Aqueous, methanolic and hydroalcoholic extracts effects of Spartium junceum and Melissa officinalis on Saprolegnia sp. and comparison them with antibiotic

Contamination of Saprolegnia sp. fungi in edible and ornamental fish is one of the common problems of fish aquaculture ponds and aquariums and has economic losses. The aqueous, methanolic, and hydroalcoholic extracts of Spartium junceum and Melissa officinalis were prepared by maceration and condensed by rotary. Four concentrations of 20, 30, 40 and 50 mg/ml of the extracts were used. The fungus was isolated from fins of the infected fish and cultivated in sabouraud dextrose agar medium. For the effectiveness of extracts, the agar well method was used. GraphPad Prism, software and Anova and Tukey tests were used. At a concentration of 50 mg/ml the M. officinalis aqueous extract with a mean halo of lack of microbial growth of 20.8 ± 1.06mm had the highest inhibitory effect on growth, followed by a hydroalcoholic extract with halo of lack of microbial growth of 17.73± 1.1mm, and then the methanolic extract of S. junceum had the mean halo of lack of microbial growth 15.4 ± 2.12 mm. The Nystatin antibiotic did not produce any halo of lack of microbial growth. Using plant extracts instead of antibiotics and malachite green could be a good alternative. Particularly, aqueous extract of M. officinalis is recommended because it has the greatest effect and is also beneficial to the health of fish and humans.