Прочностные характеристики комплекса нижняя челюсть/резец у белых крыс с дефектом большеберцовой кости после 60-дневного применения тартразина

Tartrazine is one of the most common food colorings, which is widely used in the food, leather, cosmetic and textile industries, as well as in drug capsules such as antacids and vitamins, especially in many developing countries. Tartrazine is absorbed by the intestinal epithelium and metabolized by microflora and possibly by azoreductase in the liver or intestinal wall of mammals to sulfanilic acid, which has potential carcinogenic properties

The study included 240 female rats with initial body weight 200-210 g. All animals were divided into several groups: group 1st (KBC) – control animals; group 2nd (TTZ1500) consisted of rats that were intragastrically administered 1 ml of tartrazine at a dose of 1500 mg/kg/day; group 3rd (DBK) – comprised animals with round opening in the proximal metaphysis of both tibiae made upon expiration of 60-day intake of tartrazine. The TTZ1500D group consisted of rats that had a tibial defect after 60 days of tartrazine administration, and the TTZ1500DM, TTZ1500DT, TTZ1500M, and TTZ1500T groups included rats with or without tibial damage that were simultaneously injected intraperitoneally with tartrazine inoculation and given mexidol at a dose of 50 mg/kg/day or thiotriazoline at a dose of 117,4 mg/kg/day

 In the animals of the KBC group, for the lower incisor/mandibular complex, from the 1st to the 60th day of observation terms, the specific sag decreased from 6,32±0,09 N/μM to 6,05±0,10 N/μM, which reflects an increase in its rigidity. Other indicators of the ultimate strength of the lower incisor/mandibular complex increased during the observation: the destruction moment – from 117,45±1,64 N/μM to 128,27±1,85 N/μM, and the minimum fracture energy – from 77,85±0,94 μJ to 86,26±1,47 μJ. The elasticity modulus of the lower incisor/mandibular complex decreased from 21,34±0,26 GPa to 19,31±0,30 GPa, and the ultimate strength decreased from 471,70±7,10 to 431,63±6,27 GPa (Table 1).

Intragastric administration of tartrazine 1500 mg/kg/day to experimental animals for 60 days was accompanied by a decrease in the strength of the lower incisor/mandibular complex. From 3 to 45 day after the end of the challenge, the following values were lower than the values of the DBK group: the destruction moment of the lower incisor/mandibular complex – by 12,95%, 11,66%, 8,62%, 5,60% and 6,41%, the ultimate strength – by 11,10%, 11,62%, 9,09%, 7,06% and 6,47%, as well as the minimum destruction work – by 12,99%, 10,63%, 10,34%, 7,29% and 6,47% (all the numerical differences given here and below are statistically significant, p≤0,05). Also, from the 3rd to the 15th day of the readaptation period, the specific sag of the lower incisor/mandibular complex was lower than the values of the KBC group by 8,52%, 8,76% and 5,75%, and the elasticity modulus by the 3rd and 10th days was higher by 4,89% and 7,00%. This indicates an increase in the rigidity of the lower incisor/mandibular complex from the 3rd to the 15th day of the readaptation period. DBK group was also accompanied by a decrease in the strength characteristics of the lower incisor/mandibular complex. The destruction moment of the lower incisor/mandibular complex in animals of the DBC group from 10 to 45 days after the operation was lower than the values of the KBC group by 6,08%, 7,29%, 10,55% and 4,70%, and the value of the specific sag arrow exceeded them by 5,57%, 7,82%, 9,53% and 7,68%. At the same time, the ultimate strength and the minimum fracture energy of the lower incisor/mandibular complex from 15 to 45 days after the operation lagged behind the values of the KBC group by 5,12%, 8,43% and 6,18%, and by 5,33%, 9,38% and 6,10%, respectively, and the elasticity modulus by 24 and 45 days – by 8,49% and 5,01%. The defect in the tibia after 60-day tartrazine administration at a dose of 1500 mg/kg/day was accompanied by an aggravation of the strength impairment of the lower incisor/mandibular complex. At the same time, the strength impairment in the TTZ1500D group in comparison with the TTZ1500 group was usually maximal on the 24th day after the end of the administration, then gradually recovered, but by the 45th day of the readaptation period, a statistically significant difference in all studied parameters from the TTZ1500 group remained. In comparison with the parameters of the TTZ1500 group, the specific sag of the lower incisor/mandibular complex from the 3rd to the 45th day after the operation increased by 6,05%, 13,12%, 19,84%, 23,47% and 18,46% (Table 2). At the same time, the breaking moment and elasticity modulus were less than the values of the TTZ1500 group from the 10th to the 45th day after the operation by 5,32%, 9,88%, 13,95% and 5,26%, and by 15,42%, 10,64%, 9,42% and 6,81%, the ultimate strength from the 15th to the 45th day - by 5,98%, 10,19% and 5,96%, and the minimum fracture energy from the 24th to the 45th day – by 9,42% and 6,81%.

Intraperitoneal administration of mexidol at a dose of 50 mg/kg/day or thiotriazoline at a dose of 117,4 mg/kg/day simultaneously with 60-day tartrazine administration both without damaging the tibia and after causing defects in them was accompanied by a tendency to restoration the strength of the lower incisor/mandibular complex. In the TTZ1500M group, when compared with the TTZ1500 group, statistically significant differences in the strength characteristics of the lower incisor/ mandibular complex were recorded from days 10 to 45 of the readaptation period. The ultimate strength of the lower incisor/mandibular complex in animals of the TTZ1500T group exceeded the comparison values from 10 to 45 days by 6,19%, 5,89%, 4,19% and 4,34%, and the breaking moment by day 45 by 4,44%. When comparing the results of biomechanical tests of the lower incisor/mandibular complex in animals of the TTZ1500T group with the TTZ1500 group, statistically significant differences were recorded from day 3 to day 45 of the readaptation period. The minimum fracture energy of the lower incisor/mandibular complex was greater than the values of the TTZ1500 group from the 3rd to the 45th day of the readaptation period by 6,40%, 5,80%, 5,76%, 4,82% and 5,51%, the ultimate strength from the 10th to the 45th day – by 7,89%, 7,34%, 5,30% and 5,63%, and the breaking moment by the 45th day – by 5,06%. In the TTZ1500DM group, when compared with the TTZ1500D group, statistically significant differences in the studied indicators were observed from the 3rd to the 24th day of the readaptation period. In this case, the minimum fracture energy of the lower incisor/mandibular complex in animals of the TTZ1500DM group was greater than the values of the TTZ1500D group by 3, 10 and 24 days of the readaptation period by 4,80%, 4,89% and 4,50%, the breaking moment from 10 to 24 days – by 5,38%, 5,84% and 6,79%, and the ultimate strength by 24 days – by 4,52%.

Finally, in animals of the TTZ1500DT group, the ultimate strength and the minimum fracture energy of the lower incisor/mandibular complex from the 3rd to the 45th day of the readaptation period exceeded the values of the TTZ1500D group by 6,24%, 5,71%, 5,82%, 5,365 and 4,99%, and by 5,76%, 5,77%, 5,29%, 6,72% and 4,12%, respectively. Also, the breaking moment of the lower incisor/mandibular complex from the 3rd to the 24th day exceeded the values of the TTZ1500D group by 5,92%, 6,59%, 7,32% and 6,90%. Thus, intragastric administration of tartrazine to mature rats at a dose of 1500 mg/kg/day for 60 days is accompanied by a violation of the strength of the lower incisor/mandibular complex, most pronounced immediately after the end of the administration. The violations of strength were maximal on the 3rd day after the end of the administration, then gradually recovered, but by the 45th day of the readaptation period, a statistically significant difference in the studied parameters from the KBC group remained. It is known that tartrazine causes direct damage to the mitochondrial DNA molecule, which leads to the development of oxidative stress, to a violation of ATP synthesis in the body's cells

Excessive use of tartrazine in experimental animals at a dose of 1500 mg/kg/day for 60 days is accompanied by a decrease in the strength of the lower incisor/mandibular complex. Strength impairments were maximal on the 3rd day after the end of the administraion, then gradually recovered, but by the 45th day of the readaptation period, a statistically significant difference in the studied parameters from the control group remained. Surgical perforation of the tibia at the end of tartrazine administration leads to an aggravation of the strength impairment of the lower incisor/mandibular complex and a slowdown in its recovery during the readaptation period. Simultaneous use of mexidol or thiotriazoline with tartrazine smooths out the strength impairments of the lower incisor/mandibular complex. The use of thiotriazoline is more effective.