Effects of Moringa oleifera, Allium sativum, Zingiber officinale on the haematological parameters and histopathological changes in visceral organs of Clarias gariepinus infected with Pseudomonas aeruginosa

Bacterial resistance to synthetic antibiotics is been a worrisome issue globally resulting in the search for alternative medicament for the treatment of bacterial infection in man, fish and other livestock. The study investigated the histological changes caused by selected medicinal plant extracts on sub-adults of the sharp tooth African catfish Clarias gariepinus experimentally infected with Pseudomonas aeruginosa. Phytochemical screening of test plants was done using standard methods. Agar well diffusion method was used to screen susceptibility of P. aeruginosa; ATCC 27853 to extracts of Moringa oleifera, Allium sativum, Zingiber officinale and oxytetracycline at 1000 mg/ml, 750 mg/ml and 500 mg/ml. Three fish samples from each group were tested for immune response and histopathological alterations. Saponins, terpenoids, flavonoids, cardiac glycoside, anthraquinone and alkaloids were present in test plants. Values of packed cell volume was 29.33%, 30.67%, 34.33%, 25.33% and 22.33% in fish exposed to oxytetracycline, Z. officinale, M. oleifera, A. sativum and untreated fish respectively. Similar trend was observed in the levels of red blood cell, haemoglobin and lymphocyte. White blood cell and neutrophil values were comparatively high in the untreated than treated fish. Organs of untreated fish showed degenerations in gill lamellae, gastric glands and hepatocytes while treated fish organs showed slight regeneration. The studied medicinal plant extracts showed significant antibacterial activity and compared with oxytetracycline in the treatment of P. aeruginosa diseases in fish. Use of these medicinal plants enhanced cultured fish immune responses