RESUMO
ABSTRACT The fruits of Litchi chinensis Sonn., Sapindaceae, are renowned for their biological activities. However, their leaves are poorly explored, although they represent an important source of vegetable raw material with biological properties as antioxidant, anti-inflammatory and antinociceptive. An HPLC method was developed and validated for the simultaneous quantification of epicatechin and procyanidin A2 in the leaf hydroethanolic extract of L. chinensis. The markers and other unidentified components were separated on a Luna Phenomenex C18 column (250 mm × 4.6 mm, 5 µm) with mobile phase composed of acetonitrile: water pH 3.0 (with sulfuric acid), in a gradient run; at 1.0 ml min-1, 30 ºC and 278 nm for detection. The method was linear over an epicatechin and procyanidin A2 concentration range of 10–100 µg ml-1. The Limit of Quantification for epicatechin and procyanidin A2 were 1.7 and 2 µg ml-1, respectively. The Relative Standard Deviation (%) values for markers (intra- and inter-day precision studies) were <4.0% and the accuracy was 100 ± 5%. The method was applied to ten samples collected in the state of Santa Catarina (Brazil), which showed 14.8–44.5 and 44.8–69.6 mg g-1 of epicatechin and procyanidin A2, respectively. The proposed method could be a valuable tool for quality assessment of L. chinenis leaves as well as their herbal derivatives.
RESUMO
Ipomoea pes-caprae (L.) R. Br., Convolvulaceae, is a medicinal plant that grows abundantly as a pan-tropical stand plant. The 3² (two factors and three levels) factorial design, was applied to determine the best time and drug/solvent proportion to maximize the flavonoid content in the hydroethanolic extract by maceration process. The antinociceptive and anti-inflammatory effects were studied at 5-20 mg/kg, i.p., using the writhing test and carrageenan-induced pleurisy models in mice. The optimized extract was able to inhibit more than 50% of abdominal writhing at 20 mg/kg, with 55.88%±2.4 of maximum inhibition. Indomethacin, used as positive control, inhibited 64.86% at 10 mg/kg. In the pleurisy model, the extract produced dose-dependent inhibition of the first phase of inflammation (4 h) in the pleural cavity induced by injection of carrageenan (1%) in mice. It inhibited 50%±0.82 (p<0.01) of exudation induced by carrageenan, and 60.88%±0.14 (p<0.01) of leukocyte migration to the pleural cavity. In conclusion, the results validate the technological conditions of the maceration process to produce an optimized bioactive herb extract for the development of analgesic and anti-inflammatory phytopharmaceuticals using 70 ºGL ethanol, a plant to solvent ratio of 12.5% (w/v), and ten days of maceration.