Bioavailability of β-aescin from horse chestnut seed extract: Comparative clinical studies of two galenic formulations

Abstract

The bioavailability of beta-aescin--the main active constituent of horse chestnut seed extract--in a nonretarded test medication in comparison with that in a retarded reference formulation was evaluated in 2 randomized crossover clinical trials involving 18 healthy volunteers each. Serum concentration/time curves derived under steady-state conditions and pharmacokinetic parameters measured during both studies showed no significant difference between absorption rates for the retarded versus nonretarded preparation. In the first study, investigators found a test-to-reference ratio of 1.06 (90% confidence interval [CI] range: 99-113) for the area under the curve (AUC; the primary outcome measure). Absorption rates were diminished during the night compared with daytime rates for both study preparations. In the second study, using AUC and maximum concentration (Cmax) as the primary characteristics, investigators analyzed bioavailability based on the mean of 2 consecutive daytime periods and obtained estimates of 1.07 for AUC (90% CI range: 0.96-1.19) and 1.05 for Cmax (90% CI range: 0.90-1.21). Bioequivalence of the test and reference drug preparations was thus established according to the Note for Guidance on the Investigation of Bioavailability and Bioequivalence. Both treatments were equally well tolerated.

Trade Herbal Products and Induction of CYP2C19 and CYP2E1 in Cultured Human Hepatocytes

“…According to the manufacturer, our St John's wort batch was comparable to that used by Gurley et al . However, a variation in bioavailability among herbal constituents in general can be expected, making some uncertainties in our estimation [18][19][20]. These estimates indicate that the lowest total concentration of St John's wort used in our hepatocytes, 8 μ g/ml, is in the same range as that obtained in plasma with a recommended dosing of St John's wort.…”

Seeds of Horse Chestnut (Aesculus hippocastanum L.) and Their Possible Utilization for Human Consumption

“…In view of the possible relevance of b-escin in anticancer therapy, some formulations were tested in order to establish their effectiveness on the basis of bioavailability and bioequivalence (Bassler et al, 2003). The positive results strongly encourage pursuing new cure modalities, with treatments based on well-tolerated natural products.…”

Simultaneous Determination of Escin Ia and Its Isomer Isoescin Ia by LC–MS–MS: Application to a Pharmacokinetic Study of Escin Ia in Rats

“…Only bioavailability studies of escin presented under the form of extracts or mixtures have been reported [22,23]. It is known that pharmacokinetic studies of the herbal medicinal product help in linking data from pharmacological assays to clinical effects and also in designing rational dosage regimens [24].…”

“…Radioimmunoassay (RIA) methods have been developed to study the bioavailability of escin in human [22,23]. However, these methods possess some disadvantages such as low selectivity and complicated sample preparation procedures.…”

“…Escin is a natural mixture of triterpene saponins including at least ten individual compounds [1,[22][23][24]. Although escin generally shows various pharmacological effects as a mixture, studies on single components in escin are rare.…”