Intestinal transport and absorption of bioactive phenolic compounds from a chemically characterized aqueous extract of Athrixia phylicoides.

Ethnopharmacological Relevance: Athrixia phylicoides, popularly known as "bush tea", is an indigenous aromatic shrub found in mountainous and grassland areas of the northern and eastern parts of southern Africa. The plant is traditionally used for the treatment of several ailments, including coughing, treating infected wounds, treating boils and sore throat, hypertension and heart disease. Potential anti-diabetic effects have also been demonstrated in vitro.

Comparative binding of soluble fragments (derCD23, sCD23, and exCD23) of recombinant human CD23 to CD21 (SCR 1-2) and native IgE, and their effect on IgE regulation.

IgE, responsible for type I hypersensitivities, is regulated by interactions between its receptor, CD23, and co-receptor CD21. To examine comparative binding of recombinant human CD21 SCR 1-2 and native human IgE to CD23 plus the effect of CD23 on IgE production, we engineered recombinant soluble human CD23 fragments; (1) derCD23, (2) sCD23 and (3) exCD23, formed in vivo by proteolysis. SPR analysis revealed a progressive increment in affinity of soluble fragments for IgE, upon increasing length of CD23 "stalk" domain, exCD23>sCD23>derCD23.