The impact of oral Polypodium leucotomos extract on ultraviolet B response: A human clinical study.

BACKGROUND: There is a rationale for adding systemic photoprotective agents to the current photoprotection regimen. OBJECTIVE: This study was designed to objectively evaluate the molecular and photobiologic effects of oral administration of Polypodium leucotomos extract (PLE). METHODS: In all, 22 subjects with Fitzpatrick skin phototype I to III were enrolled. On day 1, subjects were irradiated with visible light, ultraviolet (UV) A1, and UVB (using 308-nm excimer laser). Evaluation was done immediately and 24 hours after irradiation. On days 3 and 4, irradiation and evaluation process was repeated after ingestion of PLE. RESULTS: Clinical assessments and colorimetry data showed a decrease in UVB-induced changes in 17 of 22 subjects post-PLE administration; histology findings demonstrated such a decrease in all 22 subjects. LIMITATIONS: Only 2 doses of PLE were given. Furthermore, subjects with skin phototypes I to III only were studied. CONCLUSION: The results suggest that PLE can potentially be used as an adjunctive agent to lessen the negative photobiologic effects of UVB.

Prospects for skin cancer treatment and prevention: the potential contribution of an engineered virus.

Nonmelanoma skin cancers are among the most common human malignancies. Although typically not lethal, they are responsible for tissue deformity and substantial morbidity, particularly in high-risk populations. Solar UVB radiation-a major etiologic factor for this kind of malignancy-produces DNA lesions such as cyclobutane pyrimidine dimers and 6-4 photoproducts in skin. These lesions are removed through nucleotide excision repair because humans lack a DNA glycosylase required to initiate base excision repair of pyrimidine-pyrimidine photoproducts but produce all the other proteins required for this process. In this issue, Johnson et al. show that a DNA glycosylase derived from Chlorella virus and engineered to enhance tissue penetration and nuclear localization can remove UVB-induced DNA lesions in a human skin equivalent model and that the protein can be incorporated into a topical formulation for the prevention and treatment of UVB-induced DNA damage. These results suggest that such an enzyme may be incorporated into regimens for the chemoprevention of skin cancers.

Human common salivary protein 1 (CSP-1) promotes binding of Streptococcus mutans to experimental salivary pellicle and glucans formed on hydroxyapatite surface.

The saliva proteome includes host defense factors and specific bacterial-binding proteins that modulate microbial growth and colonization of the tooth surface in the oral cavity. A multidimensional mass spectrometry approach identified the major host-derived salivary proteins that interacted with Streptococcus mutans (strain UA159), the primary microorganism associated with the pathogenesis of dental caries. Two abundant host proteins were found to tightly bind to S. mutans cells, common salivary protein-1 (CSP-1) and deleted in malignant brain tumor 1 (DMBT1, also known as salivary agglutinin or gp340). In contrast to gp340, limited functional information is available on CSP-1. The sequence of CSP-1 shares 38.1% similarity with rat CSP-1. Recombinant CSP-1 (rCSP-1) protein did not cause aggregation of S. mutans cells and was devoid of any significant biocidal activity (2.5 to 10 µg/mL). However, S. mutans cells exposed to rCSP-1 (10 µg/mL) in saliva displayed enhanced adherence to experimental salivary pellicle and to glucans in the pellicle formed on hydroxyapatite surfaces. Thus, our data demonstrate that the host salivary protein CSP-1 binds to S. mutans cells and may influence the initial colonization of this pathogenic bacterium onto the tooth surface.