Protective effect evaluation of free radical scavengers on UVB induced human cutaneous erythema by skin reflectance spectrophotometry.

Synopsis This paper assesses the suitability of UVB induced skin erythema measured by reflectance spectrophotometry in humans as a model for differentiating topical efficacy of free radical scavengers. Two different formulations (aqueous gels and O/W emulsions) of each active compound (tocopherol, tocopherol acetate, superoxide dismutase (SOD), glutathione, ascorbyl palmitate) were tested on healthy human volunteers before and after skin exposure to UVB radiation. Skin erythema was monitored by calculating erythema index values from the skin spectral data obtained using a reflectance spectrophotometer. The free radical scavengers tested were not able to inhibit UVB induced skin erythema from both formulations when they were topically applied before UVB irradiation. Applying the free radical scavenger formulations after skin exposure to UVB radiation, glutathione and SOD showed the best ability in inhibiting the induced erythema (percentage inhibition 53.3 and 41.6%, respectively from gels). Tocopherol and tocopherol acetate inhibited UVB skin erythema by 27% while ascorbyl palmitate showed a poor efficacy. For all the active compounds tested, no significant difference was observed comparing the results obtained from gels to those from emulsions. Liposomal gel formulations containing the free radical scavengers which showed the best activity (SOD and glutathione) were prepared and topically applied after skin exposure to UVB radiation. SOD and glutathione liposomal formulations were more effective than the corresponding conventional gels. The proposed model, if validated by further studies, could be useful for differentiating the effectiveness of free radical scavengers in inhibiting photoaging due to long-term sunlight skin exposure.

Nuclear patterns of apoptotic and developing neurons of superior cervical ganglion of newborn rat.

Superior cervical ganglion (SCG) neurons of female rats aged 3, 5 and 7 days revealed conspicuous nuclear changes in neurons undergoing postnatal cell death. Several qualitative and quantitative data such as nuclear size and shape, the presence of atypical chromocenters and chromatin textural features discriminated well neurons candidate to degeneration and those advancing in the direction of adult maturation. At least on morphological grounds, postnatal death of SCG neurons appears to be of apoptotic type. The sequence of nuclear events observed enables the recognition of the early stages of involution which prelude neuron degeneration.

[The relationship between dietary intake of vitamin A and risk of gastrointestinal neoplasia]. / Indagine sul rapporto tra consumo alimentare di vitamina A e rischio di neoplasia gastrointestinale.

A study on dietary intake of retinol and beta-carotene was conducted in 51 patients affected by gastric (23 cases) and colorectal (28 cases) carcinoma, considering the period preceding the onset of their illness. In all patients were measured serum retinol levels. The data were compared with those in 44 control subjects. Mean values of retinol and beta-carotene intake in the two groups showed not significant differences. The mean serum levels of retinol were similar in controls and in cancer patients (68.1 and 66.8 micrograms/dl, respectively). Our data fail to confirm previous observations about relationship between alimentary intake of retinol and beta-carotene and risk of gastrointestinal cancer.