Use of ligustrazine nitrone derivatives in prevention and treatment of diabetic complication diseases

Abstract

A use of of ligustrazine nitrone derivatives and a pharmaceutical composition thereof in the preparation of medicine for preventing and treating diabetic complication diseases. The ligustrazine nitrone derivatives can be prepared into various dose forms together with drug carriers.

Claims

1. A method of treatment of a disease of diabetic complications, comprising administration of a therapeutically effectively amount of ligustrazine nitrone derivatives or a pharmaceutical composition thereof; the derivatives have a structure of formula (I): ##STR00005## wherein, R.sub.1 and R.sub.3 are each independently C1-C6 alkyl; R.sub.2 is C1-C6 alkyl or ##STR00006## and R.sub.4 and R.sub.5 are each independently sec-butyl, isobutyl, t-butyl, cyclopentyl or cyclohexyl, wherein the disease of diabetic complications is diabetic nephropathy.

2. The method according to claim 1, wherein the C1-C6 alkyl is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl or n-pentyl.

3. The method according to claim 1, wherein the ligustrazine nitrone derivatives have a structure of formula: ##STR00007##

4. The method according to claim 1, wherein the pharmaceutical composition comprises a therapeutically effective amount of the ligustrazine nitrone derivative or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

5. The method according to claim 1, wherein the derivatives may be used alone or in combination with other drugs.

6. The method according to claim 5, wherein the other drugs are antihypertensive drugs.

7. The method according to claim 6, wherein the antihypertensive drugs are angiotensin receptor blockers, angiotensin converting enzyme inhibitors or folic acid.

8. The method according to claim 4, wherein the derivatives can be formulated into various dosage forms with a pharmaceutical carrier, the dosage forms comprising tablets, granules, injections, powders, capsules, or suspensions.

9. The method according to claim 1, wherein the therapeutically effective amount is from 0.001 to 2 g/kg.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the effect of ligustrazine nitrone derivatives on body weight (FIG. 1a), water intake (FIG. 1b), and food intake (FIG. 1c) of STZ-induced DKD rats. ###P<0.001, ##P<0.01 compared with the control group (Control);***P<0.001,*P<0.05 compared with the model group (Model).

(2) FIG. 2 shows the effect of ligustrazine nitrone derivatives on urinary protein (FIG. 2a) and rat blood glucose (FIG. 2b) of STZ-induced DKD rats. ###P<0.001 compared with the control group (Control);***P<0.001,**P<0.05,*P<0.01 compared with the model group (Model).

(3) FIG. 3 shows the effect of ligustrazine nitrone derivatives on the levels of serum creatinine (FIG. 3a), urea nitrogen (FIG. 3b), cholesterol (FIG. 3c) and triglycerides (FIG. 3d) in STZ-induced DKD rats. ###P<0.001, ##P<0.01 compared with the control group (Control);**P<0.05,*P<0.01 compared with the model group (Model).

(4) FIG. 4 shows the effect of ligustrazine nitrone derivatives on kidney index in STZ-induced DKD rats. ##P<0.001 compared with the control group (Control);**P<0.05,*P<0.01 compared with the model group (Model).

(5) Table 1 in FIG. 5 lists the number of occurrences and time of appearance of retinopathy in diabetic nephropathy model rats.

DETAILED DESCRIPTION OF EMBODIMENTS

(6) Some specific embodiments or examples of the present invention will be described below. It will be understood that these specific embodiments or examples are only used for further explanation of the invention, rather than to limit the scope of the inventive subject matters as defined by the claims.

EXAMPLE 1

Preparation and Grouping of STZ-Induced Diabetic Nephropathy Rat Model

(7) 1. Model Making

(8) SD rats (200±10 g) were used as model animals, which were fasted for 12 h before injection. STZ was dissolved in citrate buffer at 1% concentration, and rats were fasted and intraperitoneally injected with 55 mg/kg STZ and placed in the cage, the rats being ensured with adequate water intake for 24 h. STZ injections need to be fast and complete within 10 minutes of injection. The normal control group was injected with an equal volume of pH 4.5 citric acid-sodium citrate buffer. The state of the animals (multiple drinking and polyuria) was observed. After 3 weeks of STZ injection, blood was collected from the tail vein, and fasting blood glucose>16.7 mmol/L was measured as the standard for diabetic nephropathy in rats.

(9) 2. Grouping

(10) DKD rats were randomly assigned to 6 groups and given with different drugs. After 6 weeks of administration, the experiment was terminated and the protective effect of the drug on DKD rats was observed.

EXAMPLE 2

Effect of 1 Ligustrazine Nitrone Derivatives on Body Weight, Food Intake and Water Intake of STZ-Induced DKD Rats

(11) The general condition and body weight changes after rat modeling were observed weekly. The general conditions include the activity, mental state, coat color, diet, water intake and urine volume of the rats. The amount of water and the amount of feed were recorded weekly.

(12) The effect of ligustrazine nitrone derivatives on the body weight of rats with STZ-induced diabetic nephropathy is shown in FIG. 1a. TBN and TN-2 have no effect on the body weight of rats with diabetic nephropathy. The changes of drinking water and feed volume in diabetic nephropathy rats are shown in FIG. 1b and FIG. 1c. The DKD rats in the TBN and TN-2 treatment groups had significantly lower water intake and food intake than the model group, indicating that TBN and TN-2 can slow the progression of diabetic disease in DKD rats, thereby improve the diabetic symptoms of more water and food intake of the DKD rats.

EXAMPLE 3

Effect of 1 Ligustrazine Nitrone Derivatives on Retinopathy of the STZ-Induced DKD Rats

(13) During the experiment, the retinopathy of rats was observed during daily administration, and the dates of retinopathy in different groups of rats were recorded.

(14) Retinopathy is one of the common complications of diabetic nephropathy and has a high correlation with diabetic nephropathy. The effect of ligustrazine nitrone derivatives on STZ-induced retinopathy of DKD rats is shown in Table 1. The number of retinopathy in DKD rats after TBN and TN-2 treatment was reduced, and the time when retinopathy occurred is relatively delayed. The results indicate that the ligustrazine nitrone derivatives TBN and TN-2 can reduce and delay the occurrence of retinopathy.

EXAMPLE 4

Effect of Ligustrazine Nitrone Derivatives on Blood Glucose and Urine Protein in DKD Rats Induced by STZ

(15) During the experiment, the blood glucose of the rats was monitored after the completion of the modeling and after the completion of the administration, and urine protein was collected once at 24 hour.

(16) The effect of ligustrazine nitrone derivatives on blood glucose of STZ-induced DKD rats is shown in FIG. 2a. The blood glucose was significantly increased after 3 weeks of STZ induction, and was significantly decreased after 6 weeks of treatment with TBN and TN-2. The effect of TBN and TN-2 on urinary protein of STZ-induced DKD rats is shown in FIG. 2b. Urinary protein content in urine of DKD rats treated with TBN and TN-2 was significantly reduced. The combined use of TBN and losartan is superior to treatment with TBN alone or losartan alone.

EXAMPLE 5

Effect of Ligustrazine Nitrone Derivatives on Serum Biochemical Parameters of STZ-Induced DKD Rats

(17) Six weeks after the administration, the rats were anesthetized, and the blood was taken from the abdominal aorta, and, after standing for 1 hour, was centrifuged at 3000 rmp for 10 min and stored at −70° C. Serum levels of creatinine, urea nitrogen, cholesterol and triglycerides were measured using an automated biochemical analyzer.

(18) Serum creatinine, urea nitrogen, cholesterol and triglyceride levels may reflect the body's lipid metabolism, carbohydrate metabolism and kidney function. The effect of ligustrazine nitrone derivatives on serum creatinine, urea nitrogen, cholesterol and triglycerides in STZ-induced DKD rats is shown in FIG. 3. TBN and TN-2 can significantly reduce serum creatinine (FIG. 3a), urea nitrogen (FIG. 3b), cholesterol (FIG. 3c) and triglyceride (FIG. 3d) levels, in a dose-dependent manner, showing improvement in lipid metabolism, carbohydrate metabolism and renal function in STZ-induced diabetic nephropathy rats.

EXAMPLE 6

Effect of Ligustrazine Nitrone Derivatives on Kidney Index of STZ-Induced DKD Rats

(19) After 6 weeks of administration, the kidney tissue was uniformly separated by an autoclave surgical instrument, and the saline was washed with normal saline. After the filter paper was blotted, the fine balance was weighed, and then stored in a refrigerator at −80° C. for use. Kidney index (relative to kidney weight) is kidney weight (mg)/body weight (g)=BW/KW.

(20) With the progress of pathological process of diabetic nephropathy, the glomerular basement membrane gradually thickens, the mesangium further widens, and focal tubular atrophy and interstitial fibrosis were finally developed with renal failure. The kidney index responds to, in certain extent, the pathological condition of diabetic nephropathy. The effect of ligustrazine nitrone derivatives on kidney index in STZ-induced DKD rats is shown in FIG. 4, TBN and TN-2 significantly reduced the kidney index of DKD rats, indicating that TBN and TN-2 can delay the progression of diabetic nephropathy.