Practical diets with essential oils of plants activate the complement system and alter the intestinal morphology of Nile tilapia

Abstract

The effect of the essential oils (EOs) of peppermint, Mentha piperita L., and tea tree, Melaleuca alternifolia (Maiden & Betche) Cheel, on the haematological, biochemical, and immunological parameters and intestinal morphology of Nile tilapia, Oreochromis niloticus L., was evaluated. Fish (58.09 ± 5.87 g) were fed 100 mg/kg and 250 mg/kg of each EO and sampled on days 7, 14, 30 and 60 after starting supplementation. The haematological and biochemical parameters were not altered by the supplementation of EOs compared to the control (p > .05). With regard to the immunological parameters, the activation of the complement system of fish fed 250 mg/kg peppermint and 100 mg/kg and 250 mg/kg tea tree EOs were significantly higher compared to the control after 60 days of feeding (p < .05). The complement system plays an essential role in innate immunity and contributes significantly to the acquired immune response; thus, its activation through supplementation with EOs is promising for the formulation of nutritional additives in aquaculture. Regarding intestinal morphology, fish fed 250 mg/kg tea tree EO presented higher villus size compared to all other groups (p < .05), which represents a healthier gut. These fish present a larger intestinal surface, which can result in better absorption and utilization of the nutrients. Based on the responses found in this study, both EOs were considered promising for the formulation of feed additives for Nile tilapia.

Supplementation of diets forOreochromis niloticuswith essential oil extracts from lemongrass (Cymbopogon citratus) and geranium (Pelargonium graveolens) and effects on growth, intestinal microbiota, antioxidant and immune activities

“…This could be related to the efficient nutrients utilization following the adequate regulation of the intestinal microbiota as evidenced in the current study. The EOs usage also may positively affect the features of gut morphology which enhance absorption and assimilation of nutrients (Valladão et al, 2017). Likewise, in another study, the addition of a commercial EOs product to rainbow trout diet modulated intestinal microbial communities (Giannenas et al, 2012).…”

“…The EOs usage also may positively affect the features of gut morphology which enhance absorption and assimilation of nutrients (Valladão et al, 2017). The EOs usage also may positively affect the features of gut morphology which enhance absorption and assimilation of nutrients (Valladão et al, 2017).…”

Effects of dietary supplementation with a microalga (Schizochytrium sp.) on the hemato-immunological, and intestinal histological parameters and gut microbiota of Nile tilapia in net cages

“…The zootechnical indexes of tilapia did not differ significantly between treatments (p > 0.05), and the final weight was consistent with the slaughter weight of this species when farmed in net cages. Recent studies have been carried out to evaluate the effects of diet on the hematological, immunological, and histological parameters or the gut microbiota of Nile tilapia [5,8,[35][36][37][38][39][40][41], which have contributed to our understanding of the effects of dietary constituents on different physiological aspects of this species. However, no study to date has evaluated these variables in an integrated manner and/or in real farming situations.…”

Effects of dietary levels of essential oil extracts from Moringa oleifera and Artemisia afra on kidney histology, haemato‐immunological parameters and disease resistance in Clarias gariepinus

“…Previous studies have demonstrated that EO from some plants can be used to enhance immunity in fish as well as killing of certain bacteria and parasites of fish (i.e. Acar, Kesbiç, Yılmaz, Gültepe, & Türker, ; Brum et al, ; Brum et al, ; Ngugi, Oyoo‐Okoth, & Muchiri, ; Sutili et al, ; Sutili, Murari, et al, ; Sutili, Velasquez, et al, ; Valladão et al, ; Valladão, Gallani, Kotzent, Assane, & Pilarski, ; Valladão et al, ). However, the usage of EO or their isolated compounds as dietary supplements in fish is still limited in scope and application.…”