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Concept: Pelargonium graveolens


BACKGROUND: Pelargonium graveolens (P. graveolens) L. is an aromatic and medicinal plant belonging to the geraniacea family. RESULTS: The chemical compositions of the essential oil as well as the in vitro antimicrobial activities were investigated. The GC-MS analysis of the essential oil revealed 42 compounds. Linallol L, Citronellol, Geraniol, 6-Octen-1-ol, 3,7-dimethyl, formate and Selinene were identified as the major components. The tested oil and organic extracts exhibited a promising antimicrobial effect against a panel of microorganisms with diameter inhibition zones ranging from 12 to 34 mm and MICs values from 0.039 to10 mg/ml. The investigation of the phenolic content showed that EtOAc, MeOH and water extracts had the highest phenolic contents. CONCLUSION: Overall, results presented here suggest that the essential oil and organic extracts of P. graveolens possesses antimicrobial and properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry.

Concepts: Pharmacology, Water, Essential oil, Oil, Oils, Rose, Rose oil, Pelargonium graveolens


OBJECTIVES/HYPOTHESIS: Topical Sesame/Rose geranium oil compound is an effective therapy for hereditary hemorrhagic telangiectasia (HHT) associated epistaxis. STUDY DESIGN: Cohort Study. METHODS: Twenty patients with HHT confirmed by the Curaçao criteria were treated with a sesame/rose geranium oil topical compound between January 2010 and June 2011. A treatment evaluation survey was conducted at least 3 months after treatment initiation. Changes in epistaxis severity scores (ESS), patient satisfaction, and any adverse effects were assessed. RESULTS: A total of 20 patients completed the study. The average (SD) age was 54.4 (14.6), and 14 (70%) were female. The median time on rose geranium oil was 183 days (IQR: 114-311). At the conclusion of the study, 18 (90%) were still using rose geranium oil. The majority (75%) of patients subjectively felt improvement with the treatment. The improvement was felt to be gradual in 25% and immediate in 50% of patients. Mean (SD) overall satisfaction using a 10-point Likert scale was 7.8 (3.1), with 50% of the patients reporting a satisfaction rating of 10. Mean (SD) epistaxis severity score (ESS) prior to treatment was 5.3 (1.7). After treatment with sesame/rose geranium oil, mean (SD) ESS was found to be 3.5 (1.8). Treatment with sesame/rose geranium oil was associated with a statistically significant improvement in ESS by 1.81 (P <0.0001). There were no adverse side-effects from the treatment. CONCLUSION: A sesame/rose geranium oil compound can significantly reduce the epistaxis severity scores of patients with hereditary hemorrhagic telangiectasia-related epistaxis. LEVEL OF EVIDENCE: 4.

Concepts: Cohort study, Statistics, Median, Arithmetic mean, Adverse drug reaction, Hereditary hemorrhagic telangiectasia, Pelargonium graveolens, Geranium


An investigation was carried out to evaluate the effect of heavy metal toxicity on growth, herb,oil yield and quality and metal accumulation in rose scented geranium (Pelargonium graveolens) grown in heavy metal enriched soils. Four heavy metals (Cd, Ni, Cr and Pb) each at two levels (10 and 20 mg kg(-1) soil) were tested on geranium. Results indicated that Cr concentration in soil at 20 mg kg(-1) reduced leaves, stem and root yield by 70, 83 and 45%, respectively, over control. Root growth was significantly affected in Cr stressed soil. Nickel, Cr and Cd concentration and accumulation in plant increased with higher application of these metals. Chromium, nickel and cadmium uptake was observed to be higher in leaves than in stem and roots. Essential oil constituents were generally not significantly affected by heavy metals except Pb at 10 and 20 ppm, which significantly increased the content of citronellol and Ni at 20 ppm increased the content of geraniol. Looking in to the higher accumulation of toxic metals by geranium and the minimal impact of heavy metals on quality of essential oil, geranium can be commercially cultivated in heavy metal polluted soil for production of high value essential oil.

Concepts: Iron, Metal, Toxicology, Heavy metal music, Chromium, Nickel, Pelargonium graveolens, System of a Down


Evaluation of ten essential oils of geranium, Pelargonium graveolens (Geraniaceae) showed all to have repellent activity against nymphs of the medically important lone star tick, Amblyomma americanum (L.). The biological tests were carried out using a vertical filter paper bioassay, where ticks must cross an area of the paper treated with repellent to approach host stimuli. One of the essential oil samples which repelled > 90% of the ticks at 0.103 mg/cm2 was selected for further fractionation studies. The sesquiterpene alcohol, (-)-10-epi-gamma-eudesmol was isolated and identified by spectral methods. (-)-10-epi-gamma-Eudesmol at 0.103 and 0.052 mg compound/cm2 filter paper repelled 90 and 73.3% of the ticks, respectively. (-)-10-epi-gamma-Eudesmol exhibited similar repellency as the reference standard DEET at concentrations of ≥0.052 mg compound/cm2 filter paper, with (-)-10-epi-gamma-eudesmol losing much of its repellency at 0.026 mg compound/cm2 and DEET at 0.013 mg compound/cm2. Isomenthone and linalool did not repel ticks at the concentrations tested. Most repellents are marketed with much higher concentrations of active ingredient than the concentrations of the natural repellents tested herein, so effective compounds, like (-)-10-epi-gamma-eudesmol, found in geranium oil, have the potential for commercial development.

Concepts: Tick, Ixodidae, Insect repellent, Amblyomma americanum, Pelargonium graveolens, Geranium, Geraniales, Pelargonium


The anxiolytic and antidepressant activities of the Reunion Geranium (Pelargonium roseum Willd) essential oil (EO) were evaluated in male Swiss albino mice by intraperitoneal administration of 10, 20, and 50 mg/kg bw using elevated plus maze (EPM), open-field test (OFT), and forced swimming test (FST). Moreover, we evaluated whether the 5-HT1Aand GABAA-benzodiazepine receptor systems are involved in the anxiolytic effects through the coadministration of WAY-100635 (a selective 5-HT1Areceptor antagonist) and flumazenil (an antagonist of benzodiazepine). GC-MS revealed the monoterpene alcohols citronellol (35.9%) and geraniol (18.5%) as the main components of the P. roseum EO. EO was effective in increasing the total number of entries and time spent in the open arms of EPM whereas number of rearing in OFT was significantly decreased in comparison with the control. In the FST, immobility time decreased in EO treated mice. Pretreatment with WAY-100635, but not Flumazenil, was able to reverse the effects of the EO in the EPM and FST, indicating that the EO activity occurs via the serotonergic but not GABAergic transmission. Overall, results of this work showed significant anxiolytic and antidepressant activity of P. roseum EO and confirmed the traditional uses of Pelargonium species as calming agents.

Concepts: Ethanol, Serotonin, Activity, Mouse, Benzodiazepine, Rose oil, Pelargonium graveolens, Pelargonium


The ability of plant extracts and preparations to reduce inflammation has been proven by different means in experimental models. Since inflammation enhances the release of specific mediators, inhibition of their production can be used to investigate the anti-inflammatory effect of plants widely used in folk medicine for this purpose. The study was performed for leaves and flowers of Malva sylvestris, and leaves of Sida cordifolia and Pelargonium graveolens. These are three plant species known in Brazil as Malva. The anti-inflammatory activity of extracts and fractions (hexane, chloroform, ethyl acetate, and residual) was evaluated by quantitation of prostaglandins (PG) PGE₂, PGD₂, PGF2α, and thromboxane B₂ (the stable nonenzymatic product of TXA₂) concentration in the supernatant of lipopolysaccharide (LPS)- induced RAW 264.7 cells. Inhibition of anti-inflammatory mediator release was observed for plants mainly in the crude extract, ethyl acetate fraction, and residual fraction. The results suggest superior activity of S. cordifolia, leading to significantly lower values of all mediators after treatment with its residual fraction, even at the lower concentration tested (10 μg/mL). M. sylvestris and P. graveolens showed similar results, such as the reduction of all mediators after treatment, with leaf crude extracts (50 μg/mL). These results suggest that the three species known as Malva have anti-inflammatory properties, S. cordifolia being the most potent.

Concepts: Photosynthesis, Pelargonium graveolens


The present study aimed to investigate the anti-Candida activity of ten essential oils (EOs) and to evaluate their potential synergism with conventional drugs. The effect on secreted aspartic protease (SAP) activity and the mechanism of action were also explored. The antifungal properties of essential oils were investigated using standard micro-broth dilution assay. Only Cinnamomum verum, Thymus capitatus, Syzygium aromaticum, and Pelargonium graveolens exhibited a broad spectrum of activity against a variety of pathogenic Candida strains. Chemical composition of active essential oils was performed by gas chromatography-mass spectrometry (GC-MS). Synergistic effect was observed with the combinations C. verum/fluconazole and P. graveolens/fluconazole, with FIC value 0.37. Investigation of the mechanism of action revealed that C. verum EO reduced the quantity of ergosterol to 83%. A total inhibition was observed for the combination C. verum/fluconazole. However, P. graveolens EO may disturb the permeability barrier of the fungal cell wall. An increase of MIC values of P. graveolens EO and the combination with fluconazole was observed with osmoprotectants (sorbitol and PEG6000). Furthermore, the combination with fluconazole may affect ergosterol biosynthesis and disturb fatty acid homeostasis in C. albicans cells as the quantity of ergosterol and oleic acid was reduced to 52.33 and 72%, respectively. The combination of P. graveolens and C. verum EOs with fluconazole inhibited 78.31 and 64.72% SAP activity, respectively. To our knowledge, this is the first report underlying the mechanism of action and the inhibitory effect of SAP activity of essential oils in synergy with fluconazole. Naturally occurring phytochemicals C. verum and P. graveolens could be effective candidate to enhance the efficacy of fluconazole-based therapy of C. albicans infections.

Concepts: Fatty acid, Cell wall, Synergy, Candida albicans, Oleic acid, Candidiasis, Essential oil, Pelargonium graveolens


Insect vectors are responsible for spreading devastating parasites and pathogens. A large number of botanicals have been suggested for eco-friendly control programs against mosquito vectors, and some of them are aromatic plants. Pelargonium roseum, a species belonging to the Geraniaceae family, due to its pleasant rose-like odor may represent a suitable candidate as mosquito repellent and/or larvicide. In this research, we evaluated the toxicity of the essential oil from P. roseum and its major constituents against the West Nile and filariasis vector Culex pipiens. The chemical composition of P. roseum essential oil was analyzed by gas chromatography-mass spectroscopy. Major constituents were citronellol (35.9%), geraniol (18.5%), and linalool (5.72%). The bioactivity of P. roseum essential oil and its three major compounds on larvae and egg rafts of Cx. pipiens was evaluated. The essential oil had a significant toxic effect on larvae and egg rafts of Cx. pipiens, with 50% lethal concentration (LC50) values of 5.49 and 0.45μg/mL, respectively. Major constituents, geraniol, citronellol and linalool resulted in LC50 values of 6.86, 7.64 and 14.87μg/mL on larvae, and 0.8, 0.67 and 1.27μg/mL on egg rafts. Essential oil and two of its constituents, citronellol and geraniol showed moderate knock-down on Cx. pipiens adults. Overall, the present investigation revealed that the major components of P. roseum and specially the whole essential oil could be helpful in developing novel and safe mosquito control tools and also offer an environmentally safe and cheap tool for reducing Cx. pipiens mosquito populations.

Concepts: Malaria, Insect, Mosquito, Toxicology, Toxicity, Dengue fever, Mosquito control, Pelargonium graveolens


Pelargonium graveolens is a member of the Geraniaceae family and has been used in folk medicine in many countries because of its anti-inflammatory activity. No studies have yet been reported to evaluate the anti-inflammatory activity of a nanoemulsion containing geranium oil (GO) model in macrophages. In this study the anti-inflammatory effect of Geranium nanoemulsion (NEG) macrophages induced with soluble proteins of Candida albicans was investigated. GO presented citronellol (17.74%) and geraniol (14.43%) as main constituents. The characterization in NEG was demonstrated, showing the particle size of 164 ± 3.5 nm, PDI of 0.12 ± 0.006 and zeta potential -10 mV ± 1.7. The MIC obtained for NEG and GO were 3.64 μg ml(-1) and 1.82 μg ml(-1), respectively. The viability of the macrophages treated with NEG and GO concentrations (½ x, 1x and 2x MIC) was evaluated. There was a significant reduction of viability and the MTT assay was not confirmed after the LDH assay. Anti-inflammatory activity was evaluated by determining nitric oxide (NO), cytokines (interleukin IL-1, IL-6 and IL-10), tumor necrosis factor-α (TNF) and the expression levels gene of interleukin (IL-2), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). The apoptosis inhibition capacity was assessed by determination of INFγ, caspase 3 and caspase 8. The results indicated that there was a significant increase of NO in the levels after treatment with NEG and significantly reduced levels after treatment with GO. The cytokines (IL-1, IL-6, IL-10, and TNF) were evaluated and NEG (½ x, 1x MIC) decreased IL-1 levels by 1.25-1.37 times, respectively. The NEG did not decrease IL-6 levels and a significant increase was observed for IL-10. GO significantly decreased IL-6 and IL-10 levels. There was a significant decrease in IL-2 and COX-2 levels and increased levels of iNOs. The levels of IFNγ and caspase-3 after treatment with NEG decreased indicating an anti-inflammatory effect and can inhibit apoptosis. Finally, the levels of caspase-8 do not change. Thus, pretreatment with NEG induced an anti-inflammatory effect against soluble proteins of C. albicans model macrophages.

Concepts: Apoptosis, Nitric oxide, Candida albicans, Nitric oxide synthase, Caspase 3, Pelargonium graveolens, Geranium, Pelargonium


Infections due to microbial biofilm formation on the surface of catheters and other medical devices are constantly reported as a major cause of morbidity and mortality in patients admitted to hospitals. Furthermore, sessile cells are more resistant to phagocytosis and most antimicrobial, which complicates the treatment of such infections. Researches aimed at new antimicrobial originating mainly from plants have increased in recent years and the development of new strategies for their release is critical in combating the formation of biofilms. Geranium oil (GO) has proven antimicrobial activity. Because of this, the aim of this study was to develop nanoemulsions containing this oil (NEG) and evaluate its activity after the biofilm formation of Candida albicans, Candida tropicalis, Candida glabrata, and Candida krusei in hospital medical supplies. For quantification of the biofilm, crystal violet, total protein, and ATP-bioluminescence assays were used. The results revealed that GO and NEG showed lower MIC for C. albicans and C. tropicalis. The biofilms formed by different species of Candida on the surfaces of polyethylene and polyurethane were quantified. GO and NEG significantly inhibited the formation of biofilms in all species tested on the surfaces of polyethylene. However, NEG antibiofilm has had better activity than GO for C. albicans, C. tropicalis and C. glabrata, according to the surface potential analysis by atomic force microscopy (AFM). The analysis of the biofilm formation on the polyethylene surface by ATP-bioluminescence and CFU showed similar results. In both methods the formation of biofilm in the catheter occurred in greater quantity for C. albicans and C. tropicalis. GO did not significantly inhibit the formation of biofilms only in C. krusei, although NEG significantly increased this activity GO in all species tested when compared to the control training biofilm. The following study shows that the development of NEG may become an effective alternative to reduce the adhesion of microorganisms and prevent infections resulting from the use of some hospital medical materials.

Concepts: Bacteria, Microbiology, Yeast, Candida albicans, Candida, Yeasts, Pelargonium graveolens