Chemical composition and antioxidant content of Thymus vulgaris honey and Origanum vulgare essential oil; their effect on carbon tetrachloride-induced toxicity

Unlocking the combined action of Mentha pulegium L. essential oil and Thym honey: In vitro pharmacological activities, molecular docking, and in vivo anti-inflammatory effect

Mentha pulegium L., a plant widely embraced for its therapeutic properties by populations worldwide, including Morocco, has long been recognized for its potential in treating various ailments. This study aims to comprehensively evaluate the antioxidant, anti-inflammatory, and dermatoprotective properties of essential oil derived from M. pulegium, and thyme honey as well as their combined effects. To unravel the chemical composition, a rigorous GC-MS analysis was conducted. Subsequently, we examined their antioxidant potential through three distinct assays: DPPH●, hydrogen peroxide assay, and xanthine oxidase assay. The anti-inflammatory properties were scrutinized through both in vitro and in vivo experiments. Simultaneously, the dermatoprotective efficacy was investigated in vitro by evaluating tyrosinase inhibition. Our findings revealed that pulegone constitutes the predominant compound in M. pulegium essential oil (MPEO), constituting a remarkable 74.82 % of the composition. Significantly, when the essential oil was combined with thym honey, it exhibited superior anti-inflammatory and dermatoprotective effects across all in vivo and in vitro tests. Moreover, our in silico molecular docking analysis hinted at the potential role of cyclohexanone, 3-methyl, an element found in the MPEO, in contributing to the observed outcomes. While this study has unveiled promising results regarding the combined in vitro, in vivo and in silico biological activities of the essential oil and honey, it is imperative to delve further into the underlying mechanisms through additional experimentation and alternative experimental methods. Understanding these mechanisms in greater detail will not only enhance our comprehension of the therapeutic potential but also pave the way for the development of innovative treatments and applications rooted in the synergy of these natural compounds. Furthermore, it would be advantageous to test different possible combinations using experimental design model. Moreover, it would be better to test the effect of single compounds of MPEO to clearly elucidate their efficiency. MPEO alone or combined with thyme honey may be a useful for the development of novel biopharmaceuticals.

Antioxidant, insecticidal, antifeedant, and repellent activities of oregano (Origanum vulgare)

This study aimed to assess the antioxidant capacity, the insecticidal, feeding deterrence, repellent effects against Tribolium confusum of the essential oil (EO) and the organic extracts (ME) of Origanum vulgare. The chemical composition of the EO revealed the presence thirty-nine components dominated by carvacrol (81%). With respect to the EO, the ME acted as a potent free radical scavenger with IC50 values of 0.127 and 0.058 mg/mL, respectively. The EO exhibited the most significant toxicity compared to the ME with a mortality of 62 and 20% at 0.08 µL/insect after 24h whereas the EO expressed the highest repellency compared to the ME with a PR of 70 and 38% after 24h. As for feeding deterrence, both samples influenced all nutritional indexes. The findings found in this work might help in the promotion of oregano as natural antioxidant, antifeedant, repellent and insecticide as an alternative to conventional harmful ones.

Effectiveness of thyme honey in the management of xerostomia in geriatric patients with end-stage renal disease: a randomized controlled clinical trial with a biochemical assessment

BACKGROUND

Taking into consideration the value of the oral health condition in geriatric people with end-stage renal disease (ESRD) associated with xerostomia and believing that salivary stimulants or substitutes could potentially be used to manage this condition. This study aimed to evaluate the clinical effectiveness of thyme honey as oral rinse in geriatric patients with ESRD using the subjective dry mouth score as a primary objective and to assess the effect of thyme honey on the salivary nitric oxide level, salivary flow rate, and salivary ph in addition to objective dry mouth score as a secondary objective.

METHODS

This was a single blinded randomized controlled trial with two equal arms, the interventional arm (thyme honey oral rinse) and the control arm (saline). Twenty-eight geriatric patients with ESRD undergoing hemodialysis complained of xerostomia were recruited from the renal dialysis center. Patients in both arms followed the same administration protocol either with thyme honey oral rinse or saline. The following clinical parameters (the subjective and objective dry mouth scores, salivary flow rate, salivary ph, and salivary nitric oxide (NO) levels) were evaluated for both groups at different intervals (baseline, 1 week, and 1 month).

RESULTS

In the current study, it was found that both the subjective and objective dry mouth scores were significantly lower after one month of using thyme honey oral rinse (1.86 ± 0.66B) and (2.21 ± 0.43B) respectively, than the control group (3.07 ± 0.73B) and (3.07 ± 0.83B), respectively with a (p < 0.001). Also, the salivary flow rate was significantly higher after one month of using thyme honey oral rinse (1.56 ± 0.51A), than the control group (0.78 ± 0.27A) with a (p < 0.001). For the NO levels, there was a significant increase in measured value after 1 month in the intervention group (p < 0.001), while for the control group the change was not statistically significant (p = 0.166).

CONCLUSIONS

The results of the current study have revealed the efficacy of Thyme honey oral rinse in the management of xerostomia in geriatric patients with ESRD. Trial registration The ClinicalTrials.gov Identifier for this study is NCT05247008.

Phytochemical Composition and Insight into Antibacterial Potential of Origanum vulgare Essential Oil from Saudi Arabia Using In Vitro and In Silico Approaches

In Saudi Arabia, Origanum vulgare is widely disseminated. In the present work, we used GC-MS analysis to identify the components of Origanum vulgare essential oil. The disc diffusion assay was used to assess the essential oil’s in vitro antibacterial efficacy against Gram-positive and Gram-negative Staphylococcus aureus and Escherichia coli. The antimicrobial efficacy against many microbial proteins, including tyrosyl-tRNA synthetase (TyrRS), DNA gyrase, and dihydrofolate reductase (DHFR), was further evaluated using molecular docking. Eighteen compounds were identified using GC-MS analysis, which constituted 99.81% of the total essential oil content. Terpinen-4-ol (34.3%), Beta-Terpineol (16.96%), 3-Epimoretenol (11.84%), and Alpha-Terpineol (3.86%) were the main substances identified. According to the antibacterial investigation, the inhibition zone against Staphylococcus aureus was 8 mm and 6 mm against Escherichia coli. High affinities were found between 3-Epimoretenol and tyrosyl-tRNA synthetase (TyrRS) and dihydrofolate reductase (DHFR) compared to positive controls (Clorobiocin, SCHEMBL2181345); the affinity values were −8.3 Kcal/mol and −9.2, respectively. The results of the present study indicate that Origanum vulgare essential oil can be used as a nutraceutical to treat infectious diseases.

Phytochemical Compounds, Acute Toxicity, Anti-Inflammatory and Antioxidant Activities of Thymus leptobotrys Murb Essential Oil

The present study was conducted to evaluate the acute toxicity and anti-inflammatory effect in vivo, as well as the antioxidant activity, of the essential oil of Thymus leptobotrys Murb. The results indicate that the tested essential oil is non-toxic, with an estimated LD50 of 2500 mg kg^-1 of mice body weight. The anti-inflammatory test revealed that, at a dose of 200 mg kg^-1, the essential oil reduced rat paw edemas by 89.59% within 3 h of oral administration, this reduction in edema size was greater than that obtained with indomethacin (75.78%). The antioxidant activity (IC50) of Thymus leptobotrys Murb essential oil was 346.896 µg mL^-1 and 861.136 mg Trolox equivalent/g essential oil in the 2.2-diphenyl1-picryl-hydrazyl radical scavenging capacity (DPPH) and Trolox equivalent antioxidant capacity (TEAC) assays, respectively. The toxicity test reveals an LD₅₀ greater than 2500 mg kg^-1 of body weight of mice which classifies it within category 5 of non-toxic substances that can be administered orally. These results suggest that the essential oil of Thymus leptobotrys Murb is not toxic, and it represents a valuable source of anti-inflammatory and antioxidant metabolites.

Potential use of essential oils from Origanum vulgare and Syzygium aromaticum to control Tetranychus urticae Koch (Acari: Tetranychidae) on two host plant species

Plant extracts and essential oils are considered alternatives to synthetic chemicals with toxic effects on insects and mites. Acaricidal, repellent, and oviposition effects of commercially available essential oils of Origanum vulgare L. (Lamiaceae) and Syzygium aromaticum (L.) (Myrtaceae) were investigated in this study on Tetranychus urticae Koch (Acari: Tetranychidae), one of the main pests in agriculture, on two host plant species using leaf disc bioassays. O. vulgare essential oil showed higher toxicity to T. urticae protonymphs and adult females inhabiting both bean and tomato leaves than S. aromaticum essential oil. The LC₅₀ values of O. vulgare essential oil were found to be 1.67 and 2.05 µl L^-1 air for the bean populations in protonymphs and adult females and 1.87 and 3.07 µl L^-1 air for the tomato populations, respectively. Five percent concentration of S. aromaticum essential oil had the highest repellent effect on the bean population of T. urticae after 1, 24, and 48 h, resulting in 61.22%, 40.81%, and 18% repellence, respectively. Although O. vulgare showed higher toxic effects, S. aromaticum was a better repellent against the bean population of T. urticae. The mortality rates of adult females of T. urticae treated with either O. vulgare or S. aromaticum essential oil increased with the increasing concentration and time on both host plants. Both essential oils caused a decrease in egg number and larvae hatching in both bean and tomato populations of T. urticae. In the light of the results obtained, O. vulgare and S. aromatium essential oils have the potential to be used in the control programs against T. urticae in both host plants.

Carvacrol prevents acrylamide-induced oxidative and inflammatory liver damage and dysfunction in rats

Background: Acrylamide causes hepatotoxicity with the effect of oxidative stress and inflammatory processes. Carvacrol is a monoterpenic phenol with antioxidant and anti-inflammatory properties. Aims: To determine the effects of carvacrol on oxidative liver injury induced by acrylamide administration in rats. Methods: Rats were divided into three groups of six animals each: healthy group acrylamide group (ACR), and acrylamide + carvacrol group (TACR). First, carvacrol (50 mg/kg) was administered intraperitoneally to the CACR group. One hour later, acrylamide (20 mg/kg) was given orally to the ACR and CACR groups. This procedure was performed for 30 days, after which the animals were sacrificed. The malondialdehyde (MDA) and total glutathione (tGSH) levels, total oxidant (TOS) and total antioxidant status (TAS), tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and nuclear factor kappa b (NF-κB) were measured in the excised liver tissues. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were determined in blood serum samples. Liver tissues were also examined histopathologically. Results: In the ACR group, malondialdehyde, TOS, ALT, AST levels, and NF-κB, IL-1β, and TNF-α levels were found to be high, and tGSH and total antioxidant status levels were low. In addition, diffuse degenerative changes and necrosis in hepatocytes, and moderate inflammation in the portal region were detected in the liver tissues of the ACR group. While carvacrol prevented the biochemical changes induced by acrylamide, it also alleviated the damage in the histological structure. Conclusion: Carvacrol may be used for liver damage caused by acrylamide.

Investigation of Chemical Compounds and Evaluation of Toxicity, Antibacterial, and Anti-Inflammatory Activities of Three Selected Essential Oils and Their Mixtures with Moroccan Thyme Honey

Throughout history, honey has been used to treat various diseases. The present work examined and assessed the in vivo anti-inflammatory potential of Moroccan thyme honey and its association with essential oils from three selected plants: Origanum vulgare L.; Mentha spicata L.; Eucalyptus globulus L. The chemical composition of the essential oils was studied, and preliminary toxicity, in vitro anti-inflammatory, and antibacterial tests were conducted. Then the anti-inflammatory effect was determined by applying carrageenan and an experimental trauma-induced paw edema test in rats. The essential oils were rich in phytochemicals and showed significant antibacterial activity against four selected ATCC bacterial strains. The results revealed the significant anti-inflammatory potential of honey and mixtures with essential oils and indicated higher efficiency of mixtures compared to honey alone. It can be concluded that the mixtures of honey and essential oils have advantageous anti-inflammatory effects and may be used for treating different types of inflammation in humans after certain clinical trials.

Chemical Profile, Antibacterial and Antioxidant Potential of Zingiber officinale Roscoe and Elettaria cardamomum (L.) Maton Essential Oils and Extracts

The aim of this work was to study the chemical composition of the essential oil extracted from ginger rhizomes (Zingiber officinale Roscoe) and cardamom seeds (Elettaria cardamomum (L.) Maton). Using gas chromatography coupled with mass spectrometry (GC/MS), a total of 43 compounds were identified in ginger essential oil and 17 compounds in cardamom. The most abundant components, respectively, were zingiberene (22.18%) and 1.8-cinéol (43.47%). Essential oils, methanol, ethanol and chloroform extracts for both plants were tested against nine bacteria and yeast. The highest sensitivity was noticed against Staphylococcus aureus with a 25 mm inhibition zone. The antioxidant potency of both oils and extracts were measured using DPPH (1,1-diphenyl-2-picryl hydrazyl) free radical scavenging and the ferric reducing power (FRP) method; the ethanolic extract of cardamom fruits exhibited the best results for both tests, with an IC 50 = 0.423 ± 0.015 mg/mL and 95.03 ± 0.076 FRP mg AAE/g.

Ethnopharmacological Survey and Comparative Study of the Healing Activity of Moroccan Thyme Honey and Its Mixture with Selected Essential Oils on Two Types of Wounds on Albino Rabbits

Wound healing consists of several continuous phases involving various cells and chemical intermediates. As a rich source of nutrition elements, honey has proved to have potential benefits in the treatment of various diseases. The present study was designed to investigate the healing effect of a honey mixture with selected essential oils on chemical and thermal wound models in rabbits. Dressing mixtures of Thymus vulgaris honey with three essential oils (Origanum vulgare, Rosmarinus officinalis, and Thymus vulgaris) were prepared and applied daily in the treatment groups. These essential oils were rich in phytochemicals and had significant antibacterial activity against four selected ATCC bacterial strains. Madecasol ointment was used as a standard control. The healing effect of the mixtures was evaluated by measuring wound surface area and comparing healing time. The results showed that the healing rate in the treatment groups was significantly higher than that of the untreated group and standard group. The best healing effect for burns was seen in the mixture of honey and Thymus vulgaris essential oil, which had wound closure rates of 85.21% and 82.14% in thermal- and chemical-induced burns, respectively, and showed the shortest healing time (14 days) in comparison to other groups. Therefore, it can be concluded that honey mixtures have significant beneficial effects on skin wound healing and, thus, they may be used as a healing agent in different types of wounds in humans after specific clinical trials.

Origanum vulgare ssp. hirtum (Lamiaceae) Essential Oil Prevents Behavioral and Oxidative Stress Changes in the Scopolamine Zebrafish Model

Origanum vulgare ssp. hirtum has been used as medicinal herbs promoting antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. We investigated the protective effects and the mechanism of O. vulgare ssp. hirtum essential oil (OEO) on cognitive impairment and brain oxidative stress in a scopolamine (Sco)-induced zebrafish (Danio rerio) model of cognitive impairment. Our results show that exposure to Sco (100 µM) leads to anxiety, spatial memory, and response to novelty dysfunctions, whereas the administration of OEO (25, 150, and 300 µL/L, once daily for 13 days) reduced anxiety-like behavior and improved cognitive ability, which was confirmed by behavioral tests, such as the novel tank-diving test (NTT), Y-maze test, and novel object recognition test (NOR) in zebrafish. Additionally, Sco-induced brain oxidative stress and increasing of acetylcholinesterase (AChE) activity were attenuated by the administration of OEO. The gas chromatography-mass spectrometry (GC-MS) analyses were used to elucidate the OEO composition, comprising thymol (38.82%), p-cymene (20.28%), and γ-terpinene (19.58%) as the main identified components. These findings suggest the ability of OEO to revert the Sco-induced cognitive deficits by restoring the cholinergic system activity and brain antioxidant status. Thus, OEO could be used as perspective sources of bioactive compounds, displaying valuable biological activities, with potential pharmaceutical applications.

Essential Oils from Fruit and Vegetables, Aromatic Herbs, and Spices: Composition, Antioxidant, and Antimicrobial Activities

In the field of food preservation, encapsulated Essential Oils (EOs) could be the best non-toxic and eco-friendly tool for food preservative applications substituting the chemicals ones that have several disadvantages for the environment and health. Thirteen commercial EOs from plants, fruits, and vegetables were characterized by GC-MS. The antioxidant activity was measured by DPPH and ABTS techniques. Antimicrobial activity was assessed by agar well-diffusion method and the Minimum Inhibitory Concentration (MIC) by agar dilution method against six bacteria, Candida albicans, and Botrytis cinerea. All the EOs tested have demonstrated antioxidant activity in the range of IC50 0.01-105.32 mg/mL. Between them, cinnamon EOs were the best, followed by oregano and thyme EOs. Fennel EO showed the lowest radical scavenging. MIC values ranged from 0.14 to 9 mg/mL. C. cassia, thyme, and oregano EOs were the most effective against the bacterial species tested, and the yeast C. albicans. On the contrary, citric fruit EOs showed low or no inhibition against most bacterial strains. The percentages of inhibition of mycelia growth of B. cinerea ranged from 3.4 to 98.5%. Thyme, oregano, mint, and fennel EOs showed the highest inhibition.

The Synergistic Beneficial Effect of Thyme Honey and Olive Oil against Diabetes and Its Complications Induced by Alloxan in Wistar Rats

Diabetes is a metabolic disorder characterized by a chronic increase in blood glucose. Owing to the limitations observed with antidiabetics in modern medicine, medicinal plants and bee products are known as good matrices for the search for new antidiabetic molecules. The present study focused on the evaluation of the hypoglycemic and the protective properties of two natural products widely used in complementary and alternative medicine (thyme honey and olive oil). To achieve this, the study was carried out on Wistar rats rendered diabetic by the injection of a single dose of alloxan monohydrate (65 mg/kg body weight (BW)). First, the physicochemical characterization and the phytochemical analysis of thyme honey and olive oil were carried out, and then in vivo study was conducted on 42 Wistar rats divided into seven groups: three groups were normal, one group was untreated diabetic, and three groups were diabetic rats treated with thyme honey (2 g/kg BW) or olive oil (10 mL/kg BW) or their combination ((1 g/kg BW of thyme honey) and (5 mL/kg BW of olive oil)). During the experiment, the glycemia was measured regularly every 10 days. After 30 days of treatment, the rats were sacrificed. The serum and urine were analyzed to determine hepatic enzymes levels (AST, ALT, ALP, and LDH), lipidic profile (total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein), and kidney parameters (urea, uric acid, creatinine, total protein, sodium, potassium, and chloride). The liver, pancreas, and kidneys were analyzed to evaluate their histological changes and to determine their enzymatic antioxidant content (catalase, GSH, and GPx) and the levels of MDA. The results obtained showed that thyme honey or olive oil, and especially their combination, improved significantly the blood glucose levels and they protect against metabolic changes and the complications induced by diabetes.

Chemical composition of essential oils from Thymus mongolicus, Cinnamomum verum, and Origanum vulgare and their acaricidal effects on Haemaphysalis longicornis (Acari: Ixodidae)

Chemical acaricides are mainly used in traditional tick control, which leads to the emergence of tick resistance and concurrently results in environmental pollution. In the present study, the chemical constituents of essential oils (EOs) from Thymus mongolicus, Cinnamomum verum, and Origanum vulgare was analyzed, and their potential application was evaluated to control the vector tick Haemaphysalis longicornis, which is widely distributed over vast areas of Eurasia, Australia, and New Zealand. Gas chromatography-mass spectrometry analysis revealed that the phenols thymol and carvacrol accounted for 34.66% and 75.72% of the EOs of T. mongolicus and O. vulgare, respectively, whereas trans-cinnamaldehyde (49.42%) was the main constituent of C. verum EO. Immersion tests showed that the EOs of C. verum and O. vulgare had significant acaricidal activity against larval H. longicornis, with the 50% lethal concentration (LC50) being 16.07 and 18.02 mg/mL, respectively, and the 95% lethal concentration (LC95) being 120.37 and 130.09 mg/mL, respectively. The EOs of O. vulgare and T. mongolicus showed significant acaricidal activity against unfed adult H. longicornis, with LC50 being 43.50 and 44.21 mg/mL, respectively, and LC95 being 113.66 and 137.99 mg/mL, respectively. The fumigant toxicity test showed significant acaricidal activity of the three EOs against both unfed and engorged nymphal and adult H. longicornis. Enzyme assays revealed that the EOs of both C. verum and O. vulgare significantly inhibited glutathione S-transferase activity (P < 0.05). In contrast, the activities of carboxylesterase and multifunction oxidases were significantly inhibited by EOs extracted from all three plants (P < 0.05). Taken together, these findings suggest that plant EOs may serve as an environment-friendly alternative for synthetic acaricides in future tick control.