Neurobiological and psychological evidence of chronic stress in prostate cancer patients.

To measure the prevalence and severity of Generalised Anxiety Disorder (GAD), hypo- and hypercortisolaemia, and their association in a sample of prostate cancer (PCa) patients, 97 Australian PCa patients completed a background questionnaire and the GAD-7, and provided a sample of saliva collected 30-45 min after waking. The mean GAD7 score was 9.67 (SD = 3.09), and prevalence rates for current anxiety were higher than those reported for non-PCa males of a similar age. Mean salivary cortisol concentrations (30.78 nmol/L, SD = 13.97 nmol/L) were also higher than for age-comparative non-PCa men. There was a significant inverse correlation between GAD and cortisol (r = -. 209, p < .05), and four subgroups of GAD-cortisol patients were able to be identified, with evidence of both hyper- and hypocortisolaemia. These findings provide initial neurobiological evidence of the chronic and profound nature of stress experienced by PCa patients, and also suggest a possible measure that might be used to identify most at-risk PCa patients.

Pharmacokinetics of leptin in female mice.

Pharmacokinetics of leptin in mammals has received limited attention and only one study has examined more than two time points and this was in ob/ob mice. This study is the first to observe the distribution of leptin over a time course in female mice. A physiologic dose (12 ng) of radiolabelled leptin was injected in adult female mice via the lateral tail vein and tissues were dissected out and measured for radioactivity over a time course up to two hours. Major targets for administered leptin included the liver, kidneys, gastrointestinal tract and the skin while the lungs had high concentrations of administered leptin per gram of tissue. Leptin was also found to enter the lumen of the digestive tract intact from the plasma. Very little of the dose (<1 %) was recovered from the brain at any time. Consequently we confirm that the brain is not a major target for leptin from the periphery, although it may be very sensitive to leptin that does get to the hypothalamus. Several of the major targets (GI tract, skin and lungs) for leptin form the interface for the body with the environment, and given the ability of leptin to modulate immune function, this may represent a priming effect for tissues to respond to damage and infection.

Autoantibodies are not predictive markers for the development of depressive symptoms in a population-based cohort of older adults.

BACKGROUND: Autoantibodies have been implicated in the etiologic pathway of depressive disorders. Here, we determine the association between the presence of a panel of autoantibodies at baseline and change in depression symptom score over 5-year follow-up in a cohort of healthy elderly Australians. METHODS: Serum samples from 2049 randomly selected subjects enrolled in the Hunter Community Study (HCS) aged 55-85 years were assayed for a range of autoimmune markers (anti-nuclear autoantibodies, extractable nuclear antigen autoantibodies, anti-neutrophil cytoplasmic autoantibodies, thyroid peroxidase autoantibodies, tissue transglutaminase autoantibodies, anti-cardiolipin autoantibodies, rheumatoid factor and cyclic citrullinated peptide autoantibodies) at baseline. Depression symptom score was assessed using the Centre for Epidemiological Study (CES-D) scale at baseline and 5 years later. RESULTS: Autoantibody prevalence varied amongst our sample with ANA being the most prevalent; positive in 16% and borderline in 36% of study population. No evidence for a relationship was found between change in CES-D score over time and any autoimmune marker. Statins and high cholesterol were significantly associated with change in CES-D score over time in univariate analysis; however, these were probably confounded since they failed to remain significant following multivariable analysis. CONCLUSIONS: Autoantibodies were not associated with change in CES-D score over time. These findings point to an absence of autoimmune mechanisms in the general population or in moderate cases of depression.

Comparison of Echinacea alkylamide pharmacokinetics between liquid and tablet preparations.

The relative oral bioavailability of alkylamides from two different Echinacea dosage forms (liquid and tablet) were compared in a small two-way crossover study in humans (n=3). The liquid preparation investigated contained a mixture of Echinacea purpurea root (300 mg/ml) and Echinacea angustifolia root (200 mg/ml) extracted in 60% ethanol. The tablet preparation investigated was also a mixture of E. purpurea root (675 mg/tablet) and E. angustifolia root (600 mg/tablet), but was prepared from the dried 60% ethanolic extracts of these two Echinacea species. Alkylamides were found to be rapidly absorbed and measurable in plasma from both preparations. No significant differences in the tetraene alkylamide pharmacokinetic parameters for T(1/2), AUC(t-lin) and C(max) in the two different preparations were found. T(max) increased from 20 min for the liquid to 30 min for the tablet, which is not unexpected as the tablet required time for disintegration before absorption could occur. These results suggested that there was no significant difference in the bioavailability of alkylamides from the liquid and tablet Echinacea formulations. Furthermore, the results also indicated that the absorption site and any alkylamide loss due to digestive processes were similar in both preparations.

Echinacea intake induces an immune response through altered expression of leucocyte hsp70, increased white cell counts and improved erythrocyte antioxidant defences.

OBJECTIVE: To study the effect of Echinacea tablets on the expression of leucocyte heat shock protein 70 (hsp70), erythrocyte haemolysis, plasma antioxidant status, serum chemistry, haematological values and plasma alkylamide concentrations. METHOD: Eleven healthy individuals (26-61 years of age) were evaluated at baseline (day 1) and on day 15 after consuming two commercially blended Echinacea tablets daily for 14 days. RESULTS: Echinacea supplementation enhanced the fold increase in leucocyte hsp70 expression after a mild heat shock (P=0.029). White cell counts (WCC) were also increased (P=0.043). We also observed a preventative effect against free radical induced erythrocyte haemolysis (P=0.006) indicative of an antioxidant effect. CONCLUSION: The pilot study suggests that Echinacea may invoke an immune response through altered expression of hsp70 and increased WCC.