Research - Antimicrobial
Chemical composition, antimicrobial and antibiotic potentiating activity of essential oils from 10 tropical medicinal plants from Mauritius
• Essential oils (EOs) from 10 tropical medicinal plants were extracted by hydrodistillation.
• Eighteen microorganisms were used to evaluate the antimicrobial potential of the EOs as well as their ability to potentiate conventional antibiotics.
• EOs showed potent bactericidal, fungicidal and antibiotic potentiating activity.
• Twenty eight major compounds were identified using GC–MS composed of monoterpenes hydrocarbons.
• Studied EOs may be exploited as complementary and alternative therapies against infectious diseases.
Infectious diseases and antibiotic resistance have become a public health issue of increasing magnitude. The discovery and development of new antimicrobial agents from herbal medicine to address this problem has attracted much attention and should be given high priority. This study was designed to evaluate the antimicrobial properties of essential oils (EOs) extracted from 10 common medicinal plants of Mauritius. Eighteen microorganisms (bacterial and fungal isolates) were used to evaluate the antimicrobial potential of the EOs as well as their ability to potentiate conventional antibiotics. The phytochemical profile was established using Gas chromatography–Mass spectrometry method. Antibacterial activities were recorded with low minimal inhibitory concentration for 4 of the EOs using the microbroth dilution assay. A synergistic effect of the EO ofCitrus hystrix D.C., Citrus reticulate (Blanco) and Melaleuca quinquenervia S.T. Blake (Cav.) were observed against Escherichia coli (ATCC 25922) and Staphylococcus epidermidis (ATCC 12228) when combined with gentamicin. Fungicidal and fungistatic effects of the EOs were observed among all the fungi irrespective of the family except forTrichophyton mentagrophytes. Twenty eight major compounds were identified and predominantly composed of monoterpene hydrocarbons at a dose-content ranging from 0.68 to 88.58%. This study has provided key information on the antimicrobial property and phytochemical composition of some tropical medicinal plants. Hence, EOs studied in the present investigation may be considered as potential medicinal candidates that could be exploited as complementary and alternative therapies for the treatment and management of infectious diseases.
Source : Journal Herbal Medicine
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Chemical composition and antimicrobial, antioxidant activities and anti-inflammatory potential of Achillea millefolium L., Anethum graveolens L., and Carum copticum L. essential oilsAbstract
Achillea millefolium L., Anethum graveolens L., and Carum copticum L. comprise several relevant species that may be used for the food, cosmetic, perfumery and pharmaceutical industries. Gas chromatography/mass spectrometry analysis revealed thymol to be a major component of A. millefolium, A. graveolens and C. copticum, with its contribution to the essential oils (EOs) being 26.47%, 20.07% and 23.14%, respectively. All three EOs exhibited significant antimicrobial activity against all tested bacterial strains, the A. millefolium oil being the most potent. In addition, A. millefolium EO had the highest antioxidant activity in all conducted assays. The A. millefolium EO had significantly greater radical scavenging activity than C. copticum EO and the reference antioxidant Trolox (IC50 values of 22.11, 26.5 and 28.32 mg/ml, respectively). In addition, a correlation between antioxidant activity and the total phenolic content was found. The A. millefolium EO significantly inhibited nitric oxide production in lipopolysaccharide-activated macrophages (an in vitro model of inflammation). These results clearly show the antimicrobial, antioxidant and anti-inflammatory effects of the plant EOs.
Source : Sci-Hub.bc
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Antimicrobial and antioxidant efficacy of Citrus limon L. peel extracts used for skin diseases by Xhosa tribe of Amathole District, Eastern Cape, South Africa
W.M. Otang, A.J. Afolayan
Skin diseases such as dermatitis, prurigo, and scabies present a major health concern in the Eastern Cape, South Africa, where there is a scarcity of dermatologists, compounded by the fact that most dermatologists are centered near urban areas and are not accessible to 70% of the rural population. Hence, many people still depend to a large extent on traditional herbs such as Citrus limon for the treatment of skin diseases. The aim of this study was therefore to screen the acetone and ethanol extracts of C. limon for its antioxidant potential and antimicrobial efficacy agents against a panel of microbes implicated in skin diseases. The highest antibacterial activity was obtained with the acetone extract of C. limon against Enterococcus faecalis and Bacillus subtilis, and the most susceptible bacteria based on the overall mean inhibition diameters were the gram-negative Salmonella typhimurium, Shigella sonnei and the gram-positive E. faecalis and B. subtilis. Both extracts were active against Candida glabrata. The DPPH scavenging activity of the acetone extract was not significantly different from those of vitamin C and rutin. Nitric oxide scavenging activity was lowest in the ethanol extract of C. limon. The reducing ability of both plant extracts was significantly lower than that of vitamin C and rutin. The fact that both extracts of C. limon exhibited a broad spectrum of antibacterial activity and comparable efficacy to the synthetic antioxidants highlights the medicinal value of C. limon as a potential source for drug development amidst the obvious dearth of effective and safe antibacterial drugs, and also validates the ethnotherapeutic claim of the plant.
Source : South African Journal of Botany
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Study of the composition of Thymus vulgaris essential oil, developing of topic formulations and evaluation of antimicrobial efficacy
Gisele Mara Silva Gonçalves1*, Silvana Mariana Srebernich2, Neura Bragagnolo3, Elisângela Serenato Madalozzo3, Vania Leandro Merhi2 and Denise Cristina Pires1
1School of Pharmaceutical Science, Pontifícia Universidade Católica de Campinas, Brazil.
2School of Nutrition, Pontifícia Universidade Católica de Campinas, Brazil.
3School of Food Engineering, UNICAMP, Brazil.
The essential oil of Thymus vulgaris has been the subject of extensive studies and developing formulations for the placement of essential oils is not an easy task due especially to it high volatility and low stability. The aims of this work were to study of the composition of T. vulgaris essential oil, development of topic formulations and evaluation of antimicrobial efficacy on Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. The composition of the oil was analyzed using gas chromatography/mass spectrometry. Microbiological disk diffusion and microdilution tests were carried out to determine the minimum inhibitory and minimum bactericidal concentrations. The substance was added to a cream gel formulation which underwent thermal stability, physical and chemical-physical tests (in addition to a drop test) to verify if the antimicrobial effects remained unchanged. The most abundant compounds were geraniol, thymol, gama-terpinene, para-cymene, citral, 3-octanone, and 3-octenol. The essential oil in formulation had similar antimicrobial effects in comparison to the essential oil itself; the formulation was partially stable during the study period. Formulations with T. vulgaris essential oil effectively inhibited microbial growth. The results show a reasonable stability of the formulation. The topical use of essential oil from thyme is a promising alternative for cosmetic and phytotherapeutic use.
Source : The Journal of Medicinal Plant Research
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