Original paperImmunomodulatory activity of Toxicodendron pubescens in experimental models
Introduction
Toxicodendron pubescens (Family – Anacardiaceae) is known as Rhus toxicodendron (Rhus tox) and is extensively used in homeopathy as treatment of inflammatory conditions. It is considered to act on the skin, rheumatic pains, mucous membrane affections and typhoid type fever.1 This plant contains a potent allergen called ‘Urushiol’ which is present in the resinous sap of its parts. Urushiol has been proved to be responsible for dermatitis caused by Rhus tox.2, 3 A recent study by Carvalho and coauthors has revealed that the anti-inflammatory effects of homeopathic dilutions of Rhus tox can be demonstrated on the carrageenan induced paw inflammation in rats. This report proves Rhus tox to be effective in 6cH, 12cH, 30cH and 200cH dilutions in reducing the edema induced by carrageenan injection in rat paws.4
Thus, the literature on this drug suggests the possibility of effects of Rhus tox on immune system as it causes contact sensitization as well as shows potent anti-inflammatory effects. Hence, present investigation was designed to evaluate the effects of Rhus tox in crude form and in homeopathically diluted form in the animal models of humoral and cellular immune response. Its effects were also evaluated on the in vitro activities of human PMN cells.
Section snippets
Material and methods
Chemicals: formyl-N-methyl-leucyl-phenylalanine (FMLP) (Cat. No. F-3506, Lot. 067K1436, CAS. No. 59880-97-6), DMSO HYBRI-MAX (Cat. No. 2650, Lot 077K2334) and sodium deoxycholate (Cat. No. D6750, Lot. No. 056K0031) were purchased from Sigma–Aldrich.
RPMI-1640 (Cat. No. AT 028), Eagle's minimum essential medium (MEM) (Cat. No. AT 020), nitroblue tetrazolium (NBT) (Cat. No. RM 578, Lot. No. 5-1860), May–Grunwald stain (Cat. No. S 011), Giemsa stain (Cat. No. S 039), agarose (electrophoresis grade,
Assessment of humoral immune function
As shown in Figure 1, in case of SRBC control group, the average titer value was 5.1, which indicates the formation of antibodies against the injected SRBCs. The Rhus tox mother tincture, 6cH, 30cH, 200cH and 1000cH potencies administered per oral (p.o.) for a period of 8 days showed the average antibody titers as 10.0, 9.3, 8.2, 7.4 and 7.1 respectively, while Rhus tox back dilution at 10 mg/kg p.o. dose administered for 7 days, showed average titer value of 6.6. The rise in antibody titer was
Discussion
T. pubescens is extensively used in homeopathic practice in treatment of inflammatory conditions.4 This plant is also known to induce severe contact dermatitis which is caused because of Urushiol [1, 2-dihydroxy-3-(pentadec-8-ynyl) benzene], a compound present in the resinous sap of this plant.16 This profile of activities of Rhus tox suggests that this plant might also alter immune response. Hence, in present study, the crude form and homeopathically diluted form of Rhus tox was evaluated
Conclusion
It is noteworthy that in all the in vivo as well as in vitro models, effect of Rhus tox dilutions and extracts showed stimulating effect in a concentration dependent manner. As the homeopathic potency increased, there was decrease in the stimulatory effect of Rhus tox. This indicates that Rhus tox shows the presence of such chemical constituents that show the dose dependent immunostimulatory activity. There was potent stimulation of both cellular and humoral immune response in Rhus tox treated
Conflict of interest
We declare that the research involved in the above manuscript has been carried out at an educational Institute as a part of dissertation work. We did not receive any funds that could influence our work. We also state here that the Institutes where we are working have not paid us any honoraria, consultancy fees and the findings of this study have not been submitted as a part or as a whole to the patenting authorities of any country.
Acknowledgment
The authors are grateful to Gurden Landeck, Head of Quality Control and Blasi Augusto, Director International Sales of Dr. Reckeweg & Co. GmBH, Germany for the issue of quality control certificates for the Rhus tox dilutions used in this study. Thanks also to D.R. Lohar, Director, Homeopathic Pharmacopoeia Laboratory, Ghaziabad, India, for generous supply of authenticated sample of crude form of T. pubescens.
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