Anti-inflammatory activity of 1.8-cineol (eucalyptol) in bronchial asthma: a double-blind placebo-controlled trial

The Efficacy of Topical Basil Essential Oil on Relieving Migraine Headaches: A Randomized Triple-Blind Study

OBJECTIVE

Complementary therapies have been increasingly used for the prevention and treatment of migraine so that there is a need for studies in this setting. This study sought to determine the effects of basil essential oil on the severity and frequency of migraine attack headaches.

METHODS

A triple-blind clinical trial study was performed on 144 patients diagnosed with migraine. Patients were randomly allocated by a stratified method to four groups of 36 titled basil essential oil 2, 4, 6%, and placebo groups. Medications were used topically every 8 h for 3 successive months. In addition, each individual received 325 mg of acetaminophen every 12 h. The severity and frequency of migraine attacks were measured prior to the study, at weeks 2, 4, 8, and 12. The visual analog scale was used to measure pain intensity. The marginal model and generalized estimation equations were used to compare changes in the intensity and frequency of pain over time.

RESULTS

The interaction of the dose and time factors was significant on both pain intensity (p < 0.001) and frequency of attack (p < 0.001). The odds ratio of higher pain intensity and rate ratio of higher frequency of attack in the intervention groups compared to the placebo group were decreased over the study time.

CONCLUSION

Time lapse and higher doses of basil essential oil would reduce both the intensity and frequency of migraine attacks.

An unsuspected and unrecognized cause of medication overuse headache in a chronic migraineur—essential oil-related medication overuse headache: A case report

Essential oils are widely used by people for common ailments like headache and backache. We report a case of chronic daily headache in an adolescent migraineur refractory to most antimigraine drugs secondary to topical application of essential oils containing camphor and eucalyptus. A 14-year-old boy presented with chronic daily headache of 1-year duration, refractory to four antimigraine drugs including valproate and topiramate. He was daily applying a balm called Amruthanjan (10% camphor and 14.5% eucalyptus) on his forehead to relieve headache. Patient had complete relief of headache in 2 weeks after stopping the balm application. All his antimigraine drugs were tapered and stopped over a period of 3 months. At 1-year follow-up, he is headache free. Brain-stimulant essential oils of camphor and eucalyptus may be an important unrecognized cause of medication overuse headache.

Rapid plant regeneration in industrially important Curcuma zedoaria revealing genetic and biochemical fidelity of the regenerants

The present investigation was carried out to establish an efficient and reproducible micropropagation protocol for the production of morphologically, genetically and chemically uniform plants of Curcuma zedoaria. Axillary bud explants of C. zedoaria were inoculated into MS basal medium supplemented with various combinations and concentrations of 6-benzyladenine (2.2-22.2 µM, BA), kinetin (2.3-23.2 µM, Kin), indole-3-acetic acid (2.9-11.4 µM, IAA), α-naphthalene acetic acid (2.7-10.2 µM, NAA) and adenine sulphate (33.9-203.6 µM, Ads). Almost 95% of rhizome buds sprouted on MS medium supplemented with 13.3 μM BA, 5.7 μM IAA and 63.9 μM Ads giving rise to an average of 12.89 ± 0.02 shoots within 6 weeks. However, the maximum number of roots (25.8 ± 0.07 roots per explant) was obtained on half strength MS medium supplemented with 7.4 µM of IBA after 4 weeks of inoculation. Morphological characteristics were similar in both conventionally propagated and micropropagated plants. Additionally, genetic homogeneity of in vitro plants was further confirmed through ISSR and flow cytometry analysis. A total of 27 ISSR primers were screened, out of which 13 ISSR primers generated 58 monomorphic and reproducible bands thereby confirming the genetic uniformity of obtained plants. The mean 2C DNA content of the mother plant (2.96 pg) was similar to that of in vitro derived plants (3.07 pg). Gas chromatography-mass spectrometry (GC-MS) analysis showed similarity in the qualitative profile of chemical constituents of essential oil and high-performance liquid chromatography analysis revealed no significant differences in curcumin content in the tissue culture regenerants and mother plants of C. zedoaria. Therefore, the present micropropagation protocol could be effectively employed to generate true to type plantlets of C. zedoaria.

Immunomodulatory and anti-inflammatory effects of hydro-ethanolic extract of Ocimum basilicum leaves and its effect on lung pathological changes in an ovalbumin-induced rat model of asthma

BACKGROUND

Ocimum species (Lamiaceae) has been traditionally used for treatment of upper respiratory tract infections, bronchitis, coughs, sore throat, and wound healing. The Immunomodulatory and anti-inflammatory effects of hydro-ethanolic extract of Ocimum basilicum (O. basilicum) leaves was examined in ovalbumin sensitized animals.

METHODS

Wistar rats were divided to six groups; non-sensitized, sensitized to ovalbumin, sensitized and treated with dexamethasone (1.25 μg/mL), and O. basilicum extract (0.75, 1.50 and 3.00 mg/mL) in drinking water for 21 days. The levels of interleukin 4 (IL-4), interferon gamma (IFN-γ), IFN-γ/IL-4 ratio, immunoglobulin E (IgE), phospholipase A2 (PLA2) and total protein (TP) in BALF, and lung pathological changes were examined.

RESULTS

A significant increase in IL-4, IgE, PLA2 and TP levels, all lung pathological indices as well as significant decrease in IFN-γ/IL-4 ratio was seen in the asthmatic compared to the control rats (P < 0.05 to P < 0.001). Treatment with O. basilicum extract resulted in decreased IL-4, IgE, PLA2 and TP levels, but increased IFN-γ/IL-4 ratio compared to untreated sensitized rats (P < 0.01 to P < 0.001). The plant significantly improved the pathological changes of sensitized rats (P < 0.05 to P < 0.01). The improvement effects of higher concentrations of the O. basilicum extract were significantly more than those of dexamethasone (P < 0.05 to P < 0.001).

CONCLUSION

The improvement effects of O. basilicum on pathological changes, immunological and inflammatory markers in sensitized rats comparable or even more potent than dexamethasone suggests the therapeutic potential of the plant in asthma.

A novel self-nanoemulsifying drug delivery system for curcumin used in the treatment of wound healing and inflammation

The main objective of this study was to develop and evaluate self-nanoemulsifying drug delivery system (SNEDDS) of curcumin (Cur) to enhance their solubility as well as improve skin permeation; and evaluate wound healing potential of Cur via SNEDDS in comparison with standards pure eucalyptus oil-SNEDDS (Euc-SNEDDS), pure curcumin suspension (Cur-S), and standard fusidic acid followed by their anti-inflammatory action. Curcumin-loaded different SNEDDS formulations were formulated through aqueous phase titration method and the zones of SNEDDS were recognized by the construction of phase diagrams. Eucalyptus oil, Tween 80 (surfactant), and Transcutol HP (co-surfactant) were selected on the basis of their solubility and highest nanoemulsion region. Characterization of thermodynamic stability for Cur-loaded SNEDDS was evaluated by its globule size, zeta potential, polydispersity index, viscosity, % transmittance, refractive index, and surface morphology. Cur-SNEDDS (Cur-SN4) was optimized and selected on the basis of their excellent physicochemical parameters for in vivo activity. The particle size (59.56 ± 0.94 nm), % transmittance (99.08 ± 0.07%), and PDI (0.207 ± 0.011 were observed for optimized Cur-SNEDDS. TEM and SEM showed their smooth and spherical shape of the morphological characterization with zeta potential (- 21.41 ± 0.89), refractive index (1.341 ± 0.06), and viscosity (11.64 ± 1.26 cp) for optimized Cur-SNEDDS. Finally, optimized Cur-SNEDDS was used to enhance skin permeation with improvement in the solubility of Cur. However, optimized Cur-SNEDDS showed significant wound healing activity as compared with pure eucalyptus oil and Cur-S on topical application. Optimized Cur-SNEDDS showed healing of wound as compared to standard fusidic acid. Optimized Cur-SNEDDS exhibited no signs of inflammatory cells on the histopathological studies of treated rats which were recommended the safety and non-toxicity of Cur-SNEDDS. Newly developed Cur-SNEDDS could be successfully used to enhance Cur-solubility and skin permeation, as well as suggested a potential role of Cur-SNEDDS for better improvement of wound healing activity followed by anti-inflammatory action of Cur via topical application.

Eucalyptus Sideroxylon Bark Anti-inflammatory Potential, Its UPLC-PDA-ESI-qTOF-MS Profiling, and Isolation of a New Phloroglucinol

Eucalyptus barks contain complex biomass of constituents with considerable chemical and structural diversity. Reports about Eucalyptus sideroxylon Cunn. ex Woolls bark composition and biological activities are limited. Non-targeted metabolomic analysis via ultra-performance liquid chromatography-quadrupole-time-of-flight-photodiode array-mass spectrometry (UPLC-qTOF-PDA-MS) enabled first-time detection of 41 secondary metabolites of which 31 were identified including; 6 flavonoids, 4 ellagic acid derivatives, 8 triterpenes, 10 fatty acids and 3 miscellaneous. The isolation and structure elucidation of methyl morolate, β-sitosterol, syringaldeyhde and 7'-deoxyguajavadial A were reported. The bark methylene chloride: methanol (8:2) extract demonstrated significant (P < 0.01) in vitro anti-inflammatory activity through membrane stabilization, protein denaturation inhibition, anti-lipoxygenase, and proteinase inhibition assays. The strongest anti-inflammatory activity was via membrane stabilization (34.4%) as compared to diclofenac sodium (26%) at the same concentration (125 μg/mL). Our study represents the sole complete map for E. sideroxylon bark components and represents it as new anti-inflammatory drug.

Accelerated infected wound healing by topical application of encapsulated Rosemary essential oil into nanostructured lipid carriers

The pathogenic bacteria delay wound healing due to their interaction in the wound area. This study is aimed to evaluate the efficiency of topical rosemary essential oil (REO) loaded into the nanostructured lipid carriers (NLCs) on in vitro antibacterial activity and in vivo infected wound healing process in the animal model. REO-NLCs morphology, size and in vitro antibacterial activity were done. Two circular full-thickness wound (each 6 mm) were made on the back of each mouse and each wound was infected with a solution containing 10⁷ CFU Staphylococcus aureus and Pseudomonas aeruginosa. Animals were divided into four groups including control, Mupirocin^® and two treated groups with a gel containing REO and REO-NLCs. For this purpose, tissue bacterial count, histological assessment, serum level of IL-3, IL-10, VEGF and SDF-1α were evaluated. REO-NLCs showed antibacterial activity against Staphylococcus epidermidis, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Pseudomonas aeruginosa. Moreover, REO-NLCs could reduce the rate of tissue bacterial colonization and wound size, while they increased the vascularization, fibroblast infiltration, re-epithelialization, collagen production, IL-3, IL-10, VEGF and SDF-1α serum levels. Our finding revealed the REO-NLCs have antibacterial properties and accelerated infected wound healing, and so that confirming their potential clinical uses for the treatment of infected wounds.

Medicinal Properties of Cannabinoids, Terpenes, and Flavonoids in Cannabis, and Benefits in Migraine, Headache, and Pain: An Update on Current Evidence and Cannabis Science

BACKGROUND

Comprehensive literature reviews of historical perspectives and evidence supporting cannabis/cannabinoids in the treatment of pain, including migraine and headache, with associated neurobiological mechanisms of pain modulation have been well described. Most of the existing literature reports on the cannabinoids Δ⁹ -tetrahydrocannabinol (THC) and cannabidiol (CBD), or cannabis in general. There are many cannabis strains that vary widely in the composition of cannabinoids, terpenes, flavonoids, and other compounds. These components work synergistically to produce wide variations in benefits, side effects, and strain characteristics. Knowledge of the individual medicinal properties of the cannabinoids, terpenes, and flavonoids is necessary to cross-breed strains to obtain optimal standardized synergistic compositions. This will enable targeting individual symptoms and/or diseases, including migraine, headache, and pain.

OBJECTIVE

Review the medical literature for the use of cannabis/cannabinoids in the treatment of migraine, headache, facial pain, and other chronic pain syndromes, and for supporting evidence of a potential role in combatting the opioid epidemic. Review the medical literature involving major and minor cannabinoids, primary and secondary terpenes, and flavonoids that underlie the synergistic entourage effects of cannabis. Summarize the individual medicinal benefits of these substances, including analgesic and anti-inflammatory properties.

CONCLUSION

There is accumulating evidence for various therapeutic benefits of cannabis/cannabinoids, especially in the treatment of pain, which may also apply to the treatment of migraine and headache. There is also supporting evidence that cannabis may assist in opioid detoxification and weaning, thus making it a potential weapon in battling the opioid epidemic. Cannabis science is a rapidly evolving medical sector and industry with increasingly regulated production standards. Further research is anticipated to optimize breeding of strain-specific synergistic ratios of cannabinoids, terpenes, and other phytochemicals for predictable user effects, characteristics, and improved symptom and disease-targeted therapies.

Volatiles Profile of the Floral Organs of a New Hybrid Cymbidium, 'Sunny Bell' Using Headspace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry Analysis

Cymbidium is one of the most important genera of flowering plants in the Orchidaceae family, and comprises a wide variety of beautiful and colorful species. Among these, only a few species possess floral scents and flavors. In order to increase the availability of a new Cymbidum hybrid, “Sunny Bell”, this study investigated the volatile floral scents. Volatiles of the floral organs of the new Cymbidium hybrid, “Sunny Bell”, at the full-flowering stage were characterized with headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis. A divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) fiber gave the best extraction for volatile components. Twenty-three components were identified as the main volatiles for the floral organs of the new Cymbidium hybrid, “Sunny Bell” at the full-flowering stage; twelve compounds in the column, sixteen compounds in the labellum, eleven compounds in the sepals, and nine compounds in the petals were identified. Terpenes are the major source of floral scents in this plant. As a result of GC-MS analysis, the most abundant compound was linalool (69–80%) followed by α-pinene (3–27%), 4,8-dimethyl-1,3,7-nonatriene (5–18%), eucalyptol (6–16%), and 2,6-dimethylnonane (2–16%). The main components were identified as monoterpenes in the petals and sepals, and as monoterpenes and aliphatics in the column and labellum. The results of this study provide a basis for breeding Cymbidium cultivars which exhibit desirable floral scents.

Essential oils, asthma, thunderstorms, and plant gases: a prospective study of respiratory response to ambient biogenic volatile organic compounds (BVOCs)

Purpose: Prevailing opinion is that wind-pollinated plants affect asthma negatively and that insect- pollinated ones do not. "Thunderstorm" asthma, too, is attributed to bursting grass pollens. Additional biogenic volatile organic compounds (BVOCs) are identified here. Essential oils' BVOCs are inhaled from plants, oil diffusers, candles, room "fresheners", perfumes, and hygiene products. Claims of BVOC "safety" for sensitive respiratory systems are questioned. Methods: Fourteen volunteers, of mixed-age and gender, with seasonal asthma recorded peak expiratory flow (PEF) and 11 symptom scores. BVOCs were collected on Tenax tubes from ambient air in autumn and spring, as were live flower emissions, before and after a thunderstorm. Gas chromatography-mass spectrometry analysis identified frequently occurring BVOCs. Air spora, meteorological, outdoor air pollution variables, and BVOCs predict respiratory symptoms in univariate linear regression models, seasonally. Results: Increased pinene, camphor, linalool, linalyl acetate, benzaldehyde, and benzoic acid predict respiratory symptoms, including reduced PEF, and increased nasal congestion; day length, atmospheric pressure and temperature predict symptoms in both seasons, differently; other variables predict a range of symptoms (0.0001≤p≤0.05). Thunder predicts different BVOC emissions in spring, compared to autumn (p≤0.05). An uncut Grevillea flower emitted linalool and hexenal before a storm; the latter is also emitted from cut grass. Increased nitrogen oxides and pinene in autumn may combine to form harmful oxidation products. Conclusion: This research supports BVOCs as contributors to seasonal asthma and allergic rhinitis, and "thunderstorm" asthma. Pinene emissions from Myrtaceae species (Eucalyptus, Melaleuca, Leptospermum, Callistemon), Brassicaceae (canola), and conifers, worldwide, may induce respiratory inflammation and maintain it, by inhibiting eosinophilic apoptosis. Widely used essential oil products containing BVOCs, like linalool, are associated here with respiratory symptoms. Lagged responses suggest that users' cognitive associations between exposure and response are unlikely, increasing potential for impaired health for vulnerable children.

Eucalyptus globulus (Labill.) : un arbre à essence aux mille vertus

Eucalyptus globulus (Labill.) [Myrtaceae] est originaire de Tasmanie en Australie et pousse surtout dans les régions chaudes. L’eucalyptus commun ou gommier bleu est un arbre sempervirent qui peut croître jusqu’à 30–55 m de haut. Ses feuilles sont la principale source de son huile essentielle (HE). Utilisée pour ses vertus médicinales, notamment antitussives et expectorantes, elle n’en a pas moins des propriétés fébrifuges, toniques, astringentes, antiseptiques, hémostatiques et vermifuges. Parmi ces composés, le 1,8- cinéole ou eucalyptol (50 à 80 %) est sans doute le plus connu, car c’est un expectorant qui peut soulager la toux et lutter contre les problèmes des voies respiratoires. En outre, pinène, limonène et au moins 250 autres composés dont citronellal, cryptone, pipéritone viendront étoffer la liste des nombreux composés aux vertus médicinales de l’eucalyptus. En phytoaromathérapie, l’essence d’eucalyptus officinal pourra trouver une place comme désinfectant atmosphérique en milieu hospitalier afin de lutter contre les infections nosocomiales et les contaminations aéroportées. Elle aide aussi à lutter contre l’asthme et peut être utilisée pour la désinfection de plaies. Notre travail se veut une revue de la littérature des propriétés thérapeutiques, préventive et/ou curative, de cet arbre à parfum et les potentiels utilisations de son HE en phytoaromathérapie anti-infectieuse ou encore comme ingrédient actif dans les préparations pharmaceutiques.

Inadequate assessment of adherence to maintenance medication leads to loss of power and increased costs in trials of severe asthma therapy: results from a systematic literature review and modelling study

Adherence to inhaled maintenance therapy in severe asthma is rarely adequately assessed, and its influence on trial outcomes is unknown. We systematically determined how adherence to maintenance therapy is assessed in clinical trials of "add-on" therapy for severe asthma. We model the improvement in trial power that could be achieved by accurately assessing adherence.A systematic search of six major databases identified randomised trials of add-on therapy for severe asthma. The relationship between measuring adherence and study outcomes was assessed. An estimate of potential improvements in statistical power and sample size was derived using digitally recorded adherence trial data.87 randomised controlled trials enrolling 22 173 participants were included. Adherence assessment was not reported in 67 trials (n=13 931, 63%). Studies that reported adherence used a range of self-report and subjective methods. None of the studies employed an objective assessment of adherence. Studies that reported adherence had a significantly reduced pooled variance in forced expiratory volume in 1 s (FEV₁) compared to those that did not assess adherence: s²=0.144 L² versus s²=0.168 L², p<0.0001. Power to detect clinically relevant changes in FEV₁ was significantly higher in trials that reported adherence assessment (mean power achieved 59% versus 49%). Modelling suggests that up to 50% of variance in FEV₁ outcomes is attributable to undetected variations in adherence. Controlling for such variations could potentially halve the required sample size.Few trials of add-on therapy monitor adherence to maintenance inhaled therapy, resulting in a greater variance in trial outcomes and inadequate power for determining efficacy.

Antimicrobial, Cytotoxic, and Anti-Inflammatory Activities of Pimenta dioica and Rosmarinus officinalis Essential Oils

Essential oils (EOs) are natural products composed of a mixture of volatile and aromatic compounds extracted from different parts of plants that have shown antimicrobial activities against pathogens. In this study, EOs extracted from Pimenta dioica (Myrtaceae) and Rosmarinus officinalis (Lamiaceae) were assessed for their antimicrobial activities using a panel of pathogenic Gram-positive, Gram-negative, and fungal strains. The antimicrobial activity was measured by the minimal inhibitory concentration required for the growth inhibition of the microorganisms. The cytotoxicity of the EOs was tested ex vivo using the model of human-derived macrophage THP-1 cells. In addition, an inflammatory response was evaluated using the anti-inflammatory cytokine IL-10 and the proinflammatory cytokines IL-6 and TNF-α. Results showed that both EOs had antimicrobial activity and different pathogens were exposed to concentrations ranging between 600 and 2000 μg/mL. In addition, the EOs showed no inflammatory activity when exposed to human macrophages, but a potent anti-inflammatory activity was measured when the oil from Rosmarinus officinalis was exposed to macrophages. This study demonstrates that the use of EOs is an effective alternative for pathogenic bacterial and fungal control, alone or in combination with antibiotic therapy. Moreover, the oil extracted from Rosmarinus officinalis could be used as potent anti-inflammatory agent.

Rosmarinus officinalis essential oil: A review of its phytochemistry, anti-inflammatory activity, and mechanisms of action involved

ETHNOPHARMACOLOGICAL RELEVANCE

Plant species Rosmarinus officinalis L. (Lamiaceae; Synonyms: Salvia rosmarinus Schleid. and Rosmarinus angustifolius Mill.) is a herb widely used worldwide. In local and traditional medicine, its used for inflammation-related diseases. Currently, studies report anti-inflammatory activity in its essential oil (EORO). However, to better understand EORO's anti-inflammatory activity its necessary to understand its phytochemistry and the signaling pathways affected by it. Hence, this review aimed to describe EORO phytochemical profile, ethnopharmacological uses, some biological activities of EORO will be described but emphasizing its anti-inflammatory potential and possible mechanisms of action involved.

MATERIALS AND METHODS

The research was performed using the databases Medline, Embase, BVS Regional Portal, Science Direct, CAPES Journals, and Scopus; using the keywords "Rosmarinus officinalis", "anti-inflammatory" and "essential oil". Additional information was gathered from related textbooks, reviews, and documents.

RESULTS AND DISCUSSION

Until now about 150 chemical compounds were identified in EORO samples, more frequently reported molecules were 1,8-cineole, α-pinene, and camphor. Studies suggest that the anti-inflammatory activity of EORO occur mainly through inhibition of NF-κB transcription and suppression of arachidonic acid cascade. Its antioxidant activity also aids by preventing injury caused by the reactive species of inflammation; its smooth muscle relaxant activity contributes to ameliorating airway inflammatory diseases. Lastly, toxicity assessments indicate low toxicity to EORO.

CONCLUSIONS

Current evidence indicates anti-inflammatory activity in EORO, supporting its ethnopharmacological uses in inflammatory-related diseases, and potential future applications. However, although considerable acute inflammatory models were tested, more chronic inflammatory models are needed; clinical studies are still absent, this may be due to the high doses needed for essential oils to exert pharmacological effects, but recent studies show this issue can be bypassed using the oil formulated as nanoemulsions to improve its bioavailability.

Systems Pharmacology Dissection of Multi-Scale Mechanisms of Action of Huo-Xiang-Zheng-Qi Formula for the Treatment of Gastrointestinal Diseases

Multi-components Traditional Chinese Medicine (TCM) treats various complex diseases (multi-etiologies and multi-symptoms) via herbs interactions to exert curative efficacy with less adverse effects. However, the ancient Chinese compatibility theory of herbs formula still remains ambiguous. Presently, this combination principle is dissected through a systems pharmacology study on the mechanism of action of a representative TCM formula, Huo-xiang-zheng-qi (HXZQ) prescription, on the treatment of functional dyspepsia (FD), a chronic or recurrent clinical disorder of digestive system, as typical gastrointestinal (GI) diseases which burden human physical and mental health heavily and widely. In approach, a systems pharmacology platform which incorporates the pharmacokinetic and pharmaco-dynamics evaluation, target fishing and network pharmacological analyses is employed. As a result, 132 chemicals and 48 proteins are identified as active compounds and FD-related targets, and the mechanism of HXZQ formula for the treatment of GI diseases is based on its three function modules of anti-inflammation, immune protection and gastrointestinal motility regulation mainly through four, i.e., PIK-AKT, JAK-STAT, Toll-like as well as Calcium signaling pathways. In addition, HXZQ formula conforms to the ancient compatibility rule of "Jun-Chen-Zuo-Shi" due to the different, while cooperative roles that herbs possess, specifically, the direct FD curative effects of GHX (serving as Jun drug), the anti-bacterial efficacy and major accompanying symptoms-reliving bioactivities of ZS and BZ (as Chen), the detoxication and ADME regulation capacities of GC (as Shi), as well as the minor symptoms-treating efficacy of the rest 7 herbs (as Zuo). This work not only provides an insight of the therapeutic mechanism of TCMs on treating GI diseases from a multi-scale perspective, but also may offer an efficient way for drug discovery and development from herbal medicine as complementary drugs.

Neuroprotective Strategies for Neurological Disorders by Natural Products: An update

Nature has bestowed mankind with surplus resources (natural products) on land and water. Natural products have a significant role in the prevention of disease and boosting of health in humans and animals. These natural products have been experimentally documented to possess various biological properties such as antioxidant, anti-inflammatory and anti-apoptotic activities. In vitro and in vivo studies have further established the usefulness of natural products in various preclinical models of neurodegenerative disorders. Natural products include phytoconstituents, like polyphenolic antioxidants, found in herbs, fruits, nuts, vegetables and also in marine and freshwater flora. These phytoconstituents may potentially suppress neurodegeneration and improve memory as well as cognitive functions of the brain. Also, they are known to play a pivotal role in the prevention and cure of different neurodegenerative diseases, such as Alzheimer's disease, epilepsy, Parkinson's disease and other neuronal disorders. The large-scale neuro-pharmacological activities of natural products have been documented due to the result of either the inhibition of inflammatory processes, or the up-regulation of various cell survival proteins or a combination of both. Due to the scarcity of human studies on neuroprotective effects of natural products, this review focuses on the various established activities of natural products in in vitro and in vivo preclinical models, and their potential neuro-therapeutic applications using the available knowledge in the literature.

1,8-cineol inhibits the Wnt/β-catenin signaling pathway through GSK-3 dephosphorylation in nasal polyps of chronic rhinosinusitis patients

Chronic rhinosinusitis with nasal polyps (CRSwNP) represents a benign neoplasm of the nasal mucosa, which leads to a decreased breathing capacity and reduced olfaction. The pathogenesis and the molecular mechanisms driving nasal polyps are not very well known. GSK-3 is involved in the regulation of various biosynthetic pathways and various kinases are able to regulate the GSK-3. Therefore, we investigated the effect of the monoterpene oxide 1,8-cineol on the regulation of the Wnt/β-catenin signaling pathway with its central regulator protein GSK-3 in vitro. We determined GSK-3 expression and phosphorylation as well as the expression of negative regulators (Akt and SGK) and downstream activation of β-catenin in nasal polyps of patients with CRSwNP by immunohistochemistry and Western blot experiments. In this study we demonstrated for the first time, that 1,8-cineol acts as a potential inhibitor of the Wnt/β-catenin signaling pathway, by affecting the inhibitory phosphorylation of GSK-3, which is the key regulator of the β-catenin activity. Our data provide novel insights in the regulatory networks responsible for the progression of CRSwNP and furthermore represent a new mechanism of 1,8-cineol activity, which may lead to novel treatment approaches to this natural drug.

Increased phosphorylation of eNOS in nasal polyps of chronic rhinosinusitis patients can be diminished by 1,8-cineol

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a significant health problem, but the pathogenesis remains unclear to date. Nitric oxide (NO) has known airway modulating functions. Therefore, we investigated nitric oxide production to determine the role of eNOS in nasal polyps, with additional analysis of the effect of the monoterpene oxide 1,8-cineol on the possible regulation of eNOS signaling and thus NO production.

METHODS

We determined eNOS expression, as well as regulatory and effector proteins like NOSTRIN and CASP8, using whole genome microarray, immunohistochemistry and western blot. To evaluate the influence of 1,8-cineol on eNOS signaling, we examined tissue samples of nasal polyps of patients with CRSwNP incubated with 100 μM 1,8-cineol using quantitative real-time PCR, western blot and phosphorylation arrays.

RESULTS

Microarray analysis revealed an increased gene expression of eNOS (1.40-fold) as well as a decreased gene expression of NOSTRIN (0.53-fold) and CASP8 (0.44-fold) in nasal polyps. At the protein level, we detected 2.3-fold higher protein expression of eNOS and significant higher phosphorylation levels of eNOS in nasal polyps (19.7-fold, p ≤ 0.001) compared to inferior turbinates. Additionally, 1,8-cineol did not influence NOSTRIN and CASP8, but decreased the eNOS phosphorylation significantly (p ≤ 0.05).

DISCUSSION

Our study demonstrated for the first time that nasal polyps exhibit an increased phosphorylation of eNOS, which could be important for vascular permeability and the associated edema and elevated inflammation. Additionally, we detected that 1,8-cineol affects the eNOS phosphorylation significantly and thus its activation. This could be important to handle the elevated inflammation and edema formation by regulating the vascular permeability.

Plant Secondary Metabolite-Derived Polymers: A Potential Approach to Develop Antimicrobial Films

The persistent issue of bacterial and fungal colonization of artificial implantable materials and the decreasing efficacy of conventional systemic antibiotics used to treat implant-associated infections has led to the development of a wide range of antifouling and antibacterial strategies. This article reviews one such strategy where inherently biologically active renewable resources, i.e., plant secondary metabolites (PSMs) and their naturally occurring combinations (i.e., essential oils) are used for surface functionalization and synthesis of polymer thin films. With a distinct mode of antibacterial activity, broad spectrum of action, and diversity of available chemistries, plant secondary metabolites present an attractive alternative to conventional antibiotics. However, their conversion from liquid to solid phase without a significant loss of activity is not trivial. Using selected examples, this article shows how plasma techniques provide a sufficiently flexible and chemically reactive environment to enable the synthesis of biologically-active polymer coatings from volatile renewable resources.

Genetic and Chemical Diversity in Perovskia abrotanoides Kar. (Lamiaceae) Populations Based on ISSRs Markers and Essential Oils Profile

Genetic and the essential oil composition variability among twelve Perovskia abrotanoides populations (PAbPs) growing wild in Iran were assessed by ISSR markers, GC-FID and GC/MS, respectively. Nine selected ISSR primers produced 119 discernible bands, of them 96 (80.7%) being polymorphic. Genetic similarity values among populations ranged between 0.07 and 0.79 which indicated a high level of genetic variation. Polymorphic information content, resolving power and marker index generated by ISSR primers were, 0.31, 6.14, and 3.32, respectively. UPGMA grouped PAbPs into four main clusters. Altogether, 38 chemical compounds were identified in the oils, and a relatively high variation in their contents was found. Camphor (11.9 - 27.5%), 1,8-cineole (11.3 - 21.3%), α-bisabolol (0.0 - 13.1%), α-pinene (5.9 - 10.8%), and δ-3-carene (0.1 - 10.5%) were the major compounds. Oxygenated monoterpenes (32.1 - 35.8%) and monoterpene hydrocarbons (25.7 - 30.4%) were the main groups of compounds in the oils studied. Cluster analysis and principal-component analysis were used to characterize the samples according to oil components. Four main chemotypes were found to be Chemotype I (camphor/1,8-cineol), Chemotype II (1,8-cineole/camphor), Chemotype III (camphor/1,8-cineol/α-bisabolol), and Chemotype IV (camphor/δ-3-carene/α-bisabolol). The information, provided here on P. abrotanoides populations, will be useful to introduce this plant into agricultural systems.

Anti-inflammatory activity of nanoemulsions of essential oil from Rosmarinus officinalis L.: in vitro and in zebrafish studies

The essential oil from Rosmarinus officinalis L. (OERO) has bioactive compounds with anti-inflammatory activity. The objective of this study was to evaluate the anti-inflammatory potency of nanoemulsions containing essential oil of Rosmarinus officinalis L. (NOERO, NECHA, NECULT, and NECOM) in vitro and in vivo. This study was accomplished in a quantitative format through tests with diphenyl picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), cellular antioxidant activity (CCA), determination of nitric oxide production, cellular viability and anti-inflammatory activity in zebrafish. OERO's were submitted to the analysis-coupled gas chromatography-mass spectrometry (GC-MS), which highlighted 1,8-cineol and camphor as major compounds. NOEROs were obtained by a low-energy method and presenting the medium size smaller than 200 nm. The efficiency of encapsulation by spectrometry and gas chromatographic analysis was 67.61 and 75.38%, respectively. In the CCA assay, all of the samples presented percentage values of inhibition similar to the quercetin pattern, indicating antioxidant activity. In the test for determination of NO·, all of the samples inhibited the production of NO· when compared to LPS, and NOEROS were more effective than OEROS to 5 µg/mL. In the cell viability assay, the cells remained viable after contact with the samples, demonstrating an absence of cytotoxicity. This study showed that all nanoemulsions (NECHA, NECULT, and NECOM) showed no toxicity to macrophages, besides demonstrating antioxidant activity and potentiation of the essential oil effect in the proliferation of viable fibroblasts. Nanoemulsions has also shown the ability to potentiate the anti-inflammatory action of essential oils by exerting immunomodulatory activity by inhibiting the production of the pro-inflammatory mediator nitric oxide. The results obtained with NECHA in zebrafish confirm the hypothesis that prominent terpenic compounds, alpha-pinene, 1,8-cineole, and camphor, became more available at the target sites, inhibiting the inflammatory process in this animal species.

Antitussive, antispasmodic, bronchodilating and cardiac inotropic effects of the essential oil from Blepharocalyx salicifolius leaves

ETHNOPHARMACOLOGY RELEVANCE

Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae) is a tree native to Argentina and Uruguay that grows and is cultivated along the riverside of the Rio de la Plata. The leaves of this plant species, locally known as "anacahuita" are used in South America to prepare infusions for the empiric treatment of cough and bronchospasm, as well as diarrhoea and other intestinal disorders. Although previous phytochemical studies have been performed with the essential oil extracted from Blepharocalyx salicifolius, pharmacological evidence supporting its traditional use is still lacking.

AIM OF THE STUDY

To experimentally evaluate the pharmacological properties of Blepharocalyx salicifolius based on its traditional use. The studies were performed with tincture (T-Bs) and essential oil (EO-Bs) prepared from its leaves, in isolated rat trachea, intestine and heart preparations.

METHODS

The ex-vivo effects of T-Bs and EO-Bs were evaluated with the agonists carbachol (CCh) and calcium chloride (Ca²⁺) in the contractile concentration-response curves (CRC) of the isolated intestine. The muscle relaxant effect of EO-Bs was evaluated in the isolated trachea and compared with the effect achieved with papaverine as a positive control. The T-Bs and EO-Bs cardiac effects were analysed by perfusion of an isolated rat heart before a period of ischemia/reperfusion (stunning model). The antitussive effect of both T-Bs and EO-Bs was evaluated in mice exposed to ammonia using codeine as a positive control.

RESULTS

Both T-Bs and EO-Bs induced a non-competitive inhibition of the CCh-CRC in the rat intestine, with IC₅₀ values of 170.3 ± 48.5µg T-Bs/mL (n = 6) and 5.9 ± 1.6µg EO-Bs/mL (n = 6), respectively. EO-Bs also inhibited non-competitively the Ca²⁺-CRC, with IC₅₀ value of 1.8 ± 0.3µg EO-Bs/mL (n = 8). A similar effect was obtained with the main active component of the EO-Bs 1,8-cineole. In isolated trachea, EO-Bs induced the relaxation of the CCh-contracted tissue (1.7 ± 0.2µg EO-Bs/mL, n = 11) up to a maximal relaxation that was 1.9 times higher than that of papaverine. In the isolated heart, EO-Bs induced a poor negative inotropic response, and did not improve the contractile and energetic recovery after ischemia and reperfusion. In the mouse cough model, EO-Bs (90mg/Kg) was as effective as codeine (30mg/Kg) in reducing cough frequency.

CONCLUSIONS

The results indicate that the preparations from Blepharocalyx salicifolius leaves were effective as central antitussive, bronchodilating and antispasmodic agents, suggestive of a mechanism associated with the inhibition of Ca²⁺ influx into smooth muscle. The EO-Bs displayed only a poor ability to reduce cardiac inotropism, and was devoid of any cardioprotective properties. Thus, the present study validates the traditional use of this South American plant for asthma, cough and bronchospasm, shedding new light into its potency and putative mechanism of action.

Spicae aetheroleum in uncomplicated acute bronchitis: a double-blind, randomised clinical trial

Background

The trial aimed to evaluate the efficacy and safety of Spicae aetheroleum (Spicae ae.), a phytomedicine obtained by steam distillation of the flowering tops of Lavandula latifolia, as compared to placebo in adult patients with acute bronchitis.

Methods

Patients with uncomplicated acute bronchitis (bronchitis severity score [BSS] ≥ 5 score points) were randomly assigned to treatment with Spicae ae. or placebo in a double-blind, parallel-group design. No additional treatment was admitted. The primary objective was the mean difference of a defined total BSS of 25% between the Spicae ae. and the placebo group after 7 days of full medication dose. Secondary endpoints included the BSS at day 10, additional signs and symptoms of bronchitis, quality of life (QoL) and safety.

Results

The mean decrease in BSS at day 7 and day 10 was significant with 4.79 vs. 3.20 (p < 0.005 for a 25% difference) and 6.47 vs. 4.32 (p < 0.009 for a 25% difference) score points respectively in the Spicae ae. (n = 119) vs. placebo group (n = 110). Accordingly, most additional signs and symptoms of acute bronchitis as well as the patients’ QoL improved significantly with Spicae ae. as compared to placebo. In all, 258 patients were eligible for safety analysis. The treatment with Spicae ae. was well tolerated; no serious adverse events occurred.

Conclusion

The defined objectives both for the primary and secondary endpoints have been met. The results of this study provide evidence that Spicae ae. is well tolerated, effective and superior to placebo in the symptomatic treatment of uncomplicated acute bronchitis in adult patients.

Investigation of Antibacterial 1,8-Cineole-Derived Thin Films Formed via Plasma-Enhanced Chemical Vapor Deposition

The need for low-fouling coatings for biomedical devices has prompted considerable interest in antibacterial compounds from natural and sustainable sources, such as essential oils. Herein, a tea tree oil-based precursor, 1,8-cineole, is used to fabricate antimicrobial films (denoted ppCin) by plasma-enhanced chemical vapor deposition. Film properties were comprehensively characterized using a variety of surface and bulk analytical tools, and the plasma gas phase is assessed using optical emission spectroscopy, which can be correlated to ppCin film properties. Notably, film wettability increases linearly with plasma pressure, yielding water contact angles ranging from ∼50° to ∼90°. X-ray photoelectron spectroscopy reveals less oxygen is incorporated at higher pressures, likely arising from the lower density of OH_(g) species. Further, we utilized H₂O_(v) plasma surface modification of the ppCin films to improve wettability and find this results in a substantial increase in surface oxygen content. To elucidate the role of film wettability and antibacterial properties, both as-deposited and H₂O_(v) plasma-modified films were exposed to Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using glass slides and hydrocarbon films deposited from 1,7-octadiene as positive controls. Overall, bacteria attach to a similar extent on all films, including controls, yet only essential oil-based films significantly prevent biofilm formation (4-7% coverage compared to ∼40% for controls).

Rapid extraction of Amomum tsao-ko essential oil and determination of its chemical composition, antioxidant and antimicrobial activities

A simple, green and efficient extraction method named modified-solvent free microwave extraction (M-SFME) was employed for the extraction of essential oils (EOs) from Amomun tsao-ko. The process of M-SFME was optimized with the prominent preponderance of such higher extraction yield (1.13%) than those of solvent free microwave extraction (SFME, 0.91%) and hydrodistillation (HD, 0.84%) under the optimal parameters. Thirty-four volatile substances representing 95.4% were identified. The IC₅₀ values of EOs determined by DPPH radical scavenging activity and β-carotene/linoleic acid bleaching assay were 5.27 and 0.63mg/ml. Furthermore, the EOs exhibited moderate to potent broad-spectrum antimicrobial activity against all tested strains including five gram-positive and two gram-negative bacteria (MIC: 2.94-5.86mg/ml). In general, M-SFME is a potential and desirable alternative for the extraction of EOs from aromatic herbs, and the EOs obtained from A. tsao-ko can be explored as a potent natural antimicrobial and antioxidant preservative ingredient in food industry from the technological and economical points of view.

Transient Receptor Potential Cation Channel Subfamily M Member 8 channels mediate the anti-inflammatory effects of eucalyptol

BACKGROUND AND PURPOSE

Eucalyptol (1,8-cineol), the major ingredient in the essential oil of eucalyptus leaves and other medicinal plants, has long been known for its anti-inflammatory properties. Eucalyptol interacts with the TRP cation channels among other targets, but it is unclear which of these mediates its anti-inflammatory effects.

EXPERIMENTAL APPROACH

Effects of eucalyptol were compared in wild-type and TRPM8 channel-deficient mice in two different models: footpad inflammation elicited by complete Freund's adjuvant (CFA) and pulmonary inflammation following administration of LPS. Oedema formation, behavioural inflammatory pain responses, leukocyte infiltration, enzyme activities and cytokine and chemokine levels were measured.

KEY RESULTS

In the CFA model, eucalyptol strongly attenuated oedema and mechanical allodynia and reduced levels of inflammatory cytokines (IL-1β, TNF-α and IL-6), effects comparable with those of ibuprofen. In the LPS model of pulmonary inflammation, eucalyptol treatment diminished leukocyte infiltration, myeloperoxidase activity and production of TNF-α, IL-1β, IFN-γ and IL-6. Genetic deletion of TRPM8 channels abolished the anti-inflammatory effects of eucalyptol in both models. Eucalyptol was at least sixfold more potent on human, than on mouse TRPM8 channels. A metabolite of eucalyptol, 2-hydroxy-1,8-cineol, also activated human TRPM8 channels.

CONCLUSION AND IMPLICATIONS

Among the pharmacological targets of eucalyptol, TRPM8 channels were essential for its anti-inflammatory effects in mice. Human TRPM8 channels are more sensitive to eucalyptol than rodent TRPM8 channels explaining the higher potency of eucalyptol in humans. Metabolites of eucalyptol could contribute to its anti-inflammatory effects. The development of more potent and selective TRPM8 agonists may yield novel anti-inflammatory agents.

Effect of 1.8-Cineole in Dermatophagoides pteronyssinus-Stimulated Bronchial Epithelial Cells and Mouse Model of Asthma

1.8-Cineole (eucalyptol) is a phytoncide, a volatile organic compound derived from plants. Phytoncides are known to have an anti-inflammatory effect. However, the effects of 1.8-cineole in house dust mite (HDM)-stimulated bronchial epithelial cells are poorly understood. The objective of this study was to assess the effect of 1.8-cineole in HDM-stimulated bronchial epithelial cells and in the HDM-induced murine asthma model. The purpose of the present study is to evaluate the anti-inflammatory effects and mechanism of 1.8-cineole action in HDM-induced airway inflammation. Human bronchial epithelial cells (HBECs) were cultured with Dermatophagoides pteronyssinus (Der p) and 1.8-cineole. Cytokine protein levels, phosphorylation of protein kinases, and intracellular Toll-like receptor 4 (TLR4) expressions were measured. In the murine model, BALB/C mice were sensitized with Der p and were exposed to Der p via intranasal route during the challenge period. 1.8-Cineole was given by inhalation 6 h before the each challenge. Treatment with 1.8-cineole inhibited the Der p-induced cytokine protein expression, phosphorylation of p38 mitogen-activated protein kinase (MAPK) and Akt and intracellular TLR4 expression in HBECs. In the Der p-induced mouse model, airway hyper-responsiveness (AHR) and the number of eosinophils in bronchoalveolar lavage fluid (BALF) was also significantly reduced by 1.8-cineole treatment. The treatment of 1.8-cineole inhibited the increased production of interleukin (IL)-4, IL-13 and IL-17A in BALF after Der p challenge. These results suggest that 1.8-cineole suppresses Der p-induced IL-8, IL-6 and granulocyte macrophage-colony stimulating factor (GM-CSF) production in HBECs. Finally, we confirmed that 1.8-cineole decreases AHR and eosinophilic airway inflammation in Der p-induced asthma mice.

Metadynamics supports molecular dynamics simulation-based binding affinities of eucalyptol and beta-cyclodextrin inclusion complexes

The development of various molecular dynamics methods enables the detailed investigation of association processes, like host–guest complexes, including their dynamics and, additionally, the release of the guest compound.

Medicinal Plants of the Australian Aboriginal Dharawal People Exhibiting Anti-Inflammatory Activity

Chronic inflammation contributes to multiple ageing-related musculoskeletal and neurodegenerative diseases, cardiovascular diseases, asthma, rheumatoid arthritis, and inflammatory bowel disease. More recently, chronic neuroinflammation has been attributed to Parkinson's and Alzheimer's disease and autism-spectrum and obsessive-compulsive disorders. To date, pharmacotherapy of inflammatory conditions is based mainly on nonsteroidal anti-inflammatory drugs which in contrast to cytokine-suppressive anti-inflammatory drugs do not influence the production of cytokines such as tumour necrosis factor-α or nitric oxide. However, their prolonged use can cause gastrointestinal toxicity and promote adverse events such as high blood pressure, congestive heart failure, and thrombosis. Hence, there is a critical need to develop novel and safer nonsteroidal anti-inflammatory drugs possessing alternate mechanism of action. In this study, plants used by the Dharawal Aboriginal people in Australia for the treatment of inflammatory conditions, for example, asthma, arthritis, rheumatism, fever, oedema, eye inflammation, and inflammation of bladder and related inflammatory diseases, were evaluated for their anti-inflammatory activity in vitro. Ethanolic extracts from 17 Eucalyptus spp. (Myrtaceae) were assessed for their capacity to inhibit nitric oxide and tumor necrosis factor-α production in RAW 264.7 macrophages. Eucalyptus benthamii showed the most potent nitric oxide inhibitory effect (IC₅₀  5.57 ± 1.4 µg/mL), whilst E. bosistoana, E. botryoides, E. saligna, E. smithii, E. umbra, and E. viminalis exhibited nitric oxide inhibition values between 7.58 and 19.77 µg/mL.

Optimization of Extraction Conditions for Maximal Phenolic, Flavonoid and Antioxidant Activity from Melaleuca bracteata Leaves Using the Response Surface Methodology

Melaleuca bracteata is a yellow-leaved tree belonging to the Melaleuca genus. Species from this genus are known to be good sources of natural antioxidants, for example, the “tea tree oil” derived from M. alternifolia is used in food processing to extend the shelf life of products. In order to determine whether M. bracteata contains novel natural antioxidants, the components of M. bracteata ethanol extracts were analyzed by gas chromatography–mass spectrometry. Total phenolic and flavonoid contents were extracted and the antioxidant activities of the extracts evaluated. Single-factor experiments, central composite rotatable design (CCRD) and response surface methodology (RSM) were used to optimize the extraction conditions for total phenolic content (TPC) and total flavonoid content (TFC). Ferric reducing power (FRP) and 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging capacity were used as the evaluation indices of antioxidant activity. The results showed that the main components of M. bracteata ethanol extracts are methyl eugenol (86.86%) and trans-cinnamic acid methyl ester (6.41%). The single-factor experiments revealed that the ethanol concentration is the key factor determining the TPC, TFC, FRP and DPPH·scavenging capacity. RSM results indicated that the optimal condition of all four evaluation indices was achieved by extracting for 3.65 days at 53.26°C in 34.81% ethanol. Under these conditions, the TPC, TFC, FRP and DPPH·scavenging capacity reached values of 88.6 ± 1.3 mg GAE/g DW, 19.4 ± 0.2 mg RE/g DW, 2.37 ± 0.01 mM Fe²⁺/g DW and 86.0 ± 0.3%, respectively, which were higher than those of the positive control, methyl eugenol (FRP 0.97 ± 0.02 mM, DPPH·scavenging capacity 58.6 ± 0.7%) at comparable concentrations. Therefore, the extracts of M. bracteata leaves have higher antioxidant activity, which did not only attributed to the methyl eugenol. Further research could lead to the development of a potent new natural antioxidant.

Beneficial and Healthy Properties of Eucalyptus Plants: A Great Potential Use

Eucalyptus (Eucapyptusspp.), an evergreen tall tree native to Australia and Tasmania, has been used since ancient times by the aboriginal population for several purposes. In particular, the speciesE. globulusis widely used in the pulp industry, as well as for the production of eucalyptus oil extracted on a commercial scale in many countries as raw materials in perfumery, cosmetics, food, beverages, aromatherapy and phytotherapy. The 1,8-cineole (eucalyptol), the principal and the most important constituent extracted from eucalyptus leaves, demonstrated an antimicrobial and anti-inflammatory activities. Despite the fact that the healthy effects of eucalyptus have been well established by research, further studies are necessary to investigate other prime effects of the plant and its possible implication in the treatment of a greater number of pathological conditions.

Mentha longifolia protects against acetic-acid induced colitis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Mentha longifolia L (Wild Mint or Habak) (ML) is used in traditional medicine in treatment of many gastrointestinal disorders.

AIM OF THE STUDY

This study aimed to evaluate potential protecting effect of ML and its major constituent, eucalyptol, against acetic acid-induced colitis in rats, a model of human inflammatory bowel disease (IBD).

MATERIALS AND METHODS

Rats were divided into ten groups (n=8) given orally for three days (mg/kg/day) the following: normal control, acetic acid-induced colitis (un-treated, positive control), vehicle (DMSO), sulfasalazine (500), ML extract (100, 500, 1000), and eucalyptol (100, 200, 400). After 24h-fasting, two ML of acetic acid (3%) was administered intrarectally. On the fifth day, serum and colonic biochemical markers, and histopathological changes were evaluated.

RESULTS

Colitis significantly increased colonic myeloperoxidase activity and malonaldehyde level, and serum tumor necrosis factor-α, interleukin-6, and malonaldehyde levels while significantly decreased colonic and serum glutathione levels. All treatments (except ML 100, ML 1000, and eucalyptol 100) significantly reversed these changes where eucalyptol (400) showed the highest activity in a dose-dependent manner. The colitis-induced histopathological changes were mild in sulfasalazine and eucalyptol 400 groups, moderate in ML 500 and eucalyptol 200 groups, and severe in ML 100, ML 1000, and eucalyptol 100 groups nearly similar to colitis-untreated rats.

CONCLUSION

ML (in moderate doses) and eucalyptol (dose-dependently) exerted protective effects against acetic acid-induced colitis in rats possibly through antioxidant and antiinflammatory properties suggesting a potential benefit in treatments of IBD. To our knowledge this is the first report addressing this point.