Protective properties of geniposide against UV-B-induced photooxidative stress in human dermal fibroblasts.

CONTEXT: Geniposide (genipin-1-O-ß-d-glucoside) is a major bioactive ingredient in the fruits of gardenia [Gardenia jasminoides J. Ellis (Rubiaceae)], a traditional herbal medicine in Asian countries. OBJECTIVE: This work assesses the skin anti-photoaging potential of geniposide in human dermal fibroblasts under UV-B irradiation. MATERIALS AND METHODS: The anti-photoaging property of geniposide, at varying concentrations (5, 12 and 30 µM) treated for 30 min prior to UV-B irradiation, was evaluated by analysing reactive oxygen species (ROS), promatrix metalloproteinase-2 (proMMP-2), glutathione (GSH), superoxide dismutase (SOD), nuclear factor erythroid 2-related factor 2 (Nrf2) and cellular viability. RESULTS: Geniposide suppressed the ROS elevation under UV-B irradiation, which was revealed using three ROS-sensitive fluorescent dyes. The use of 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), dihydroethidium (DHE) and dihydrorhodamine 123 (DHR-123) elicited the IC50 values of 10.5, 9.8 and 21.0 µM, respectively. Geniposide attenuated proMMP-2 at activity and protein levels that were elevated under UV-B-irradiation. Geniposide at 5, 12 and 30 µM augmented the UV-B-reduced total GSH content to 1.9 ± 0.1-, 2.2 ± 0.2- and 4.1 ± 0.2-fold, respectively. Geniposide at 5, 12 and 30 µM upregulated total SOD activity to 2.3 ± 0.1-, 2.5 ± 0.3- and 3.3 ± 0.3-fold, respectively, under UV-B irradiation. The UV-B-reduced Nrf2 levels were also upregulated by geniposide treatment. Geniposide, at the concentrations used, was unable to interfere with cellular viabilities under UV-B irradiation. DISCUSSION AND CONCLUSIONS: After the skin anti-photoaging potential of geniposide may be further verified, it can be utilized as a safer resource in the manufacture of effective anti-aging cosmetics.

Antagonism of VEGF-A-induced increase in vascular permeability by an integrin α3ß1-Shp-1-cAMP/PKA pathway.

In cancer, VEGF-induced increase in vascular permeability results in increased interstitial pressure, reducing perfusion and increasing hypoxia, which reduce delivery of chemotherapeutic agents and increase resistance to ionizing radiation. Here, we show that both TIMP-2 and Ala + TIMP-2, a TIMP-2 mutant without matrix metalloproteinase inhibitory activity, antagonize the VEGF-A-induced increase in vascular permeability, both in vitro and in vivo. Like other agents known to preserve endothelial barrier function, TIMP-2 elevates cytosolic levels of cAMP and increases cytoskeletal-associated vascular endothelial cadherin in human microvascular endothelial cells. All of these effects are completely ablated by selective knockdown of integrin α3ß1 expression, expression of a dominant negative protein tyrosine phosphatase Shp-1 mutant, administration of the protein tyrosine phosphatase inhibitor orthovanadate, or the adenylate cyclase inhibitor SQ22536. This TIMP-2-mediated inhibition of vascular permeability involves an integrin α3ß1-Shp-1-cAMP/protein kinase A-dependent vascular endothelial cadherin cytoskeletal association, as evidenced by using siRNAs to integrin α3ß1 and Shp-1, or treatment with Shp-1 inhibitor NSC87877 and protein kinase A inhibitor H89. Our results demonstrate the potential utility for TIMP-2 in cancer therapy through "normalization" of vascular permeability in addition to previously described antiangiogenic effects.