Background: The homeopathic preparation, Traumeel S, has been used as a valuable alternative to conventional non-steroidal anti-inflammatory drugs (NSAIDS) for over 30 years. This antihomotoxic, anti-phlogistic drug has been widely used by sportsmen and women in the treatment of lesions and inflammatory processes which result from exercise-induced skeletal muscle microtrauma. Although numerous randomised, double-blind placebo-controlled trials have confirmed the efficacy of Traumeel S as an anti-inflammatory agent, there are few in vivo studies which have specifically investigated the mechanism by which Traumeel S is effective in reducing inflammatory response to exercise-induced muscle cell damage. Aim: To establish whether the administration of Traumeel S during the five days before participation and three days following participation, significantly attenuates the systemic markers of the inflammatory response, following a 90-minute downhill running trial. Method: Twenty-four healthy athletes (14 men and 10 women), aged 20-50 years, were recruited for this study. Following baseline laboratory testing and familiarisation with the treadmill as well as a field test, subjects were matched according to gender, BMI, training age, training status, peak performance and foot strike patterns and randomised into Traumeel (TRS) and Control (PLAC) groups in a placebo-controlled, double-blind design. One Traumeel S or Placebo tablet was ingested three times per day for five days prior to and three days following a 90-minute exercise trial on a downhill (-6% gradient) at 75% V02 max- Blood samples were collected prior to the 90-minute trial (PRE), immediately after the trial (IPE) and 24 hours (24 PE), 48 hours (48 PE) and 72 hours (72 PE) following the trial. Each subject was also requested to complete a training record prior to the trial and keep a record of the daily symptoms of delayed onset muscle soreness (DOMS) both at rest (general pain) and during walking (daily living). Full blood counts (FBC), serum creatine kinase (CK), lactate dehydrogenase (LDH) and Cortisol concentrations were measured using standard haematological laboratory procedures and serum C-Reactive Protein (CRP) was determined by immunoturbidimetric assay. Sandwich ELISA's were used to determine myeloperoxidase (MPO) and plasma interleukin-6 (IL-6) concentrations. All results obtained were adjusted for changes in plasma volume as calculated from the red blood cell indices. Results: Mean ± SD characteristics of the gender-matched subjects in the experimental (TRS) and placebo-control (PLAC) groups did not differ significantly in terms of BMI, age, % body fat, FVC, FEVi, training age and status, foot strike pattern or peak running performance, maximal Heart Rate, VE, V02peak> RER, RPE during the maximal exercise test (p > 0.05). This indicated that the randomised pairs were well matched. The 90-minute downhill running protocol resulted in significant elevations in total circulating white blood cell count (WBC), neutrophil, CK, LDH, Cortisol, CPR, MPO and IL-6 concentrations (p < 0.001). When comparing the TRS and PLAC groups, mean ± SD total and differential WBC count, neutrophil count, CK, LDH, Cortisol, CPR, MPO and IL-6 concentrations did not differ (p > 0.05) over the 5 time points. At 24 PE, MPO concentrations were significantly higher in the TRS group than in the PLAC group (p = 0.03). The lower mean ± SD post-trial DOMS scores reported by the TRS group were not significantly different from those reported by the PLAC group (p > 0.05). Conclusion: Although the findings of this study did not identify differences in circulating CK, LDH, Cortisol, CPR and IL-6 concentrations between the TRS and PLAC groups, the elevated MPO concentration at 24 PE did provide preliminary novel evidence of enhanced activation of neutrophil oxidative burst activity following exercise-induced muscle damage which is hypothesized to accelerate the recovery process. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, 2008.