Evidence for altered metabolic pathways during environmental stress: (1)H-NMR spectroscopy based metabolomics and clinical studies on subjects of sea-voyage and Antarctic-stay.

The Antarctic context is an analogue of space travel, with close similarity in ambience of extreme climate, isolation, constrained living spaces, disrupted sleep cycles, and environmental stress. The present study examined the impact of the harsh habitat of Antarctica on human physiology and its metabolic pathways, by analyzing human serum samples, using (1)H-NMR spectroscopy for identification of metabolites; and quantifying other physiological and clinical parameters for correlation between expression data and metabolite data. Sera from seven adult males (of median age 36years) who participated in this study, from the 28th Indian Expeditionary group to the Antarctica station Maitri, were collected in chronological sequence. These included: i) baseline control; ii) during ship journey; iii) at Antarctica, in the months of March, May, August and November; to enable study of temporal evolution of monitored physiological states. 29 metabolites in serum were identified from the 400MHz (1)H-NMR spectra. Out of these, 19 metabolites showed significant variations in levels, during the ship journey and the stay at Maitri, compared to the base-line levels. Further biochemical analysis also supported these results, indicating that the ship journey, and the long-term Antarctic exposure, affected kidney and liver functioning. Our metabolite data highlights for the first time the effect of environmental stress on the patho-physiology of the human system. Multivariate analysis tools were employed for this metabonomics study, using (1)H-NMR spectroscopy.

Wintering in Antarctica: impact on immune response of Indian expeditioners.

The immune system is one of the major thrust areas in understanding the effects of adverse climatic conditions on human health. Exposure to the Antarctic environment, such as isolation, cold, UV radiations, magnetic field, blizzards, circadian biorhythms, and fear of the unknown, modify various components of the immune system. Members of Antarctic expeditions suffer significant emotional strain as a result of physical isolation and social deprivation. The present study was performed on winter team members of the 28th Indian Scientific Expedition. In this study, different immunological parameters, which mainly include cytokines (TNF-α, IFN-γ, TGF-ß, and IL-4), chemokine MIP-1α, immunoglobulins (IgA, IgM and IgG), cortisol and netrin-1, were assayed in sera by ELISA. Results showed that TNF-α and MIP-1α levels were significantly increased in March, May and August while IFN-γ levels were increased in March and May while TGF-ß levels showed a significant decrease in March and May. Serum IgA levels were significantly increased during the entire period of the stressful expedition. Therefore, the present study suggests that serum IgA could be a potential biomarker for extreme environmental conditions.

Ship-borne journey induces Th1 cytokines level in antarctic summer expeditioners.

It has become apparent that extreme environmental conditions of Antarctic continent alters many immune responses. The present study was conducted on 28th Indian Antarctic expeditioners. The investigations were carried out to explore the effect of multiple stresses like isolation, cold and UV exposure on human immunity. Thirty blood samples were collected between 6 and 7 AM, after an overnight fast at different stages of the expedition - viz. the pre-exposure sample was collected at Delhi on 25(th) October 2008. The expedition started its ship journey from Capetown, on 6(th) January, 2009 and on-board blood was collected on 31(st) January 2009. After 1 month stay at Maitri, blood was collected on 3(rd) March 2009. Different parameters studied included levels of cytokines, chemokines and cortisol. The ship-borne journey induced a dramatic increase in TNF-α, IFN-γ, and B cell activating factor (BAFF) levels and moderate decreases in TGF-ß and cortisol levels. However, after being off board for 1 month at Maitri station, levels of above cytokines, cortisol and BAFF were decreased but MIP-1α was significantly increased. These data for the first time suggest that ship-borne journey to the Antarctic continent results in tremendous stress to the body, which eventually resulted in increased TH1-biased immunity.