Rapid Induction of Protective Tolerance to Potential Terrorist Agents: A Systematic Review of Low and Ultra-low Dose Research

Principal Investigators: Astrid Szeto, MPH, Florence Rollwagen, PhD, Wayne B. Jonas, MD

Affiliations: Uniformed Services University of the Health Sciences and the Samueli Institute for Information Biology

Background: The concept that low dose [LD] and ultra-low dose [ULD], sublethal exposures of toxic substances can induce tolerance to higher doses has been postulated for centuries.  The modern concept of hormesis, defined as the stimulation of biological processes at subinhibitory dose levels, has been shown for a variety of substances with implications for risk assessment and chemical exposure policy and prevention.  These effects involve various chemicals of a toxic nature important in public health, including: alcohol and metabolites, hydrocarbons, antibiotics, insecticides, auxin-related chemicals, metals, fungicides, pesticides and herbicides.  These effects have been documented in animals, humans, bacteria, plants, fungi and protozoa.  The range of endpoints includes cancer, reproduction, growth, survival, longevity, metabolic effects, mortality and others.  A similar but smaller literature examining ULD modulation of toxic effects has been reported in the homeopathic literature.

Objective of the study: To systematically review the literature on the ability of low and ultra-low dose toxin exposure to prevent and treat biological and chemical threats.

Methods and Design: Laboratory research articles on protection or treatment from low-dose exposure for the top thirteen chemical and biological warfare threats were collected and systematically evaluated for quantity and scientific quality using pre-defined methodological criteria.

Results: Over 2,600 articles were screened.  Only five studies met the inclusion criteria examining stimulation and protective effects of low or ultra-low dose exposures to the thirteen pre-identified biological and chemical agents.  The quality evaluation (QE) of these studies was above average with a mean QE score of 70.6% of maximum.  Two articles of fair to good quality reported both protective and treatment efficacy from exposure of animals or humans to low and ultra-low dose exposures to toxins of risk in biochemical warfare.

 

Publication: Homeopathy. 2004 Oct;93(4):173-8