Synergistic effects of Ruta montana (Clus.) L. essential oil and antibiotics against some pathogenic bacteria

Antibiotic resistance has been called one of the world’s most pressing public health threats. The combination of essential oils with conventional antibiotics is one of the emerging approaches that could help prevent this problem. In light of this, this study aimed to investigate the impact of combination of Ruta montana essential oil with conventional antibiotics on some pathogenic bacteria. The essential oil isolated by steam-hydrodistillation was first analyzed using GC-MS then tested alone and in combination with five recommended antibiotics against three bacterial strains by the agar disc diffusion and broth micro-dilution methods. Out of forty-nine peaks, thirty-eight components were identified representing 98.17% of the total oil composition. The major components were 2-Undecanone (63.39%), 2-Nonanone (5.65%), 2-Acetoxytetradecane (4.94%), 2-Decanone (4.47%) and 2-Dodecanone (3.35%). While R. montana essential oil showed only weak antibacterial activity compared to the antibiotics tested alone, unexpectedly, the combination of RM essential oil with antibiotics remarkably increased the antibacterial activity of the antibiotics through synergistic effects in up to 70% of cases. These results suggest that combining antibiotics with essential oils, even those with low antibacterial activity, may be effective in overcoming problems caused by increasing bacterial resistance.

Ruta Essential Oils: Composition and Bioactivities

Ruta L. is a typical genus of the citrus family, Rutaceae Juss. and comprises ca. 40 different species, mainly distributed in the Mediterranean region. Ruta species have long been used in traditional medicines as an abortifacient and emmenagogue and for the treatment of lung diseases and microbial infections. The genus Ruta is rich in essential oils, which predominantly contain aliphatic ketones, e.g., 2-undecanone and 2-nonanone, but lack any significant amounts of terpenes. Three Ruta species, Ruta chalepensis L., Ruta graveolens L., and Ruta montana L., have been extensively studied for the composition of their essential oils and several bioactivities, revealing their potential medicinal and agrochemical applications. This review provides a systematic evaluation and critical appraisal of publications available in the literature on the composition and bioactivities of the essential oils obtained from Ruta species and includes a brief outlook of the potential applications of nanotechnology and chitosan-based products of Ruta essential oils.

Ruta montana evokes antihypertensive activity through increase of prosta-glandins release in L-NAME-induced hypertensive rats

Aims: The aim of the study was to investigate experimentally the antihypertensive effect of Ruta Montana. Background: Ruta montana L. is traditionally used in Moroccan herbal medicine to treat hypertension. This study aimed to evaluate experimentally the hypotensive and vasoactive properties of this plant. Objective: The objective of the study was to evaluate the effect of the aqueous extract of Ruta Montana on blood pressure parameters in LNAME-induced hypertensive rats and to determine the vasorelaxant activity of this aqueous extract. Methods: The antihypertensive effect of the aqueous extract obtained from Ruta montana aerial parts (RMAPAE) (200 mg/kg) was evaluated in normal and anesthetized hypertensive rats. Blood pressure parameters (systolic blood pressure (SBP), mean blood pressure (MBP) and diastolic blood pressure (DBP)) and heart rate were measured using a tail-cuff and a computer-assisted monitoring device. The acute and chronic effect of RMAPAE was recorded during 6 hours for the acute experiment and during 7 days for the sub-chronic test. In the other set, the vasorelaxant effect of RMAPAE on the contractile response was undertaken in isolated thoracic aorta. Results: The results indicated that RMAPAE extract significantly decreased SBP, MBP, DBP and heart rate in L-NAMEinduced hypertensive rats. Furthermore, RMAPAE was demonstrated to induce a dose dependent relaxation in the aorta precontracted with Epinephrine or KCl. More interestingly, this vasorelaxant activity of RMAPAE seems to be probably mediated through the prostaglandins pathway. Conclusion: The present study illustrates the beneficial action of Ruta montana on hypertension and supports then its use as an antihypertensive agent.

GC–MS Analysis, Antioxidant and Antimicrobial Activities of Achillea Odorata Subsp. Pectinata and Ruta Montana Essential Oils and Their Potential Use as Food Preservatives

In order to discover new natural resources with biological properties, the chemical composition, the antioxidant and antimicrobial activities, and the potential use as food preservative of essential oils of Moroccan Achillea odorata subsp. pectinata (AOpEO) and Ruta montana (RMEO) were studied. Gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of 21 and 25 compounds in AOpEO and RMEO, respectively. The results showed that the major compounds of AOpEO are camphor (45.01%), bornyl acetate (15.07%), borneol (11.33%), β-eudesmol (4.74%), camphene (3.58%), and 1.8-cineole (eucalyptol) (2.96%), whereas 2-undecanone (63.97%), camphor (3.82%) and cyclopropanecarboxylic acid (3.66%) were the main components of RMEO. The antioxidant activities were evaluated by diphenylpicrylhydraziyl radical (DPPH) and reducing power assays. The antimicrobial activities of essential oils were tested against bacterial strains and food contaminant yeast using agar disc diffusion and microdilution methods. A significant antimicrobial activity of AOpEO was observed against Bacillus subtilis, Proteus mirabilis and Candida albicans, compared to RMEO. The efficacy of AOpEO was also evaluated in model food systems (cabbage and barley) artificially inoculated during storage. The results found that the adding of a minimal inhibitory concentration (MIC) and 4× MIC were potent in decreasing the Proteus mirabilis growth in food model systems. Our findings suggested that AOpEO may be potentially used as an alternative food preservative.

In-Vitro Antioxidant Activity and Total Phenolic Content of Ruta montana L. Extracts

The aim of this study is to evaluate in vitro antioxidant activities of Ruta montana L. extracts. This activity was evaluated by three methods : DPPH (2, 2'-diphenyl- 1- picrylhydrazy), bleaching of β-carotene and chelation of ferrous iron. Results showed that ethyl acetate extract (EAE) represents the highest amount of total polyphenols, tannins and flavonoids with 257,1 ± 0,703µg gallic acid equivalent/mg of extract, 251 ± 1.41 µg tannic acid equivalent /mg of extract,117,4 ± 3,451 µg quercetin equivalents/mg of extract, 139,5 ± 4,107 µg rutin equivalents/mg of extract, respectively. In the DPPH assay, ethyl acetate extract showed the higher scavenging capacity (IC50 = 0.044 ± 0.001 mg/ml) followed by methanol, aqueous and chloroform extract. Whereas, AqE showed the best chelating effect and the best inhibitory capacity of the coupled oxidation of linoleic acid/ β-carotene. Keywords: Ruta montana L; polyphenols; antioxidant activity; free radical scavenging.

Repellent and fumigant toxic potential of three essential oils against Ephestia kuehniella

Essential oils, when used as bio-insecticides in the control of insect pests of stored grains have shown specificity and variation in the potentiality of their mode of action. In the present study, three essential oils extracted from three aromatic plants of different families, white wormwood (Artemisia herba alba, Asteraceae), oregano (Origanum vulgare, Lamiaceae) and rue (Ruta montana, Rutaceae), were evaluated for their repellent and fumigant toxic potential against the flour moth larvae, Ephestia kuehniella (Lepidoptera, Pyralidae), under laboratory conditions. The essential oils extraction was done by the hydrodistillation method. The repellent activity was carried out in Petri dishes using a filter paper treated with different oil dilutions (25, 75, 100, 120, 130, 150 µL/mL). The fumigant toxicity was determined on three concentrations (50, 130, 150 µL/L air). Two plants were shown to be repellent against the E. kuehniella larvae. Origanum oil was the most repellent with 67% of repellency rate followed by Artemisia oil (46%) at 120µL/mL after 2 hours of exposure. The oil of R. montana had an attractant activity against the larvae and was the most toxic with 56.7% of larval mortality in the first 24 hours. The median lethal concentrations (LC50) recorded were 11.6, 175.4 and 1100.0 µL/L air for the plant oils R. montana, O. vulgare and A. herba alba, respectively. R. montana and O. vulgare essential oil are shown to be efficient with high toxic and repellent properties against E. kuehniella larvae. Their specific potential could be integrated in the selection of the best bioinsecticides for the optimum protection of stored grain.