Effects of aqueous extract of Capsicum frutescens (Solanaceae) against the fish ectoparasite Ichthyophthirius multifiliis

Abstract

Abstracts Ichthyophthirius multifiliis is an important fish ectoparasite that often results in significant economic losses to freshwater aquaculture. The search of alternative substances to control infections of I. multifiliis became stringent after malachite green, an effective and widely used chemotherapeutant, is banned on fish farms because of its carcinogenicity and teratogenicity. In this study, the effects of the aqueous extract of Capsicum frutescens, which is readily available and affordable, were evaluated under in vitro and in vivo conditions. The results in the in vitro conditions showed that the aqueous extracts of C. frutescens with the ratios (V SS /V T -V SS , the volume of stock solution; V T , the volume of total solution) of 1:32 and 1:64 led to more than 70 % mortality of I. multifiliis theronts during 4 h of exposure and significantly reduced the survival of the tomonts and the total number of theronts released by the tomonts within 22 h (P<0.05). A 96-h bioassay was carried out to determine the acute toxicity of the aqueous extract of C. frutescens to goldfish. No visible effect was observed in the treatments with the aqueous extracts of C. frutescens with the ratios (V SS /V T ) of 1:32, 1:64 and 1:128, while in the other treatments, the erratic behaviour of fish was noted. In addition, in vitro tests demonstrated that the aqueous extract of C.frutescens had an adverse effect on I. multifiliis trophonts in situ. Fish treated with the aqueous extracts of C. frutescens in ratios V SS /V T of 1:32 and 1:64 carried significantly fewer parasites than the control and the other treatments (P<0.05). These results suggest, therefore, that aqueous extracts of C. frutescens have potential for the control of ichthyophthiriasis in the aquaculture industry, though further phytochemical studies will need to be performed for isolation and identification of the active compounds.

Evaluation of an antiparasitic compound extracted from Galla chinensis against fish parasite Ichthyophthirius multifiliis

“…The result showed that tomonts were more resistant to the parasiticides than theronts. Similar results have also been noted in Ich treatment trials with other chemical (Buchmann et al, 2003) or plant extracts (Yi et al, 2012;Ling et al, 2012).…”

“…Therefore it is important to kill theronts in order to control ichthyophthiriasis. Reports in the literature indicated that theronts are more sensitive to plant-active parasitisides (Chu et al, 2010;Ling et al, 2012;Yi et al, Table 4 Results of prevention of Ich infestation on channel catfish by using the extract from G. chinesis at 15 days (mean ± SD of 3 tanks).…”

“…Several studies demonstrated that plant extracts could kill free-swimming stages of Ich (Buchmann et al, 2003;Ekanem et al, 2004;Chu et al, 2010;Yao et al, 2010Yao et al, , 2011Ling et al, 2012;Yi et al, 2012). The studies have suggested that some plants, including traditional Chinese medicinal plants, possess effective parasiticide properties.…”

The in vitro and in vivo effect of tannic acid on Ichthyophthirius multifiliis in zebrafish (Danio rerio) to treat ichthyophthiriasis

“…In general, chemical treatments may rapidly release poisonous and hazardous residuals with long degradation kinetics into water and soil ecosystems (Gholami‐Seyedkolaei et al., ; Yao et al., ). Moreover, there are other important problems in the use of chemicals to control ichthyophthiriasis in aquaculture systems such as low effectiveness, high cost, enhanced resistance of I. multifiliis to other antiparasitic compounds and also significant damage to the human health (Ling et al., , ; Sapkota et al., ; Tieman & Goodwin, ; Zhou, Liu, Zhang, Fu, & Lin, ). Therefore, there is a serious effort to reduce the use of these compounds or replace them with some eco‐friendly and safe compounds with natural origin to remove the contamination and infection caused by I. multifiliis in fish farms.…”

EXTRATOS DE PIMENTAS (Capsicum spp.) PARA INIBIÇÃO DO CRESCIMENTO MICELIAL IN VITRO DE Rhizoctonia solani Kuhn

“…Estudos com plantas do gênero Capsicum demonstram uma grande diversidade de metabólitos secundários, inclusive com ação inseticida e antifúngica (RIBEIRO & BEDENDO, 1999;LING et al, 2012;GUIMARÃES et al, 2014;VASCONCELOS et al, 2014). Apesar disto, há poucos estudos com Capsicum sobre o controle de fitopatógenos importantes economicamente.…”