSD) being less than 10% with four concentrations ranging from 50–500 ng/mL. Since this method requires no solvents and minimal sample preparation, it provides a rapid and economical alternative to traditional extraction techniques. The method also eliminates the need to remove salts or buffers, which are commonly present in biological matrices. Although this method was developed to quantify in vitro metabolism of one analyte, it could easily be adapted to detect or quantify numerous volatiles and/or semi-volatiles found in biological matrices.

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.

Clove Essential Oil (Syzygium aromaticum L. Myrtaceae): Extraction, Chemical Composition, Food Applications, and Essential Bioactivity for Human Health

Clove (Syzygium aromaticum L. Myrtaceae) is an aromatic plant widely cultivated in tropical and subtropical countries, rich in volatile compounds and antioxidants such as eugenol, β-caryophyllene, and α-humulene. Clove essential oil has received considerable interest due to its wide application in the perfume, cosmetic, health, medical, flavoring, and food industries. Clove essential oil has biological activity relevant to human health, including antimicrobial, antioxidant, and insecticidal activity. The impacts of the extraction method (hydrodistillation, steam distillation, ultrasound-assisted extraction, microwave-assisted extraction, cold pressing, and supercritical fluid extraction) on the concentration of the main volatile compounds in clove essential oil and organic clove extracts are shown. Eugenol is the major compound, accounting for at least 50%. The remaining 10-40% consists of eugenyl acetate, β-caryophyllene, and α-humulene. The main biological activities reported are summarized. Furthermore, the main applications in clove essential oil in the food industry are presented. This review presents new biological applications beneficial for human health, such as anti-inflammatory, analgesic, anesthetic, antinociceptive, and anticancer activity. This review aims to describe the effects of different methods of extracting clove essential oil on its chemical composition and food applications and the biological activities of interest to human health.

Thermal decomposition and oxidation of β-caryophyllene in black pepper during subcritical water extraction

Subcritical water extraction is an efficient technique for extracting components from various plants by changing the polarity of water. β-caryophyllene is a natural bicyclic sesquiterpene with the highest content found among black pepper essential oils. In this study, the efficiency of extraction and yield of β-caryophyllene from black pepper were investigated using a subcritical water extraction technique. The optimal conditions of β-caryophyllene (1.19 ± 0.38 mg/g), and caryophyllene oxide (0.82 ± 0.38 mg/g) were obtained from black pepper under extraction conditions of 170 °C/10 min, and 200 °C/15 min, respectively. As the extraction temperature was increased, β-caryophyllene oxidation proceeded and the extraction content of caryophyllene oxide increased. It is anticipated that both β-caryophyllene and caryophyllene oxide with high biological activity can be used to selectively extract compounds using subcritical water extraction, which will be helpful in industrial applications.

Analgesic Potential of Terpenes Derived from Cannabis sativa

Pain prevalence among adults in the United States has increased 25% over the past two decades, resulting in high health-care costs and impacts to patient quality of life. In the last 30 years, our understanding of pain circuits and (intra)cellular mechanisms has grown exponentially, but this understanding has not yet resulted in improved therapies. Options for pain management are limited. Many analgesics have poor efficacy and are accompanied by severe side effects such as addiction, resulting in a devastating opioid abuse and overdose epidemic. These problems have encouraged scientists to identify novel molecular targets and develop alternative pain therapeutics. Increasing preclinical and clinical evidence suggests that cannabis has several beneficial pharmacological activities, including pain relief. Cannabis sativa contains more than 500 chemical compounds, with two principle phytocannabinoids, Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). Beyond phytocannabinoids, more than 150 terpenes have been identified in different cannabis chemovars. Although the predominant cannabinoids, Δ9-THC and CBD, are thought to be the primary medicinal compounds, terpenes including the monoterpenes β-myrcene, α-pinene, limonene, and linalool, as well as the sesquiterpenes β-caryophyllene and α-humulene may contribute to many pharmacological properties of cannabis, including anti-inflammatory and antinociceptive effects. The aim of this review is to summarize our current knowledge about terpene compounds in cannabis and to analyze the available scientific evidence for a role of cannabis-derived terpenes in modern pain management. SIGNIFICANCE STATEMENT: Decades of research have improved our knowledge of cannabis polypharmacy and contributing phytochemicals, including terpenes. Reform of the legal status for cannabis possession and increased availability (medicinal and recreational) have resulted in cannabis use to combat the increasing prevalence of pain and may help to address the opioid crisis. Better understanding of the pharmacological effects of cannabis and its active components, including terpenes, may assist in identifying new therapeutic approaches and optimizing the use of cannabis and/or terpenes as analgesic agents.

Development and Validation of a Reversed Phase High Performance Liquid Chromatography-Photodiode Array Detection Method for Simultaneous Identification and Quantification of Coumarin, Precocene-I, β-Caryophyllene Oxide, α-Humulene, and β-Caryophyllene in Ageratum Conyzoides Extracts and Essential Oils from Plants

BACKGROUND

Ageratum conyzoides is an aromatic plant. It is considered as an invasive and cosmopolite weed, widely spread in tropical and subtropical regions. Phytochemicals such as benzopyrenes, flavonoids, and terpenoids are reported from A. conyzoides.

OBJECTIVE

Development and validation of a reversed-phase HPLC-photodiode array (PDA) detection method for simultaneous identification and quantification of coumarin, precocene-I, β-caryophyllene oxide, α-humulene, and β-caryophyllene in extracts of A. conyzoides and essential oils was carried out.

METHODS

Separation of analytes was achieved on a RP-18 (250 mm × 4.6 mm, 5 µm) column using a solvent system comprising of a mixture of acetonitrile and water with 0.05% trifluoroacetic acid in gradient elution mode at ambient temperature with flow rate of 1 mL/min.

RESULTS

The retention time of coumarin, precocene-I, β-caryophyllene oxide, α-humulene, and β-caryophyllene was 4.38, 12.86, 20.10, 33.34, and 35.11 min, respectively. Limits of detection for coumarin, precocene-I, β-caryophyllene oxide, α-humulene, and β-caryophyllene were 2.5, 2.5, 2.5, 0.025, and 2.5 µg/mL, respectively. Similarly, LOQ were 10, 10, 10, 0.10, and 10 µg/mL for coumarin, precocene-I, β-caryophyllene oxide, α-humulene, and β- caryophyllene, respectively. Repeatabilities (RSD, %) values for intraday and interday precision for coumarin, precocene-I, β-caryophyllene oxide, α-humulene, and β-caryophyllene was 0.765-2.086 and 0.886-2.128; 0.879-1.672 and 0.979-1.825; 0.696-2.418 and 0.768-2.592; 1.728-2.362 and 1.965-2.378; 1.615-2.897 and 1.658-2.906, respectively.

CONCLUSIONS

The separation of five analytes was achieved within 50 min. The developed and validated HPLC-PDA method was successfully applied for identification and quantification of above five analytes in A. conyzoides extracts and essential oils. The method could be used for meeting the characterization criteria of phytoformulations.

Sub-Tissue Localization of Phytochemicals in Cinnamomum camphora (L.) J. Presl. Growing in Northern Italy

In the present paper, we focused our attention on Cinnamomum camphora (L.) J. Presl. (Lauraceae), studied at three levels: (i) micromorphological, with the analysis of the secretory structures and a novel in-depth histochemical characterization of the secreted compounds; (ii) phytochemical, with the characterization of the essential oils from young stems, fruits, and leaves, subjected to different conservation procedures (fresh, dried, stored at −20 °C, stored at −80 °C) and collected in two different years; (iii) bioactive, consisting of a study of the potential antibacterial activity of the essential oils. The micromorphological investigation proved the presence of secretory cells characterized by a multi-layered wall in the young stems and leaves. They resulted in two different types: mucilage cells producing muco-polysaccharides and oil cells with an exclusive terpene production. The phytochemical investigations showed a predominance of monoterpenes over sesquiterpene derivatives; among them, the main components retrieved in all samples were 1,8-cineole followed by α-terpineol and sabinene. Conservation procedures seem to only influence the amounts of specific components, i.e., 1,8-cineole and α-terpineol, while analyses on each plant part revealed the presence of some peculiar secondary constituents for each of them. Finally, the evaluation of the antibacterial activity of the essential oil showed a promising activity against various microorganisms, as Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa. In conclusion, we combined a micromorphological and phytochemical approach of the study on different plant parts of C. camphora, linking the occurrence of secretory cells to the production of essential oils. We compared, for the first time, the composition of essential oils derived from different plant matrices conserved with different procedures, allowing us to highlight a relation between the conservation technique and the main components of the profiles. Moreover, the preliminary antibacterial studies evidenced the potential activity of the essential oils against various microorganisms potentially dangerous for plants and humans.

Humulene Inhibits Acute Gastric Mucosal Injury by Enhancing Mucosal Integrity

This study was designed to determine whether α-humulene, a major constituent in many plants used in fragrances, has a protective role against gastric injury in vivo and in vitro. A rat model of hydrochloric acid (HCl)/ethanol-induced gastritis and human mast cells (HMC-1) were used to investigate the mucosal protective effect of α-humulene. α-Humulene significantly inhibited gastric lesions in HCl/ethanol-induced acute gastritis and decreased gastric acid secretion pyloric ligation-induced gastric ulcers in vivo. In addition, α-humulene reduced the amount of reactive oxygen species and malondialdehyde through upregulation of prostaglandin E2 (PGE2) and superoxide dismutase (SOD). In HMC-1 cells, α-humulene decreased intracellular calcium and increased intracellular cyclic adenosine monophosphate (cAMP) levels, resulting in low histamine levels. α-Humulene also reduced the expression levels of cytokine genes such as interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF) by downregulating nuclear factor-κB (NF-κB) nuclear translocation. Finally, α-humulene upregulated the expression levels of mucin 5AC (Muc5ac), Muc6, trefoil factor 1 (Tff1), trefoil factor 2 (Tff2), and polymeric immunoglobulin receptor (pigr). α-Humulene may attenuate HCl/ethanol-induced gastritis by inhibiting histamine release and NF-κB activation and stimulating antioxidants and mucosal protective factors, particularly Muc5ac and Muc6. Therefore, these data suggest that α-humulene is a potential drug candidate for the treatment of stress-induced or alcoholic gastritis.

Insights into oral bioavailability enhancement of therapeutic herbal constituents by cytochrome P450 3A inhibition

Herbal plants typically have complex compositions and diverse mechanisms. Among them, bioactive constituents with relatively high exposure in vivo are likely to exhibit therapeutic efficacy. On the other hand, their bioavailability may be influenced by the synergistic effects of different bioactive components. Cytochrome P450 3A (CYP3A) is one of the most abundant CYP enzymes, responsible for the metabolism of 50% of approved drugs. In recent years, many therapeutic herbal constituents have been identified as CYP3A substrates. It is more evident that CYP3A inhibition derived from the herbal formula plays a critical role in improving the oral bioavailability of therapeutic constituents. CYP3A inhibition may be the mechanism of the synergism of herbal formula. In this review, we explored the multiplicity of CYP3A, summarized herbal monomers with CYP3A inhibitory effects, and evaluated herb-mediated CYP3A inhibition, thereby providing new insights into the mechanisms of CYP3A inhibition-mediated oral herb bioavailability.

Improvement of Oxidative Stress and Mitochondrial Dysfunction by β-Caryophyllene: A Focus on the Nervous System

Mitochondrial dysfunction results in a series of defective cellular events, including decreased adenosine triphosphate (ATP) production, enhanced reactive oxygen species (ROS) output, and altered proteastasis and cellular quality control. An enhanced output of ROS may damage mitochondrial components, such as mitochondrial DNA and elements of the electron transport chain, resulting in the loss of proper electrochemical gradient across the mitochondrial inner membrane and an ensuing shutdown of mitochondrial energy production. Neurons have an increased demand for ATP and oxygen, and thus are more prone to damage induced by mitochondrial dysfunction. Mitochondrial dysfunction, damaged electron transport chains, altered membrane permeability and Ca²⁺ homeostasis, and impaired mitochondrial defense systems induced by oxidative stress, are pathological changes involved in neurodegenerative disorders. A growing body of evidence suggests that the use of antioxidants could stabilize mitochondria and thus may be suitable for preventing neuronal loss. Numerous natural products exhibit the potential to counter oxidative stress and mitochondrial dysfunction; however, science is still looking for a breakthrough in the treatment of neurodegenerative disorders. β-caryophyllene is a bicyclic sesquiterpene, and an active principle of essential oils derived from a large number of spices and food plants. As a selective cannabinoid receptor 2 (CB2) agonist, several studies have reported it as possessing numerous pharmacological activities such as antibacterial (e.g., Helicobacter pylori), antioxidant, anti-inflammatory, analgesic (e.g., neuropathic pain), anti-neurodegenerative and anticancer properties. The present review mainly focuses on the potential of β-caryophyllene in reducing oxidative stress and mitochondrial dysfunction, and its possible links with neuroprotection.

Medical food development by dietetic management of the endocannabinoid system through dietary sources of β-caryophyllene

Objective: To research the biological impact on the endocannabinoid system (ECS) from dietary sources of [Formula: see text]-caryophyllene (BCP). This will encompass pre-clinical and clinical research for BCP. The bioavailability of BCP will be explored, focusing on bioavailability improvement. This research will establish if there is justification to warrant the development of a medical food for supporting the ECS through dietetic supplementation of BCP.

Methods: Research and review papers were identified through the search engines Google Scholar, PubMed, and ScienceDirect. Main keywords included [Formula: see text]-caryophyllene, endocannabinoid system, dietary cannabinoids, cannabinoid type-2 receptor, and bioavailability.

Results: The human body is limited in the digestion of BCP from food. This is because BCP is poorly absorbed in the gut. Everyone has different underlying endocannabinoid efficiency and most people do not have the full potential of supporting their ECS through diet.

Conclusion: A medical food can be developed to use BCP with a delivery system, so that the bioactive food cannabinoid is readily absorbed. This will deliver dietary support to the ECS, that otherwise would be available from food.

This review provides insight into the efficacy of using BCP in medical foods as dietary support for the ECS. Supporting the ECS can assist in maintaining homeostasis, regulating immune function, pain intensity, inflammatory markers, sleep patterns, mood, appetite, and stress susceptibility.

Nanocapsules containing Saussurea lappa essential oil: Formulation, characterization, antidiabetic, anti-cholinesterase and anti-inflammatory potentials

Plant-based remedies have been widely used for the management of variable diseases due to their safety and less side effects. In the present study, we investigated Saussurea lappa CB. Clarke. (SL) given its largely reported medicinal effects. Specifically, our objective was to provide an insight into a new polymethyl methacrylate based nanocapsules as carriers of SL essential oil and characterize their biologic functions. The nanoparticles were prepared by nanoprecipitation technique, characterized and analyzed for their cytotoxicity, anti-inflammatory, anti-Alzheimer and antidiabetic effects. The results revealed that the developed nanoparticles had a diameter around 145 nm, a polydispersity index of 0.18 and a zeta potential equal to +45 mV and they did not show any cytotoxicity at 25 μg·mL^-1. The results also showed an anti-inflammatory activity (reduction in metalloprotease MMP-9 enzyme activity and RNA expression of inflammatory cytokines: TNF-α, GM-CSF and IL1β), a high anti-Alzheimer's effect (IC50 around 25.0 and 14.9 μg·mL^-1 against acetylcholinesterase and butyrylcholinesterase, respectively), and a strong antidiabetic effect (IC50 were equal to 22.9 and 75.8 μg·mL^-1 against α-amylase and α-glucosidase, respectively). Further studies are required including the in vivo studies (e.g., preclinical), the pharmacokinetic properties, the bioavailability and the underlying associated metabolic pathways.

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.

Chemical Composition and Immunomodulatory Activity of Hypericum perforatum Essential Oils

Hypericum L. (Hypericaceae) extracts have been used for their therapeutic effects; however, not much is known about the immunomodulatory activity of essential oils extracted from this plant. We isolated essential oils from the flowers and leaves of H. perforatum and analyzed their chemical composition and innate immunomodulatory activity. Analysis of flower (HEO_Fl) versus leaf (HEO_Lv) essential oils using gas chromatography–mass spectrometry revealed that HEO_Fl was comprised mainly of monoterpenes (52.8%), with an abundance of oxygenated monoterpenes, including cis-p-menth-3-en-1,2-diol (9.1%), α-terpineol (6.1%), terpinen-4-ol (7.4%), and limonen-4-ol (3.2%), whereas the sesquiterpenes were found in trace amounts. In contrast, HEO_Lv was primarily composed of sesquiterpenes (63.2%), including germacrene D (25.7%) and β-caryophyllene (9.5%). HEO_Lv also contained oxygenated monoterpenes, including terpinen-4-ol (2.6%), while monoterpene hydrocarbons were found in trace amounts. Both HEO_Fl and HEO_Lv inhibited neutrophil Ca²⁺ mobilization, chemotaxis, and reactive oxygen species (ROS) production, with HEO_Lv being much more active than HEO_Fl. Furthermore, the pure sesquiterpenes germacrene D, β-caryophyllene, and α-humulene also inhibited these neutrophil responses, suggesting that these compounds represented the active components of HEO_Lv. Although reverse pharmacophore mapping suggested that potential protein targets of germacrene D, β-caryophyllene, bicyclogermacrene, and α-humulene could be PIM1 and mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MAPKAK2), a kinase binding affinity assay did not support this finding, implying that other biological targets are involved. Our results provide a cellular and molecular basis to explain at least part of the beneficial immunotherapeutic properties of the H. perforatum essential oils.

The Pharmaceutical Ability of Pistacia lentiscus L. Leaves Essential Oil Against Periodontal Bacteria and Candida sp. and Its Anti-Inflammatory Potential

BACKGROUND

Given the increasing request for natural pharmacological molecules, this study assessed the antimicrobial capacity of Pistacia lentiscus L. essential oil (PLL-EO) obtained from the leaves of wild plants growing in North Sardinia (Italy) toward a wide range of periodontal bacteria and Candida, including laboratory and clinical isolates sp., together with its anti-inflammatory activity and safety.

METHODS

PLL-EO was screened by gas chromatography/mass spectrometry. The minimal inhibitory concentration (MIC) was determined. The anti-inflammatory activity was measured by cyclooxygenase (COX-1/2) and lipoxygenase (LOX) inhibition, while the antioxidant capacity was determined electro-chemically and by the MTT assay. The WST-1 assay was used to ascertain cytotoxicity toward four lines of oral cells.

RESULTS

According to the concentrations of terpens, PLL-EO is a pharmacologically-active phytocomplex. MICs against periodontal bacteria ranged between 3.13 and 12.5 µg/ml, while against Candida sp. they were between 6.25 and 12.5 µg/mL. Oxidation by COX-1/2 and LOX was inhibited by 80% and 20% µg/mL of the oil, respectively. Antioxidant activity seemed negligible, and no cytotoxicity arose.

CONCLUSIONS

PLL-EO exhibits a broad-spectrum activity against periodontal bacteria and Candida, with an interesting dual inhibitory capacity toward COX-2 and LOX inflammatory enzymes, and without side effects against oral cells.

Effect on essential oil components and wedelolactone content of a medicinal plant Eclipta alba due to modifications in the growth and morphology under different exposures of ultraviolet-B

In the present study sensitivity of a medicinal plant Eclipta alba L. (Hassk) (False daisy) was assessed under intermittent (IT) and continuous (CT) doses of elevated ultraviolet-B (eUV-B). Eclipta alba is rich in medicinally important phytochemical constituents, used against several diseases. The hypothesis of this study is that alterations in UV-B dose may modify the quantity and quality of medicinally valuable components with changes in the morphological and physiological parameters of test plant. To fulfill our hypothesis IT and CT of eUV-B (ambient ± 7.2 kJ m^-2 day^-2) was given for 130 and 240 h respectively to assess the impact of UV-B stress. Growth and physiological parameters were adversely affected under both the treatments with varying magnitude. The observation of leaf surfaces showed increase in stomatal and trichome densities suggesting the adaptive resilience of the plants against UV-B. Besides, biosynthesis of wedelolactone, a major medicinal compound of E. alba was observed to be stimulated under UV-B exposure. The essential oil content was reduced under IT while increased under CT. A total of 114 compounds were identified from oil extract of E. alba. n-Pentadecane (25.79%), n-Octadecane (12.98%), β-Farnesene (9.43%), α-Humulene (4.95%) (E)-Caryophyllene (4.87%), Phytol (4.25%), α-Copaene (2.26%), Humulene epoxide (1.46%), β-Pinene (1.07) and β-Caryophyllene oxide (1.06%) were identified as major components of oil. CT induced the synthesis of some medicinally important compounds such as α-terpineol, δ-cadinene, linolenic acid, methyl linoleate and myristic acid amide. Hence, the study revealed that continuous UV-B exposure of low intensity could be helpful for commercial exploitation of essential oil in E. alba.

β-Caryophyllene: A Sesquiterpene with Countless Biological Properties

β-Caryophyllene (BCP), a natural bicyclic sesquiterpene, is a selective phytocannabinoid agonist of type 2 receptors (CB2-R). It isn’t psychogenic due to the absence of an affinity to cannabinoid receptor type 1 (CB1). Among the various biological activities, BCP exerts anti-inflammatory action via inhibiting the main inflammatory mediators, such as inducible nitric oxide synthase (iNOS), Interleukin 1 beta (IL-1β), Interleukin-6 (IL-6), tumor necrosis factor-alfa (TNF-α), nuclear factor kapp a-light-chain-enhancer of activated B cells (NF-κB), cyclooxygenase 1 (COX-1), cyclooxygenase 2 (COX-2). Peroxisome proliferator-activated receptors alpha (PPAR-α) effects are also mediated by the activation of PPAR-α and PPAR-γ receptors. In detail, many studies, in vitro and in vivo, suggest that the treatment with β-caryophyllene improves the phenotype of animals used to model various inflammatory pathologies, such as nervous system diseases (Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, amyotrophic lateral sclerosis, stroke), atherosclerosis, and tumours (colon, breast, pancreas, lymphoma, melanoma and glioma cancer). Furthermore, pre-clinical data have highlighted that BCP is potentially useful in Streptococcus infections, osteoporosis, steatohepatitis, and exerts anticonvulsant, analgesic, myorelaxing, sedative, and antidepressive effects. BCP is non-toxic in rodents, with a Lethal dose, 50% (LD50) greater than 5000 mg/kg. Nevertheless, it inhibits various cytochrome P450 isoforms (above all, CYP3A4), which metabolise xenobiotics, leading to adverse effects, due to drug levels over therapeutic window. All the reported data have highlighted that both pharmacological and toxicological aspects need to be further investigated with clinical trials.

Repellent activities of essential oils rich in sesquiterpenoids from Saussurea amara (L.) DC. and Sigesbeckia pubescens Makino against two stored-product insects

The essential oils (EOs) from aerial parts of Saussurea amara (L.) DC. (SAEO) and Sigesbeckia pubescens Makino (SPEO) were analyzed for their chemical composition by GC-MS, and their repellent activities against adults of the red flour beetle, Tribolium castaneum Herbst, as well as the booklouse, Liposcelis bostrychophila Badonnel, were evaluated for the first time. Results of GC-MS analysis indicated that both SAEO and SPEO were characterized by high content of sesquiterpenoids (relative content > 70%) including oxygenated sesquiterpenoids. The two oil samples and their major component caryophyllene oxide exerted beneficial repellent effects on T. castaneum and L. bostrychophila at 2 and 4 h post-exposure. At 4 h post-exposure, the PR value of caryophyllene oxide could still reach 92% (class V) against T. castaneum at minimum testing concentration of 3.15 nL/cm², and this compound was observed to result in the greatest repellency (PR = 100%) against L. bostrychophila at 12.63 nL/cm². This work confirmed the potent repellent efficacy of SAEO and SPEO for controlling pest damage and suggested their potential to be developed into botanical repellents.

beta-caryophyllene oxide and trans-nerolidol affect enzyme activity of CYP3A4 - in vitro and in silico studies

Evaluation of possible interactions with enzymes of drug metabolism is an important part of studies on safety and, in general, on the properties of any drug or biologically active compound. Here, focus is given on interactions of three sesquiterpenes (beta-caryophyllene oxide (CAO), trans-nerolidol (tNER) and farnesol (FAR)) with CYP3A4. To determine the CYP3A4 activity, specific substrates testosterone (TES) and midazolam (MDZ) were used. In human liver microsomes, the CAO inhibited the MDZ 1´-hydroxylation by mixed type inhibition and K(i) 46.6 microM; TES 6beta-hydroxylation was inhibited more strongly by tNER by the same mechanism and with K(i) of 32.5 microM. Results indicated a possibility of different mode of interaction of both compounds within the active site of CYP3A4 and this was why the molecular docking study was done. The docking experiments showed that the studied sesquiterpenes (CAO and tNER) bound to the CYP3A4 active site cause a significant decrease of binding affinity of substrates tested which corresponded well to the inhibition studies. The inhibition observed, however, most probably does not pose a real harm to microsomal drug metabolism as the levels of sesquiterpenes in plasma (assuming the use of these compounds as spices or flavoring additives) does not usually exceed micromolar range. Hence, the interaction of drugs metabolized by CYP3A4 with sesquiterpenes is less probable.

Untargeted/Targeted 2D Gas Chromatography/Mass Spectrometry Detection of the Total Volatile Tea Metabolome

Identifying all analytes in a natural product is a daunting challenge, even if fractionated by volatility. In this study, comprehensive two-dimensional gas chromatography/mass spectrometry (GC×GC-MS) was used to investigate relative distribution of volatiles in green, pu-erh tea from leaves collected at two different elevations (1162 m and 1651 m). A total of 317 high and 280 low elevation compounds were detected, many of them known to have sensory and health beneficial properties. The samples were evaluated by two different software. The first, GC Image, used feature-based detection algorithms to identify spectral patterns and peak-regions, leading to tentative identification of 107 compounds. The software produced a composite map illustrating differences in the samples. The second, Ion Analytics, employed spectral deconvolution algorithms to detect target compounds, then subtracted their spectra from the total ion current chromatogram to reveal untargeted compounds. Compound identities were more easily assigned, since chromatogram complexities were reduced. Of the 317 compounds, for example, 34% were positively identified and 42% were tentatively identified, leaving 24% as unknowns. This study demonstrated the targeted/untargeted approach taken simplifies the analysis time for large data sets, leading to a better understanding of the chemistry behind biological phenomena.

α-Humulene inhibits hepatocellular carcinoma cell proliferation and induces apoptosis through the inhibition of Akt signaling

Hepatocellular carcinoma (HCC) is a prevalent malignancy and a leading cause of cancer-related mortality. α-Humulene (HML) is a natural 11-membered monocyclic terpene with three E-configured double bonds isolated from Eupatorium odoratum L. We recently showed that HML has significant anti-HCC activity in vitro and in vivo. We found that HML was cytotoxic to HCC cells and induced mitochondrial apoptosis of HCC cells, promoting caspase-3 activation and PARP cleavage. HCC cells show abnormal Akt signaling to resist apoptosis. Mechanistically, HML was found to inhibit Akt activation, subsequently decreasing GSK-3 and Bad phosphorylation, promoting apoptotic induction. HML also inhibited cell proliferation and enhanced apoptosis in HCC tumor xenografts further highlighting its activity in vivo. Although HML showed minimal cytotoxicity to normal hepatocytes, weight loss was observed in mice administered HML. Taken together, these data provide important and novel insights into the anti-HCC effects of HML through its ability to inhibit Akt, reduced HCC cell proliferation, and enhanced HCC cell apoptotic induction in vitro and in vivo.

Sesquiterpenes Are Agonists of the Pregnane X Receptor but Do Not Induce the Expression of Phase I Drug-Metabolizing Enzymes in the Human Liver

Sesquiterpenes, the main components of plant essential oils, are bioactive compounds with numerous health-beneficial activities. Sesquiterpenes can interact with concomitantly administered drugs due to the modulation of drug-metabolizing enzymes (DMEs). The aim of this study was to evaluate the modulatory effects of six sesquiterpenes (farnesol, cis-nerolidol, trans-nerolidol, α-humulene, β-caryophyllene, and caryophyllene oxide) on the expression of four phase I DMEs (cytochrome P450 3A4 and 2C, carbonyl reductase 1, and aldo-keto reductase 1C) at both the mRNA and protein levels. For this purpose, human precision-cut liver slices (PCLS) prepared from 10 patients and transfected HepG2 cells were used. Western blotting, quantitative real-time PCR and reporter gene assays were employed in the analyses. In the reporter gene assays, all sesquiterpenes significantly induced cytochrome P450 3A4 expression via pregnane X receptor interaction. However in PCLS, their effects on the expression of all the tested DMEs at the mRNA and protein levels were mild or none. High inter-individual variabilities in the basal levels as well as in modulatory efficacy of the tested sesquiterpenes were observed, indicating a high probability of marked differences in the effects of these compounds among the general population. Nevertheless, it seems unlikely that the studied sesquiterpenes would remarkably influence the bioavailability and efficacy of concomitantly administered drugs.

Volatile Compounds Determined by SPME-GC, Bioactive Compounds, In Vitro Antioxidant Capacity and Physicochemical Characteristics of Four Native Fruits from South America

The aim of the present study was to identify volatile organic compounds (VOCs) by SPME-GC and quantify the bioactive compounds (ascorbic acid, total flavonoids and total phenolic content), antioxidant capacity (DPPH and ORAC) and physicochemical characteristics of ocorocillo, cambucá, murici da praia and murici do campo, four native South American fruits. A total of 41 volatile compounds were identified in ocorocillo, of which 17 were terpenes. Cambuca's volatile profile contained aldehydes, aromatic hydrocarbons and alcohols. Murici da praia and murici do campo contained high levels of fatty acid volatiles and esters, that contribute to their remarkable aroma. Ocorocillo contained high levels of ascorbic acid and total flavonoids, while cambucá presented lower ascorbic acid, flavonoid and phenolic levels. Murici da praia and murici do campo contained high amounts of phenolic compounds and high free-radical scavenging capacity (DPPH and ORAC). In addition, this fruit was sweeter and less acid compared to the other assessed fruits. The results suggest that these native fruits constitute a good source of volatile compounds and bioactive compounds, which may aid in their preservation interest and potential use in the food, cosmetic and pharmaceutical industries.

Evaluation of efficacy of the essential oil from Ostericum viridiflorum (Turcz.) Kitagawa in control of stored product insects

The natural and ecologically safe control of stored product insects has gained considerable attention in modern society. In this study of further searching for botanical pesticides from wild-growing plant, the contact toxicity and repellency towards Tribolium castaneum and Liposcelis bostrychophila were assessed for the essential oil (EO) from Ostericum viridiflorum. The EO was distilled from aboveground parts of O. viridiflorum and checked by gas chromatography-mass spectrometry. Twenty-two compounds were identified and the main components were β-caryophyllene (24.3%), α-humulene (21.0%), apiol (10.2%), and carotol (2.5%). For bioactivity tests, results indicated that the EO and its two main compounds (β-caryophyllene and α-humulene) all showed potent contact toxicity towards L. bostrychophila with LD₅₀ values of 44.52 μg/cm², 74.11 μg/cm², and 118.56 μg/cm², respectively. The EO and the two main compounds also exhibited comparable repellency towards T. castaneum and L. bostrychophila. The results evidenced the EO of O. viridiflorum aboveground parts and its major compounds could be considered for the development of eco-friendly botanical insecticides and repellents in controlling stored product insects.

Carbon tetrachloride induced hepato/renal toxicity in experimental mice: antioxidant potential of Egyptian Salvia officinalis L essential oil

The present research designed to assess the protective role of Salvia officinalis essential oil (SO) against carbon tetrachloride (CCl₄)-induced liver and kidney damage in mice. This is evidenced by estimation of antiradical scavenging activity of SO using DPPH assay, biochemical markers, histological investigation of liver and kidney sections, and comet assay. Mice were given CCl₄ (1.2 mL/kg for 24 h or 0.8 mL/kg for 2 weeks, 3 times/week) and with or without SO (0.1, 0.2, and 0.4 mL/kg, for 2 week, 5 times/week). The findings demonstrated that both acute and subacute treatment with CCl₄ alone had adverse side effects on liver and kidney of mice. These effects were evidenced by a significant increase in serum hepatic enzymes (ALT, AST, ALP, LDH, and G-GT), bilirubin, and renal function markers (blood urea, creatinine). Toxic effect of CCl₄ was accompanied by a decline in the serum total protein, albumin, globulin, and prothrombin (%). CCl₄ induced oxidative stress as evidenced by increasing serum lipid peroxidation (LPO) along with decreasing serum total glutathione S transferase (GST). A remarkable increase in hepatic DNA strand breakages and histopathological distortion in liver and kidney specimens were observed in CCl₄-intoxicated groups. Ultrastructurally, hepatocytes exhibited irregular nuclei, vacuolated cytoplasm, and distorted microorganelles. Essential oil form S. officinalis possessed antiradical scavenging (EC₅₀ = 4602 μg/mL) lower than ascorbic acid (EC₅₀ = 5.9 μg/mL). This oil was effectively exhibited hepato-nephroprotective activity especially at its higher concentrations in co-treated groups (SO plus CCl₄). The activity of SO was associated with lowering the liver enzymes, bilirubin, urea, and creatinine, along with increasing total protein, albumin, globulin, and prothrombin. The increase in GST content and the decrease in LPO and DNA breakage levels, alongside repairing the histo-architectural distortions further confirmed the protective activity of SO. SO is a potential candidate for counteracting hepato/renal injury associating CCl₄. This effect may occur via antioxidant defense mechanism which in part related to the complexity of its chemical constituents.

Medicinal properties of terpenes found in Cannabis sativa and Humulus lupulus

Cannabaceae plants Cannabis sativa L. and Humulus lupulus L. are rich in terpenes - both are typically comprised of terpenes as up to 3-5% of the dry-mass of the female inflorescence. Terpenes of cannabis and hops are typically simple mono- and sesquiterpenes derived from two and three isoprene units, respectively. Some terpenes are relatively well known for their potential in biomedicine and have been used in traditional medicine for centuries, while others are yet to be studied in detail. The current, comprehensive review presents terpenes found in cannabis and hops. Terpenes' medicinal properties are supported by numerous in vitro, animal and clinical trials and show anti-inflammatory, antioxidant, analgesic, anticonvulsive, antidepressant, anxiolytic, anticancer, antitumor, neuroprotective, anti-mutagenic, anti-allergic, antibiotic and anti-diabetic attributes, among others. Because of the very low toxicity, these terpenes are already widely used as food additives and in cosmetic products. Thus, they have been proven safe and well-tolerated.