Abstract
A study was conducted to investigate the infectious fish disease recovery of some carps and catfish by applying indigenous herbal solvent extracts and the comparative study of herbal active compound with antibiotic. The study area was greater Mymensingh and adjacent districts. The total experiments were conducted for a period of March, 2012 to June, 2015. Selected medicinal plants and antibiotics were Neem (Azadirachta indica), Kalojira (Nigella sativa), Garlic (Allium sativum), Akanda (Calotorpis gigantea), Shoti (Curcumia zedoaria), Basok (Adhatoda zeylanica), Turmeric (Curcuma longa), Mahogoni (Swietenia mahagoni) and Eryvet (Antibiotic). Previously collected pathogenic bacteria (Aeromonas hydrophila) stock from Fish Disease Laboratory, Faculty of Fisheries, BAU, Mymensingh was used. Three herbal oils (Neem seed oil, kalojira seed oil and Mehagoni seed oil) were collected from grocer shops, Chotobazar, Mymensingh and Rampal, Bagerhat. The experimental fishes were Sharputi (Puntius gonionotus), Rui (Labeo rohita), Shing (Heteropneustes fossilis), Thai koi (Anabas testudineus) and Thai pangus (Pangasius hypophthalmus). In sensitivity test it was observed that, Kalojira solvent extract, Kalojira seed oil and Garlic solvent extract exhibited best antibacterial activity followed by Neem, Shoti and Basak solvent extracts whereas, Akanda, Turmeric and Mahagoni extracts showed poor activity. Five experiments were conducted to observe the best performed herbal extract in fish disease recovery. According to experiments, clinically, the fish had several large blackish ulcers on the base of pectoral fin, operculum, lateral line, caudal region and pelvic region. Reddish spot on pelvic fin, large reddish lesion on abdomen, loss of scale, missing of muscle, eroded pelvic fin and cottony appearance on the ulcer were observed. Histologically, epidermis partly lost, dermis separated from muscle, deep injury reached up to muscle, necrosis and vacuums present in muscle and in kidney, tubular degeneration, vacuums, necrosis, hemorrhage and melanomecrophase were present. After treatment, it was observed that, Kalojira seed extract (95±2.45) and antibiotic (100) had the best recovery in all the fishes within 21 days compared with other mentioned herbal extracts. Among all the experiments, Kalojira seed extract and Kalojira seed oil had significantly (p<0.0001) higher disease recovery performances than Neem leaf solvent extract, Mehogoni seed oil, Neem seed oil, Akanda solvent extract, Shoti solvent extract, Basok solvent extract and Turmeric solvent extract. Due to more rapid recovery of injury and infections, compared to other treatments, the Kalojira seed extract was analyzed up to compound level. The bioactive single chemical compound was isolated and identified from Kalojira seed in the Post Graduate Laboratory 2, Department of Agricuraltural Chemistry, BAU, Mymensingh. The identified compound was characterized through infra red (IR), 1H-NMR and MASS spectrum at BCSIR Laboratory, Dhaka. From the previous study it was found that, disease recovery was achieved within 21 to 28 days of treatment, where, oil and solvent herbal extracts were used. In later experiment, bioactive single compound showed 98% disease recovery with the dose of 6 ml/kg feed within 10. days whereas, antibiotic treated fishes also showed 99% recovery with the dose of 6 ml/kg feed within 8 to 10 days. Thus it can be concluded that, concentrated single compound of Kalojira seed, performed best disease recovery of infectious fish when compared with herbal oils and solvent extracts and almost similar to synthetic antibiotic.