Antiparasitic effect of Mentha × villosa hydrolate against monogenean parasites of the Nile tilapia

Laura Rafaela Da Silva,Fabiano Cleber Bertoldi,Marina Oliveira Pereira,Julio Cesar Bailler Rodhermel,Adolfo Jatobá,Amanda Chaaban,Jaqueline Inês Alves De Andrade

doi:10.1590/0103-8478cr20190980

Laura Rafaela Da Silva, Fabiano Cleber Bertoldi + Show 5 more

Open Access

https://doi.org/10.1590/0103-8478cr20190980

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Abstract

ABSTRACT: This paper o evaluated different concentrations and exposure times of Mentha × villosa hydrolate for the control of monogeneans in Nile tilapia (Oreochromis niloticus). Mentha × villosa leaves (150 g) were homogenized and the hydrolate was obtained by hydrodistillation for 4 h in a Clevenger apparatus. Fifty tilapia were then divided into ten groups (five fish each) and subjected to therapeutic baths for 15 minutes in five different hydrolate concentrations (0, 10, 20, 40, and 80 ml.L-1;× 2 replicates). After a suitable hydrolate concentration was identified, another 50 tilapia were divided into ten groups (five fish each) and subjected to therapeutic baths at the identified hydrolate concentration for five different durations (0, 15, 30, 45, and 60 minutes;× 2 replicates). In both steps, the mucus and gills were analyzed to determine parasitological indices. The hydrolate concentration of 20 ml.L-1 showed an efficacy of 59.9% and the biggest decrease in pathogen prevalence, average abundance, and average infection compared to the control and the lowest concentration (10 ml.L-1). For duration, the best antiparasitic effects were achieved with the 60-minute therapeutic bath, as it resulted in 89.28% antiparasitic efficacy. Therefore, it was concluded that therapeutic baths of M. × villosa hydrolate at a concentration of 20 ml.L-1 for 60 minutes have satisfactory antiparasitic effects and could be used to control monogenetic infestations in the gills and mucus of Nile tilapia (O. niloticus).

Highlights

Parasitic diseases are a common problem in aquaculture
Plants of the genus Mentha are valuable for industry, as their extracts and derived essential oils exert notable effects against a broad spectrum of bacteria, fungi, and yeasts, when tested in vitro (SALEHI et al, 2018), and their use has been observed in aquaculture (HASHIMOTO et al, 2016)
Carvone was the most abundant compound in the Menta × villosa hydrolate, representing almost 90 % of the sample profile (Table 1), the same compound was a predominant chemical (89.7%) in the crude volatile oil of Sphaeranthus amaranthoides (MURFADUNNISA et al, 2014). This compound has previously been investigated as a feed additive for veterinary and medicinal use (EFSA, 2014), and may have a role in aquaculture as an anesthetic (MORCIA et al, 2016)

Summary

Introduction

Parasitic diseases are a common problem in aquaculture. In particular, ectoparasites are of specific note as they can serve as vectors for other pathogens (bacteria, fungi, and viruses); and help to spread disease and harm animal performance. No previous studies have elucidated the medicinal use of hydrolate, a byproduct of the extraction of essential oils from plants, in therapeutic baths for the treatment of parasitized fish. This study evaluated different concentrations and exposure times of Mentha × villosa hydrolate for the control of monogeneans in Nile tilapia (Oreochromis niloticus).

Results

Conclusion