Essential oils of Varronia curassavica accessions have different activity against white spot disease in freshwater fish.

The aim of this study was to evaluate the antiprotozoal activity of essential oils from Varronia curassavica accessions against different stages of Ichthyophthirius multifiliis. Essential oils from each accession were tested in vitro at the concentrations 0, 10, 25, 50, 75, 100, and 200 mg/L. The VCUR-001, VCUR-202, VCUR-509, and VCUR-601 accessions presented the major compounds α-pinene, germacrene D-4-ol, (E)-caryophyllene and epiglobulol, and sabinene, respectively. These isolated compounds were tested in vitro at a concentration proportional to that found in the essential oil which caused 100% mortality of the parasite. The concentrations of 10 and 50 mg/L of the essential oil of accession VCUR-202 provided 100% mortality of trophonts and tomonts, respectively. For the accession VCUR-509, 100% mortality of trophonts and tomonts was observed at concentrations 75 and 200 mg/L of essential oil, respectively. The same mortality was observed at concentration 200 mg/L in both stages of the parasite for the other accessions. The major compounds α-pinene, sabinene, and the (E)-caryophyllene + epiglobulol mixture caused 100% mortality of trophonts and tomonts. The in vivo assay for white spot disease control was performed in a therapeutic bath of 1 h with the essential oil of accession VCUR-202 at concentrations of 0.5 and 2.0 mg/L. A significant reduction of about 30% of trophonts on infected fish was observed, independent of the oil concentration. The V. curassavica essential oil, especially the VCUR-202 accession, is a potential source of raw material for the formulation and commercialization of bioproducts to control freshwater white spot disease in fish.

Antidermatophytic and antileishmanial activities of essential oils from Lippia gracilis Schauer genotypes.

Lippia gracilis, popularly known in Brazil as 'alecrim-de-tabuleiro', is used for many purposes, especially antimicrobial and antiseptic activities. The leaves of three L. gracilis genotypes, including LGRA-106, LGRA-109 and LGRA-110 were collected from the Active Germplasm Bank located in the "Campus Rural da UFS" research farm at the São Cristóvão country, Sergipe State, Brazil. The essential oils were obtained from leaves of L. gracilis plants by hydrodistillation. Chemical analysis of the essential oils was performed by gas chromatography-mass spectrometry (GC-MS). The susceptibility of Trichophyton rubrum strains, MYA3108 and TruMDR2, to the two L. gracilis genotypes (LGRA-106 and LGRA-109) essential oils was determined by the serial microdilution method. Leishmanicidal activity of essential oil from LGRA-106 and LGRA-110 was assayed by tetrazolium-dye (MTT) colorimetric method. The oxygenated monoterpene thymol was the main component of the essential oil from genotype LGRA-106, while Carvacrol was more abundant in LGRA-109 and LGRA-110. The concentrations of LGRA-106 and LGRA-109 essential oils that completely eliminate the fungi were determined and these concentrations were similar to those observed for fluconazole, a common antifungal drug. Among the genotype tested, LGRA-106 essential oil exhibited the best fungicidal activity at 46.87µgmL(-1). Regarding to leishmanicidal activity, the IC50, for LGRA-106 and LGRA-110, was 86.32 and 77.26µgmL(-1), respectively. The results showed that L. gracilis essential oil, rich in thymol and thymol itself presented best antidermatophytic activity, while the best leishmanicidal activity was obtained with essential oil from genotype rich in Carvacrol and Carvacrol itself.

Anti-inflammatory and analgesic activity of Peperomia pellucida (L.) HBK (Piperaceae).

An aqueous extract of the aerial part of Peperomia pellucida (L.) HBK (Piperaceae) was tested for anti-inflammatory (paw edema induced by carrageenin and arachidonic acid) and analgesic activity (abdominal writhes and hot plate) in rats and mice, respectively. Oral administration of 200 and 400 mg/kg of the aqueous extract exhibited an anti-inflammatory activity in the carrageenin test, which was based on interference with prostaglandin synthesis, as confirmed by the arachidonic acid test. In the abdominal writhing test induced by acetic acid, 400 mg/kg of the plant extract had the highest analgesic activity, whereas in the hot-plate test the best dose was 100 mg/kg. The LD(50) showed that Peperomia pellucida (5000 mg/kg) presented low toxicity.