In vitro intestinal permeability studies, pharmacokinetics and tissue distribution of 6-methylcoumarin after oral and intraperitoneal administration in Wistar rats

ABSTRACT 6-Methylcoumarin (6MC) is a semisynthetic coumarin with important in vitro and in vivo anti-inflammatory activity. In order to continue the pre-clinical characterization of this molecule, in vitro intestinal permeability, plasma profile and tissue distribution after oral administration in rats were studied. The permeability of 6MC was evaluated by the Caco-2 cellular model in both the apical-basal (A-B) and basal-apical (B-A) directions. The pharmacokinetics and biodistribution were evaluated in rats after oral and intraperitoneal administration at doses of 200 mg/kg. Transport experiments with Caco-2 cells showed that 6MC presented high permeability at all concentrations evaluated. This finding suggested that 6MC could be transported across the gut wall by passive diffusion. The plasma concentration-time curve showed that the maximum concentration (Cmax) was 17.13 ± 2.90 µg/mL at maximum time (Tmax) of 30 min for the oral route and Cmax 26.18 ± 2.47 µg/mL at 6.0 min for the intraperitoneal administration, with elimination constant of (Ke ) 0.0070 min-1 and a short life half time of (T1/2 ) lower that 120 min. The distribution study showed that 6MC has high accumulation in the liver, and widespread distribution in all the organs evaluated.

Chemical profiles of traditional preparations of four South American Passiflora species by chromatographic and capillary electrophoretic techniques

ABSTRACT Several species of the genus Passiflora are distributed all over South America, and many of these species are used in popular medicine, mainly as sedatives and tranquilizers. This study analyzes the chemical profile of extracts of four Passiflora species used in folk medicine, focusing on the flavonoids, alkaloids and saponins. We employed simple and fast fingerprint analysis methods by high performance liquid chromatography, ultra performance liquid chromatography and capillary electrophoresis techniques. The analysis led to the detection and identification of C-glycosylflavonoids in all the plant extracts, these being the main constituents in P. tripartita var. mollissima and P. bogotensis. Saponins were observed only in P. alata and P. quadrangularis, while harmane alkaloids were not detected in any of the analyzed extracts in concentrations higher than 0.0187 ppm, the detection limit determined for the UPLC method.