Ruta graveolens, Pelargonium graveolens E Hibiscus cannabinus COMO INIBIDORES NATURAIS DO CRESCIMENTO DE Candida albicans

Candidiasis is an infection caused by fungi of the genus Candida, Candida albicans being the species that most causes the disease in Brazil. The Fluconazole is the conventional medicine used as a treatment of these infections; however, it causes many adverse reactions in the patient and its continued use can induce the resistance of the pathogen. The medicinal plants can be very effective as an alternative treatment of diseases and have been used in folk medicine for years. In this study, it was evaluated the antifungal activity of extracts of Ruta graveolens, Pelargonium graveolens and Hibiscus cannabinus against the fungal development of Candida albicans, comparing the efficiency of these extracts to Fluconazole. The extracts were prepared in the concentration of 1g of the plant for each 5 mL of alcohol 70%. The data were obtained using the agar diffusion method. The minimum inhibitory concentration test (MIC) was performed, and showed that R. graveolens was able of inhibiting 100% of the pathogen when using 100 mg.ml-1 concentration. From the results obtained, it was possible to conclude that R. graveolens was the most effective extract when compared to Fluconazole, suggesting that this extract can be used as an alternative to conventional treatment to improve the efficiency of current treatments. The extracts of P. graveolens and H. cannabinus also presented antifungal activity but in smaller proportion than Fluconazole. The data from this study suggests that R. graveolens extract can be tested in future in vivo studies with the objective of proposing its use in alternative or simultaneous treatment of the synthetic drug used.

Copper Tolerance and Accumulation on Pelargonium graveolens L’Hér. Grown in Hydroponic Culture

Heavy metal contamination is a major health issue concerning the commercial production of medicinal and aromatic plants (MAPs) that are used for the extraction of bioactive molecules. Copper (Cu) is an anthropogenic contaminant that, at toxic levels, can accumulate in plant tissues, affecting plant growth and development. On the other hand, plant response to metal-induced stress may involve the synthesis and accumulation of beneficial secondary metabolites. In this study, hydroponically grown Pelargonium graveolens plants were exposed to different Cu concentrations in a nutrient solution (4, 25, 50, 100 μM) to evaluate the effects Cu toxicity on plant growth, mineral uptake and distribution in plants, some stress indicators, and the accumulation of bioactive secondary metabolites in leaf tissues. P. graveolens resulted in moderately tolerant Cu toxicity. At Cu concentrations up to 100 μM, biomass production was preserved and was accompanied by an increase in phenolics and antioxidant capacity. The metal contaminant was accumulated mainly in the roots. The leaf tissues of Cu-treated P. graveolens may be safely used for the extraction of bioactive molecules.

Chemical Characterization and Antidiabetic Activity of Essential Oils from Pelargonium graveolens Leaves

Pelargonium graveolens (Geranium) is a source of the finest quality of fragrance and its essential oils are used as antibacterial, and antifungal agents. The aim of the current research is to determine chemical constituents in the essential oil of P. graveolens by GC-MS and evaluate its antidiabetic activity via α-glucosidase inhibition assay. The chemical composition of P. graveolens essential oil was determined by GC/MS and its antidiabetic activity was assessed through inhibition of α-glucosidase enzyme in in-vitro models. GC-MS analysis determines 36 chemical components in the essential oil of P. graveolens leaves, and citronellyl isovalerate (10.41 %), menthol (9.61 %), linalool (8.63 %), p-menthone (6.31 %), and geranyl tiglate (4.99 %) were recorded as major constituents. The essential oil of P. graveolens leaves showed concentration dependant inhibition of α-glucosidase enzyme ranging from 28.13±1.41 to 74.24±2.53 µg/mL for concentration ranging from 31.25 to 1000 µg/mL. The IC50 values for of P. graveolens and acarbose were found as 93.72±4.76 and 80.4±2.17 µg/mL, respectively against the α-glucosidase enzyme. The study finding explores the chemical components of P. graveolens growing in the Iraqi Kurdistan region and scientifically supported its possible use in diabetic patients for controlling postprandial hyperglycemia.

CYTOKININ, GIBBERELLIC ACID AND DEFOLIATION ON DENSITY AND MORPHOLOGY OF TRICHOME OF Pelargonium graveolens L’Hér FOR ESSENTIAL OIL BIOSYNTHESIS

The density and morphology of glandular trichomes in rose geranium (Pelargonium graveolens L’Her.) are often correlated to the essential oil biosynthesis. However, whether the different organs in the same rose geranium plant are affected by hail damage, or if they recover similarly following hail damage is still unknown concerning the essential oil biosynthesis. The objective of this study was to evaluate the effects of split-applying cytokinin (CK), gibberellic acid (GA) and defoliation on rose geranium trichome morphology and density, and essential oil biosynthesis. The experiment was carried out in a hail-net covered tunnel structure during 2017-2018 growing season. The experimental design was a complete randomized blocks with a 3x3 factorial arrangement of treatments: three defoliation levels (0, 50, and 100%), two levels of split-application of CK and GA (0.32 mg L-1 CK + 150 mg L-1 GA; and 0.64 mg L-1 CK + 300 mg L-1 GA), and a control. The attenuate, peltate, and capitate trichome groups were identified in the leaf. Morphologically, the attenuate trichome group was less dense on both recovered and new plant leaves, despite split-applied CK and GA treatment. With the peltate group, brevicollate trichome density declined in all plant leaves treated with 0.64 mg L-1 CK + 300 mg L-1 GA on both leaf surfaces. Application of 0.64 mg L-1 CK + 300 mg L-1 GA led to high density of the elongated-capitate type on leaves recovered from 50 and 100% defoliation. The essential oil yield was not affected by density and morphological changes of the trichomes. However, the application of 0.32 mg L-1 CK + 150 mg L-1 GA increased the citronellol content where plants endured 100% defoliation. Results demonstrated that the effects of hail damage stress and subsequent split-applied CK and GA could transform the morphology of trichomes, subsequently increasing the density.