CHARACTERISTICS OF THE MECHANISMS OF CYTOPROTECTIVE ACTIVITY OF CRYOPRESERVED PLACENTA EXTRACT ACCORDING TO MORPHOLOGICAL AND BIOCHEMICAL STUDIES OF THE GASTRIC MUCOSA IN THE EXPERIMENT
Authors: Hladkykh F.V. , Vernygorodskyi S.V. , Chyzh M.O. 
Published: January 2022

Relevance. Non-steroidal anti-inflammatory drugs (NSAIDs) are used as antipyretics and analgesics. In this case, NSAIDs have a side effect - ulcerogenic. Therefore, it is important to find means to correct the ulcerogenic action of NSAIDs. Potential antiulcerogenic action may be in cryopreserved human placenta extract "Cryocell-placental cryoextract".
Objective: to investigate the effect of cryopreserved placenta (CEP) extract on the morphological state of the stomach and the processes of protein synthesis in the gastric mucosa with the introduction of NSAIDs diclofenac sodium in rats with experimental rheumatoid arthritis.
Materials and methods. The study was performed on 28 nonlinear male rats weighing 200-220 g. The animals were divided into 4 groups: I (n = 7) – intact rats; II (n = 7) – rats with adjuvant arthritis (AA), this is a treatment without treatment; III (n = 7) – rats with AA, treated with diclofenac sodium (DN), 8.0 mg / kg, intragastrically (i/g); IV (n = 7) – rats with AA, treated with DN, 8.0 mg / kg, i/g and CEP, 0.16 ml / kg body weight, intramuscularly (i/m).
AA was simulated by subplantar injection of complete Freund's adjuvant into the hind right limb at a rate of 0.1 ml per rat. The day of adjuvant administration was considered as the "0" day of the experiment. AA treatment was performed from 14 to 28 days. DN was applied daily, and CEP – with an interval of 3 days: for 14, 17, 20, 23 and 26 days. On day 28, the animals were removed from the experiment by cervical dislocation under inhalation anesthesia.
To assess morphological changes, gastric fragments were fixed in 10.0% neutral formalin solution. Histological sections 5–7 μm thick were stained with hematoxylin and eosin, as well as Schiff's reagent (fuchsin sulfuric acid) with iodic acid. The concentration of total protein (TP) was determined spectrophotometrically by light absorption at a wavelength of 546 nm. The content of RNA and DNA in the homogenates of the gastric mucosa was determined spectrophotometrically by reaction with perchloric acid.
Results. In rats with AA, the mucous membrane (MM) had a preserved structure in all animals. There were no signs of hyper- or hyposecretion of mucins when stained with a chic reaction with alcyan blue. There were foci of desquamation of the superficial epithelium and single lymphocytes. The introduction of DN in rats with AA led to signs of erosive changes in MM. Deep erosions and single ulcerative defects were found in 28.6% of rats, reaching the depth of the lesion to the muscle plate. There is a small amount of mucopolysaccharides with a predominance of acidic glycoproteins. Reduced content of neutral glycoproteins. Single desquamated epitheliocytes were detected. Focal lympho-plasmacytic infiltration with exudate with eosinophilic leukocytes was noted in the submucosal layer of MM. Against the background of the combined use of DN and CEP in rats with AA in any animal, no significant violations of the histoarchitectonics of the MM, except for isolated foci of desquamation of the superficial epithelium.
In gastric MM homogenates in rats with AA there was a decrease (p <0.01) in the level of TP by 14.1% and a decrease (p <0.05) in the content of RNA and DNA by 27.5% and 14.3%, respectively, relative to indicators of intact animals.
Against the background of DN monotherapy, there was an even greater decrease (p <0.001) in the level of TP: by 26.2% (40.3 ± 1.43 μg / mg) relative to intact animals (54.6 ± 1.39 μg / mg). And the content of RNA and DNA was 0.59 ± 0.57 μg / ml and 2.21 ± 0.27 μg / ml, respectively.
Against the background of the combined use of DN and CEP, comparable to the level of intact animals indicators of TP and DNA were noted. Thus, the level of TP was 53.0 ± 2.09 μg / mg, which was only 2.9% lower than intact animals (54.6 ± 1.39 μg / mg), and the DNA content by 5.1% (p = 0.3) was lower than intact animals (3.1 ± 0.12 μg / ml) and was respectively 2.94 ± 0.08 RNA level (1.72 ± 0.12 μg / ml) on 17.6% exceeded (p = 0.1) intact animals (1.46 ± 0.08 μg / ml).
Conclusions. The combined use of placental cryoextract and diclofenac sodium eliminates the negative effect of the latter on protein metabolism in the gastric mucosa of rats with adjuvant arthritis. Thus, the level of total protein was 53.0 ± 2.09 μg / mg, which is only 2.9% lower than intact animals. Restoration of diclofenac sodium-induced mucin secretion by the integumentary epithelium of the gastric mucosa is one of the mechanisms of cytoprotective activity of cryopreserved placenta extract in experimental ulcerogenesis.