Systemic Administration of Calea pinnatifida Inhibits Inflammation Induced by Carrageenan in a Murine Model of Pulmonary Neutrophilia.

OBJECTIVE: The aim of this study was to investigate the anti-inflammatory effects of the crude extract (CE), derived fraction, and isolated compounds from Calea pinnatifida leaves in a mouse model of pulmonary neutrophilia. METHODS: The CE and derived fractions, hexane, ethyl acetate, and methanol, were obtained from C. pinnatifida leaves. The compounds 3,5- and 4,5-di-O-E-caffeoylquinic acids were isolated from the EtOAc fraction using chromatography and were identified using infrared spectroscopic data and nuclear magnetic resonance (1H and 13C NMR). Leukocytes count, protein concentration of the exudate, myeloperoxidase (MPO) and adenosine deaminase (ADA), and nitrate/nitrite (NO x ), tumor necrosis factor-alpha (TNF-α), interleukin-1-beta (IL-1ß), and interleukin-17A (IL-17A) levels were determined in the pleural fluid leakage after 4 h of pleurisy induction. We also analyzed the effects of isolated compounds on the phosphorylation of both p65 and p38 in the lung tissue. RESULTS: The CE, its fractions, and isolated compounds inhibited leukocyte activation, protein concentration of the exudate, and MPO, ADA, NO x , TNF-α, IL-1ß, and IL-17A levels. 3,5- and 4,5-di-O-E-caffeoylquinic acids also inhibited phosphorylation of both p65 and p38 (P < 0.05). CONCLUSION: This study demonstrated that C. pinnatifida presents important anti-inflammatory properties by inhibiting activated leukocytes and protein concentration of the exudate. These effects were related to the inhibition of proinflammatory mediators. The dicaffeoylquinic acids may be partially responsible for these anti-inflammatory properties through the inhibition of nuclear transcription factor kappa B and mitogen-activated protein kinase pathways.

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, ß-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.

Phenolic Compounds Isolated from Calea uniflora Less. Promote Anti-Inflammatory and Antioxidant Effects in Mice Neutrophils (Ex Vivo) and in Mice Pleurisy Model (In Vivo).

The literature shows that phenolic compounds possess important antioxidant and anti-inflammatory activities; however, the mechanism underlying these effects is not elucidated yet. The genus Calea is used in folk medicine to treat rheumatism, respiratory diseases, and digestive problems. In this context, some phenolic compounds were isolated with high purity from Calea uniflora Less. and identified as noreugenin (NRG) and α-hydroxy-butein (AH-BU). The aim of this study was to analyze the effect of these compounds on cell viability, the activity of myeloperoxidase (MPO), and apoptosis of mouse neutrophils using ex vivo tests. Furthermore, the effect of these compounds on the cytokines, interleukin 1 beta (IL-1ß), interleukin 17A (IL-17A), and interleukin 10 (IL-10), and oxidative stress was investigated by analyzing lipid peroxidation (the concentration of thiobarbituric acid reactive substances (TBARS)) and activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST), using a murine model of neutrophilic inflammation. The NRG and AH-BU reduce MPO activity and increase neutrophil apoptosis (p < 0.05). These compounds reduced the generation of oxygen reactive species and IL-1ß and IL-17A levels but increased IL-10 levels (p < 0.05). This study demonstrated that NRG and AH-BU show a significant anti-inflammatory effect by inhibiting the MPO activity and increasing neutrophil apoptosis in primary cultures of mouse neutrophils. These effects were at least partially associated with blocking reactive species generation, inhibiting IL-1ß and IL-17A, and increasing IL-10 levels.

Anti-Leishmania and cytotoxic activities of perillaldehyde epoxide synthetic positional isomers.

Leishmaniasis belongs to a complex of zoonotic disease caused by protozoa of the genus Leishmania and is considered a major public health problem. Several essential oil chemical components have inhibitory effect against protozoa, including Leishmania donovani. Thus, the aim of this study was to evaluate for the first time the anti-Leishmania activity of two p-menthane monoterpene isomers (EPER-1: perillaldehyde 1,2-epoxide and EPER-2: perillaldehyde 8,9-epoxide) against L. donovani promastigotes as well as evaluating cytotoxic effect on mononuclear peripheral blood cells. Results of anti-Leishmania assay revealed that EPER-2 (IC50 = 3.8 µg.mL-1) was 16-fold more potent than its isomer EPER-1 (IC50 = 64.6 µg.mL-1). In contrast to PBMC cells, EPER-2 was not cytotoxic (IC50 > 400 µg.mL-1) when compared to positive control. These data suggest that the disposition of epoxide group into the p-menthane skeleton affects the anti-Leishmania activity, being that the presence of the exocyclic epoxide group considerably increased potency. Thus, it was possible to observe that the location of the epoxide group into the p-menthane skeleton resulted in different potencies.

A Comparative Evaluation of the Cytotoxic and Antioxidant Activity of Mentha crispa Essential Oil, Its Major Constituent Rotundifolone, and Analogues on Human Glioblastoma.

Cancer is a major public health problem around the globe. This disorder is affected by alterations in multiple physiological processes, and oxidative stress has been etiologically implicated in its pathogenesis. Glioblastoma (GBM) is considered the most common and aggressive brain tumor with poor prognosis despite recent improvements in surgical, radiation, and chemotherapy-based treatment approaches. The purpose of this study was to evaluate antitumor activity from Mentha crispa essential oil (MCEO), its major constituent rotundifolone (ROT), and a series of six analogues on the human U87MG glioblastoma cell line. Cytotoxic effects of the compounds on the human U87MG-GBM cell line were assessed using in vitro cell viability and oxidative and molecular genetic assays. In addition, biosafety assessment tests were performed on cultured human blood cells. Our findings revealed that MCEO, 1,2-perillaldehyde epoxide (EPER1), and perillaldehyde (PALD) were the most cytotoxic compounds against U87MG cells, with IC50 values of 16.263, 15.087, and 14.888 µg/mL, respectively. Further, these compounds increased the expressions of BRAF, EGFR, KRAS, NFκB1, NFκB1A, NFκB2, PIK3CA, PIK3R, PTEN, and TP53 genes at different degrees and decreased the expression of some genes such as AKT1, AKT2, FOS, and RAF1. Finally, treatment with MCEO, EPER1, and PALD did not lead to genotoxic damage in blood cells. Taken together, our findings reveal antiproliferative potential of MCEO, its major component ROT, and its tested analogues. Some of these chemical analogues may be useful as prototypes for the development of novel chemotherapeutic agents for treating human brain cancer and/or other cancers due to their promising activities as well as nonmutagenic property and safety.

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.

Antidepressant Flavonoids and Their Relationship with Oxidative Stress.

Depression is a serious disorder that affects hundreds of millions of people around the world and causes poor quality of life, problem behaviors, and limitations in activities of daily living. Therefore, the search for new therapeutic options is of high interest and growth. Research on the relationship between depression and oxidative stress has shown important biochemical aspects in the development of this disease. Flavonoids are a class of natural products that exhibit several pharmacological properties, including antidepressant-like activity, and affects various physiological and biochemical functions in the body. Studies show the clinical potential of antioxidant flavonoids in treating depressive disorders and strongly suggest that these natural products are interesting prototype compounds in the study of new antidepressant drugs. So, this review will summarize the chemical and pharmacological perspectives related to the discovery of flavonoids with antidepressant activity. The mechanisms of action of these compounds are also discussed, including their actions on oxidative stress relating to depression.

Calea uniflora Less. attenuates the inflammatory response to carrageenan-induced pleurisy in mice.

Calea uniflora Less. (family Asteraceae), also named "arnica" and "erva-de-lagarto", is a native plant to the South and Southeast of Brazil. This species was used to treat rheumatism, respiratory diseases, and digestive problems in Brazilian folk medicine. In vitro studies have shown the important biological effects of C. uniflora. However no studies have focused on the mechanism of action of anti-inflammatory activity of C. uniflora. The aim of this study was to evaluate the anti-inflammatory effects of the crude extract, its fractions, and isolated compounds obtained from of C. uniflora, using mouse model of carrageenan-induced inflammation. The following inflammatory parameters: leukocyte influx, degree of exudation, myeloperoxidase (MPO) and adenosine deaminase (ADA) activities, nitric oxide metabolites (NOx), proinflammatory cytokines and phosphorylation of the p65 subunit of NF-κB (p-p65 NF-κB), and p38 mitogen-activated protein kinase (p-p38 MAPK) levels were determined. The crude extract of C. uniflora, its fractions and its isolated compounds reduced the leukocyte influx, degree of exudation, MPO and ADA activities, NOx, TNF-α, IFN-γ, MCP-1 and IL-6 levels (p<0.05). The isolated compounds reduced p-p65 NF-κB and p-p38 MAPK levels (p<0.01). This study demonstrated that C. uniflora exhibits a significant anti-inflammatory activity via inhibition of the leukocyte influx and degree of exudation. These effects were associated with a decrease in the levels of several proinflammatory mediators. The mechanism of the anti-inflammatory action of C. uniflora may be, at least in part, via the inhibition of p65 NF-κB and p38 MAPK activation by the isolated compounds.

Evaluation of Antiparasitc Activity of Mentha crispa Essential Oil, Its Major Constituent Rotundifolone and Analogues against Trypanosoma brucei.

Considering the pressing need for new drugs to treat sleeping sickness and Nagana disease, Mentha crispa essential oil, its principal constituent rotundifolone, and four related p-menthane-type monoterpenes (two stereoisomers of limonene epoxide, perillyl alcohol, and perillyl aldehyde) were investigated for their activity against bloodstream forms of Trypanosoma brucei. The general cytotoxicity of the compounds was determined with human myeloid HL-60 cells. The effect of the M. crispa essential oil and the monoterpenes on the growth of parasite and human cells was evaluated in cell cultures with the resazurin viability assay. Of all of the compounds tested, M. crispa essential oil, rotundifolone, and perillyl aldehyde showed the highest trypanocidal activities with 50 % growth inhibition (GI50) and minimum inhibitory concentration values of 0.3 µg/mL and 1 µg/mL, respectively. In contrast, HL-60 cells were considerably less sensitive to the compounds with minimum inhibitory concentration values of 100 µg/mL and GI50 values ranging between 3.4 to 13.8 µg/mL. As a consequence of this, GI50 and minimum inhibitory concentration ratios of cytotoxic to trypanocidal activity (selectivity index) of these three compounds were promising with values of 11-45 and 100, respectively. These results indicate that the p-menthane-type monoterpenes rotundifolone and perillyl aldehyde are interesting lead candidates for further rational antitrypanosomal drug development.

Evaluation of the cytotoxicity of structurally correlated p-menthane derivatives.

Compounds isolated from essential oils play an important role in the prevention and treatment of cancer. Monoterpenes are natural products, and the principal constituents of many essential oils. The aim of this study was to investigate the cytotoxic potential of p-menthane derivatives. Additionally, analogues of perillyl alcohol, a monoterpene with known anticancer activity, were evaluated to identify the molecular characteristics which contribute to their cytotoxicity, which was tested against OVCAR-8, HCT-116, and SF-295 human tumor cell lines, using the MTT assay. The results of this study showed that (-)-perillaldehyde 8,9-epoxide exhibited the highest percentage inhibition of cell proliferation (GI = 96.32%-99.89%). Perillyl alcohol exhibited high cytotoxic activity (90.92%-95.82%), while (+)-limonene 1,2-epoxide (GI = 58.48%-93.10%), (-)-perillaldehyde (GI = 59.28%-83.03%), and (-)-8-hydroxycarvotanacetone (GI = 61.59%-94.01%) showed intermediate activity. All of the compounds tested were less cytotoxic than perillyl alcohol, except (-)-perillaldehyde 8,9-epoxide (IC50 = 1.75-1.03 µL/mg). In general, replacement of C-C double bonds by epoxide groups in addition to the aldehyde group increases cytotoxicity. Furthermore, stereochemistry seems to play an important role in cytotoxicity. We have demonstrated the cytotoxic influence of chemical substituents on the p-menthane structure, and analogues of perillyl alcohol.

Oxime derivatives with larvicidal activity against Aedes aegypti L.

Oximes containing secondary metabolites constitute an important group of bioactive compounds and have been described and frequently updated in the literature due to their pharmacological properties. Thus, the aim of this study was to evaluate the larvicidal activity of a series of fourteen structurally related [1,4]-Benzoquinone mono-oximes on third-instar Aedes aegypti larvae and to investigate structure-activity relationships (SAR) of these compounds. Results of larvicidal assay revealed that all oximes were found to have larvicidal activity. Compound 2,6-dimethyl-[1,4]-benzoquinone oxime tosylate (11) was the most bioactive (LC50 = 9.858 ppm), followed by 2-methyl-[1,4]-benzoquinone oxime tosylate (9) (LC50 = 14.450 ppm). [1,4]-benzoquinone oxime (1) exhibited the lowest potency, with an LC50 = 121.181 ppm. The molecular characteristics which may help to understand the assayed compounds larvicidal activity were identified. SAR indicates that the addition of alkyl groups attached to the ring, number, position in the unsaturated cyclic structure, and size of these groups influence the larvicidal activity. Moreover, the lipophilicity seems to play an important role in increasing the larvicidal effect, because, in general, tosyl-containing products were more potent than products containing free OH.

Antitumor activity of monoterpenes found in essential oils.

Cancer is a complex genetic disease that is a major public health problem worldwide, accounting for about 7 million deaths each year. Many anticancer drugs currently used clinically have been isolated from plant species or are based on such substances. Accumulating data has revealed anticancer activity in plant-derived monoterpenes. In this review the antitumor activity of 37 monoterpenes found in essential oils is discussed. Chemical structures, experimental models, and mechanisms of action for bioactive substances are presented.

Jungia sellowii suppresses the carrageenan-induced inflammatory response in the mouse model of pleurisy.

This study was conducted to explore the anti-inflammatory effect of Jungia sellowii (Asteraceae) using a murine model of pleurisy induced by carrageenan (Cg). This plant is used in southern Brazil to treat inflammatory diseases. J. sellowii leaves were extracted with ethanol/water to obtain the crude extract (CE), which was fractionated with different solvents, yielding n-hexane (Hex), dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol (BuOH) fractions, and aqueous fraction (Aq). The major compounds succinic acid (SA) and lactic acid (LA) were isolated from Aq fraction, and their structures were determined by (1)H and (13)C NMR. Pleurisy was induced by Cg (Saleh et al. 1996). The leukocytes, exudation, myeloperoxidase (MPO) and adenosine-deaminase (ADA) activities, metabolites of nitric oxide (NO x ) levels, protein levels and mRNA expression for interleukin 1 beta (IL-1ß), tumour necrosis factor alpha (TNF-α), interleukin 17A (IL17A) and inducible of nitric oxide synthase (iNOs), and p65 protein phosphorylation (NF-κB) were analysed 4 h after pleurisy induction. Animals pre-treated with CE, BuOH, Aq, SA, or LA inhibited leukocytes, exudation, MPO and ADA activities, NO x , IL-1ß, TNF-α, and IL-17A levels, and the mRNA expression for IL-1ß, TNF-α, IL-17A, iNOS, and p65 protein phosphorylation (NF-κB) (p < 0.05). Our study demonstrated that J. sellowii can protect against inflammation induced by Cg by decreasing the leukocytes and exudation. Its effects are related to the decrease of either proinflammatory cytokines and/or NO x . The isolated compounds SA and LA may play an important role in this anti-inflammatory action by inhibiting all the studied parameters. The anti-inflammatory properties of these compounds are due to the downregulation of NF-κB.

Anticonvulsant effects of acute treatment with cyane-carvone at repeated oral doses in epilepsy models.

Epilepsy affects about 40 million people worldwide. Many drugs block seizures, but have little effect in preventing or curing this disease. So the search for new drugs for epilepsy treatment using animal models prior to testing in humans is important. Increasingly pharmaceutical industries invest in the Re​search & Drug Development area to seek safe and effective new therapeutic alternatives to the currently available epilepsy treatment. In this perspective, natural compounds have been investigated in epilepsy models, particularly the monoterpenes obtained from medicinal plants. In our study we investigated the effects of cyane-carvone (CC), a synthetic substance prepared from natural a monoterpene, carvone, against pilocarpine- (PILO), pentylenetetrazole- (PTZ) and picrotoxine (PTX)-induced seizures in mice after acute treatment with repeated oral doses (CC 25, 50 and 75 mg/kg) for 14 days. CC in all doses tested showed increase in latency to first seizure, decrease in percentages of seizuring animals as well as reduction percentages of dead animals (p<0.05) in PILO, PTZ and PTX groups when compared with vehicle. However, these effects were not reversed by flumazenil, benzodiazepine (BZD) antagonist used to investigate the CC action mechanism. Our results suggest that acute treatment with CC at the doses tested can exert anticonvulsant effects in PILO, PTZ and PTX epilepsy models. In addition, our data suggest that CC could act in an allosteric site of GABAA, which would be different from the site in which BDZ acts, since flumazenil was not able to reverse any of CC effects on the modulation of seizure parameters related with epilepsy models investigated. New studies should be conducted to investigate CC effects in other neurotransmitter systems. Nevertheless, our study reinforces the hypothesis that CC could be used, after further research, as a new pharmaceutical formulation and a promising alternative for epilepsy treatment, since it showed anticonvulsant effects.

Cyane-carvone, a synthetic derivative of carvone, inhibits inflammatory response by reducing cytokine production and oxidative stress and shows antinociceptive effect in mice.

Cyane-carvone (CC) was studied to elucidate its anti-inflammatory, antinociceptive, and antioxidant effects in Mus musculus. Anti-inflammatory (bradykinin, histamine, prostaglandin E2, serotonin, and carrageenan) and antinociceptive (acetic acid and formalin) models were utilized. Myeloperoxidase activity, interleukin (IL)-1ß, tumor necrosis factor alpha (TNF-α), and glutathione (GSH) levels were evaluated. Analysis of variance followed by Student-Newman-Keuls' test was done. Results were compared with control groups (significantly when p < 0.05). In bradykinin, histamine, prostaglandin E2, and serotonin tests, 75 mg/kg CC decreased significantly paw edema (t = 30, 60, 90, and/or 120 min). In carrageenan test, 50 and 75 mg/kg CC (t = 3 h and t = 4 h) and 25 mg/kg CC (t = 4 h) decreased significantly paw edema. CC (75 mg/kg) inhibited significantly mieloperoxidase activity and decreased IL-1ß and TNF-α, and all doses increased GSH levels. CC (75 mg/kg) decreased significantly the number of contortions of animals and time of licking (phase 2). CC showed anti-inflammatory, antinociceptive, and antioxidant effects in mice.

Larvicidal activity of Mentha x villosa Hudson essential oil, rotundifolone and derivatives.

The aim of this study was to evaluate the larvicidal activity of Mentha x villosa essential oil (MVEO) and its major constituent, rotundifolone, against larvae of Aedes aegypti. Additionally, a set of 15 analogues of the rotundifolone were evaluated to identify the molecular characteristics which contribute to the larvicidal effect. The results from the present study showed that the MVEO exhibited outstanding toxic effects against Ae. aegypti larvae (LC50=45.0ppm). Rotundifolone exhibited reasonable larvicidal activity (LC50=62.5ppm). With respect to comparative study of rotundifolone and its analogues, all tested compounds were less potent than rotundifolone, except (-)-limonene. In general, replacement of C-C double bonds by epoxides groups decreases the larvicidal potency. The presence of α,ß-unsaturated carbonyls contributes to the larvicidal toxicity. The addition of hydroxyl groups in the chemical structure resulted in less potent compounds. Furthermore, the enantioselectivity seems to play an important role for the larvicidal toxicity.

Anticonvulsant and antioxidant effects of cyano-carvone and its action on acetylcholinesterase activity in mice hippocampus.

The anticonvulsant effect of cyano-carvone, a monoterpene monocyclic, was investigated in epilepsy model induced by pilocarpine. Cyano-carvone at doses of 25, 50 or 75 mg/kg promoted a reduction of 16.7, 33 and 66.7%, respectively, against pilocarpine-induced seizures, and it was efficacious in increasing both the latency to first seizures and the survival percentage, resulting in 33.3, 67 and 91.7% of protection against death induced by seizures, respectively (P < 0.05). The reference drug atropine (25 mg/kg) also produced a significant protection (100%). Its monoterpene, at 25, 50 and 75 mg/kg, was also capable to increase the latency for installation of status epilepticus induced by pilocarpine, and presented a significant protection against lipid peroxidation and nitrite formation in mice hippocampus (P < 0.05). In addition, it was observed that the cyano-carvone pretreatment increased the acetylcholinesterase activity in mice hippocampus after pilocarpine-induced seizures. The present results clearly indicate the anticonvulsant ability of cyano-carvone, which can be, at least in part, explained by the increased activity of the acetylcholinesterase enzyme. Our data suggest that the action mechanism can also be due to a direct activation of the antioxidant enzymes that could be associated with a reduction observed in oxidative stress in mice hippocampus, probably involving an inhibition of free radical production.