Chemical composition, antibacterial and antifungal activities of Ruta graveolens L. volatile oils

Anticancer and antimicrobial evaluation of extract from brown algae Hormophysa cuneiformis

AIM

We investigated the antimicrobial and anticancer properties of an ethanol crude extract of Red Sea brown alga (Hormophysa cuneiformis) from Egypt.

METHODS

Extraction was achieved by mixing 100 g of sample powder with absolute ethanol, incubating at 37 °C overnight in a shaking incubator, and then collecting the extract. The extract's antimicrobial activity was tested using a well diffusion assay against the tested pathogens (Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Candida albicans) in comparison to commercial antibiotics. Anticancer activity was assessed using MTT assay on MCF-7, HepG-2, and HEP-2 cell lines. The anticancer mechanism of action against the HepG-2 cell line was investigated using cell cycle analysis, Annexin V, and antioxidant enzymes, in addition to transmission electron microscopy.

RESULTS

GC-MS phytoconstituent profile of the extract was dominant with fatty acids. A broad antimicrobial effect against all the pathogenic isolates of E. coli, S. aureus, B. subtitles, and C. albicans was demonstrated, especially at the high concentration in comparison to commercial antibiotics. The extract could inhibit the growth of the tested cell lines. We observed the most significant effect on HepG-2 cells, and the concentration of the extract played a role in the level of inhibition (IC50 of 44.6 ± 0.6 µg/ml). The extract had negligible effects on Vero normal cell lines at the lower concentration, with slight toxicity (90.8% viability) at the highest concentration (500 µg/ml). At this same concentration, the extract caused 80-92% inhibition of the cancer cell lines. The extract appears to have demonstrated promising effects on cancer cells. It induces programmed cell death (apoptosis), arrests the cell cycle, and affects the oxidative/antioxidant balance within the cells, potentially leading to the suppression or elimination of cancer cells. These findings are encouraging and may have implications for cancer treatment or further research in this area. More action of extract was seen against bacteria than fungi, with a wide antibacterial impact against all of the tested isolates, notably at the high concentration in comparison to conventional antibiotics.

CONCLUSION

According to the findings, H. cuneiformis may be a valuable source of chemicals that are both antimicrobial and anticancer.

A Candidate for Health Promotion, Disease Prevention and Treatment, Common Rue (Ruta graveolens L.), an Important Medicinal plant in Traditional Medicine

BACKGROUND

Ruta graveolens L. belongs to Rutaceae; it is a semi-wood perennial or a small evergreen sub-shrub, which is native to Southern Europe, West of Asia and Northern Africa.

OBJECTIVE

The goal of this manuscript was to outline the most notable traditional and modern advantages and pharmaceutical benefits of common rue.

METHODS

The manuscript covers review articles, randomized control experiments, analytical studies and observations, which have been gathered from different sources such as Google Scholar, Scopus, Science Direct and PubMed. A review of the literature was carried out using the keywords rutin, Ruta graveolens L., rue, common rune, coumarin, natural products and pharmaceutical benefits.

RESULTS

Rue contains quinoline alkaloids, such as graveoline and graveolinine, acridone alkaloids, such as furacridone and gravacridone, the furanoquinoline dictamnine, coumaris, such as gravelliferone, isorutarin, rutacultin, rutaretin, and suberenone, and the furanocoumarins 5-methoxypsoralen (bergapten) and 8-methoxypsoralen (xanthotoxine). Most of its aromatic and medicinal properties are from its rutin, and essential oil. It has been used in folk medicines as a stimulant, anti-inflammatory and analgesic properties, anti-androgenic activity, anti-hyperglycemic effects, anti-hyperlipidemic effects, xanthine oxidase inhibition activity, anticancer properties.

CONCLUSION

According to pharmacological and phytochemical advantages, pennyroyal shows its importance as a medicinal plant in both modern medicinal science and traditional medicine.

The Bacillary Postbiotics, Including 2-Undecanone, Suppress the Virulence of Pathogenic Microorganisms

Secreted molecules from probiotic Bacilli have often been considered potential pharmaceuticals to fight infections caused by bacterial or yeast pathogens. In the present study, we investigated the antagonistic potential of secreted probiotic filtrates (hereafter, postbiotics) derived from Lactobacillus plantarum cells against pathogenic microorganisms, such as Escherichia coli, Staphylococcus aureus, and Candida albicans. We found that the postbiotics mitigate the biofilms of the tested pathogens with no notable effect on their planktonic growth. In addition, the postbiotics suppressed some virulence traits, for instance, the dendrite swarming motility of E. coli and yeast-to-hyphal switch in C. albicans. Further assays with an active constituent produced by the L. plantarum cells–2-undecanone revealed two significant findings: (i) 2-undecanone inhibits C. albicans biofilms and hyphae in vitro and in a Caenorhabditis elegans model, and (ii) it interacts specifically with Gln 58 amino acid residue of hyphal wall protein-1 (Hwp-1) in molecular docking analysis. The results suggest the targeted mode of antagonistic action of 2-undecanone against C. albicans biofilm. In total, the findings of the study depict an appealing strategy to use postbiotics, including specific ketone molecules, produced by L. plantarum for developing novel antibiofilm and anti-hyphal pharmaceuticals.

Brocchia cinerea (Delile) Vis. Essential Oil Antimicrobial Activity and Crop Protection against Cowpea Weevil Callosobruchus maculatus (Fab.)

Antibiotics and synthetic pesticides are now playing a role in the spread of resistant pathogens. They continue to have negative consequences for animal and plant health. The goal of this work is to identify the chemical composition of Brocchia cinerea (Delile) Vis. essential oil (EO) using GC-MS(Gas Chromatography-Mass Spectrometer), evaluate its antimicrobial properties, and investigate its insecticidal and repellent effectiveness against Callosobruchus maculatus (C. maculatus). The GC-MS indicated the presence of 21 chemicals, with thujone (24.9%), lyratyl acetate (24.32%), camphor (13.55%), and 1,8-cineole (10.81%) being the most prominent. For the antimicrobial assay, the yeast Candida albicans was very sensitive to the EO with a growth inhibition diameter of (42.33 mm), followed by Staphylococcus aureus (31.33 mm). Fusarium oxysporum is the mycelia strain that appeared to be extremely sensitive to the utilized EO (88.44%) compared to the two species of Aspergillus (A. flavus (48.44%); A. niger (36.55%)). The results obtained in the microdilution method show that Pseudomonas aeruginosa was very sensitive to the EO, inhibited by a very low dose (0.0018 mg/mL). The minimum inhibitory concentration (MIC) results were between 0.0149 and 0.06 mg/mL. B. cinerea EO also demonstrated a potent insecticidal effect and a medium repulsive effect against C. maculatus. Thus, the LC₅₀ value in the contact test was 0.61 μL/L of air, lower than that observed in the inhalation test (0.72 μL/L of air). The present study reveals that B. cinerea EO has the potential to be an antimicrobial and insecticidal agent with a better performance against several pathogenic microorganisms.

Chemical Profile of Ruta graveolens, Evaluation of the Antioxidant and Antibacterial Potential of Its Essential Oil, and Molecular Docking Simulations

The research aimed to investigate the chemical composition and antioxidant and antibacterial potential of the essential oil (EO) isolated from the aerial parts (flowers, leaves, and stems) of Ruta graveolens L., growing in western Romania. Ruta graveolens L. essential oil (RGEO) was isolated by steam distillation (0.29% v/w), and the content was assessed by gas chromatography-mass spectrometry (GC-MS). Findings revealed that 2-Undecanone (76.19%) and 2-Nonanone (7.83%) followed by 2-Undecanol (1.85%) and 2-Tridecanone (1.42%) are the main detected compounds of the oil. The RGEO exerted broad-spectrum antibacterial and antifungal effects, S. pyogenes, S. aureus, and S. mutans being the most susceptible tested strains. The antioxidant activity of RGEO was assessed by peroxide and thiobarbituric acid value, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and β-carotene/linoleic acid bleaching testing. The results indicated moderate radical scavenging and relative antioxidative activity in DPPH and β-carotene bleaching tests. However, between the 8th and 16th days of the incubation period, the inhibition of primary oxidation compounds induced by the RGEO was significantly stronger (p < 0.001) than butylated hydroxyanisole (BHA). Molecular docking analysis highlighted that a potential antimicrobial mechanism of the RGEO could be exerted through the inhibition of D-Alanine-d-alanine ligase (DDl) by several RGEO components. Docking analysis also revealed that a high number RGEO components could exert a potential in vitro protein-targeted antioxidant effect through xanthine oxidase and lipoxygenase inhibition. Consequently, RGEO could be a new natural source of antiseptics and antioxidants, representing an option for the use of synthetic additives in the food and pharmaceutical industry.

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.

Colombian Essential Oil of Ruta graveolens against Nosocomial Antifungal Resistant Candida Strains

Drug resistance in antifungal therapy, a problem unknown until a few years ago, is increasingly assuming importance especially in immunosuppressed patients and patients receiving chemotherapy and radiotherapy. In the past years, the use of essential oils as an approach to improve the effectiveness of antifungal agents and to reduce antifungal resistance levels has been proposed. Our research aimed to evaluate the antifungal activity of Colombian rue, Ruta graveolens, essential oil (REO) against clinical strains of Candida albicans, Candida parapsilopsis, Candida glabrata, and Candida tropicalis. Data obtained showed that C. tropicalis and C. albicans were the most sensitive strains showing minimum inhibitory concentrations (MIC) of 4.1 and 8.2 µg/mL of REO. Time–kill kinetics assay demonstrated that REO showed a fungicidal effect against C. tropicalis and a fungistatic effect against C. albicans. In addition, an amount of 40% of the biofilm formed by C. albicans was eradicated using 8.2 µg/mL of REO after 1 h of exposure. The synergistic effect of REO together with some antifungal compounds was also investigated. Fractional inhibitory concentration index (FICI) showed synergic effects of REO combined with amphotericin B. REO Lead a disruption in the cellular membrane integrity, consequently resulting in increased intracellular leakage of the macromolecules, thus confirming that the plasma membrane is a target of the mode of action of REO against C. albicans and C. tropicalis.

Reduction of Postharvest Quality Loss and Microbiological Decay of Tomato "Chonto" (Solanum lycopersicum L.) Using Chitosan-E Essential Oil-Based Edible Coatings under Low-Temperature Storage

The tomato (Solanum lycopersicum L.) is one of the many essential vegetables around the world due to its nutritive content and attractive flavor. However, its short shelf-life and postharvest losses affect its marketing. In this study, the effects of chitosan-Ruta graveolens (CS + RGEO) essential oil coatings on the postharvest quality of Tomato var. "chonto" stored at low temperature (4 °C) for 12 days are reported. The film-forming dispersions (FFD) were eco-friendly synthesized and presented low viscosities (between 0.126 and 0.029 Pa s), small particle sizes (between 1.29 and 1.56 μm), and low densities. The mature index (12.65% for uncoated fruits and 10.21% for F4 coated tomatoes), weight loss (29.8% for F1 and 16.7% for F5 coated tomatoes), and decay index (3.0 for uncoated and 1.0 for F5 coated tomatoes) were significantly different, indicating a preservative effect on the quality of the tomato. Moreover, aerobic mesophilic bacteria were significantly reduced (in five Log CFU/g compared to control) by using 15 μL/mL of RGEO. The coatings, including 10 and 15 μL/mL of RGEO, completely inhibited the mold and yeast growth on tomato surfaces without negatively affecting the consumer acceptation, as the sensorial analysis demonstrated. The results presented in this study show that CS + RGEO coatings are promising in the postharvest treatment of tomato var. "chonto".

Colletotrichum gloesporioides inhibition using chitosan-Ruta graveolens L essential oil coatings: Studies in vitro and in situ on Carica papaya fruit

In this study we assessed the efficacy of chitosan (CHI) (2%) emulsion added with Ruta graveolens L. essential oil (REO) at different concentrations (0.5%, 1.0% and 1.5%) to control C. gloesporioides grows both "in situ" and "in vitro" in papaya Maradol (Carica papaya L.). In vitro studies showed a decrease on fungal growth (mycelia diameter) with the increase of REO concentration, while 0.5% of REO induce a reduction of 56.42%, REO at 1.0% and 1.5% induced a reduction of 97%. Microscopic analysis showed irreversible deleterious morphological and ultrastructural alterations as well as changes in conidia morphology, and conidia germination inhibition up to 90%. Among the most abundant REO constituents, 2-Nonanol showed strong antifungal activity followed by 2-Undecanone, Benzyl acetate, 2-Nonanone, 2-Tridecanone and 2-Dodecanone. Studies "in situ" on papaya fruit during 12 days at 20 °C, showed a reduction of the C. gloesporioides lesion expansion by 50% using CHI-REO 0.5% emulsions and by 100% with treatments of CHI-REO 1.0 and 1.5%, in addition the emulsions were efficacious to reduce the fruit surface microbiota. On the other hand, physicochemical analysis of the papaya fruits demonstrated that CHI-REO emulsions treatment delayed papaya ripening without affecting the organoleptic characteristics. All these results demonstrated for the first time the application of coatings CHI-REO as a postharvest treatment for the control of anthracnose on papaya fruit.

Assessment of Chitosan-Rue (Ruta graveolens L.) Essential Oil-Based Coatings on Refrigerated Cape Gooseberry (Physalis peruviana L.) Quality

Cape gooseberry (Physalis peruviana L.) is one of the main exotic fruits in demand throughout the world market. However, this fruit has problems with physical and microbial decay causing losses up to thirty percent during post-harvest stage and market storage. As an alternative for conservation, technologies based on edible coatings of biopolymers incorporating essential oils have been developed. In this paper we studied the effect of edible coatings based on chitosan (CS) and Ruta graveolens L. essential oil (RGEO) at different concentrations applied on the surface gooseberries at 18 ± 2 °C. The emulsions exhibited a reduction in the viscosity and the particle size with the increasing in the RGEO amount (from 124.7 cP to 26.0 cP for CS + RGEO 0.5% and CS + RGEO 1.5%, respectively). A lower weight loss was obtained for fruits coated with CS + RGEO 0.5% (12.7%) as compared to the uncoated (15%), while the maturity index increased in a lower amount for CS + RGEO coated than the uncoated fruits. The mesophyll growth was delayed three days after the coating applications for CS + RGEO 1.0% and 1.5%. At day twelve of the coating process, fruits with CS + RGEO 1.5% presented only 3.1 Log UFC/g of aerobic mesophylls and 2.9 Log UFC/g of molds and yeasts, while the uncoated fruits presented 4.2 Log UFC/g of aerobic mesophylls and 4.0 Log UFC/g of molds and yeasts, demonstrating a microbial barrier of the coatings incorporating RGEO in a concentration dependent manner. The CS + RGEO coating also preserve the antioxidant property of case gooseberries after twelve days of treatment under storage according to the 2,2′-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethyl-benzothiazoline-6-sulphonic acid) (ABTS) results. It was demonstrated by the ABTS method that T5 antioxidant capacity from day one to day twelve only decreases from 55% to 44%, while in the uncoated fruits (T1) the antioxidant capacity decreased from 65% to 18%. On the other hand, using the DPPH method the reduction was from 73% to 24% for the uncoated samples and 55% to 43% for T5. From the sensorial analysis, we recommend the use of CS + RGEO 0.5% that was still accepted by the panelists after the sixth day of application. These results show the potential application of these coatings as postharvest treatment under storage and low temperature conditions during twelve days of treatment for cape gooseberry fruits.

Synthesis, Characterization, and Histological Evaluation of Chitosan-Ruta Graveolens Essential Oil Films

The development of new biocompatible materials for application in the replacement of deteriorated tissues (due to accidents and diseases) has gained a lot of attention due to the high demand around the world. Tissue engineering offers multiple options from biocompatible materials with easy resorption. Chitosan (CS) is a biopolymer derived from chitin, the second most abundant polysaccharide in nature, which has been highly used for cell regeneration applications. In this work, CS films and Ruta graveolens essential oil (RGEO) were incorporated to obtain porous and resorbable materials, which did not generate allergic reactions. An oil-free formulation (F1: CS) and three different formulations containing R. graveolens essential oil were prepared (F2: CS-RGEO 0.5%; F3: CS+RGEO 1.0%; and F4: CS+RGEO 1.5%) to evaluate the effect of the RGEO incorporation in the mechanical and thermal stability of the films. Infrared spectroscopy (FTIR) analyses demonstrated the presence of RGEO. In contrast, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis showed that the crystalline structure and percentage of CS were slightly affected by the RGEO incorporation. Interesting saturation phenomena were observed for mechanical and water permeability tests when RGEO was incorporated at higher than 0.5% (v/v). The results of subdermal implantation after 30 days in Wistar rats showed that increasing the amount of RGEO resulted in greater resorption of the material, but also more significant inflammation of the tissue surrounding the materials. On the other hand, the thermal analysis showed that the RGEO incorporation almost did not affect thermal degradation. However, mechanical properties demonstrated an understandable loss of tensile strength and Young’s modulus for F3 and F4. However, given the volatility of the RGEO, it was possible to generate a slightly porous structure, as can be seen in the microstructure analysis of the surface and the cross-section of the films. The cytotoxicity analysis of the CS+RGEO compositions by the hemolysis technique agreed with in vivo results of the low toxicity observed. All these results demonstrate that films including crude essential oil have great application potential in the biomedical field.

A review of the antimicrobial potential of herbal drugs used in popular Italian medicine (1850s-1950s) to treat bacterial skin diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Before the advent of modern antibiotics, microbial infections were treated with herbal medicine or cauterization. Literature from the latter half of the nineteenth to the early mid-twentieth century, when antibiotics became widely available, arguably holds the most progressive information about herbal remedies to treat bacterial skin diseases. The corpus of literature produced in Italy during that period is not easily accessible and mostly out of print.

MATERIAL AND METHODS

Plant-based remedies utilized in popular Italian medicine to treat anthrax, boils, erysipelas, impetigo, pustules, and whitlow were sourced from literature indexed in and available through the National Library Service website of the Italian Libraries Network. The remedies are assessed for their antimicrobial potential based on a detailed search of the herbal drug species in scientific databases.

RESULTS

A considerable part of the reviewed recipes included specific excipients (41 out of 139) and others were produced with fresh plant material (48 out of 139). Out of the 52 identified herbal drug species used in popular Italian medicine against dermatologic infections, extracts of 43 were shown to have moderate in vitro activity against Gram-positive and Gram-negative bacteria.

CONCLUSION

The antibacterial activity of the extracts and pure compounds as reported in the reviewed literature is mostly based on in vitro assays and generally does not encourage follow up studies. The effectiveness of the reported recipes, which include fresh plant material and excipients can only be assessed through in vivo studies. Those remedies including herbal drugs with reported antimicrobial activity might have the potential as complementary therapies. The reviewed plant based antimicrobial recipes might serve as inspirations in the search for alternative topical antibacterial strategies and the search for their synergistic and potentiating ingredients.

Elevated Bioactivity of Ruta graveolens against Cancer Cells and Microbes Using Seaweeds

Human cancer and pathogenic microbes cause a significant number of deaths every year. Modulating current sources of natural products that control such diseases becomes essential. Natural algae, such as Ascophyllum nodosum and Ecklonia maxima, can modulate the metabolic processes as well the bioactivities of Ruta graveolens L. The R. graveolens plants were subjected to nine soil drenches of A. nodosum (7 mL L−1), E. maxima (7 mL L−1), or both extracts. Morphological performance, gas exchange parameters, and essential oils (EOs) composition (GC-MS) were studied and the bioactivity was assessed against several cancer cells and pathogenic bacteria or fungi. Treatment with A. nodosum + E. maxima seaweed extracts (SWE) led to the highest morphological performance and gas exchange parameters. The highest antiproliferative, apoptotic, and caspase-3/7 activities of EO were against HeLa in SWE mixture treated plants. The best EO antimicrobial activities were obtained against Staphylococcus aureus and Penicillium ochrochloron. SWE mixtures treated plants showed the best bioactivities against microbes and cancer cells. The highest abundance of 2-undecanone (62%) and 2-nonanone (18%) was found in plants treated with SWE mixtures and caused the best anticancer and antimicrobial effects. Seaweed mixtures act as natural elicitors of pharmaceutical industries and favored 2-undecanone and 2-nonanone in R. graveolens.

Colletotrichum Gloesporioides Inhibition In Situ by Chitosan-Ruta graveolens Essential Oil Coatings: Effect on Microbiological, Physicochemical, and Organoleptic Properties of Guava (Psidium guajava L.) during Room Temperature Storage

Guava is a fruit appreciated worldwide for its high content of bioactive compounds. However, it is considered a highly perishable fruit, generally attacked by pathogenic species such as the fungi Colletotrichum gloeosporioides, which causes anthracnosis. To diminish the losses caused by pathogenic fungi, coatings of chitosan (CS) with Ruta graveolens essential oil (RGEO) in different concentrations (0.5, 1.0, 1.5% v/v) were applied in situ and their effects on the physical properties and microbiological quality of the guavas were studied. The CS+RGEO coated fruits exhibited better physicochemical behavior and lower microbiological decay as compared to the uncoated guavas, demonstrating the effectiveness of the coatings, especially those with 1.5% of RGEO content. All the fruits coated had greater acceptance and quality than the controls, being more those with essential oil incorporation. In situ investigation of C. gloesporioides infection of guavas demonstrated that the CS+RGEO coated guavas showed a high percentage of inhibition in the development of anthracnose lesions. In the present investigation, an alternative method has been proposed to extend the stability of the guavas fruit up to 12 days with application in the food industry.

Essential oil composition and antibacterial activity of Pteridium aquilinum (L.) Kuhn

INTRODUCTION

The present work aims to study the chemical composition of Pteridium aquilinum (L.) Kuhn essential oil and its antibacterial activity against three important phytopathogenic Gram-negative bacteria: Erwinia amylovora, Pectobacterium carotovorum subsp. caroto-vorum, and Pseudomonas savastanoi pv. savastanoi.

METHODS

The chemical composition of P. aquilinum L. essential oil produced by hydrodistillation was determined by gas chromatography-mass spectrometry. The antibacterial activity was tested using disk diffusion method and by determination of minimum inhibitory concentration values. The major components were linalool (10.29%), carvacrol (8.15%), benzaldehyde (5.95%), 2-undecanone (5.32%), and cuminaldehyde (4.57%).

RESULTS

The essential oil tested revealed a powerful antibacterial effect against all tested strains, with inhibition zone diameters ranging from 32.0 ± 0.58 to 33.7 ± 0.88 mm.

DISCUSSION

P. aquilinum EO contained 32.86% of oxygenated monoterpenes, which are known for their very powerful antimicrobial activities. The minimum inhibitory concentration values showed that P. aquilinum essential oil has very strong activity against E. amylovora (0.625 ul/ml), followed by P. carotovorum subsp. carotovorum (2.50 ul/ml) and P. savastanoi pv. savastanoi (5.00 ul/ml). The results obtained could contribute to the development of new potential agents for the control of bacterial diseases.