Evaluation of anticataract potential of Triphala in selenite-induced cataract: In vitro and in vivo studies

Abstract

Triphala (TP) is composed of Emblica officinalis, Terminalia chebula, and Terminalia belerica. The present study was undertaken to evaluate its anticataract potential in vitro and in vivo in a selenite-induced experimental model of cataract. In vitro enucleated rat lenses were maintained in organ culture containing Dulbecco's Modified Eagles Medium alone or with the addition of 100μM selenite. These served as the normal and control groups, respectively. In the test group, the medium was supplemented with selenite and different concentrations of TP aqueous extract. The lenses were incubated for 24 h at 37°C. After incubation, the lenses were processed to estimate reduced glutathione (GSH), lipid peroxidation product, and antioxidant enzymes. In vivo selenite cataract was induced in 9-day-old rat pups by subcutaneous injection of sodium selenite (25 μmole/kg body weight). The test groups received 25, 50, and 75 mg/kg of TP intraperitoneally 4 h before the selenite challenge. At the end of the study period, the rats' eyes were examined by slit-lamp. TP significantly (P < 0.01) restored GSH and decreased malondialdehyde levels. A significant restoration in the activities of antioxidant enzymes such as superoxide dismutase (P < 0.05), catalase (P < 0.05), glutathione peroxidase (P < 0.05), and glutathione-s-transferase (P < 0.005) was observed in the TP-supplemented group compared to controls. In vivo TF 25mg/kg developed only 20% nuclear cataract as compared to 100% in control. TP prevents or retards experimental selenite-induced cataract. This effect may be due to antioxidant activity. Further studies are warranted to explore its role in human cataract.

Keywords: Anticataract; antioxidant; glutathione; malondialdehyde; selenite; superoxide dismutase; triphala.

Figure 1

HPTLC profile of the phenolic compounds of methanolic extract of Triphala, Two major peaks and five minor peaks separated from the methanolic extract. The peaks labeled 1, 4 and 5 accounted for 35.20, 19.05 and 34.37% of the total area respectively

Figure 2

Effect of Triphala on morphology of lens, (a) Control (DMEM+100μM of sodium selenite), (b) Normal (DMEM only) remains transparent after 24 h incubation, (c) Treated (DMEM+100μM of sodium selenite+Triphala 800 μg/ml)

Figure 3

Effect of Triphala on GSH levels in selenite-induced oxidative stress in vitro, Normal: DMEM, Control: DMEM+100μM of Sodium selenite, Treated: DMEM+100μM of Sodium selenite + Triphala. Incubation period 24 h. Values are mean±SD. *P<0.01 (control vs treated) and #P <0.005 (control vs normal) as compared to contril. n=6.

Figure 4

Effect of Triphala on MDA levels in selenite-induced oxidative stress in vitro, Normal: DMEM, Control: DMEM+100μM of Sodium selenite, Treated: DMEM+100μM of Sodium selenite + Triphala. Incubation period 24 h. Values are mean±SD. *P<0.01 and #P <0.05 as compared to control. n=6.

Figure 5

Different grades of selenite cataract in rat pups

Figure 6

Effect of Triphala on selenite cataract in rat pups, Control: Sodium selenite Treated 1: Sodium selenite-Triphala 25 mg/kg, Treated 2: Sodium selenite-Triphaia 50mg/kg and Treated 3: Sodium selenite-Triphala 75 mg/kg, **P<0.005 (Control vs treated) n**12.