The study of the effect of the lyophilized extract of fireweed herb on the histological condition of the gastric mucosa in rats on the model of ethanol-predinisolone ulcer

Abstract

For more than 150 years, gastric ulcer (GU) continues to be a health problem as a chronic, relapsing disease, which occupies the central place among diseases of the gastrointestinal tract due to severity of course, complications and mortality. Despite significant advances in the research of the pathogenesis of GU, the introduction of a large number of modern treatments, a large arsenal of anti-ulcer drugs, there is now an increase of this pathology both in Ukraine and worldwide. Today, pharmacotherapy of GU includes more than 500 different drugs and about 1000 of their combinations. For the treatment of GU a wide range of drugs is used, most of them are synthetic with a significant number of side effects and a number of contraindications. One of the ways of solving this problem is the use of herbal medical products (HMP). In gastroenterology, HMP can be used during the exacerbation of the disease as a means of complementary therapy in combination with basic drugs, as well as therapeutic and prophylactic agents at the initial stages of the disease, at the stage of antirecession therapy and in the period of rehabilitation.  The plant world is a promising source of biologically active substances (BAS) that can be used for prophylaxis and in the complex treatment of GU taking into account that HMP contain valuable natural BAS (such phenolic compounds as flavonoids, tannins, hydroxycinnamic acids, coumarins, polysaccharides, amino and organic acids, etc.). In this regard, the lyophilized extract of fireweed herb (Chamaenerion angustifolium) is of considerable interest; it can be the source for obtaining a new drug with the anti-ulcerative activity. Therefore, it is advisable to study the anti-ulcer activity of the lyophilized extract of fireweed herb (LEFH) obtained from herb of the species under study.

Aim. To study the corrective effect of LEFH on the microscopic structure of the gastric mucosa (GM) on the model of ethanol-prednisolone ulcer of the stomach in rats.

Materials and methods. Gastroprotective properties of the lyophilized extract of fireweed herb were studied on the model of acute ulcer of the stomach in rats; it was stimulated by intragastric administration of the mixture of prednisolone in the dose of 20 mg/kg and 80 % ethanol in the dose of 6 ml/kg. LEFH in the dose of 20 mg/kg and “Gastrofit” were administered in 7 days before, on the day of administration and on the second day after the introduction of the alcohol-prednisolone mixture. Samples for histological examination were prepared by the general methods and stained with hematoxylin and eosin; and Schiff-method (Mc Manus) was used to identify neutral mucopolysaccharides and determine the activity of mucus secretion by secretory elements of the stomach.

Results. The introduction of the ethanol-prednisolone mixture to rats provoked the development of the acute ulcerative and erosive process in different parts of the gastric mucosa, and it was accompanied by significant disorders of the microcirculation and edema of the stroma. In most cases, ulcers spread to the entire depth or a large part of the glands. It was revealed that there was a reduction in mucus secretion of the surface epithelium in areas outside the destruction zones and particular stimulation and release of pepsinogen and enhancement of acid formation (due to the morphological condition of main and parietal cells). After administration of LEFH acute ulcers and erosions in the gastric mucosa were detected in 60 % of cases. But they were located only in the prepyloronic and pyloric parts of the stomach, and most of the defects in depth were definitely smaller than in control pathology. The remnants of the tubular secretory portions under the areas with defects were somewhat better preserved. The signs of the stromal edema around the destruction zone were less pronounced, but there were focal disorders of the microcirculation. The functional activity of mucocytes was visually within the normal range. After administration of the reference drug “Gastrofit” in the similar mode acute ulcers and erosions were detected in 80 % of animals. Localization and the histological condition of defects differed little from those in rats of the previous group.  Around the defect areas, quite moderate subepithelial edema of the stroma was observed, while manifestations of local microcirculation disorders were more visible.

Conclusions. LEFH does not significantly prevent the development of the pathological process in the gastric mucosa; however, under its effect the depth of glands injury and expressiveness of microcirculatory disorders are somewhat limited, the signs of edema are reduced, the mucus secretion is stabilized, and the functional state of parietal and main cells improves. All this allows us to recognize that in this experimental model of the gastric pathology LEFH has shown some gastroprotective effect, which is not inferior to that of the reference drug “Gastrofit” or even exceeds it.