Intestinal and liver morphometry of the Yellow Tail Tetra (Astyanax altiparanae) fed with oregano oil

Abstract

This study aimed to evaluate the effect of oregano oil on the intestinal and liver morphometry of yellow tail tetra, Astyanax altiparanae. Fish (1.46 ± 0.09 g) were kept in a 60-L aquaria, at a stocking density of 0.5 fi sh L -1 . Six diets containing varying amounts of oregano oil were evaluated (0.0; 0.5; 1.0; 1.5; 2.0 and 2.5 g of oregano oil kg -1 ). At the end of 90 days, the fi sh were euthanised. Four intestines and four livers were collected per treatment, which were fi xed in Bouin and embedded in resin. For height and width folds, the absorption surface area and thickness of the muscular layer a positive linear effect of oregano oil was observed. A decrescent linear effect on the total number of goblet cells was also observed. For the cytoplasmic percentage of hepatocytes and liver glycogen, a positive linear effect of oregano oil was observed. There was a decreasing linear effect on the percentage of nuclei in the hepatocytes and capillaries. Thus, the oregano essential oil promotes increased absorption areas, modulates the amount of goblet cells involved in protecting the intestinal mucosa and promotes cytoplasmic increase with greater deposition of liver glycogen in yellow tail tetra.

Intestinal histology and stereology in rainbow trout (Oncorhynchus mykiss ) administrated with nanochitosan/zeolite and chitosan/zeolite composites

“…This could result in enhanced absorption and lubrication necessary to facilitate the passage of food (Ferreira et al, 2016). Similarly, administrating oregano oil to yellow tail tetra, Astyanax altiparanae, resulted in thicker muscular layer in fish intestine (Ferreira et al, 2016).…”

“…Villus width or diameter was calculated using the same three folds at three points; near the apex, middle part and the other near the base of folds (μm). Average of these measurements was expressed as villus width in each fold (Ferreira et al., ; Reda, & Selim, ).…”

“…The absorption surface area (ASA) magnification ratio for each villus was calculated according to Kisielinski, Willis, Prescher, Klosterhalfen, & Schumpelick, formula modified by Ferreira et al., as follows: ASA = (height of villus × width of villus)/(width of villus/2) 2 . Finally, ASA magnification ratio in each mm 2 was obtained by multiplying the mean of villus ASA in each region of intestine by villus density per mm 2 of that same region.…”

“…Tunica muscularis thickness was measured from the inner to the outer muscular layer in four regions of two perpendicular axes. Average of these measurements was expressed as tunica muscularis thickness in each section (Ferreira et al., ).…”

“…The effects of zeolite, chitosan/zeolite and nanochitosan/zeolite composites on goblet cells density in different part of intestine. Columns with different letter were significantly difference (p < .05) HAMIDIAN ET AL.| 1807Average of these measurements was expressed as tunica muscularis thickness in each section(Ferreira et al, 2016).2.10 | Estimation of intraepithelial mononuclear leukocytes distributionThe number of intraepithelial mononuclear leukocytes (IELs) was determined in five well-oriented different villi by counting the number of IELs per 100 epithelial cells (enterocyte) in each villus, and calculating the mean. The predominant distribution (villousbase, villous-tip and villous body) and epithelial location (supranuclear and subnuclear) of the mononuclear leukocyte was noted.…”