The novel Sinupret® dry extract exhibits anti-inflammatory effectiveness in vivo

Abstract Sinupret® is frequently used as a herbal medicinal product to treat sinusitis, and it was assumed that anti-inflammatory effects might contribute to its overall beneficial properties. Here, we investigated the effects of a Sinupret® drug mixture (SIN) as well as of the novel Sinupret® dry extract (SIN DE) with the latter containing higher concentrations of active ingredients, in an in vivo model of acute inflammation, the carrageenan-induced pleurisy in rats. Both SIN and SIN DE were administered to rats orally at doses of 100 mg/kg (low dose) and 500 mg/kg (high dose) 1 h prior to intrapleural injection of carrageenan. Although both SIN and SIN DE significantly reduced the exudate volume and leukocyte numbers in the pleural exudate at the high and the low dose 4 h after carrageenan injection, the novel SIN DE was more efficient than SIN at the low dose, implying higher efficiency. In parallel, the novel dry extract SIN DE, but not SIN, at 500 mg/kg significantly lowered the levels of prostaglandin (PG)E 2 in the exudates and reduced the amounts of cyclooxygenase (COX)-2 protein in the lungs. Together, SIN and SIN DE exert significant oral anti-inflammatory effects, which rationalize their therapeutic use in the management of sinusitis and other viral/microbial nasal infections that are associated with inflammation. Moreover, our results suggest that based on the higher efficiency and the accompanied reduction of COX-2 expression and PGE 2 formation, the novel dry extract SIN DE might be superior over the former SIN drug mixture.