Reticulo-Endothelial System Stimulating Compounds and Their Mechanism of Action

Abstract

A series of compounds are described which exhibit therapeutic activity in experimental tuberculosis, acting exclusively on the host. The active compounds (citronellyl acetate, d-limonen, linalyl acetate) induce a local India ink and trypan blue accumulation and also stimulate the macrophages in vitro and in vivo to an increased phagocytic activity. Sera of the animals treated with therapeutically active compounds stimulate the macrophages of normal animals to an increased phagocytosis. A correlation between chemical structure of the reticulo-endothelial system stimulating compounds and the above effects is discussed.

Effect of Some Essential Oils on Phagocytosis and Complement System Activity

“…Most of the volatile oils tested inhibited phagocytosis, although the mixture of bornyl and isobornyl acetates showed a mild stimulating activity (21.3%) at the highest concentration tested (55.90 μg/mL). Some authors have also found stimulatory effects on phagocytosis for a few essential oils, such as those of Rheum palmatum L. and Allium sativum L., and for some pure constituents, such as citronellyl acetate and linalyl acetate. ,, Essential oils from cajuput, tarragon, and coriander showed no activity whatsoever on phagocytosis at the concentrations tested.…”

“…Some authors have also found stimulatory effects on phagocytosis for a few essential oils, such as those of Rheum palmatum L. and Allium sativum L., and for some pure constituents, such as citronellyl acetate and linalyl acetate. 8,11,18 Essential oils from cajuput, tarragon, and coriander showed no activity whatsoever on phagocytosis at the concentrations tested.…”

“…In vitro evaluations of eugenol by different authors resulted in a reduction of phagocytosis. , In other in vitro experiments, it was found that eugenol was able to recover macrophage phagocytic capacity previously diminished by treatment with nicotine . Other volatile compounds and essential oils, such as 3-carene and basil oil, have been dubbed in the literature as phagocytic inhibitors. , In in vivo and in vitro experiments, limonene (the main constituent of lemon oil and lemon terpenes) showed a stimulating effect over phagocytosis or the recuperation of the macrophages phagocytic capacity previously reduced. − Those results differ from ours, although it is important to highlight that employed cells and methodologies were different. Essential oils from juniper, rosemary, palmarosa, and Spanish oregano, lemon terpenes, and carvacrol showed a significant inhibition of phagocytosis, but it was lower than 25% at the highest tested concentration.…”

“…3-Carene was found to be a phagocytosis inhibitor in vitro . On the other hand, limonene, citronellyl acetate, linalyl acetate, and methyl nonyl ketone clearly stimulated phagocytosis, ,− whereas camphor, menthol, and eucalyptol were found to be rather inactive . The activity of eugenol on phagocytosis has not been tested on untreated cells.…”