Extraction optimization and UHPLC method development for determination of the 20-hydroxyecdysone in Sida tuberculata leaves

Sida tuberculata (ST) is a Malvaceae species widely distributed in Southern Brazil. In traditional medicine, ST has been employed as hypoglycemic, hypocholesterolemic, anti-inflammatory and antimicrobial. Additionally, this species is chemically characterized by flavonoids, alkaloids and phytoecdysteroids mainly. The present work aimed to optimize the extractive technique and to validate an UHPLC method for the determination of 20-hydroxyecdsone (20HE) in the ST leaves. Box-Behnken Design (BBD) was used in method optimization. The extractive methods tested were: static and dynamic maceration, ultrasound, ultra-turrax and reflux. In the Box-Behnken three parameters were evaluated in three levels (-1, 0, +1), particle size, time and plant:solvent ratio. In validation method, the parameters of selectivity, specificity, linearity, limits of detection and quantification (LOD, LOQ), precision, accuracy and robustness were evaluated. The results indicate static maceration as better technique to obtain 20HE peak area in ST extract. The optimal extraction from surface response methodology was achieved with the parameters granulometry of 710 nm, 9 days of maceration and plant:solvent ratio 1:54 (w/v). The UHPLC-PDA analytical developed method showed full viability of performance, proving to be selective, linear, precise, accurate and robust for 20HE detection in ST leaves. The average content of 20HE was 0.56% per dry extract. Thus, the optimization of extractive method in ST leaves increased the concentration of 20HE in crude extract, and a reliable method was successfully developed according to validation requirements and in agreement with current legislation.

Significant fluctuations in ecdysteroid receptor gene (EcR) expression in relation to seasons of molt and reproduction in the grapsid crab, Metopograpsus messor (Brachyura: Decapoda)

Metopograpsus messor, a brachyuran crab inhabiting the estuaries of North Kerala (India), is a prolific breeder releasing approximately 14-16 broods a year. The present paper reports the sequence information on the DNA binding domain (C domain, DBD), linker (D domain) and ligand binding domain (E domain, LBD) of M. messor ecdysteroid receptor (MmEcR) gene, the first grapsid brachyuran crab EcR examined. We have also measured MmEcR transcript levels in the ovary and the hepatopancreas throughout the annual cycle, with special reference to seasons of molt and reproduction. MmEcR expression in both the tissues is found to be at its peak (P<0.05) in late premolt crabs (January/May, molt/reproduction season); the expression levels are lowest (P<0.05) during June/July, when the females would neither molt nor reproduce (season for molt/reproduction repose). Intermediate levels of expression were found during the breeding season (August/December). Interestingly, this pattern of gene expression is in concordance with the fluctuating ecdysteroid levels of the hemolymph and Y organ secretory activity. The significant levels of fluctuation in the ovarian expression of MmEcR strongly suggest the ovary as a potential target for ecdysteroid action. A season-wise comparison of the gene expression reveals that ovarian MmEcR transcript levels are higher in breeding crabs (August/December) than the non-breeding animals (June/July), implicating a possible ecdysteroid role in reproduction in M. messor.