Role of Cytochrome Modulators in Altering the Occurrence of Cataract in Rats.

BACKGROUND: Cataract is one of the primary causes of blindness all over the world. It indicates the onset of secondary complications of diabetes. The only treatment available is surgery as there are no satisfactory drugs which can prevent or retard the initiation and maturation of cataract. It was hypothesized that cytochrome P 450 (CYP) inducers or inhibitors can modify the cataract occurrence by accelerating or delaying the occurrence of cataract respectively. OBJECTIVE: To study the effect of two commonly used drugs, phenytoin (CYP inducer) and ciprofloxacin (CYP inhibitor) on the initiation and maturation of cataract with the galactose- induced cataract model. MATERIALS AND METHODS: The experiment was conducted in 24 new born male Wistar rats. Cataract formation was induced with a 50% galactose diet. The rats were randomized into four groups of 6 rats each: Group 1 rats received a normal diet; Group 2, 3 and 4 rats received 50% galactose diet day 23 onwards. In addition, Group 3 rats were pre-treated with ciprofloxacin (20mg/kg) and Group 4 rats were pre-treated with phenytoin (50mg/kg) day 18 onwards once a day orally. The appearance of cataract was checked daily with an ophthalmoscope. The maturation pattern was examined using Fundus Fluorsen Angiographer (FFA). The cataract was graded according to Sippel's classification. The experimental and control groups were compared by chi square test and the results were considered significant at p< 0.05. RESULTS: The initiation of cataract was significantly delayed with ciprofloxacin as compared to galactose; however, there was no difference in the maturation pattern of cataract in both the groups. In spite of being a CYP inducer, the initiation of cataract was not accelerated in phenytoin group. Rather, it was significantly delayed and the cataract did not progress to stage 5 even on 30(th) day of galactose administration. CONCLUSION: CYP450 modulators have a significant effect on the initiation of cataract without significantly altering the maturation pattern. It is not reasonable to extrapolate the results of one enzyme inhibitor or inducer to other CYP modulators. Hence, further studies are needed to identify the pharmacological profile of various CYP modulators on the occurrence of cataractogenesis.

Diabetic retinopathy before and after renal transplantation: a longitudinal study.

Retinal evaluation was performed in 20 consecutive type 2 diabetics before and after renal transplantation. This included 19 men and 1 woman of mean age 52 years (range 30 to 60 years). Before renal transplantation, 95% of these patients showed diabetic retinopathy (50% nonproliferative and 45% proliferative diabetic retinopathy). There was no change in retinopathy at 3 months after renal transplantation. At 1 year, two patients (10%) showed deterioration in their diabetic retinopathy, while the remaining 90% did not show any change. Also 25% of renal allograft recipients developed posterior capsular cataracts.

Alkaptonuria.

A case of alkaptonuria, a rare autosomal recessive metabolic disorder is being reported. The patient presented with passage of dark coloured urine, cutaneous and scleral pigmentation and joint pains. The diagnosis was confirmed by the detection of homogentisic acid in the urine.

Antimalarials. 3. 1,2,4-Triazines.

The syntheses of a number of substituted 1,2,4-triazines as potential antimalarials are described. The structural requirements for antimalarial activity are discussed with reference to the substituents of a phenyl group in the 6 position and amino groups at the 3 and 5 positions. Of the compounds tested, 2,5, and 7 produced cures in mice infected with plasmodium berghei. Compounds 2(3,5-diamino-6-(4-trifluoromethylphenyl)-1,2,4-triazine),3,5,8,12,and 37 produced cures in chicks infected with Plasmodium gallinaceum.