Essential Oil Prepared from Cymbopogon citrates Exerted an Antimicrobial Activity Against Plant Pathogenic and Medical Microorganisms

Ethnobotanical uses, phytochemistry and bioactivities of Cymbopogon plants: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbopogon (Poaceae) plants have been used for various purposes by many indigenous peoples in all continents. In particular, almost all species in the genus have traditionally been used as folk medicine to treat ailments. Traditional application records indicated that Cymbopogon might be used extensively to treat cold, dizziness, headache, loss of appetite, abdominal pain, rheumatism, diarrhea, whole grass for cold, sore throat, tracheitis and others.

AIMS OF THE REVIEW

Despite several research confirmed that Cymbopogon includes a range of active components, no review has been undertaken to consolidate information on its traditional uses, phytochemistry, pharmacology, and/or quality control. Thus this article aims to update a comprehensive review about the traditional uses, phytochemistry, pharmacology, cultivation techniques, economic benefits, trade, threats, and future conservation implications of Cymbopogon species. It may provide informative data for future development and further investigation of this important plant group.

MATERIALS AND METHODS

Traditional medicinal books and ethnomedicinal publications related to Cymbopogon from 1992 to 2023 were collated to investigate its ethnobotanical, phytochemical and pharmacological information. The online databases including Google Scholar, SciFinder, Web of Science, Scopus, Springer Link, PubMed, Wiley, China National Knowledge Infrastructure (CNKI), Baidu Scholar, and WanFang Database were screened.

RESULTS

Cymbopogon (Gramineae or Poaceae) plants have been grown worldwide. Traditional Chinese medicine and other medicinal systems believes that Cymbopogon has the effect of relieve a cough, analgesia, treating dizziness, traumatic injury and can relieve abdominal pain. A total of 153 compounds, including flavonoids, terpenoids, fatty acid and other compounds were isolated or identified from Cymbopogon species by phytochemical studies. The extracts or compounds from Cymbopogon have exhibited numerous biological activities such as antibacterial, antiinflammatory, antiviral, antineoplastic, antiarrhythmic, antidiabetic and other activities. The rich contents of citronellal, citronellol and geraniol found in Cymbopogon also provide significant nutritional benefits.

CONCLUSION

Based on their traditional uses, phytochemicals, and pharmacological activities, Cymbopogon plants are potential medicinal and edible resources with diverse pharmacological effects. Due to various advantages of this group, they possess huge application potential in food and pharmaceutical industries, and animal husbandry. Among them, citronella is very important in terms of economic development. Further comprehensive research to evaluate the medicinal properties of Cymbopogon species will be necessary for future development.

Review of phytomedicine, phytochemistry, ethnopharmacology, toxicology, and pharmacological activities of Cymbopogon genus

The Cymbopogon genus belongs to the Andropoganeae family of the family Poaceae, which is famous for its high essential oil concentration. Cymbopogon possesses a diverse set of characteristics that supports its applications in cosmetic, pharmaceuticals and phytotherapy. The purpose of this review is to summarize and connect the evidence supporting the use of phytotherapy, phytomedicine, phytochemistry, ethnopharmacology, toxicology, pharmacological activities, and quality control of the Cymbopogon species and their extracts. To ensure the successful completion of this review, data and studies relating to this review were strategically searched and obtained from scientific databases like PubMed, Google Scholar, ResearchGate, ScienceDirect, and Elsevier. Approximately 120 acceptable reviews, original research articles, and other observational studies were included and incorporated for further analysis. Studies showed that the genus Cymbopogon mainly contained flavonoids and phenolic compounds, which were the pivotal pharmacological active ingredients. When combined with the complex β-cyclodextrin, phytochemicals such as citronellal have been shown to have their own mechanism of action in inhibiting the descending pain pathway. Another mechanism of action described in this review is that of geraniol and citral phytochemicals, which have rose and lemon-like scents and can be exploited in soaps, detergents, mouthwash, cosmetics, and other products. Many other pharmacological effects, such as anti-protozoal, anti-bacterial, anti-inflammatory and anti-cancer have been discussed sequentially, along with how and which phytochemicals are responsible for the observed effect. Cymbopogon species have proven to be extremely valuable, with many applications. Its phytotherapy is proven to be due to its rich phytochemicals, obtained from different parts of the plant like leaves, roots, aerial parts, rhizomes, and even its essential oils. For herbs of Cymbopogon genus as a characteristic plant therapy, significant research is required to ensure their efficacy and safety for a variety of ailments.

Toxicology of diatomaceous earth, phyto oils and their admixed emulsions against adults of Tribolium castaneum (Herbst)

Tribolium castaneum (Herbst), one of the invasive stored pest, is resistant to the most of synthetic insecticides used against this it. Moreover, synthetic insecticides are a major threat to human health, the environment, and the ecosystem. The development of some smart tools is needed to minimize the use of hazardous chemicals. As an alternative, nano-insecticides are on the horizon. Emulsions are expressed as sustain release of insecticidal components to achieve maximum efficacy and low residual toxicity. In this study, some essential oils (Cymbopogon citratus (DC.) Stapf, Ocimum basilicum L., Curcuma longa L., and Trachyspermum ammi L.), diatomaceous earth (DE), and their nano-emulsions are evaluated against T. castaneum. Essential oils and DE were tested at four (60 ppm, 30 ppm, 15 ppm, 7.5 ppm) different concentrations with and without emulsions, and data was recorded after 6, 12, 24, 48, and 72 h of exposure respectively. The mortality observed in essential oils of C. citratus, O. basilicum, and C. longa without emulsion after 72 h of treatment at the highest concentration was 98%, 95%, and 85%, respectively. While, at the highest concentration the lowest mortalities were observed with DE and T. ammi i.e. 65%. Insecticidal activity of emulsion essential oils increased to 100%, 98%, 90%, and 68.3% for C. longa, C. citratus, O. basilicum, and T. ammi, respectively. The results support that these admixed emulsions could be used as an alternative to synthetic insecticides in conventional formulations.

The in vitro antimicrobial activity of Cymbopogon essential oil (lemon grass) and its interaction with silver ions

BACKGROUND

It is well known that Cymbopogon (lemon grass) essential oil exhibits antimicrobial activity while the efficacy of silver ions as a disinfectant is equally well reported.

HYPOTHESIS

The antimicrobial activity of CEO and Ag(+) and their synergistic combinations will be useful in improving the current treatment strategies for various infections.

STUDY DESIGN

In the present study, we determined the chemical composition and in vitro antimicrobial activity of six different Cymbopogon essential oils (CEO's) alone and in combination with silver ions (Ag(+)) against two Gram-positive (Staphylococcus aureus and Enterococcus faecalis), two Gram-negative (Escherichia coli and Moraxella catarrhalis) and two yeast species (Candida albicans and Candida tropicalis). The nature of potential interactions was determined by fractional inhibitory concentration indices (FICIs) for CEO's and Ag(+) calculated from microdilution assays and time-kill curves.

RESULTS

Gas chromatography-mass spectrometry results confirmed the presence of nerol, geranial and geraniol as major volatile compounds. Minimum inhibitory concentration (MIC) values confirmed that all the tested pathogens are variably susceptible to both CEO's as well as Ag(+). The MIC of CEO's and Ag(+) against all the tested pathogens ranged from 0.032 mg/ml to 1 mg/ml and 0.004 and 0.064 mg/ml respectively, whereas when assayed in combination the FICI values were drastically reduced to range between 0.258 and 2.186, indicating synergy, additive and indifferent interactions. The most prominent interaction was observed between Cymbopogon flexuosus essential oil and Ag(+) against C. albicans with ∑FIC = 0.254. The synergistic interactions were further confirmed through the construction of isobolograms and time-kill plots. Transmission electron microscopy showed disturbance in the cell envelope upon the concomitant treatment of CEO's and Ag(+), which ultimately leads to cell death.

CONCLUSION

Results suggest that CEO's and Ag(+) when used in combination offers an opportunity to the formulation scientist to produce novel combinations acting synergistically in the continued quest to control important infectious pathogens.

Cymbopogon species; ethnopharmacology, phytochemistry and the pharmacological importance

Cymbopogon genus is a member of the family of Gramineae which are herbs known worldwide for their high essential oil content. They are widely distributed across all continents where they are used for various purposes. The commercial and medicinal uses of the various species of Cymbopogon are well documented. Ethnopharmacology evidence shows that they possess a wide array of properties that justifies their use for pest control, in cosmetics and as anti-inflammation agents. These plants may also hold promise as potent anti-tumor and chemopreventive drugs. The chemo-types from this genus have been used as biomarkers for their identification and classification. Pharmacological applications of Cymbopogon citratus are well exploited, though studies show that other species may also useful pharmaceutically. Hence this literature review intends to discuss these species and explore their potential economic importance.