ABSTRACT
Our preliminary studies with tylophora alkaloids had shown that they inhibit cellular immune responses like contact sensitivity to dinitro-flurobenzene and delayed hypersensitivity to sheep red blood cells, in vivo. Investigations were hence carried out to determine the cellular targets of tylophora alkaloids in in vitro systems. Con A induced proliferation of splenocytes was used as a model system to study the effect of the alkaloids on cellular immune responses. The alkaloid mixture was found to inhibit proliferation of splenocytes at higher concentrations and augment the same at lower concentrations. Both macrophages and T cells were found to be vulnerable to tylophora alkaloids. The alkaloid mixture suppressed IL-2 production in Con A stimulated splenocytes at the inhibitory or higher concentrations and enhanced production at the lower concentrations. IL-1 production by activated macrophages on the contrary was doubled in the presence of inhibitory concentrations of tylophora. These studies indicate that tylophora alkaloids have a concentration dependent biphasic effect on Con A induced mitogenesis. At lower concentrations they augment Con A induced lymphoproliferation by enhancing IL-2 production. Inhibition of proliferation at higher concentrations of the alkaloid is due to inhibition of IL-2 production and activation of macrophages, which have a cytostatic effect.
Subject(s)
Adjuvants, Immunologic/pharmacology , Concanavalin A/pharmacology , Lymphocytes/drug effects , Magnoliopsida , Plant Extracts/pharmacology , Spleen/drug effects , Alkaloids/pharmacology , Animals , Cell Cycle/drug effects , Cell Division/drug effects , Cell Survival/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Flow Cytometry , Interleukin-1/metabolism , Interleukin-2/metabolism , Macrophages/metabolism , Medicine, Ayurvedic , Mice , Mice, Inbred C3H , Plant Leaves/chemistry , Plant Lectins , Spleen/cytology , T-Lymphocytes/metabolismABSTRACT
Extraction of promethium(III), uranium(VI), plutonium(IV), americium(III), zirconium(IV), ruthenium(III), iron(III) and palladium(II) has been carried out with a mixture of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and tributyl phosphate (TBP) in dodecane. The effects of nitric acid, TBP and CMPO concentrations on the extraction of these metal ions have been studied. The nature of the species of the above metal ions extracted into the organic phase has been suggested.
