Pharmacological Studies on the Potential Anti-inflammatory Effects of a Natural Product(s)

Abstract

Over the past two centuries, natural products have played an invaluable role in drug discovery contributing enormously to the development of therapeutic agents currently used in modern medicine. Dietes bicolor, commonly known as Yellow Wild Iris, Peacock Flower or Butterfly Iris is a rhizomatous perennial herb belonging to family Iridaceae. The phytochemical and pharmacological properties of this genus have never been reported. Aim: The current study was designed to investigate the anti- inflammatory of Dietes bicolor leaf extract. Moreover, phytochemical analysis of the biologically active fraction was carried out. Methodology: The total leaf extract and its fractions were examined for possible anti-inflammatory activity in two experimental models: the carrageenan-induced rat edema model and the croton oil– induced ear edema model. Collectively, the parameters assessed included paw volume, PGE2 level, cytokines (TNF-α, IL-6, IFN-γ, IL-1α, IL-1β, MCP-1, RANTES and Macrophage Inflammatory Protein (MIP)), ear edema, ear tissue MPO and histopathology. Results: Dietes bicolor extract demonstrated a dose-related reduction in both carrageenan-induced rat paw edema and croton oil-induced ear edema models. A flavone C-glycoside was isolated from the biologically active fraction which may contribute to its anti- inflammatory.

Topical application of Dietes bicolor reduced ear edema induced by croton oil in rats. In the same animal model, Dietes bicolor reduced neutrophil infiltration, as indicated by decreased myeloperoxidase (MPO) activity. In addition, Dietes bicolor reduced the histopathological changes affected by croton oil application. The biologically active fraction was subjected to further phytochemical analysis utilizing several chromatographic techniques. One major compound was isolated and its structure was elucidated using different spectroscopic techniques.