COMPARATIVE CHARACTERISTICS OF MORPHOLOGICAL AND MORPHOMETRIC PARAMETERS OF LIVER SINUSOIDS OF WHITE RATS AFTER 4 AND 8 WEEKS OF EXPERIMENTAL EXPOSURE TO 10% CANNABIDIOL OIL

Cannabidiol (CBD) is a non-psychoactive phytocannabinoid of Cannabis sativa, characterized by a wide range of possible therapeutic effects, including anticonvulsant, anti-inflammatory, antioxidant, anxiolytic, neuroprotective and other properties.The aim of the study was to establish morphological features and conduct a comparative morphometric analysis of liver sinusoids of white rats after 4 and 8 weeks of experimental exposure to 10% cannabidiol oil.Materials and methods. The study was conducted using 40 sexually mature white non-linear male rats weighing 180-230 g, whose age at the beginning of the experiment was 5-7 months. The main group of the experiment was divided into two subgroups (series) of 14 rats each. Rats in the first series were administered 10% cannabidiol oil orally dripped at a dose of 10 mg/kg/day once a day for 4 weeks. Rats in the second series were administered 10% cannabidiol oil orally dripped at a dose of 10 mg/kg/day once a day for 8 weeks (long-term chronic exposure to CBD). The control group consisted of 12 sexually mature white male rats (6 rats each) to compare the two series of the experimental study. All experiments, as well as housing, care, feeding, marking and euthanasia were carried out in compliance with the requirements of the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (Strasbourg, 1986), Council of Europe Directive 2010/63/EU, Law of Ukraine No. 3447-IV “On the Protection of Animals from Cruelty to Animals”. Liver tissue was used as the material for morphological studies. A morphological study of the sinusoids of the hepatic lobule and a morphometric study of the average diameters of the sinusoids with statistical calculation were carried out. The reliability criteria of Pearson (χ2), Mann-Whitney (U), Wilcoxon T-test, McNemar p (McN) were used. The difference was considered statistically significant at a minimum significance level of p<0.05.Results. The morphological study allowed us to establish that the macroscopic structure and microscopic organization of the liver lobule were preserved and did not undergo histopathological changes under the conditions of experimental exposure to 10% CBD oil (10 mg/kg/day) as a dietary supplement for four and eight weeks. Comparative characteristics of morphometric parameters of liver sinusoidal hemocapillaries after four and eight weeks of the experiment demonstrated that the average sinusoidal diameter after 4 weeks did not differ significantly from the control group (p=0.59). In the experimental series after 8 weeks of CBD exposure, i.e. after long-term use of the cannabinoid, the average sinusoidal diameter was 9.72±0.33 μm and significantly differed from the control group (p<0.05) and the experimental series after 4 weeks of CBD exposure. Statistical calculations of single and multiple dilated and hyperemic sinusoids in the respective series, their comparison with the control group and in dynamics indicate that the single dilated and hyperemic sinusoids in both series differed from the control group. The significance of the difference according to the Pearson criterion (χ2) corresponded to the value of p=0.56 in the series after 4 weeks of CBD exposure and p=0.003 in the series after 8 weeks of CBD exposure. Multiple dilated and full-blooded sinusoids were observed only in the experimental series after 8 weeks of CBD exposure, which indicates the vasodilation effect of CBD and increased blood flow after long-term use of the cannabinoid.Conclusions. The results of morphological and morphometric analysis of liver sinusoids after four and eight weeks of experimental exposure to CBD indicate the safety of using 10% CBD oil at a dose of 10 mg/kg/day.