[Preparation and Evaluation of Intranasal in situ Gel of Bupleuri Radix Volatile Oil and Baicalin].

OBJECTIVE: To prepare and evaluate a new formulation of thermosensitive and ion-sensitive in situ gel for nasal administration, using the volatile oil of Bupleuri radix and baicalin, the effective component extracted from Scutellariae radix . METHODS: Formulation of in situ nasal gel of Bupleuri radix volatile oil and baicalin was prepared by using poloxamer 407 and deacetylated gellan gum as the gel base, 10% pharmasolve and 2% polysorbate 80 as the solubilizer, and 0.8% triethanolamine as the pH regulator. The physical appearance, phase transition temperature, and baicalin release performance of the prepared gel were examined. The pharmacodynamic evaluation was done with the rat fever model developed with dry yeast and the mouse auricle swelling inflammation model. RESULTS: The phase transition temperature of the gel was optimized to be 36 ℃. The release of baicalin from the gel showed obvious features of sustained release, which accorded well the zero-order kinetics equation. The results of experiments with the rat dry yeast fever model and the mouse xylene auricle swelling inflammation model showed that the gel had significant antipyretic and anti-inflammatory effects that were significantly better than those of the groups treated with the blank gel base and the Bupleuri radix and Scutellariae radix granule. Results from the cilia toxicity test showed that the gel did not have obvious toxic effect on toad palate mucosal cilia. CONCLUSION: The in situ nasal gel of Bupleuri radix volatile oil and baicalin prepared in the study had a rapid onset time, high efficiency, and prolonged release of active ingredients, thus showing promises for further applicational development.

Occurrence, function and potential medicinal applications of the phytohormone abscisic acid in animals and humans.

Abscisic acid (ABA) is an important phytohormone that regulates plant growth, development, dormancy and stress responses. Recently, it was discovered that ABA is produced by a wide range of animals including sponges (Axinella polypoides), hydroids (Eudendrium racemosum), human parasites (Toxoplasma gondii), and by various mammalian tissues and cells (leukocytes, pancreatic cells, and mesenchymal stem cells). ABA is a universal signaling molecule that stimulates diverse functions in animals through a signaling pathway that is remarkably similar to that used by plants; this pathway involves the sequential binding of ABA to a membrane receptor and the activation of ADP-ribose cyclase, which results in the overproduction of the intracellular cyclic ADP-ribose and an increase in intracellular Ca²âº concentrations. ABA stimulates the stress response (heat and light) in animal cells, immune responses in leukocytes, insulin release from pancreatic ß cells, and the expansion of mesenchymal and colon stem cells. ABA also inhibits the growth and induces the differentiation of cancer cells. Unlike some drugs that act as cell killers, ABA, when functioning as a growth regulator, does not have significant toxic side effects on animal cells. Research indicated that ABA is an endogenous immune regulator in animals and has potential medicinal applications for several human diseases. This article summarizes recent advances involving the discovery, signaling pathways and functions of ABA in animals.