Protective effects of Cassia tora leaves in experimental cataract by modulating intracellular communication, membrane co-transporters, energy metabolism and the ubiquitin-proteasome pathway

Abstract

Context: Cataract is the clouding of eye lens which causes impairment in vision and accounts for the leading factor of global blindness. Functional food-based prevention of cataract finds application in vision research because of its availability and easy access to all classes of the society. Cassia tora Linn. (Caesalpinaceae) is an edible plant mentioned in the traditional systems of medicine for whole body health, especially to the eyes.

Objective: The present study evaluates the potential of ethyl acetate fraction of Cassia tora leaves (ECT) on experimental cataract.

Materials and methods: Cataract was induced by a single subcutaneous injection of sodium selenite (4 μg/g body weight) on 10th day. ECT was supplemented orally from 8th day up to 12th day at a concentration of 5 μg/g body weight and marker parameters were evaluated after 30 days.

Results: The production of MPO and the activation of calpain were reduced 52.17% and 36.67% by ECT in lens tissue, respectively. It modulated the energy status by significantly increasing the activity of CCO 1 (55.56%) and ATP production (41.88%). ECT maintained the ionic balance in the lens by reducing the level of sodium (50%) and increasing the level of potassium (42.5%). It also reduced cell junction modifications and preserved a functional ubiquitin-proteasome pathway.

Discussion and conclusion: The results reinforce the growing attention on wild plant food resources for preventive protection against cataract. The data suggest the value of Cassia tora leaves as a functional food for ameliorating cataract pathology.

Keywords: Blindness; functional food; oxidative stress; selenite cataract.

Figure 1.

Activity of superoxide dismutase (a) and catalase (b) in different experimental groups. Each value represents mean ± SEM of six values. N: Normal; S: Selenite. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; Cataract group is compared with control group and treatment group is compared with cataract group. ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 2.

Activity of MPO in the lenses of experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 3.

Activity of calpain in the lenses of experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 4.

Photographic and graphical representation of mRNA expression of calpain and MIP in the lenses of different experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; Cataract group is compared with control group and treatment group is compared with cataract group. ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 5.

Photographic and graphical representation of mRNA expression of E Cadherin and N Cadherin in different experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; Cataract group is compared with control group and treatment group is compared with cataract group. ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 6.

Photographic and graphical representation of mRNA expression of NKCC 1 in different experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; Cataract group is compared with control group and treatment group is compared with cataract group. ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 7.

The level of ATP in the lenses of experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 8.

(A) Photographic and graphical representation of mRNA expression of CCO 1 in different experimental groups. (B) Protein expression of CCO 1 in the lenses of different experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 9.

(A) Photographic and graphical representation of mRNA expression of Ub e1 and Ub e2 in different experimental groups. (B) Protein expression of Ub E1 in the lenses of different experimental groups. N: Normal; S: Selenite. Each value represents mean ± SEM of six values. Different alphabets indicate significant difference between different groups at p < 0.05. Comparison is carried out between the groups; Cataract group is compared with control group and treatment group is compared with cataract group. ^aindicates normal group, ^bindicates significantly different from normal group and ^cindicates significantly different from cataract group.

Figure 10.

Biochemical events associated with the protective effect of Cassia tora in cataract.