Effect of Lemongrass Essential Oil based Mouthwash against Microflora Associated with Dental Plaque

Mouthwash is one of the most convenient and effective method employed for dental plaque management. The aim of the undertaken study was to establish the antimicrobial and anti-biofilm properties of lemongrass essential oil (LGEO) based mouthwash on microbial flora from dental plaque and also check cytotoxicity of mouthwash formulation. Five main colonizers of dental plaque representing dental microflora and three different bacterial species mainly responsible for the formation of biofilm were selected in this study. LGEO based mouthwash was developed and its stability was also determined. The antimicrobial and anti-biofilm activity of LGEO based mouthwash has been evaluated against the representative dental microflora as per CLSI guidelines. Cytotoxicity of mouthwash was checked by globally used MTT assay employing NIH 3T3 mouse fibroblast cell line. The mouthwash has been found to exhibit the stability in its major component, citral and also found exhibit antimicrobial and anti-biofilm activity against dental microflora. No cytotoxic effect was observed on mouse fibroblast cell line. LGEO in formulated mouthwash being a natural, herbal material isolated from traditional medicinal plants appears as a good and effective substitute to control the microflora linked with dental plaque.

Lemongrass Essential Oil Components with Antimicrobial and Anticancer Activities

The prominent cultivation of lemongrass (Cymbopogon spp.) relies on the pharmacological incentives of its essential oil. Lemongrass essential oil (LEO) carries a significant amount of numerous bioactive compounds, such as citral (mixture of geranial and neral), isoneral, isogeranial, geraniol, geranyl acetate, citronellal, citronellol, germacrene-D, and elemol, in addition to other bioactive compounds. These components confer various pharmacological actions to LEO, including antifungal, antibacterial, antiviral, anticancer, and antioxidant properties. These LEO attributes are commercially exploited in the pharmaceutical, cosmetics, and food preservations industries. Furthermore, the application of LEO in the treatment of cancer opens a new vista in the field of therapeutics. Although different LEO components have shown promising anticancer activities in vitro, their effects have not yet been assessed in the human system. Hence, further studies on the anticancer mechanisms conferred by LEO components are required. The present review intends to provide a timely discussion on the relevance of LEO in combating cancer and sustaining human healthcare, as well as in food industry applications.

Composition, Anti-MRSA Activity and Toxicity of Essential Oils from Cymbopogon Species

Many of the essential oils obtained from medicinal plants possess proven antimicrobial activity and are suitable for medicinal purposes and applications in the food industry. The aim of the present work was the chemical analysis of 19 essential oils (EOs) from seven different Cymbopogon species (C. nardus, C. citratus, C winterianus, C. flexuosus, C. schoenanthus, C. martinii, C. giganteus). Five different chemotypes were established by GC/MS and TLC assay. The EOs, as well as some reference compounds, i.e., citronellol, geraniol and citral (neral + geranial), were also tested for their antimicrobial and antibiofilm activity against methicillin-resistant Staphylococcus aureus (MRSA) by the microdilution method and direct bioautography. The toxicity of EOs was evaluated by Danio rerio ‘Zebrafish’ model assay. All examined EOs showed moderate to high activity against MRSA, with the highest activity noted for C. flexuosus—lemongrass essential oil, both in microdilution and direct autobiography method. Significant difference in the toxicity of the examined EOs was also detected.

Correction: Moustafa et al. Insecticidal Activity of Lemongrass Essential Oil as an Eco-Friendly Agent against the Black Cutworm Agrotis ipsilon (Lepidoptera: Noctuidae). Insects 2021, 12, 737

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Anti-bacterial Activity of Alginate Based Edible Coating Solution Added with Lemongrass Essential Oil Against Some Pathogenic Bacteria

Edible coating is a thin layer that can be made of several materials, one of which is polysaccharides, such as alginates, carrageenan, agar, chitin, chitosan, pectin, starch, cellulose derivatives, and gums. The application of food products with edible coatings has been widely carried out and has been proven to improve quality and extend the shelf life of the product. Antibacterial agent can be added to improve the performance of edible coating. This study was aimed to explore the potential of lemongrass essential oil as an antibacterial agent in alginate based antibacterial edible coating solutions, especially against pathogenic bacteria. Edible coating is made of alginate powder, modified cassava flour (Mocaf), beeswax, glycerol and antibacterial agent. The additional levels of lemongrass essential oil into edible coating formula were 0.25, 1.50 and 0.75%. The antibacterial activity of the edible coating solution produced was tested against Escherichia coli, Staphylococcus aureus, Salmonella, and Pseudomonas aeruginosa by employing a disk diffusion testing method. Antibacterial agents used in previous studies to develop alginate-based antibacterial edible coatings and potential applications of the developed alginate-based edible coatings incorporated with lemongrass essential oil were identified by browsing through the internet. The results showed that various antibacterial agents have been explored to improve the performance of alginate based edible coatings. An antibacterial activity study exhibited that the highest antibacterial activity was found in the edible coating with the addition of 0.50% lemongrass essential oil, except for S. aureus at the addition level of 0.75%. This study suggests that the addition of lemongrass essential oil for the manufacture of alginate based edible coating solution is 0.50%. The potential uses of edible coatings made from alginate with the addition of lemongrass essential oil are to coat various animal and plant based food products.

Potential use of lemongrass essential oil as fungicide against Aspergillus brasiliensis and as post-harvest protectant of wheat

Fungi are among the main responsible for damage and loss in stored grains, its control has been done through synthetic substances, which are harmful to man and the environment. Brazil, one of the leading countries in agriculture, has optimal environmental conditions for the development of mycotoxigenic fungi. Most of the synthetic chemicals used as preservatives have often been realized to be toxic to humans and also cause adverse environmental effects. Thus, it is necessary to search for alternative methods of controlling. In this study the aimed was to evaluate the efficacy of lemongrass essential oil in the control of the Aspergillus brasiliensis. In vitro and serial microdilution tests were carried out at different concentrations of essential oil and citral, which corresponds to 72% of the total oil composition. Inhibition of fungal growth on contaminated wheat grain was evaluated. The in vitro test results showed that the essential oil has fungicidal potential at concentrations from 0.6 μL mL-1, the minimum inhibitory concentration was determined at 0.8 μL mL-1. The tests with citral showed fungal control at concentrations from 0.6 μL mL-1 onwards. For wheat grain, fungal growth inhibition was obtained at the concentration of 1.6 μL mL-1. The essential oil of Cymbopogon flexuosus showed fungicidal activity against the fungus Aspergillus brasiliensis.