OPC 15161

The effect of a newly developed free radical scavenger (OPC-15161) on the progression of nephrotoxic serum (NTS) nephritis was evaluated. NTS nephritis rats were sacrificed immediately before and 1, 2, 3, 6, and 24 h and 13 and 19 days after intravenous injection of NTS. The tissue content of phosphatidylcholine hydroperoxide, the activity of superoxide, the activity of superoxide dismutase in the renal cortex, and the serum malondialdehyde levels were measured. The phosphatidylcholine hydroperoxide content in the renal cortex of OPC-15161-treated NTS nephritis rats was lower than that in the control rats 24 h after NTS injection. The activity of superoxide dismutase in OPC-15161-treated rats was sustained in contrast to the decrease in this activity in the control rats 6 h after injection of NTS. The effects of OPC-15161, dipyridamole, and prednisolone on NTS nephritis rats were investigated. OPC-15161 (20 mg/kg p.o.) showed a potent inhibitory effect on the urinary protein excretion, whereas dipyridamole (30 and 100 mg/kg p.o.) and prednisolone (2 mg/kg p.o.) had less suppressive effects. In view of these results, we conclude that OPC-15161 notably ameliorated the urinary protein excretion by way of the suppression of lipid peroxidation in the renal tissue of NTS nephritis rats.

A component of fungus Thielavia minor, OPC-15161, has been shown to inhibit the proliferation and extracellular matrix production of extracellular matrix-producing mesangial cells in the kidney in vivo. In this study, we examined the effects of OPC-15161 on the proliferation and extracellular matrix production of rat cultured hepatic stellate cells (HSCs). To determine the effect of OPC-15161 on proliferation of HSCs, the cell number and the uptake of [3H]thymidine were investigated in the presence and absence of interleukin-1beta (IL-1beta). IL-1beta significantly increased the uptake of [3H]thymidine in the HSCs, and the addition of OPC-15161 inhibited the uptake in a dose-dependent manner. The cell number of HSCs was also increased by IL-1beta, which was inhibited by OPC-15161. Production of extracellular matrix by OPC-15161 was studied by the production of [3H]-hydroxyproline in the presence and absence of transforming growth factor-beta1 (TGF-beta1). TGF-beta1 significantly increased the production of [3H]-hydroxyproline in the cells, whereas the addition of OPC-15161 inhibited this effect dose dependently. We also investigated the effects of OPC-15161 on Ca2+ mobilization and measured D-myo-inositol 1,4,5-triphosphate (IP3) in the HSCs. IL-1beta induced the increase of intracellular Ca2+ and IP3 concentrations in the HSCs, which were decreased by OPC-15161. Based on these results, we conclude that OPC-1 5161 inhibited the proliferation and production of hydroxyproline in cultured rat HSCs, and thus, it may have a role in prevention of liver fibrosis in vivo.

Purpose: We investigated the effects of OPC-15161 on the growth of cultured human Tenon's capsule fibroblasts (TCFs), as well as on the production of type I procollagen, fibronectin, and laminin. These effects were examined in the presence or absence of TGF-beta1. Methods: Cell proliferation was assayed by counting cell number and assay of DNA synthesis. Cytotoxicity was determined by the MTT method. Matrix components were assayed by enzyme immunoassay of material in the medium and in the cell lysate with or without OPC-15161. Total protein content was determined. Cellular ultrastructure was also evaluated. Results: Treatment with OPC-15161 (up to 100.0 microg ml(-1)) significantly reduced the proliferation and DNA synthesis of TCFs. No significant decrease in MTT values was observed in confluent TCF cultures with OPC-15161 (up to 100.0 microg ml(-1)). TGF-beta1 enhanced the TCF production of procollagen I and fibronectin. OPC-15161 significantly decreased the procollagen I content in both the medium, in the cell lysate of TGF-beta1-stimulated cells, and fibronectin content in the lysate. OPC-15161 did not affect the laminin or total protein content, either with or without TGF-beta1. No ultrastructural evidence of cytotoxicity was observed. Conclusions: OPC-15161 inhibited the proliferation of TCFs, and reduced their production of procollagen I and fibronectin in the presence of TGF-beta1 without evidence of cytotoxicity. OPC-15161 may be useful in inhibiting the excessive fibrosis produced in the wound in response to filtering surgery.