title: Propolis, a Constituent of Honey, Inhibits the Development of Sugar Cataracts and High-Glucose-Induced Reactive Oxygen Species in Rat Lenses.
abstract: Purpose. This study investigated the effects of oral propolis on the progression of galactose-induced sugar cataracts in rats and the in vitro effects of propolis on high-glucose-induced reactive oxygen species (ROS) and cell death in cultured rat lens cells (RLECs). Methods. Galactose-fed rats and RLECs cultured in high glucose (55 mM) medium were treated with propolis or vehicle control. Relative lens opacity was assessed by densitometry and changes in lens morphology by histochemical analysis. Intracellular ROS levels and cell viability were measured. Results. Oral administration of propolis significantly inhibited the onset and progression of cataract in 15% and 25% of galactose-fed rats, respectively. RLECs cultured with high glucose showed a significant increase in ROS expression with reduced cell viability. Treatment of these RLECs with 5 and 50 μg/mL propolis cultured significantly reduced ROS levels and increased cell viability, indicating that the antioxidant activity of propolis protected cells against ROS-induced damage. Conclusion. Propolis significantly inhibited the onset and progression of sugar cataract in rats and mitigated high-glucose-induced ROS production and cell death. These effects may be associated with the ability of propolis to inhibit hyperglycemia-evoked oxidative or osmotic stress-induced cellular insults.
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Shibata
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Shibata
authors.affiliation: Department of Oncogenic Pathology, Kanazawa Medical University, Ishikawa 920-0293, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kiyokawa
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan.
authors.forename: Hiroshi
authors.identifier: 0000-0002-6458-5330
authors.initials: H
authors.lastname: Sasaki
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198-5540, USA.
authors.forename: Dhirendra P
authors.initials: DP
authors.lastname: Singh
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, Ishikawa 920-0293, Japan.
authors.forename: Eri
authors.identifier: 0000-0001-6789-9311
authors.initials: E
authors.lastname: Kubo