Cordycepin inhibits UVB-induced matrix metalloproteinase expression by suppressing the NF-kappa B pathway in human dermal fibroblasts

Cordycepin (3'-deoxyadenosine) has been shown to exhibit many pharmacological activities, including anti-cancer, anti-inflammatory, and anti-infection activities. However, the anti-skin photoaging effects of cordycepin have not yet been reported. In the present study, we investigated the inhibitory effects of cordycepin on matrix metalloproteinase-1 (MMP-1) and -3 expressions of the human dermal fibroblast cells. Western blot analysis and real-time PCR revealed cordycepin inhibited UVB-induced MMP-1 and -3 expressions in a dose-dependent manner. UVB strongly activated NF-kappa B activity, which was determined by I kappa B alpha degradation, nuclear localization of p50 and p65 subunit, and NF-kappa B binding activity. However, UVB-induced NF-kappa B activation and MMP expression were completely blocked by cordycepin pretreatment. These findings suggest that cordycepin could prevent UVB-induced MMPs expressions through inhibition of NF-kappa B activation. In conclusion, cordycepin might be used as a potential agent for the prevention and treatment of skin photoaging.

Non-antimicrobial properties of tetracyclines - dental and medical implications

The tetracyclines are a group of broad-spectrum antimicrobial agents. The first of these compounds, chlortetracycline was isolated from Streptomyces aureofaciens by Benjamin Duggar and introduced into the market in 1948. In 1952, tetracycline was derived semisynthetically from chlortetracycline by removal of its chlorine atom by catalytic hydrogenation. Methacycline, doxycycline and minocycline are all semi-synthetic derivatives. The tetracyclines are closely congeneric derivatives of polycyclic napthacenecarboxamide. The tetracyclines posses a wide range of antimicrobial activity against gram-positive and gram-negative bacteria. In vitro, these drugs are primarily bacteriostatic. Tetracycline have been used extensively as antimicrobial, chemically modified non-antimicrobial properties by Golub. The tetracyclines and their non-antimicrobial, chemically modified analogues have properties that appear to modulate host response by inhibiting the activity of the matrix metalloproteinases that cause collagen destruction. They also inhibit osteoclast function, stimulate osteoblastic bone formation, and regulate angiogenesis.(Au)