Search

Background: Microgravity is associated with an increase in peroxidative damage. The effect is more pronounced after long-duration space flights and can even last for several weeks after landing. The objective of the study is to determine the influence of simulated microgravity on the periodontal status and salivary and serum oxidant/antioxidant status of the body in simulated microgravity (-6° head-down-tilt [HDT) bed rest)., Methods: Twenty healthy male volunteers were studied before and after 60 days of simulated microgravity (-6° HDT bed rest). We measured salivary and serum oxidative markers, such as malondialdehyde (MDA), 8-oxo-7,8 dihydro-2 deoxyguanosine (8-OHdG), and vitamins C and E, and clinical periodontal parameters (probing depth [PD] and clinical attachment level [CAL])., Results: Serum and salivary vitamin C and E concentrations were significantly decreased, whereas MDA and 8-OHdG levels were significantly increased after 60 days of simulated microgravity. Serum and salivary markers showed a strong and significant correlation. CAL and PD were higher but not statistically significant in simulated microgravity., Conclusions: This study suggests that oxidative stress in the microgravity environment was increased but did not significantly influence periodontal parameters after 2 months. Also, this study indicates the possibility that the findings may have a broader clinical relevance to patients on bed rest or who are physically inactive. Studies on larger patient samples and follow-up for a longer time are required to verify the relationship between antioxidant status in the space microgravity condition and periodontal health.

Extensive research within the past half-century has indicated that curcumin (diferuloylmethane), a yellow pigment in curry powder, exhibits anti-oxidant, anti-inflammatory, and pro-apoptotic activities. We investigated whether the anti-pre-cancer activities assigned to curcumin are mediated through an anti-oxidant and DNA-protecting mechanism. Patients with oral leukoplakia, oral submucous fibrosis or lichen planus, and healthy individuals (n = 25 for each group) aged 17-50 years were selected. Salivary and serum oxidative markers such as malonaldehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), vitamins C and E were measured just prior to the intake of curcumin, after one week of curcumin intake and following clinical cure of precancerous lesions. Serum and salivary vitamins C and E showed increases, while MDA and 8-OHdG levels showed decreases in patients with oral leukoplakia, submucous fibrosis and lichen planus after intake of curcumin for all categories of precancerous lesions. The changes in these values were observed to be statistically significant after clinical cure of the disease (P < 0.05). The five-point rating scale for pain, as well as lesion size in oral leukoplakia, submucous fibrosis and lichen planus, improved significantly (P < 0.05). In addition, in submucous fibrosis, mouth opening (P < 0.05) recovered significantly. In oral leukoplakia, submucous fibrosis and lichen planus, the levels of serum and salivary vitamins C and E increased significantly, while MDA and 8-OHdG levels decreased after 131(15), 211(17), and 191(18) days, respectively. Values for serum and salivary vitamins C and E showed a significant decrease in oral leukoplakia, submucous fibrosis and lichen planus, in contrast to healthy individuals, but increased significantly in all groups subsequent to curcumin administration after clinical cure of lesions. Based on these results, we can conclude that curcumin mediates its anti-pre-cancer activities by increasing levels of vitamins C and E, and preventing lipid peroxidation and DNA damage.

Lipid peroxidation may be involved in cancer and essential nutrients that can scavenge free radicals, such as vitamins E and C, operate in concert. Levels of antioxidant vitamins E and C were estimated in 50 patients with oral cancer and 24 healthy persons served as control. Significantly lower levels of vitamins E and C were observed in oral cancer patients as compared to controls (P < 0.011). Antioxidant nutrients may be utilized to a greater extent in oral cancer patients to counteract free radical-mediated cell disturbances, resulting in a reduction in salivary antioxidant levels.

Abstract: Objective: To determine the preventive effects of curcumin on peroxidative damage under two bed rest conditions. Methods: 20 healthy male (10 with curcumin and 10 without curcumin) volunteers were selected. They were studied before, during, and just on bed rest conditions at −6° head-down-tilt (HDT) bed rest and bed rest position (BD) for 10 days. We measured the salivary and serum oxidative markers such as Malonaldehyde, 8-hydroxydeoxyguanosine, vitamin C and E just before HDT & BD, during HDT & BD experiment, and in course time of recovery with curcumin and without curcumin groups. Results: The values of serum and salivary vitamin C & E showed statistically significant decrease in both bed rest conditions as compared to those of the conditions before and during the recovery stage. However, these levels were not significantly lowered in curcumin groups in contrast to the groups without curcumin (P>0.05). MDA and 8-OHdG levels showed significant increase in simulating microgravity and zero gravity conditions as compared to those before and in the recovery stage. However, these levels were lower in curcumin groups in contrast to the groups without curcumin(P<0.05). Serum and salivary correlation analysis revealed a strong and highly significant correlation for MDA, vitamin C & E and 8 dihydro-2 deoxyguanosine (8-OHdG) in the conditions before, during and in the recovery periods in both bed rest conditions. Since saliva collection is easy and non-invasive, measurements of salivary marker levels may prove to be useful in the space research. Conclusions: Curcumin prevents peroxidative damage in both bed rest conditions. Further study is required on antioxidation actions of curcumin in space microgravity conditions. [Copyright &y& Elsevier]