The nearest research of the scientist Zambia showed a potential of chilli in the treatment and protection of tilapia from bacterial diseases.
Capsaicin in red chilli
In the whole world, the demand for farmed fish is increasing due to a decrease in natural seafood. The fishery plays an important role in filling the deficiency of fish and contributes to the economic development of many countries. The expansion of aquaculture led to an increase in diseases in fish farms. Some bacterias that have been identified as the cause of disease outbreak in tilapia such as Aeromonas hydrophila, Streptococcus agalactiae, Streptococcus iniae và Lactococcus garvieae. A tilapia infected by Lactococcus garvieae has a slow growth rate and underestimated due to skin lesions.
The most common remedy is using antibiotics. However, indiscriminate use of antibiotics leads to drug resistance that has been reported with several bacterial diseases in tilapia. Herbal extracts (plant or animal products) are considered as a potential alternative to antibiotics. Hot red chili (Capsicum annum) is one of the widest herbs and spices used around the world.
Capsaicin in red chili has an antibacterial ability that helps cultivated species to fight against bacterial diseases and act as an anti-inflammatory and immune-strengthening, too. Up to now, many pieces of research have shown capsaicin’s effects on bacteria and efficiency to use for terrestrial animals, but there is little information about its effects on bacterial diseases in aquatic species. This study aimed to determine the efficiency of the extract of Capsicum annum chili in preventing Lactococcus garvieae infection in three-spot tilapia (Oreochromis andersonii).
The extract of chilli prevents Lactococcosis disease on tilapia.
Capsaicin was extracted from local chilli (Capsicum annum) by the common solvent extraction method. Capsaicin was mixed with Lactococcus garvieae bacteria and inoculated into an agar environment to define the minimum bactericidal concentration. There were 4 groups (100 fish):
- Group 1 was injected with capsaicin,
- Group 2 was injected with pathogenic bacteria and capsaicin,
- Group 3 was only injected with the bacteria that cause disease,
- Group of 4 was injected with common saline (negative control).
Fish was observed for 7 days after treatment, the experiment was repeated three times. The protective ability from using chili extract was measured by the fish were not infected with clinical disease and the survival rate of the fish during the trial period.
On the second day of the experiment, the mortality (20%) was recorded in the group of Lactococcus garvieae and Capsaicin, then stabilized until the end of the experiment. Particularly, many fish in the group injected with bacteria and capsaicin had a higher survival rate than those in the group injected only bacteria. The experiment figured out that chilli extract can prevents Lactococcus garvieae infection in tilapia.
In this study, Capsicum annum extract proved antibacterial activities against Lactococcus garvieae. The minimum bactericidal concentration of capsaicin for the growth of bacteria Lactococcus garvieae is 0.1967 mg/ml (the capsaicin concentration in local chilli is 19.67mg / g).
The prophylactic use of Capsicum annum extract for tilapia infected with the bacteria Lactococcus garvieae gave very good results. This is a potential for using herbal extracts like Capsicum annum to control animal diseases and limit antibiotic resistance in the aquaculture sector.
The results of this study showed that diseases caused by Lactococcus garvieae bacteria on tilapia can be treated by injecting Capsicum annum extract. However, the injection method is difficult to be applied to fish, so it is necessary to have additional studies on applying of chili extract in preventing Lactococcus garvieae bacteria in cultured tilapia with the trading scale.
The Potential of Capsicum annum Extracts to Prevent Lactococcosis in Tilapia by Kunda Ndashe, Stellah Ngh’ake, Emelda Pola, Emmanuel Masautso Sakala, Emmanuel Kabwali, Ladslav Moonga, Alexander Shula Kefi, Bernard Mudenda Hang’ombe.