Antinociceptive and anti-inflammatory effects of the monoterpene α,β-epoxy-carvone in mice

Traditional Chinese medicine in the era of immune checkpoint inhibitor: theory, development, and future directions

Immune checkpoint inhibitors (ICIs) have revolutionized cancer management and have been widely applied; however, they still have some limitations in terms of efficacy and toxicity. There are multiple treatment regimens in Traditional Chinese Medicine (TCM) that play active roles in combination with Western medicine in the field of oncology treatment. TCM with ICIs works by regulating the tumor microenvironment and modulating gut microbiota. Through multiple targets and multiple means, TCM enhances the efficacy of ICIs, reverses resistance, and effectively prevents and treats ICI-related adverse events based on basic and clinical studies. However, there have been few conclusions on this topic. This review summarizes the development of TCM in cancer treatment, the mechanisms underlying the combination of TCM and ICIs, existing studies, ongoing trials, and prospects for future development.

Preclinical evaluation of Zanthoxylum piperitum Benn., traditional muscle pain remedy, for joint inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum piperitum has been used as a traditional Asian medicine to treat hypertension, stroke, bruise and muscle pain. It has been known to induce detoxification; affect anti-bacterial, anti-oxidant, and tyrosinase activity; inhibit osteosarcoma proliferation; anti-osteoarthritis inflammation. In this study, we aim to identify the therapeutic effect of Z. piperitum 90% EtOH extract (ZPE-LR) on rheumatoid arthritis.

MATERIAL AND METHODS

We investigated the anti-rheumatoid arthritis and -immunomodulatory activities of the ZPE-LR in collagen-induced arthritic (CIA) mice, a rheumatoid arthritis animal model. In order to assess the analgesic effects of ZPE-LR in vivo, acetic acid injection, formaldehyde injection, hot plate model was used. The mechanism for anti-inflammatory activity of ZPE-LR was identified with LPS-stimulated Raw 264.7 cells.

RESULTS

Pharmacologically, oral administration of ZPE-LR into CIA mice resulted in a significant and dose-dependent decrease in clinical arthritis score and paw swelling compared to untreated negative control. Pathologic examination showed that ZPE-LR prevented morphological change in cartilage and destruction of phalanges in CIA mice. This protective effect was associated with reduced pain, inflammatory mediators such as NO, TNF-α, IL-1β, and IL-6, as well as COX-2 and iNOS expression. Furthermore, reduction of phosphor-ERK and BDNF indicates a novel rheumatoid arthritis-regulating mechanism by ZPE-LR treatment.

CONCLUSIONS

These data suggest that the administration of ZPE-LR remarkably inhibited CIA progression and might be helpful in suppressing inflammation and pain in rheumatoid arthritis.

Health Benefits and Pharmacological Properties of Carvone

Carvone is a monoterpene ketone contained in the essential oils of several aromatic and medicinal plants of the Lamiaceae and Asteraceae families. From aromatic plants, this monoterpene is secreted at different concentrations depending on the species, the parts used, and the extraction methods. Currently, pharmacological investigations showed that carvone exhibits multiple pharmacological properties such as antibacterial, antifungal, antiparasitic, antineuraminidase, antioxidant, anti-inflammatory, and anticancer activities. These studies were carried out in vitro and in vivo and involved a great deal of knowledge on the mechanisms of action. Indeed, the antimicrobial effects are related to the action of carvone on the cell membrane and to ultrastructural changes, while the anti-inflammatory, antidiabetic, and anticancer effects involve the action on cellular and molecular targets such as inducing of apoptosis, autophagy, and senescence. With its multiple mechanisms, carvone can be considered as natural compounds to develop therapeutic drugs. However, other investigations regarding its precise mechanisms of action as well as its acute and chronic toxicities are needed to validate its applications. Therefore, this review discusses the principal studies investigating the pharmacological properties of carvone, and the mechanism of action underlying some of these properties. Moreover, further investigations of major pharmacodynamic and pharmacokinetic studies were also suggested.

Anti-inflammatory activity of different isolated sites of Chloranthus serratus in complete Freund's adjuvant-induced arthritic rats

Chloranthus serratus is a traditional Chinese medicine for treating arthritis and bruises. The aim of the present study was to investigate the anti-arthritic activities and possible associated mechanisms of different isolated sites of Chloranthus serratus (DISC) in adjuvant-induced arthritis (AA) rats. The therapeutic effects of the extracts were assessed through changes in body weights, swelling rates, arthritis indexes (AI) and organ indexes. The levels of nitric oxide (NO), malondialdehyde and superoxide dismutase were determined using one-step method, TBA method and hydroxylamine method, respectively; the levels of TNF-α, IL-1β, IL-6, prostaglandin E2, macrophage inhibitor factor-1, VEGF, immunoglobulin (Ig) G, IgM and IFN-γ in serum were determined using ELISA. Pathological changes and positive expression of VEGF in the ankle joints were investigated using hematoxylin-eosin staining and immunohistochemical staining, respectively. DISC treatment increased the weight gains and thymus indexes, and decreased the swelling rates, spleen indexes and AI in AA rats. The water isolated site (WA) and ethyl acetate isolated site (EA) significantly reversed complete Freund's adjuvant (CFA)-induced changes in the levels of NO, IL-6, TNF-α, IgG and IFN-γ, while the n-butanol isolated site (NB) only reversed the changes in IL-6 and IgG contents. Some changes in the chloroform isolated site group showed the same trend as those in the model group. The extracts relieved synovial hyperplasia, inflammatory cell infiltration and articular surface defects, and reduced the positive expression rate of VEGF in the synovial tissues of the AA rats to varying degrees. The WA exhibited the most marked effects, followed by the EA and NB, indicating that WA had optimal therapeutic effects on CFA-induced arthritic rats, which may be mediated by the oxidative stress and inhibition of inflammatory factors. C. serratus may serve as a potential candidate for the treatment of rheumatoid arthritis.

Monoterpenes as a perspective for the treatment of seizures: A Systematic Review

BACKGROUND

Epilepsy affects more than 65 million people worldwide. Treatment for epileptic seizures is ineffective and has many adverse effects. For this reason, the search for new therapeutic options capable of filling these limitations is necessary.

HYPOTHESIS/PURPOSE

In this sense, natural products, such as monoterpenes, have been indicated as a new option to control neurological disorders such as epilepsy.

STUDY DESIGN

Therefore, the objective of this study was to review the monoterpenes that have anticonvulsive activity in animal models.

METHODS

The searches were performed in the PubMed, Web of Science and Scopus databases in September, 2020 and compiled studies using monoterpenes as an alternative to seizure. Two independent reviewers performed the study selection, data extraction and methodological quality assessment using the Syrcle tool.

RESULTS

51 articles that described the anticonvulsant activity of 35 monoterpenes were selected with action on the main pharmacological target, including GABAA receptors, glutamate, calcium channels, sodium and potassium. In addition, these compounds are capable of reducing neuronal inflammation and oxidative stress caused by seizure.

CONCLUSION

These compounds stand out as a promising alternative for acting through different pharmacological mechanisms, which may not only reduce seizure, but also promote neuroprotective effect by reducing toxicity in brain regions. However, further studies are needed to determine the mechanism of action and safety assessment of these compounds.

Carvone suppresses oxidative stress and inflammation in the liver of immobilised rats

OBJECTIVE

The investigation of the effect of carvone (a natural monoterpene) on liver damage caused by chronic immobilisation.

METHODS

Male Wistar rats were divided into four groups: control, carvone, stress, and stress-carvone. To induce stress, rats were placed in a restrainer (6 h/21 day) and carvone was treated by gavage at a dose of 20 mg/kg.

RESULTS

Alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase activities were significantly increased in sera of immobilised rats. Chronic immobilisation also increased malondialdehyde levels and decreased reduced glutathione content, as well as increased TNF-α, IL-1β, IL-6, and NF-κB mRNA expression and also led to the infiltration of inflammatory cells in the liver parenchyma. Carvone's 21-day treatment prevented all of these changes in immobilised rats.

CONCLUSION

It is concluded that carvone has effectively prevented chronic immobilisation-induced liver injury, most probably through its antioxidant and anti-inflammatory capabilities.

Anti-inflammatory effects of the root, stem and leaf extracts of Chloranthus serratus on adjuvant-induced arthritis in rats

Context: Chloranthus serratus [(Thunb.) Roem. et Schult, (Chloranthaceae)] is a folk medicine used for the treatment of rheumatoid arthritis.Objective: The aim of this study was to investigate anti-arthritic effects of the ethanol extracts of the roots (ER), stems (ES) and leaves (EL) of C. serratus on adjuvant arthritis rats and related mechanisms.Materials and methods: The rats were immunized by intradermal injection of complete Freund's adjuvant (CFA, 0.18 mL) into the right hind feet, and received intragastric administrations of the ER, ES and EL (2.07, 1.61 and 0.58 g/kg/d, respectively) for 14 days. The anti-arthritic activity was assessed by swelling rates, serum indicators, antioxidant capacity, histopathological and immunohistochemical analyses.Results: The LD₅₀ of the ER, ES and EL was higher than 10.35, 8.05 and 2.90 g/kg/p.o., respectively. Extract treatments decreased swelling rates, tumour necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), interleukin 1 beta (IL-1β), migration inhibitory factor 1 (MIF-1), immunoglobulin G (IgG) and immunoglobulin M (IgM) levels and positive expression of VEGF in the arthritic rats (p < 0.01 or p < 0.05). The ER significantly decreased NO (3.91 ± 0.61 µmol/L), IL-6 (75.67 ± 16.83 pg/mL) and malondialdehyde (MDA) (2.28 ± 0.32 nmol/mL) contents and clearly increased IFN-γ (2082 ± 220.93 pg/mL) and superoxide dismutase (SOD) (601.98 ± 38.40 U/mL) levels. The ES and EL did not reverse the changes in some indicators. All the extracts alleviated inflammatory cell infiltration and synovial cell proliferation. Among them, the ER was the most pronounced.Discussion and conclusions: ER exerts the most promising effects, as shown by inhibiting the releases of inflammatory cytokines and enhancing antioxidant capacity, which provides a scientific basis for further research on C. serratus and its clinical applications.

Menthacarin attenuates experimental colitis

BACKGROUND

Peppermint oil and caraway oil are established remedies in gastroenterological medicine because of their spasmolytic/analgesic effects.

PURPOSE

We investigated whether Menthacarin, a combination of both oils, exerted anti-inflammatory effects in a dextran sodium sulphate (DSS, 2%) murine model of colitis.

STUDY DESIGN AND METHODS

C57BL/6 mice were orally administered Menthacarin in doses of 10, 30, 60, and 120 µg/g body weight (BW), and control mice received 0.2% agar, 10 µl/g BW, during 8 days of DSS-induced colitis. Colitis was monitored by BW measurements and colonoscopies. Colons of euthanised mice were excised for histological staining and ELISA measurements of the cytokines TNFα, IL-6, IL-10, IL-1β, and TGF-β.

RESULTS

Menthacarin-treated mice compared to controls showed improved macroscopical and microscopical parameters and lower BW loss during the course of colitis. Menthacarin changed the colonic cytokine profile towards a regulatory/anti-inflammatory phenotype.

CONCLUSION

Menthacarin attenuates experimental colitis and may be a promising add-on therapy for the treatment of IBD.

Anticonvulsant Essential Oils and Their Relationship with Oxidative Stress in Epilepsy

Epilepsy is a most disabling neurological disorder affecting all age groups. Among the various mechanisms that may result in epilepsy, neuronal hyperexcitability and oxidative injury produced by an excessive formation of free radicals may play a role in the development of this pathology. Therefore, new treatment approaches are needed to address resistant conditions that do not respond fully to current antiepileptic drugs. This paper reviews studies on the anticonvulsant activities of essential oils and their chemical constituents. Data from studies published from January 2011 to December 2018 was selected from the PubMed database for examination. The bioactivity of 19 essential oils and 16 constituents is described. Apiaceae and Lamiaceae were the most promising botanical families due to the largest number of reports about plant species from these families that produce anticonvulsant essential oils. Among the evaluated compounds, β-caryophyllene, borneol, eugenol and nerolidol were the constituents that presented antioxidant properties related to anticonvulsant action. These data show the potential of these natural products as health promoting agents and use against various types of seizure disorders. Their properties on oxidative stress may contribute to the control of this neurological condition. However, further studies on the toxicological profile and mechanism of action of essential oils are needed.

Water-separated part of Chloranthus serratus alleviates lipopolysaccharide- induced RAW264.7 cell injury mainly by regulating the MAPK and Nrf2/HO-1 inflammatory pathways

Background

Chloranthus serratus (Chloranthaceae) has been used to treat bruises, rheumatoid and bone pain. However, the anti-inflammatory mechanisms of C. serratus in vitro have not been fully elucidated. The present study aimed to explore the anti-inflammatory activity and potential mechanisms of C. serratus’s separated part of water (CSSPW) in lipopolysaccharide (LPS)-induced RAW264.7 cells.

Methods

The concentrations of CSSPW were optimized by CCK-8 method. Nitric oxide (NO) content was detected by one-step method. The levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assay (ELISA). Gene expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was detected by real-time quantitative PCR (qPCR). Immunofluorescence and DCFH-DA fluorescent probes were used to detect p65 nuclear translocation and reactive oxygen species (ROS) content, respectively. Western blotting was used to assay the protein expression of mitogen-activated protein kinases (MAPK), nuclear factor-kappa B (NF-κB) and nuclear transcription factor E2 related factor 2/haem oxygenase-1 (Nrf2/HO-1) pathways.

Results

The final concentrations of 15 ng/mL, 1.5 μg/mL and 150 μg/mL were selected as low, medium and high doses of CSSPW, respectively. CSSPW treatment significantly reduced the generation of NO, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandinE₂ (PGE₂), iNOS mRNA and COX-2 mRNA in response to LPS stimulation. Furthermore, the protein expression of the MAPK and NF-κB pathways was suppressed by CSSPW treatment, as well as p65 nuclear translocation and ROS production. In contrast, the protein expression of the Nrf2/HO-1 pathway was markedly upregulated.

Conclusions

CSSPW exerts its anti-inflammatory effect via downregulating the production of pro-inflammatory mediators, inhibiting the activation of NF-κB and MAPK pathways, as well as activating Nrf2/HO-1 pathway in LPS-induced RAW264.7 cells.

A dynamical (e,2e) investigation into the ionization of the outermost orbitals of R-carvone

We report an experimental and theoretical investigation into the dynamics of electron-impact ionization of R-carvone. Experimental triple differential cross sections are obtained in asymmetric coplanar kinematic conditions for the ionization of the unresolved combination of the three outermost molecular orbitals (41a-39a) of R-carvone. These cross sections are compared with theoretical cross sections calculated within a molecular 3-body distorted wave (M3DW) framework employing either a proper orientation average or orbital average to account for the random orientation of the molecule probed in the experiment. Here, we observe that the overall scattering behavior observed in the experiment is fairly well reproduced within the M3DW framework when implementing the proper average over orientations. The character of the ionized orbitals also provides some qualitative explanation for the observed scattering behavior. This represents substantial progress when trying to describe the scattering dynamics observed for larger molecules under intermediate-impact energy and asymmetric energy sharing scattering conditions.

Hydroxyl Group and Vasorelaxant Effects of Perillyl Alcohol, Carveol, Limonene on Aorta Smooth Muscle of Rats

The present study used isometric tension recording to investigate the vasorelaxant effect of limonene (LM), carveol (CV), and perillyl alcohol (POH) on contractility parameters of the rat aorta, focusing in particular on the structure-activity relationship. LM, CV, and POH showed a reversible inhibitory effect on the contraction induced by electromechanical and pharmacomechanical coupling. In the case of LM, but not CV and POH, this effect was influenced by preservation of the endothelium. POH and CV but not LM exhibited greater pharmacological potency on BayK-8644-induced contraction and on electromechanical coupling than on pharmacomechanical coupling. In endothelium-denuded preparations, the order of pharmacological potency on electrochemical coupling was LM < CV < POH. These compounds inhibited also, with grossly similar pharmacological potency, the contraction induced by phorbol ester dibutyrate. The present results suggest that LM, CV and POH induced relaxant effect on vascular smooth muscle by means of different mechanisms likely to include inhibition of PKC and IP3 pathway. For CV and POH, hydroxylated compounds, it was in electromechanical coupling that the greater pharmacological potency was observed, thus suggesting a relative specificity for a mechanism likely to be important in electromechanical coupling, for example, blockade of voltage-dependent calcium channel.

Comparison of behavioral, neuroprotective, and proinflammatory cytokine modulating effects exercised by (+)-cis-EC and (-)-cis-EC stereoisomers in a PTZ-induced kindling test in mice

Epoxy-carvone (EC) has chiral centers that allow generation of stereoisomers, including (+)-cis-EC and (-)-cis-EC, whose effects in the kindling tests have never been studied. Accordingly, this study aims to comparatively investigate the effect of stereoisomers (+)-cis-epoxy-carvone and (-)-cis-epoxy-carvone on behavioral changes measured in scores, in the levels of cytokines (IL-1β, IL-6, and TNFα) and neuronal protection in the face of continuous treatment with pentylenetetrazol. Swiss mice were divided into five groups (n = 10), receiving vehicle, (+) - cis-EC, (-) - cis-EC (both at the dose of 30 mg/kg), and diazepam (4 mg/kg). Thirty minutes after the respective treatment was administered to the animals one subconvulsive dose of PTZ (35 mg/kg). Seven subconvulsives treatments were made on alternate days, in which each treatment several parameters were recorded. In the eighth treatment, the animals receiving the highest dose of PTZ (75 mg/kg) and were sacrificed for quantification of cytokines and histopathologic analysis. All drugs were administered by intraperitoneal route. In the kindling test, (+)-cis-EC and (-)-cis-EC reduced the average scores. The stereoisomer (+)-cis-EC decreased levels of proinflammatory cytokines IL-1β, IL-6, and TNFα, whereas comparatively (-)-cis-EC did not reduce IL-1β levels. Histopathological analysis of the mice hippocampi undergoing this methodology showed neural protection for treated with (+)-cis-EC. The results suggest that the anticonvulsant effect of (+)-cis-EC possibly takes place due to reduction of proinflammatory cytokines involved in the epileptogenic process, besides neuronal protection, yet further investigation of the mechanisms involved is required.

Analgesic-Like Activity of Essential Oil Constituents: An Update

The constituents of essential oils are widely found in foods and aromatic plants giving characteristic odor and flavor. However, pharmacological studies evidence its therapeutic potential for the treatment of several diseases and promising use as compounds with analgesic-like action. Considering that pain affects a significant part of the world population and the need for the development of new analgesics, this review reports on the current studies of essential oils’ chemical constituents with analgesic-like activity, including a description of their mechanisms of action and chemical aspects.

Essential Oils and Compounds against Pains in Animal Studies

The positive impact of essential oils and compounds has been known for a long time. Essential oils are multicomponent mixtures and obtained by steam distillation of leaves or flowers or simply by pressing orange peels for example. Due to the broad-spectrum activity, essential oils can be used for a variety of disorders like sleeping problems, colds or gastrointestinal complaints. The focus of this paper is the use of essential oils against pain in animal studies. The broad use of analgesics like NSAIDs against headaches or menstrual cramps for example, is often associated with unpleasant side effects. Essential oils may help to reduce the analgesic doses.

Antimanic-like effects of (R)-(-)-carvone and (S)-(+)-carvone in mice

Carvone is a monoterpene that is present in spearmint (Mentha spicata) and caraway (Carum carvi) essential oils and has been shown to have anticonvulsant effects, likely through the blockade of voltage-gated sodium channels, and anxiolytic-like effects. Considering that some anticonvulsants that blocked voltage-gated sodium channels (e.g., sodium valproate and carbamazepine) exert clinical antimanic effects, the aim of the present study was to evaluate (R)-(-)-carvone and (S)-(+)-carvone in animal models of mania (i.e., hyperlocomotion induced by methylphenidate and sleep deprivation). Mice that were treated with methylphenidate (5mg/kg) or sleep-deprived for 24h using a multiple-platform protocol exhibited an increase in locomotor activity in an automated activity box. This effect was blocked by pretreatment with acute (R)-(-)-carvone (50-100mg/kg), (S)-(+)-carvone (50-100mg/kg), and lithium (100mg/kg, positive control). These doses did not alter spontaneous locomotor activity in the methylphenidate-induced experiments while (S)-(+)-carvone decreased spontaneous locomotor activity in sleep deprivation experiment, indicating a sedative effect. Chronic 21-day treatment with (R)-(-)-carvone (100mg/kg), (S)-(+)-carvone (100mg/kg), and lithium also prevented methylphenidate-induced hyperactivity. The present results suggest that carvone may have an antimanic-like effect.

Comparative Anticonvulsant Study of Epoxycarvone Stereoisomers

Stereoisomers of the monoterpene epoxycarvone (EC), namely (+)-cis-EC, (-)-cis-EC, (+)-trans-EC, and (-)-trans-EC, were comparatively evaluated for anticonvulsant activity in specific methodologies. In the pentylenetetrazole (PTZ)-induced anticonvulsant test, all of the stereoisomers (at 300 mg/kg) increased the latency to seizure onset, and afforded 100% protection against the death of the animals. In the maximal electroshock-induced seizures (MES) test, prevention of tonic seizures was also verified for all of the isomers tested. However, the isomeric forms (+) and (-)-trans-EC showed 25% and 12.5% inhibition of convulsions, respectively. In the pilocarpine-induced seizures test, all stereoisomers demonstrated an anticonvulsant profile, yet the stereoisomers (+) and (-)-trans-EC (at 300 mg/kg) showed a more pronounced effect. A strychnine-induced anticonvulsant test was performed, and none of the stereoisomers significantly increased the latency to onset of convulsions; the stereoisomers probably do not act in this pathway. However, the stereoisomers (+)-cis-EC and (+)-trans-EC greatly increased the latency to death of the animals, thus presenting some protection. The four EC stereoisomers show promise for anticonvulsant activity, an effect emphasized in the isomers (+)-cis-EC, (+)-trans-EC, and (-)-trans-EC for certain parameters of the tested methodologies. These results serve as support for further research and development of antiepileptic drugs from monoterpenes.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Anti-ulcer activity of essential oil constituents

Essential oils have attracted considerable worldwide attention over the last few decades. These natural products have wide-ranging pharmacological activities and biotechnological applications. Faced with the need to find new anti-ulcer agents and the great effort on the development of drugs for the treatment of ulcers, in this review, the anti-ulcer activities of 21 bioactive compounds found in essential oils are discussed.

Genotoxic and oxidative damage potentials in human lymphocytes after exposure to terpinolene in vitro

Terpinolene (TPO) is a monocyclic monoterpene found in the essential oils of various fir and pine species. Recent reports indicated that several monoterpenes could exhibit antioxidant effects in both human and animal experimental models. However, so far, the nature and/or biological roles of TPO have not been elucidated in human models yet. The aim of this study was to investigate the genetic, oxidative and cytotoxic effects of TPO in cultured human blood cells (n = 5) for the first time. Human blood cells were treated with TPO (0-200 mg/L) for 24 and 48 h, and then cytotoxicity was detected by lactate dehydrogenase (LDH) release and [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay, while DNA damage was also analyzed by micronucleus assay, sister chromatid exchanges assay and 8-oxo-2-deoxyguanosine (8-OH-dG) level. In addition, biochemical parameters [total antioxidant capacity (TAC) and total oxidative stress (TOS)] were examined to determine oxidative effects. The results of LDH and MTT assays showed that TPO (at concentrations greater than 100 mg/L) decreased cell viability. In our in vitro test systems, it was observed that TPO had no genotoxicity on human lymphocytes. Again, TPO (at 10, 25, 50 and 75 mg/L) treatment caused statistically important (p < 0.05) increases of TAC levels in human lymphocytes without changing TOS levels. In conclusion, TPO can be a new resource of therapeutics as recognized in this study with its non-genotoxic and antioxidant features.

In vitro assessment of cytogenetic and oxidative effects of α-pinene

α-Pinene (α-pinene), a bicyclic monoterpene, is present in the oils of many species of coniferous trees, most notably the pine, and is known for its diverse biological properties such as antimicrobial, anti-inflammatory, antiproliferative and antioxidant. However, there are limited data on the cytogenetic and antioxidant effects of α-pinene in cultured human blood cells (n = 5) for the first time. The purpose of this study was to investigate the genetic, oxidative, and cytotoxic effects of α-pinene in cultured human blood cells (n = 5) for the first time. Human blood cells were treated with α-pinene (0 to 200 mg/L) for 24 and 48 h, and then cytotoxicity was detected by lactate dehydrogenase (LDH) release and (3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide) (MTT) assay, while DNA damage was also analyzed by micronucleus (MN) assay, chromosomal aberration (CA) assay and 8-oxo-2-deoxyguanosine (8-OH-dG). In addition, biochemical parameters (total antioxidant capacity (TAC) and total oxidative stress (TOS)) were examined to determine oxidative effects. The results of LDH and MTT assays showed that α-pinene (at 200 mg/L) decreased cell viability. In our in vitro test systems, it was observed that α-pinene did not cause any statistically important changes in the rates of studied genotoxicity endpoints but dose-dependent alterations were observed in TAC and TOS levels. α-Pinene treatment caused increases in TAC levels (at 25 and 50 mg/L) and decreases in TOS levels (only at 200 mg/L) on human lymphocytes. In conclusion, the findings of the present study confirm for the first time that α-pinene could be a significant source of natural antioxidant compound that may have beneficial health effects.