HPLC-PDA method validated for the determination of hibalactone in Hydrocotyle umbellata subterraneous parts and its ultrasound-assisted extraction optimization

ABSTRACT In this work, we developed and validated a HPLC-PDA method for the quantification of hibalactone in Hydrocotyle umbellata L., Araliaceae, subterraneous parts extracts and optimized its ultrasound-assisted extraction. Chromatographic separations were carried out with an isocratic mobile phase of acetonitrile/methanol/water (10:65:25), a flow of 0.8 ml min−1, detection at 290 nm and C18 column (250 × 4.6 mm, 5 µm). The method validation parameters were determined according to Brazilian legislation. The optimization of the hibalactone ultrasound-assisted extraction was performed using Box-Behnken design and response surface methodology. The HPLC method for hibalactone quantification proved to be selective, linear, precise, accurate and robust, being useful for the analysis of hibalactone in H. umbellata subterraneous parts extracts. The optimal ultrasound-assisted extraction conditions were obtained with solid-to-liquid ratio of 1:5 g ml−1, ethanolic strength of 70% (v/v) and temperature of 65 °C. The results can provide support of the quality control and standardization of raw materials from H. umbellata.

Mechanism involved in the anti-inflammatory effect of Spiranthera odoratissima (Manacá)

Acetic acid-induced writhing, hot-plate, carrageenan-induced pleurisy, formalin-induced pain, croton oil-induced ear edema, vascular permeability tests and phospholipase A2 activity assay were used to study the analgesic and/or anti-inflammatory activity of the hydromethanolic fraction of ethanolic extract from Spiranthera odoratissima A. St.-Hil., Rutaceae, leaves (HMF) and its subfraction (sub-Fr10-28). HMF and sub-Fr10-28 reduced the leukocyte migration on the carrageenan-induced pleurisy test; sub-Fr10-28 reduced the pain reaction time in the second phase of formalin-induced pain, as well as the ear edema and vascular permeability. Both HMF and sub-Fr10-28 inhibited the phospholipase A2 activity. These results suggest that the analgesic effect of this plant could be, in part, due to an anti-inflammatory action produced by the inhibition of phospholipase A2 activity.

Anxiolytic-like and sedative effects of Hydrocotyle umbellata L., Araliaceae, extract in mice

The plant Hydrocotyle umbellata L., Araliaceae (water pennywort), is widely used in Brazilian folk medicine to reduce anxiety. This work investigates the anxiolytic-like effects of the ethanol extract from H. umbellata subterraneous parts as well as the extract's other putative central nervous system effects that could justify its common use. Oral dosing of the extract (0.3 and 1 g/kg) clearly showed an anxiolytic-like profile in the elevated plus maze test where it increased the percentage of entries into and the time spent in the open arms of the maze. In the marble-burying test, the extract induced anxiolytic-like effects only at a dose of 1 g/kg, which also causes mild sedative properties in other models. The sedated state was characterized by a slight reduction in spontaneous exploratory activity during the open field test and a potentiating of pentobarbital-induced hypnosis. No signs of motor impairment were detected in the rota rod or chimney tests. The extract did not show antidepressant properties in mice as assessed by the forced swimming test. These results support the use of H. umbellata in Brazilian folk medicine as an anxiolytic and contribute to the scientific knowledge of this possible phytotherapeutic resource.

Bioactivity of crude ethanol extract and fractions of Eugenia uniflora (Myrtaceae) in the hepatopancreas of Oreochromis niloticus L

This study evaluates the bioactivity of the crude ethanol extract and ethyl acetate, hexane and chloroform fractions obtained from Eugenia uniflora leaves using the hepatopancreas of Oreochromis niloticus L. as an experimental model. The ethanol extract and fractions were administered to the fish orally with their feed. Twenty-four hours later, the fish were sacrificed and their livers dissected, fixed in neutral formalin, embedded in paraffin and sectioned. Histological analyses were performed using Masson's trichrome and Haematoxylin-Eosin. Histochemical studies were performed using Feulgen, PAS (Periodic Acid Schiff) and PAS + salivary amylase and Sudan IV stain. The qualitative analysis of the material showed that the crude extract and the ethyl, chloroform and hexane fractions induced vasodilation, vascular congestion and toxicity due to the presence of eosinophilic granular cells, rodlet cells, some leukocytic infiltrate and rare focal necroses. The Nile tilapia proved to be a satisfactory model for screening plant products.