ABSTRACT
Fructus arctii is commonly used in Chinese medicine, and arctiin and arctigenin are its main active ingredients. Arctiin has low bioavailability in the human body and needs to be converted into arctigenin by intestinal microbes before it can be absorbed into the blood. Arctigenin has antiviral, anti-inflammatory, and anti-tumour effects and its development has important value. In this study, we used external microbial fermentation with Aspergillus awamori and Trichoderma reesei to process and convert arctiin from F. arctii powder into arctigenin, hence increasing its bioavailability. We developed a fermentation process by optimising the carbon and nitrogen source/ratio, fermentation time, pH, liquid volume, inoculation volume, and substrate solid-liquid ratio. This allowed for an arctiin conversion rate of 99.84%, and the dissolution rate of the final product was 95.74%, with a loss rate as low as 4.26%. After the fermentation of F. arctii powder, the average yield of arctigenin is 19.51 mg/g. Crude fermented F. arctii extract was purified by silica gel column chromatography, and we observed an arctigenin purity of 99.33%. Our technique effectively converts arctiin and extracts arctigenin from F. arctii and provides a solid basis for further development and industrialisation.
ABSTRACT
Fructus arctii, also known as great power seed, is the dried fruit of Arctium lappa of the family Compositae. It is a commonly used veterinary herbal medicine, and arctigenin is the main active ingredient. The aim of this study was to characterize the absorption, distribution, metabolism, and excretion of arctigenin and Fructus arctii powder in piglets. These data were used to provide a theoretical reference for the development and clinical use of new veterinary drugs. Sixteen healthy piglets (mean weight 30.0 ± 5.0 kg) were divided into two groups. One group was administered 2.0 mg/kg body weight (bw) arctigenin intravenously, and the other was administered 1.0 g/kg.bw Fructus arctii powder by gavage. Blood samples were collected from the anterior vena cava at different time points, and the concentration of arctigenin in the plasma of the piglets was determined using high-performance liquid chromatography (HPLC). Arctigenin conformed to a two-compartment model with no absorption, and the main pharmacokinetic parameters were as follows: distribution half-life (t 1/2α)-0.166 ± 0.022 h; elimination half-life (t 1/2ß)-3.161 ± 0.296 h; apparent volume of distribution (V d)-0.231 ± 0.033 L/kg; clearance rate (CLb)-0.057 ± 0.003 L/(h.kg); and area under the curve (AUC)-1.189 ± 0.057 g.h/mL. The pharmacokinetic parameters of arctigenin following oral administration of the Fructus arctii powder were as follows: absorption half-life (t 1/2ka)-0.274 ± 0.102 h, t 1/2α-1.435 ± 0.725 h, t 1/2ß-63.467 ± 29.115 h, V d-1.680 ± 0.402 L/kg, CLb-0.076 ± 0.028 L/(h kg), peak time (t max)-0.853 ± 0.211 h, peak concentration (C max)-0.430 ± 0.035 g/mL, and AUC-14.672 ± 4.813 g/mL. These results indicated that intravenous arctigenin was sparingly distributed in tissues. In contrast, orally administered Fructus arctii powder was rapidly absorbed, more widely distributed, and more slowly eliminated than the intravenous arctigenin, which may indicate its sustained pharmacological effects.
