Table 1.
Effects of pirenoxine on age-related cataract: Evidence from in vitro studies arranged by method of cataract induction.
| Induction of Cataract | Source of Lens | Name/Dose/Route/Duration of PRX | Major Findings | Interpretation | Ref | ||
|---|---|---|---|---|---|---|---|
| Lens Opacity | Oxidative Stress | Others | |||||
| Ca or selenite (10 mM) |
Pig lens homogenate |
Pure PRX/0.03, 0.1, and 0.3 μM/ 0–4 d |
↓ | PRX decelerated Ca- and selenite-induced lens opacification. | [15] | ||
| Ca or selenite (10 mM) |
Pig lens homogenate |
PRX/ 1 μM/5 d |
↓ | PRX decelerated Ca- and selenite-induced lens opacification. | [16] | ||
| Selenite (10 mM) |
SD-rat pup lens homogenate |
Catalin/0.016, 0.032, 0.080, and 0.1 μM/ 0–4 d Only cataV in Catalin/ 0–4 d |
0.016 μM: ⟷ 0.032, 0.080, and 0.1 μM: ↓ (only at d1) ⟷ |
↓ degradation of water-insoluble lens proteins | High dose PRX decelerated early selenite-induced lens opacification by a deceleration of degradation of water-insoluble lens proteins. CataV in Catalin had no effect on selenite-induced lens opacification. |
[15] | |
| Fe3+ (10 μM)/ascorbate |
Rat lens homogenate |
Catalin/ 0.1–1000 μM/2 h |
↓ TBA ↓ lipid hydroperoxide |
Catalin prevented ROS damage of the lens after induction with Fe3+/ascorbate. | [17] | ||
| Fe3+/ascorbate, Hb (10 μM), fMLP-stimulated macrophages (10 nM) | Rat whole lens | Catalin/ 0.1–1000 μM/2 h |
↓ TBA ↓ lipid hydroperoxide |
Catalin prevented ROS damage of the lens after an induction with either Fe3+/ascorbate, Hb, or stimulated macrophages. | [17] | ||
| X (600 μM)/ XO (0.1 U/mL) |
Rat whole lens | Catalin/ 0.1–1000 μM/2 h |
↓ lipid peroxidation ⟷ Superoxide ⟷ Urate |
Catalin prevented ROS damage of the lens with mechanisms other than inhibition of X/XO system. | [17] | ||
| UVC (4 h) |
Pig lens homogenate |
Pure PRX/ 0.1, 1, 10, 100, and 1000 μM/ 0–4 h |
PRX (1000 μM): ↓ PRX (<1000 μM): ⟷ |
Pure PRX and cataV provided comparable benefits in decelerating lens protein opacity via the deceleration of lens degradation. The combination therapy provided greater efficacy than the monotherapy. |
[15] | ||
| Catalin/ 16, 32, 80, and 100 μM PRX + cataV/ 0–4 h Only cataV in Catalin/ 0–4 h |
↓ ↓ |
↓ degradation of γ-crystallins ↓ degradation of γ-crystallins |
|||||
| m-calpain activated by Ca |
Pig lens homogenate |
Catalin/ 0, 32, 80, and 100 μM Pure PRX/100 μM |
⟷ degradation of β- and α-crystallins | Catalin failed to decelerated proteolysis of lens induced by m-calpain. | [15] | ||
| UVB (6 h) |
Pig lens homogenate |
Catalin/ 0.1, 1, 10, and 100 μM/2 h |
⟷ | Catalin had no protective effect against UVB-induced cataract. | [15] | ||
Abbreviations: <: less than, ⟷: no change/no effect on, ↓: decrease, Ca: calcium, cataV: Catalin-formulated vehicle only, d: day, ELISA: enzyme-linked immunosorbent assay, fMLP: N-formyl methionyl-leucylphenylalanine, GSH: reduced glutathione, Hb: hemoglobin, h: hour, K: potassium, Na: sodium, PRX: pirenoxine, Ref: references, qid: 4 times a day, ROS: reactive oxygen species, Rx: treatment, SD: Sprague–Dawley, SOD: superoxide dismutase, SC: subcutaneous, SPE: single-point energy, TBA: thiobarbituric acid, UVB: ultraviolet-B, UVC: ultraviolet-C, X/XO: xanthine/xanthine oxidase.