Addition Of Vitamin C Research Articles

Effects of vitamin C on androgen receptor mediated actions in human prostate adenocarcinoma cell line LAPC-4

Objectives To examine the effects of vitamin C (VC) on androgen receptor (AR)-mediated functions in a human prostate cancer cell line, Los Angeles prostate cancer (LAPC-4). VC is an essential dietary substance in the maintenance and preservation of vital functions in humans. However, the role of VC in prostate cancer remains to be elucidated. Methods Cell proliferation and the expression of two well-known androgen regulated proteins, prostate-specific antigen and human glandular kallikrein-2, were studied in the presence of VC. Results In the presence of androgen and VC, both cell growth and the expression of prostate-specific antigen and human glandular kallikrein-2 proteins were decreased. Moreover, AR-mediated transcription activity of the prostate-specific antigen gene was suppressed with VC, similar to the phenomenon observed when cells were treated with hydrogen peroxide. These effects were reversed with catalase. However, additional studies did not reveal changes in the expression level of AR protein or its androgen-binding activity with the addition of VC. Conclusions The results of our study suggest that the pro-oxidant property of VC might be one of the mechanisms by which it modulates AR-mediated function in LAPC-4 cells.

Hydrotrope and hydrotrope-solubilization action ofof Vitamin C

Vitamin C (VC) is found to show the hydrotrope action when the aqueous solubility of surfactant is enhanced while it will show the hydrotrope-solubilization action when the solubility amount of oil in O/W microemulsion and that of water in W/O microemulsion are increased. Both the hydrotrope action and the hydrotrope-solubilization action of VC are selective so that they can only be found in cationic surfactant hexadecyltrimethylammonium bromide (CTAB) system. The addition of VC in CTAB system with n-C 5H 11OH as co-surfactant enlarges the O/W and W/O areas in the phase diagram and expands the bicontinuous region by reducing the lamellar liquid crystal area. The results show that the hydrotrope-solubilization action of VC is in fact a structural transition from the lamellar liquid crystal phase to the bicontinuous structure.

Hydrotrope Action of Vitamin C (VC) and Its Application in a Sunscreen

The solubility regions of the sunscreen 2-ethyIhexyl p-methoxycinnamate (E557) in the CTAB/ n-CsHnOH/ H2 O system with and without the hydrotrope agent vitamin C (VC) are determined. E357 was only sohibilized in the bicontinuous microemulsion (BI), the W/ O microemulsion area and the lamellar liquid crystal region (LLC). The addition of VC in the system greatly enlarged the solubility amount of E557in the bicontinuous region, but reduced h in the lamellar liquid crystal area. Small angle X-ray diffraction measurement was used to determine the location of E557 in the lamellar liquid crystal showing the suncreen molecule penetrating between the hydrocarbon chains in the liquid crystal structure.The UV absorption spectra of E557 in various media was measured, surprisingly showing a dependence on the colloidal structure.

Modelling cortical cataractogenesis. XI. Vitamin C reduces γ-crystallin leakage from lenses in diabetic rats

Normal and streptozotocin diabetic female Wistar rats were given vitamin C (VC) at 0·3% or 1·0% ( w w ) in the diet: 1% dietary VC resulted, in 12–24 hr, in significant increases in serum ascorbate levels and lens ascorbate concentrations in normal rats. The increase was biphasic, with VC concentrations falling to a lower level which was still significantly elevated compared to controls in the period of 1·7–4 days for serum and 1·7–5 days for lenticular VC. At the end of 10 weeks the rats were examined for weight gain or loss, general body condition and cataracts. At the time of killing, blood was collected for measurement of serum glucose. Alpha-crystallin levels were determined in vitreous and aqueous humours using a radioimmunoassay. One lens from each rat was fixed for either scanning electron microscopy or light microscopy; the other lens was homogenized in 8 m guanidinium chloride for adenosine triphosphate analysis. In normal rats, a small amount of γ-crystallin was found in the vitreous humour, and an even smaller amount in the aqueous humour. Diabetes caused a five-fold increase in the vitreous humour and a 2·5-fold increase in γ-crystallin in the aqueous humour. Diabetes also led to a significant worsening in general body condition, loss of body weight, formation of cataracts, and decrease in lens adenosine triphosphate levels. Addition of VC to the diet of diabetic animals resulted in reduction in cataracts and a decrease of γ-crystallin leakage into the aqueous and vitreous humours. VC had no effect on lens adenosine triphosphate levels. Neither streptozotocin diabetes nor VC in the diet appeared to affect the weight of the lenses.