Repeated-doses and reproductive toxicity studies of the monoterpene 1,8-cineole (eucalyptol) in Wistar rats

Repellency, Toxicity, and Chemical Composition of Plant Essential Oils from Myrtaceae against Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera Liviidae)

Diaphorina citri Kuwayama (D. citri) is one of the major pests in the citrus industry, which spreads Citrus Huanglongbing disease. It has developed resistance to chemical insecticides. Therefore, searching for greener solutions for pest management is critically important. The main aim of this study was to evaluate the repellent and insecticidal efficacy of essential oils (EOs) from four species of Myrtaceae plants: Psidium guajava (PG), Eucalyptus robusta (ER), Eucalyptus tereticornis (ET), and Baeckea frutescens (BF) against D. citri and to analyze their chemical compositions. GC-MS analysis was performed, and the results indicated that the EOs of PG, ER, ET, and BF were rich in terpenoids, ketones, esters, and alcohol compounds. The repellent rate of all four EOs showed that it decreased with exposure time but increased with the concentration of EOs from 80.50% to 100.00% after treating D. citri for 6 h with four EOs at 100% concentration and decreased to 67.71% to 85.49% after 24 h of exposure. Among the compounds from the EOs tested, eucalyptol had the strongest repellent activity, with a 24 h repellency rate of 100%. The contact toxicity bioassay results showed that all EOs have insecticidal toxicity to D. citri; the LC50 for nymphs was 36.47-93.15 mL/L, and for adults, it was 60.72-111.00 mL/L. These results show that when PG is used as the reference material, the ER, ET, and BF EOs have strong biological activity against D. citri, which provides a scientific basis for the further development of plant-derived agrochemicals.

Biological Properties of Mentha viridis L. Essential Oil and Its Main Monoterpene Constituents

This research aimed to evaluate the antidiabetic, dermatoprotective, and antibacterial activities of Mentha viridis L. essential oil (MVEO) collected in the province of Ouezzane (Northwest Morocco). Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the main constituents of MVEO were carvone (37.26 %), 1,8-cineole (11.82 %), limonene (5.27 %), α-terpineol (4.16 %), and β-caryophyllene (4.04 %). MVEO showed strong inhibitory effects on α-amylase and α-glucosidase activities, exceeding those of acarbose, but weak anti-elastase activity. The main compounds, β-caryophyllene (IC50=79.91±2.24 and 62.08±2.78 μg/mL) and limonene (IC50=90.73±3.47 and 68.98±1, 60 μg/mL), demonstrated the strongest inhibitory effects on both digestive enzymes (α-glucosidase and α-amylase, respectively). In silico investigations, using molecular docking, also showed the inhibitory potential of these bioactive compounds against the enzymes tested. In conclusion, MVEO, due to its main components such as limonene, 1,8-cineole, β-caryophyllene, carvone, and α-terpineol, shows promising prospects for drug discovery and natural therapeutic applications.

Ingredients in Commercially Available Mouthwashes

OBJECTIVES

Mouthwashes, a cornerstone of oral and dental hygiene, play a pivotal role in combating the formation of dental plaque, a leading cause of periodontal disease and dental caries. This study aimed to review the composition of mouthwashes found on retail shelves in Turkey and evaluate their prevalence and side effects, if any.

METHODS

The mouthwashes examined were sourced from the 5 largest chain stores in each district of Istanbul. A comprehensive list of the constituents was meticulously recorded. The research was supported by an extensive compilation of references from scholarly databases such as Google Scholar, PubMed, and ScienceDirect. Through rigorous analysis, the relative proportions of mouthwash ingredients and components were determined.

RESULTS

A total of 45 distinctive variations of mouthwashes, representing 17 prominent brands, were identified. Amongst the 116 ingredients discovered, 70 were evaluated for potential adverse effects and undesirable side effects. The aroma of the mouthwash (n = 45; 100%), as welll as their sodium fluoride (n = 28; 62.22%), sodium saccharin (n = 29; 64.44%), sorbitol (n = 21; 46.6%), and propylene glycol (n = 28; 62.22%) content were the main undesireable features.

CONCLUSIONS

The limited array of mouthwashes found on store shelves poses a concern for both oral and public health. Furthermore, the intricate composition of these products, consisting of numerous ingredients with the potential for adverse effects, warrants serious attention. Both clinicians and patients should acknowledge the importance and unwarranted side effects of the compnents of the mouthwashes.

The Fate of 1,8-cineole as a Chemical Penetrant: A Review

The stratum corneum continues to pose the biggest obstacle to transdermal drug delivery. Chemical penetrant, the first generation of transdermal drug delivery system, offers a lot of potential. In order to fully examine the permeation mechanism of 1,8-cineole, a natural monoterpene, this review summarizes the effects of permeation-enhancing medications on drugs that are lipophilic and hydrophilic as well as the toxicity of this substance on the skin and other tissues. For lower lipophilic drugs, 1,8-cineole appears to have a stronger osmotic-enhancing impact. An efficient and secure tactic would be to combine enhancers and dose forms. 1,8-cineole is anticipated to be further developed in the transdermal drug delivery system and even become a candidate drug for brain transport due to its permeability and low toxicity.

Behavioral and electrophysiological (ECoG) effects of haplophyllum robustum and TRPA1 antagonist in adult male wistar rats

This article aimed to investigate the effects of Haplophyllum robustum hydroalcoholic extract on animals' behavioral and electrocorticographic changes. This plant is mainly found in Turkey, Iran, and Central Asia, and is reported to have convulsive effects. In this article, we worked on the effects of its hydroalcoholic extract on electrocorticography (ECoG), along with changes induced by intracerebroventricular administration of GABAA antagonists. Furthermore, the effects of low doses of this extract on behavioral depression were examined. Four animal sets were used to compare ECoG in Wistar rats. A group of negative control, a group of positive control (PTZ), and two groups received an injection of plant extract (500 mg/kg, ip), with or without administration of Diazepam (5 mg/kg). Also, three sets were applied to compare receiving and not receiving intracerebroventricular (icv) injection of Transient receptor potential ankyrin 1 antagonist (HC-030031) (2 μg/kg) on plant-induced seizure delay and animal death. Two groups of control and a group with plant extract together with TRPA1 antagonist were administrated. Furthermore, in the present study, the forced swimming test (FST) was used as a model of depression. The behaviors of animals in three groups of negative control and positive control (Fluoxetine) and plant extract (200 mg/kg, ip) were compared. According to the ECoG, high doses of extract of plants led to seizures similar to PTZ, which were then reduced by diazepam injection. At this dose, injection of TRPA1 antagonist did not significantly delay the onset of seizures or the death of the animals. Further, a subconvulsive dose of hydroalcoholic plant extracts was equally effective in treating depression as Fluoxetine injections.

Phytochemical Profile, Preliminary Toxicity, and Antioxidant Capacity of the Essential Oils of Myrciaria floribunda (H. West ex Willd.) O. Berg. and Myrcia sylvatica (G. Mey) DC. (Myrtaceae)

The essential oils (EOs) of Myrciaria floribunda (Mflo) and Myrcia sylvatica (Msyl) (Myrtaceae) were obtained by hydrodistillation. The analysis of volatile constituents was performed by GC/MS. Preliminary toxicity was assessed on Artemia salina Leach. The antioxidant capacity was measured by the ABTS•+ and DPPH• radical inhibitory activities. The results indicate that the Mflo EO had the highest yield (1.02%), and its chemical profile was characterized by high levels of hydrocarbon (65.83%) and oxygenated (25.74%) monoterpenes, especially 1,8-cineole (23.30%), terpinolene (22.23%) and α-phellandrene (22.19%). Regarding the Msyl EO, only hydrocarbon (51.60%) and oxygenated (46.52%) sesquiterpenes were identified in the sample, with (Z)-α-trans-bergamotene (24.57%), α-sinensal (13.44%), and (Z)-α-bisabolene (8.33%) at higher levels. The EO of Mflo exhibited moderate toxicity against A. salina (LC50 = 82.96 ± 5.20 µg.mL−1), while the EO of Msyl was classified as highly toxic (LC50 = 2.74 ± 0.50 µg.mL−1). In addition, relative to Trolox, the EOs of Mflo and Msyl showed significant inhibitory effects (p < 0.0001) against the DPPH• radical. This study contributes to the expansion of chemical and biological knowledge on the EOs of Myrtaceae species from the Amazon region.

Natural products in the treatment of pulmonary emphysema: Therapeutic effects and mechanisms of action

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a class of lung diseases including chronic bronchitis, asthma, and emphysema. Long-time smoking is considered the main reason for developing emphysema. Emphysema can be defined as damage to the walls of the air sacs (alveoli) of the lung. It has been demonstrated that natural compounds with antioxidant and anti-inflammatory effects can effectively improve or protect the lung against this disease. This paper is dedicated to systematically review the effective natural compounds in the treatment of pulmonary emphysema.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating pulmonary emphysema STUDY DESIGN AND METHODS: A systematic and comprehensive review was done based on Scopus, PubMed, and Cochrane Library databases were searched using the "emphysema", "plant", "herb", and "phytochemical" keywords. Non-English, review, and repetitive articles were excluded from the study. Search results were included in the Prisma diagram.

RESULTS

From a total of 1285 results, finally, 22 articles were included in the present study. The results show that some herbs such as Scutellaria baicalensis Georgi and Monascus adlay and some phytochemicals such as gallic acid and quercetin and blackboard tree indole alkaloids affect more factors in improving the lung emphysema. Also, some natural compounds such as marijuana smoke and humic acid also play an aggravating role in this disease. It also seems that some of the medicinal plants such as PM014 herbal formula, pomegranate juice and açaí berry sometimes have side effects that are inconsistent with their therapeutic effects.

CONCLUSION

We concluded that natural compounds can effectively improve pulmonary emphysema due to their antioxidant, anti-inflammatory, and anti-apoptotic properties. However, additional studies are suggested to prove efficacy and side effects.

Reduced-Pressure Process for Fabricating Tea Tree Oil-Polyvinylpyrrolidone Electrospun Fibers

Electrospun fibers containing tea tree oil (TTO) can be explored for practical applications due to the antimicrobial and anti-inflammatory activities of TTO. Considering that there are potentially toxic components in TTO, it is necessary to eliminate or reduce its content in the preparation process of TTO-doped electrospun fibers. In this work, electrospun TTO-PVP (polyvinylpyrrolidone) fibers containing an 18.18 wt.% decreased content of 1,8-Cineole were successfully fabricated by intense evaporation of a self-made reduced-pressure electrospinning (RP-ES) setup (as low as 94.4 kPa). In addition, such intense evaporation led to a morphology change, where a typical average fiber diameter increased from 0.831 to 1.148 μm, fewer and smaller beads in fibers, along with a rougher and grooves fiber surface. These morphology changes allowed Terpinen-4-ol to remain in the fiber for a more extended period. In addition, RP-ES proved the possibility for intense evaporation and continuous vapor removal by continuously environmental vacuum pumping of electrospinning.

FEMA GRAS assessment of natural flavor complexes: Eucalyptus oil and other cyclic ether-containing flavoring ingredients

In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a program for the re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavor ingredients. This publication, the sixth in the series, will summarize the re-evaluation of eight NFCs whose constituent profiles are characterized by significant amounts of eucalyptol and/or other cyclic ethers. This re-evaluation was based on a procedure first published in 2005 and subsequently updated in 2018 that evaluates the safety of naturally occurring mixtures for their intended use as flavoring ingredients. The procedure relies on a complete chemical characterization of the NFC intended for commerce and the organization of its chemical constituents into well-defined congeneric groups. The safety of the NFC is evaluated using the well-established and conservative threshold of toxicological concern (TTC) concept in addition to data on absorption, metabolism and toxicology of the constituents of the congeneric groups and the NFC under evaluation. Eight NFCs derived from the Eucalyptus, Melaleuca, Origanum, Laurus, Rosmarinus and Salvia genera were affirmed as generally recognized as safe (GRAS) under their conditions of intended use as flavor ingredients based on an evaluation of each NFC and the constituents and congeneric groups therein.

1,8-cineole ameliorates ischaemic brain damage via TRPC6/CREB pathways in rats

OBJECTIVES

A previous in vitro study reported that the monoterpene oxide 1,8-cineole (cineole) attenuates neuronal caused by oxygen-glucose deprivation/reoxygenation in culture. However, to date, there is no in vivo evidence showing neuroprotective effects of cineole against stroke. This study aimed to investigate whether cineole attenuates cerebral ischaemic damage in rats.

METHODS

A rat model of middle cerebral artery occlusion (MCAO) followed by 24 h reperfusion was applied. Male rats were treated with oral cineole (100 mg/kg) for 7 consecutive days, then subjected to MCAO surgery. Infarct volume, neurologic deficits, apoptosis and expression levels of all-spectrin breakdown products of 145 kDa (SBDP145), transient receptor potential canonical (subtype) 6 (TRPC6) and phosphorylated CREB (p-CREB) were measured in ischaemic brain tissues.

KEY FINDINGS

Cineole treatment significantly reduced infarct volume, neurological dysfunction, neuronal apoptosis, SBDP145 formation and TRPC6 degradation and enhanced p-CREB expression in MCAO rats compared with vehicle treatment. These neuroprotective effects were markedly suppressed by pharmacological inhibition of MEK or CaMKIV signalling.

CONCLUSIONS

Our study provides in vivo evidence demonstrating that cineole pretreatment attenuates ischaemic stroke-induced brain damage, mainly through blocking calpain-induced TRPC6 degradation and activating CREB via MEK/CREB and CaMKIV/CREB signalling pathways.

Antibacterial and Antifungal Activities and Toxicity of the Essential Oil from Callistemon viminalis Complexed with β-Cyclodextrin

The essential oil from Callistemon viminalis (EOC) is rich in monoterpenes, with a variety of biological properties: antibacterial, antifungal, insecticide, and antioxidant. Inclusion complexes (ICs) with cyclodextrins (CDs) is an alternative to prevent toxicity, improve the activity, and reduce the concentration to be used. Thus, the objective of this work was to prepare an IC (EOC/β-CD) and evaluate the antibacterial, antifungal and phospholipase activities, as well as the toxicity. Antimicrobial activity used the agar diffusion test and antifungal activity the disc diffusion test. Toxicity tests were carried out using Lactuca sativa L. The inhibition of phospholipase activity using the venom of Bothrops atrox as an inducer was performed. Antibacterial and antifungal tests demonstrated a decrease in the minimum inhibitory concentration (MIC) of the IC. It was most significantly observed for the bacterium Listeria monocytogenes, for which there was a decrease in the MIC from 250 µg mL^-1 to 62.5 µg mL^-1 after complexation, and for the fungus Aspergillus flavus, with a decrease in MIC from 125 µg mL^-1 to 62.5 µg mL^-1 after complexation. Toxicity tests with Lactuca sativa showed a decrease in toxicity after complexation in all parameters analyzed, with no statistical difference from the negative control. Inhibition of phospholipase activity induced by Bothrops atrox venom was more expressive in the highest proportion studied (1:10 m:m), exerting 23% inhibition. The assays demonstrated that the complexation between the EOC and β-CD is a promising alternative for use in different branches, especially in food industry, to fully exploit its application potential.

Safety and efficacy of feed additives consisting of expressed lemon oil and its fractions from Citrus limon (L.) Osbeck and of lime oil from Citrus aurantiifolia (Christm.) Swingle for use in all animal species (FEFANA asbl)

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of expressed lemon oil and distilled lemon oil from Citrus limon (L.) Osbeck and lime oil from Citrus aurantiifolia (Christm.) Swingle, when used as sensory additives in feed for all animal species. The use of the expressed lemon oil and its residual fraction and the use of lime oil in feed is not expected to increase the exposure to furocoumarins and methoxycoumarins and perillaldehyde of those target species that are already fed citrus by-products a relevant extent (< 10%). For companion animals and ornamental fish not normally exposed to citrus by-products, no conclusion can be drawn. For the other species and for the distilled fraction of expressed lemon oil, the FEEDAP Panel concludes that the additives under assessment are safe at the maximum proposed or at reduced use levels in complete feed. The Panel considers that the use in water for drinking is safe provided that the total daily intake of the additive does not exceed the daily amount that is considered safe when consumed via feed. No concerns for consumer safety were identified following the use of the additives at the maximum proposed use level in feed. The additives under assessment should be considered as irritants to skin and eyes and the respiratory tract and as skin sensitisers. Since expressed lemon oil and its fractions contain furocoumarins, they may cause phototoxicity. The use of the additives under the proposed conditions of use in animal feed is not expected to pose a risk for the environment. Since C. limon and C. aurantiifolia and their preparations are recognised to flavour food and its function in feed would be essentially the same as that in food, no further demonstration of efficacy is considered necessary.

Supercritical carbon dioxide extracts of small cardamom and yellow mustard seeds have fasting hypoglycaemic effects: diabetic rat, predictive iHOMA2 models and molecular docking study

In the present investigation, the supercritical carbon dioxide (SC-CO2) extracts of small cardamom (SC) and yellow mustard (YM) seeds have been investigated for their efficacies in combating type 2 diabetes in streptozotocin-induced Wistar albino rats. Fasting blood glucose (FBG) levels in the rats were monitored on days 8, 15 and 21. On day 15, FBG level reduced appreciably by 31·49 % in rats treated with SC seed extract and by 32·28 % in rats treated with YM seed extract, comparable to metformin (30·70 %) and BGR-34 (a commercial polyherbal drug) (31·81 %) administered rats. Either extract exhibited desirable effects on hepatic glucose-6-phosphatase, glucose-6-phosphate dehydrogenase (G6PD) and catalase activities in controlling diabetes. A molecular docking exercise was conducted to identify specific compounds in the extracts which possessed augmenting effect on G6PD. The results revealed that all the bioactive compounds in the extracts have binding affinities with the enzyme and contributed to the antidiabetic efficacies of the extracts as G6PD augmenters. The effects of the extracts on insulin sensitivity and glucose uptake were investigated using non-invasive modelling by iHOMA2 software. This in vitro approach indicated that extract administration resulted in increased both insulin sensitivity of the liver and glucose uptake in the gut. The findings of the present study attest these SC-CO2 extracts of the spices as safe alternatives of metformin and BGR-34 in combating type 2 diabetes and could be safely subjected to clinical studies. These extracts could also be employed in designing proactive food supplements in mitigating the metabolic disorder.

Seasonal and Circadian Rhythm of a 1,8-Cineole Chemotype Essential Oil of Calycolpus goetheanus From Marajó Island, Brazilian Amazon

Chemical composition of essential oils (EOs) of Calycolpus genus have been reported in the literature. However, there is only 1 report about volatile profile from Calycolpus goetheanus. This work aims to evaluate the seasonal and circadian influences on EO composition and yield of C. goetheanus collected in Marajó Island, Brazilian Amazon. For the circadian study, the leaves were collected in January (rainy season) and July (dry season) every 3 hours during a period of 15 hours. The EOs were obtained by hydrodistillation and their chemical compositions analyzed by gas chromatography coupled to mass spectrometry and flame ionization detectors. The major compound identified in all EO samples was 1,8-cineole with amounts ranged from 14.4% (January, 6 am) to 33.0% (July, 3 pm). The highest average of 1,8-cineole was obtained during circadian study of the dry season (25.5% ± 5.8%) and the lowest during the circadian study of the rainy season (15.6% ± 1.5%). The multivariate analysis grouped the samples into 2 different groups: Group I characterized by the lowest amounts of 1,8-cineole (16.0%-18.7%), and Group II characterized by a higher content of 1,8-cineole (24.0%-33.0%). The oil yield and chemical composition did not show relationship with climate parameters (solar radiation, humidity, and temperature). Therefore, there was only quantitative variability in the EOs compositions during the circadian rhythm evaluated on dry and rainy seasons.

Anti-Inflammatory and Physicochemical Characterization of the Croton Rhamnifolioides Essential Oil Inclusion Complex in β-Cyclodextrin

Croton rhamnifolioides is used in popular medicine for the treatment of inflammatory diseases. The objective of this study was to characterize and evaluate the anti-inflammatory effect of C. rhamnifolioides essential oil complexed in β-cyclodextrin (COEFC). The physicochemical characterization of the complexes was performed using different physical methods. The anti-inflammatory activity was evaluated in vivo by ear edema, paw edema, cotton pellet-induced granuloma, and vascular permeability by Evans blue extravasation. The mechanism of action was validated by molecular docking of the major constituent into the cyclooxygenase-2 (COX-2 enzyme). All doses of the COEFC reduced acute paw edema induced by carrageenan and dextran, as well as vascular permeability. Our results suggest the lowest effective dose of all samples inhibited the response induced by histamine or arachidonic acid as well as the granuloma formation. The complexation process showed that the pharmacological effects were maintained, however, showing similar results using much lower doses. The results demonstrated an involvement of the inhibition of pathways dependent on eicosanoids and histamine. Complexation of β-cyclodextrin/Essential oil (β-CD/EO) may present an important tool in the study of new compounds for the development of anti-inflammatory drugs.

Is 1,8-Cineole-Rich Extract of Small Cardamom Seeds More Effective in Preventing Alzheimer's Disease than 1,8-Cineole Alone?

The present study demonstrates the efficacies of synthetic 1,8-cineole and an 1,8-cineole-rich supercritical carbon dioxide (SC-CO₂) extract of small cardamom seeds in preventing oligomerization of amyloid beta peptide (Aβ42) and inhibiting iron-dependent oxyradical production in vitro. The oligomerization of Aβ42 was monitored by thioflavin T assay and MALDI-TOF analysis of the oligomers. The iron-dependent production of oxygen free radicals was detected by fluorometric benzoate hydroxylation assay. We observed that both pure 1,8-cineole and 1,8-cineole-rich extract of small cardamom seeds at concentrations of 50 µM and 100 µM prevented the production of reactive hydroxyl radicals from a mixture of Fe²⁺ and ascorbate. However, the 1,8-cineole-rich extract of small cardamom seeds prevented in vitro Aβ42 oligomerization more effectively vis-à-vis the synthetic (99% pure) 1,8-cineole. Additional study on SHSY5Y cells indicated that both pure 1,8-cineole and 1,8-cineole-rich SC-CO₂ extract of small cardamom seeds prevented iron-dependent cell death. Since oxidative damage, Aβ42 aggregation and loss of cell viability (iron-induced) are characteristics of onset of Alzheimer's disease pathology, our results suggest a putative therapeutic role of 1,8-cineole-rich extract of small cardamom seeds over pure 1,8-cineole in preventing this neurodegenerative disease.

Treatment with eucalyptol mitigates cigarette smoke-induced lung injury through suppressing ICAM-1 gene expression

The present study was conducted to investigate the clinical significance of Eucalyptol in treating cigarette smoke-induced lung injury with the potential mechanism involved in the event. Rats were exposed to air (control) and cigarette smoke (smoking) after they were treated with Eucalyptol (260 mg/kg) orally once a day for 12 weeks. Cell counts of bronchoalveolar lavage fluid (BALF), measurements of mean liner intercept (MLI) and mean alveolar number (MAN), and lung function test were executed in experimental animals. Contents of cytokines and intercellular adhesion molecule (ICAM)-1 in BALF and ICAM-1 protein and mRNA expression in lung tissues were determined by ELISA, immunohistochemistry (IHC), and RT-PCR, respectively. A rat model of chronic obstructive pulmonary disease (COPD) displayed declining lung function, increased cell counts and cytokine production in BALF, and emphysema-like lesions in cigarette smoke-exposed lungs compared with the controls (all P<0.01). Treatment with Eucalyptol partly reversed lung function decline with obvious decrease in inflammatory cell infiltrate, TNF-α, IL-6, and ICAM-1 expression levels in the challenged lungs (all P<0.05 and 0.01). Furthermore, oral administration of the drug not only reduced the emphysema-associated lung lesions but also suppressed ICAM-1 protein and mRNA expression in the lungs compared with the control (all P<0.05 or 0.01). Intervention of Eucalyptol mitigates the ongoing inflammatory process in airways and ameliorates the cigarette smoke-induced lung injury through suppressing ICAM-1 gene expression in the diseased lungs.

Antiulcer Activity and Potential Mechanism of Action of the Leaves of Spondias mombin L

Spondias mombin L. is used in folk medicine for the treatment of inflammation and gastrointestinal diseases. Our study investigated the antiulcer activity of S. mombin ethanolic extract (SmEE) and its majority compounds gallic acid (GA) and ellagic acid (EA). Phytochemical characterization was performed by HPLC. The SmEE was screened for in vitro antioxidant activities using phosphomolybdenum, ABTS, DPPH, and FRAP assays. The antiulcer activity of SmEE, GA, EA, or GA + EA was evaluated by gastric lesion models induced by absolute ethanol and indomethacin. Following this, it is capable of stimulating mucus production, antisecretory capacity, and the influence of −SH groups and NO in the effect of SmEE. Its healing activity was demonstrated by acetic acid-induced chronic ulcer model. Anti-Helicobacter pylori activity was assessed by determining the MIC of the SmEE (64–1024 μg/mL). The HPLC results identified the presence of gallic acid and ellagic acid in SmEE. The extract showed antioxidant activity in vitro. SmEE (50, 100, and 200 mg/kg) reduced the area of ulcerative lesions induced by ethanol in 23.8, 90.3, and 90.2%, respectively. In NSAID model, the SmEE induced protection of 36.8, 49.4, and 49.9%, respectively. GA (10 mg/kg) or EA (7 mg/kg) or the association of GA + EA (10 + 7 mg/kg) inhibited the ethanol-induced lesions in 71.8, 70.9, and 94.9%, respectively, indicating synergistic action. SmEE (100 mg/kg) decreased acid secretion and H⁺ concentration in the gastric contents, increased levels of mucus, and showed to be dependent of −SH groups and NO on the protection of the gastric mucosa. In chronic ulcer model, SmEE reduced the gastric area lesion. SmEE showed anti-H. pylori activity. In conclusion, our study showed that SmEE has antiulcerogenic activity. GA and EA are isolated gastric protectors and, when associated, acted synergistically to protect the gastric mucosa.

Gastroprotective effect and mechanism of action of Croton rhamnifolioides essential oil in mice

BACKGROUND

Croton rhamnifolioides Pax is a plant species that have been used in the folk medicine to treat ulcers, inflammations and hypertension. However, despite the relevant data obtained from ethnopharmacological studies, the pharmacological properties endorsing the efficacy of this plant to treat ulcer remain to be elucidated.

HYPOTHESIS/PURPOSE

The present study aimed to characterize the chemical profile and evaluate the gastroprotective activity of the essential oil obtained from C. rhamnifolioides Pax (OECC) in mice.

METHODS

The essential oil of Croton rhamnifolioides was obtained by hydrodistillation and analyzed by gas-phase chromatography coupled to mass spectrometry (GC/MS). The median lethal dose was determined employing an acute toxicity test. The gastroprotective activity of the OECC was investigated using animal models of gastric ulcer induced by the administration of absolute ethanol, acidified ethanol or indomethacin. Mechanisms of action were investigated using the physical barrier test and by in vivo evaluation of the involvement of the following molecular pathways: nitric oxide, ATP - dependent potassium channels, α₂ - noradrenergic receptors, capsaicin - sensitive afferent neurons and opioid receptor.

RESULTS

We identified the presence of 21 compounds in OECC, including spathulenol and 1,8 - cineole as major constituents. In orally administered mice, OECC caused no significant toxicity. OECC significantly prevented gastric lesions in all mice models. The barrier test demonstrated that the gastroprotective activity of OECC occurs in a systemic dimension. Our results demonstrated that the gastroprotective effect of OECC involves mechanisms that are related to modulation of opioid receptors and nitric oxide.

CONCLUSION

In conclusion, OECC demonstrated significant gastroprotective activity associated with low toxicity, providing scientific evidences that C. rhamnifolioides have the potential for the development of new antiulcer drugs.