Assessment of antibacterial and immunostimulating activity of black cumin (Nigella sativa) extract against vibriosis in white shrimp (Litopenaeus vannamei)

Abstract

It is assumed that the active components of Black cumin seed (Nigella sativa) contain beneficial effects on shrimp health as in humans. Therefore, this study aims to explore the antibacterial and immunostimulant potential of black cumin extract for disease control across V. harveyi. Treatments applied include the administration of ethanol extract mixed into shrimp feed at varying dosages (2500, 5000, 7500 ppm), hereinafter referred to as treatments A, B, C, respectively. All shrimps were exposed to pathogen V. harveyi at a density of 106 CFU ml-1 after 14 days of testing duration excluding the negative control group. The immune responses of the shrimps were recognized as Average Total Haemocyte Count (THC) and Differential Haemocyte Count (DHC). In addition, the vibrio challenge test was applied to assess the resistance of shrimp and the population of bacteria and Relative Percent Survival (RPS) were consequently determined. The results indicated that the highest THC, the best proportion in both granula cells and hyalin cells, and the highest RPS (68%) was found in the treatment of 7500 ppm compared to other treatments at all sampling times. Also, it was able to suppres the proliferation of V. harveyi bacteria more prominently in the shrimp gut. Extract addition in the diet can control vibriosis especially at a dose of 7500 ppm, indicated by a decrease in the bacterial population and a better immune response. Therefore, extract of black cumin seeds has antibacterial as well as immunostimulant activity.