Preclinical Pharmacokinetic and Pharmacodynamic Investigation of 5'-Methoxynobiletin from Ageratum conyzoides: In vivo and In silico Approaches.

PURPOSE: 5'-methoxynobiletin (5'-MeONB), a polymethoxyflavone isolated from A. conyzoides, has shown anti-inflammatory property. Nevertheless, the antinociceptive activity and pre-clinical pharmacokinetics (PK) characteristics of 5'-MeONB remain unknown. Considering the anti-inflammatory potential of the 5'-MeONB, this study aimed to investigate the pre-clinical PK behavior of 5'-MeONB, as well as its time course antinociceptive activity. METHODS: 5'-MeONB plasma concentrations were determined in Wistar rats after intravenous (i.v.) (10 mg/kg) and oral (50 mg/kg) administration, and in Swiss mice after oral administration (100 mg/kg). Plasma samples were deproteinization and 5'-MeONB quantified by a validated UPLC-MS method. Additionally, the antinociceptive activity of 5'-MeONB was evaluated after 15, 30, 60, 180 and 360 min following oral administration on the acute nocifensive behavior of mice induced by formalin. RESULTS: 5'-MeONB rats and mice plasma concentration-time profiles were best one-compartment model. After i.v. administration to rats, a short half-life, a high clearance and moderate volume of distribution at steady state were observed. Similar results were obtained after oral administration. The oral bioavailability ranged from 8 to 11%. Additionally, 5'-MeONB exhibited antinociceptive activity in both formalin phases, especially in the inflammatory phase of the model, inhibiting 68% and 91% of neurogenic and inflammatory responses, respectively, after 30 min of oral administration. CONCLUSIONS: The results described here provide novel insights on 5'-MeONB pharmacokinetics and pharmacodynamic effect, serving as support for future studies to confirm this compound as anti-nociceptive and anti-inflammatory effective agent.

Simple and fast UPLC-MS method for quantifying the anti-inflammatory candidate 5'-methoxynobiletin in rat plasma: Validation and application in a preliminary pharmacokinetic study.

This study presents the development and validation of a fast and simple bioanalytical ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) method intended for quantifying the anti-inflammatory candidate 5'-methoxynobiletin (5'-MeONB) in rat plasma. Standard of 5'-MeONB was purified from A. conyzoides extract by using preparative HPLC. After a pretreatment of plasma samples with acetonitrile, chromatographic separations were efficiently achieved with a C18 column using a 9 min gradient system of 0.1% aqueous formic acid and acetonitrile as eluent. Drug candidate 5'-MeONB and chrysin (internal standard, IS) detection were carried out using ESI+ through the extracted ion chromatograms approach, monitored at m/z 433.1494 (for 5'-MeONB, tR:1.78 min) and m/z 255.0657 (for IS, tR:1.57 min). Method was validated according to US FDA guidelines, presenting linearity (R2 > 0.999) over concentration range of 30-750 ng/mL. Relative standard deviation (RSD) of repeatability and intermediary precision respectively ranged between 1.93-3.65% and 2.16-7.54%, considering lower limit of quantitation (30 ng/mL) and quality control (90, 360 and 600 ng/mL) samples, while accuracy was between 82.51 and 109.44%. Moreover, no interference from plasma endogenous substances, no carryover effect, and no influence of extraction method even in hemolyzed blood samples were observed. Sample stability in auto-sampler and long-term -80 °C storage, as well as matrix effect were within acceptable limits. For the first time, using the validated UPLC-MS bioanalytical method, the plasma pharmacokinetics of 5'-MeONB following 2 mg/kg intravenous bolus dosing to Wistar rats was characterized allowing the determination of the parameters describing drug distribution and elimination.

Phytochemical profile of different anatomical parts of jambu (Acmella oleracea (L.) R.K. Jansen): A comparison between hydroponic and conventional cultivation using PCA and cluster analysis.

Jambu [Acmella oleracea (L.) R.K. Jansen] is an edible plant with a wide range of constituents of biological interest. In this study, the chemical composition of leaves, flowers and stems of jambu cultivated in hydroponic and conventional systems was investigated. In both crop systems, the leaves showed the highest total phenolic content, total flavonoid content and in vitro antioxidant capacity. The extracts were characterized by determining 45 compounds, including phenolic acids, glycosylated flavonoids, alkamides and fatty acids, by LC-MS analysis. Of these compounds, 31 are described for the first time in this species, five of which are reported for the first time in the literature. The PCA and cluster analysis results distinguished different anatomical parts (PC1 and PC2) and cultivation systems (PC3) into well-defined groups.

A single-step isolation by centrifugal partition chromatography of the potential anti-inflammatory glaucolide B from Lepidaploa chamissonis.

Sesquiterpene lactones (SL) are commonly found in Asteraceae and present a promising anti-inflammatory activity. Previously described in Lepidaploa genus, glaucolide B has never been investigated for its anti-inflammatory potential. This study aimed to establish an efficient process for the extraction of glaucolide B (1) from Lepidaploa chamissonis leaves and to develop a simple and fast method for its purification by using centrifugal partition chromatography (CPC), as well as to investigate in vitro the anti-inflammatory effects of glaucolide B. Thus, an optimized washing extractive process performed on L. chamissonis leaves allowed to obtain a SL enriched extract (4.11 g). After a successful defatting pretreatment of the crude extract, the glaucolide B enriched ethyl acetate portion (2.00 g) was fractionated by CPC affording, in a single-step isolation, compound 1 (1.04 g) in great yield (25%) and purity (97%). Cytotoxicity effect of 1 on RAW 264.7 macrophages was determined by using MTT assay, revealing a CC10 of 14.11 µM. Compound 1 at 1, 3 and 10 µM inhibited the nitrite/nitrate (NOx) metabolites production and the pro-inflammatory interleukin 6 (IL-6) secretion on lipopolysaccharide-stimulated RAW 264.7 cells. The extractive process used turned to be selective for SL and CPC technique proved a simple and effective tool for the isolation of 1 within few hours. Isolated for the first time from L. chamissonis leaves, glaucolide B presented a significant inhibitory effect on both NO and IL-6 secretion under non-toxic concentrations.

Spectrophotometric determination of the total flavonoid content in Ocimum basilicum L. (Lamiaceae) leaves.

BACKGROUND: The chemical characterization is essential to validate the pharmaceutical use of vegetable raw materials. Ultraviolet spectroscopy is an important technique to determine flavonoids, which are important active compounds from Ocimum basilicum. OBJECTIVE: The objective of this work was to optimize a spectrophotometric method, based on flavonoid-aluminum chloride (AlCl3) complexation to determine the total flavonoid content (TFC) in leaves of O. basilicum (herbal material), using response surface methodology. MATERIALS AND METHODS: The effects of (1) the herbal material: Solvent ratio (0.02, 0.03, 0.05, 0.07, and 0.08 g/mL), (2) stock solution volume (0.8, 2.3, 4.4, 6.5, and 8.0 mL) and (3) AlCl3 volume (0.8, 1.0, 1.2, 1.4, and 1.6 mL) on the TFC were evaluated. The analytical performance parameters precision, linearity and robustness of the method were tested. RESULTS: The herbal material: Solvent ratio and stock solution volume showed an important influence on the method response. After choosing the optimized conditions, the method exhibited a precision (RSD%) lower than 6% for repeatability (RSD%) and lower than 8% for intermediate precision (on the order of literature values for biotechnological methods), coefficient of correlation of 0.9984, and no important influence could be observed for variations of the time of complexation with AlCl3. However, the time and temperature of extraction were critical for TFC method and must be carefully controlled during the analysis. CONCLUSION: Thus, this study allowed the optimization of a simple, fast and precise method for the determination of the TFC in leaves of O. basilicum, which can be used to support the quality assessment of this herbal material.