The protective effects of vitamin C on apoptosis, DNA damage and proteome of pufferfish (Takifugu obscurus) under low temperature stress

The aim of this study was to investigate the protective effects of vitamin C on apoptosis, DNA damage and proteome of pufferfish under low temperature stress. Six diets were formulated to contain 2.60, 48.90, 95.50, 189.83, 382.40, 779.53mg/kg vitamin C. After 8-week feeding trial, fish were exposed to low temperature challenge. The results showed that pufferfish receiving vitamin C diet exhibited a significant decrease in ROS production (48.9-189.83mg/kg vitamin C diet groups), cytoplasmic free-Ca²⁺ concentration (48.9-779.53mg/kg vitamin C diet groups), apoptotic cell ratio (95.5-779.53mg/kg vitamin C diet groups) and DNA damage (189.83-779.53mg/kg vitamin C diet groups) under low temperature stress in comparison with those of control. We also investigated the alteration in protein expression under low temperature stress by a comparative proteomic analysis. The results demonstrated that 24 protein spots showed significantly differential expression in the cold-stress-treated group compared with those of the control group, and 5 protein spots were successfully identified. Furthermore, comparative proteomic analysis revealed that vitamin C could increase expressed proteins related to energy metabolism, immune responses and cytoskeleton. These findings would be helpful to understand the protective effects of vitamin C against cold stress.

DNA protective effect of ginseng and the antagonistic effect of Chinese turnip: A supplementation study

AIM

The aim of this clinical study is to provide scientific evidence for supporting traditional Chinese application and usage to the patients. For this purpose, we tested the ability if Panax ginseng extract to lower oxidative damage to nuclear DNA in human lymphocytes by comparing the effect of cooked Chinese turnip on this effect.

MATERIALS AND METHODS

Seven healthy subjects (4 males and 3 females from 37 to 60 years) participated two occasions which were at least 2 weeks apart. About 2 mL of fasting blood sample for baseline measurement was taken on arrival. They were requested to ingest the content of 5 ginseng capsules in 200 mL water. The subject remained fasting for 2 h until the second blood sample taken. In the other occasion, the experiment was repeated except a piece of cooked turnip (10 g) was taken with the ginseng extract. The two occasions could be interchanged. Comet assay was performed on two specimens on the same day for the evaluation of lymphocytic DNA damage with or without oxidative stress.

RESULTS

For the group with ginseng supplementation, there was a significant decrease in comet score for hydrogen peroxide (H₂O₂) treatment over the 2-h period while no change in DNA damage for unstressed sample. For the group with ginseng together with turnip supplementation, there was no significant difference in comet score for both H₂O₂ treatment and phosphate-buffered saline treatment. Ginseng extract could reduce DNA damage mediated by H₂O₂ effectively, but this protection effect was antagonized by the ingestion of cooked turnip at the same time.

CONCLUSION

In the current study, commercial ginseng extract was used for supplementing volunteers. Ginseng extract could protect DNA from oxidative stress in vivo while turnip diminished the protection.

Rapid but mild genoprotective effect on lymphocytic DNA with Panax notoginseng extract supplementation

BACKGROUND

Panax notoginseng (PN) is a well-known Chinese medicinal herb traditionally used as a hemostatic agent that strengthens and builds blood. The free radicals scavenging and antioxidant property of PN have been demonstrated in various studies either in vitro or in animal models, however, the genoprotective effect at human cellular level remains to be elucidated.

AIM

The current supplementation study aimed to investigate the genoprotective effect of PN. The study explored the DNA protection effect after a single dose of 2500 mg commercial notoginseng extract in water.

MATERIALS AND METHODS

Six subjects, (3 males, 3 females) were recruited and each attended two trials. In the first trial, pre-ingestion and 2 hour-post-ingestion blood samples were collected and they were challenged with 50 µM H2O2. In the second trial, water was taken instead as control. Lymphocytes with or without challenge were then subjected to comet assay. DNA damage was assessed under fluorescent microscope.

RESULTS

Results showed a significant (P < 0.05) but mild decrease (3%) in the comet score after PN supplementation, indicating that PN supplementation reduces the H2O2-induced DNA damage in the lymphocytes and enhanced their resistance to oxidative damage giving a mild acute genoprotective effect against oxidant challenge. No change of comet score was observed in control trial.