Oldenlandia Affinis (Roem & Schult) DC is a medicinal plant from the Rubiaceae family that contains cyclotides which has been known to have a role in the host-defence of plants as well as other biological properties. In this study, we investigated the immunomodulatory and anti-inflammatory properties of the methanol-methylene chloride extract of O. affinis (MME) and its cyclotide-rich fraction (CRF) in various animal models.
Various models such as carbon clearance test, haemolytic activity of complement system, leucopoiesis in immunocomoetent mice, haemagglutination assay, DTH Response and humoral antibody assays utilizing the ELISA technique to determine antibody responses were employed in the study for immunomodulatory activities. The anti-inflammatory effects were investigated using carrageenan-induced paw oedema and formaldehyde-induced arthritis models in rats.
Phytochemical analysis revealed alkaloids, flavonoids and proteins to be abundantly present in both extract and fractions. Acute toxicity studies in mice showed an Ld50 above 5000 mg/kg per oral, for both extract and fraction, thus being safe for all practical studies, and in addition, produced no signs of intoxication.