Objective. The aim of this study was to determine the chemical characteristics and antibacterial activity of Fontitrygon margarita liver oil against the bacteria responsible for food poisoning. Methods. Oils were extracted from F. margarita liver using two methods (exudation and cooking-pressing) and analyses by Fourier transform infrared (FTIR) spectroscopy. Quality indexes were determined using standard methods and the fatty acid profile was carried out by gas chromatography with a flame ionization detector (GC-FID). Antibacterial activities of these oils, their emulsion, and their interactions with common antibiotics were evaluated by the broth microdilution method. Results. Extraction yield was higher with cooking-pressing (16.90%) compared to exudation (14.49%). The quality indexes of both oils were conformed to Codex Alimentarius Standard. Thiobarbituric acid index was higher with exudation compared to cooking-pressing (3.20 ± 0.14 and 2.36 ± 0.14 μmol MDA/kg, respectively) while acid, iodine, peroxide, and anisidine values did not significantly vary with the extraction methods (2.15-2.30 mgKOH/g, 102.42-106.65 gI2/100 g, 3.34-3.57 meqO2/kg, and 2.85-3.32 respectively). FTIR analyses clearly show that the two spectra are similar (no differences in the frequency and absorbance of their bands). The fatty acid profile revealed that, regardless of the extraction methods, F. margarita oil is richer in monounsaturated (55.97-55.41%) followed by polyunsaturated (28.17-28.52%) and saturated fatty acids (15.86-16.07%). Moreover, these oils showed antibacterial activity on all the bacteria strains tested with MICs between 16 and 256 mg/ml. Regardless of the extraction methods, emulsions showed higher activity (6.25 ≤ MIC ≤25 mg/ml) compared to crude oils. Additionally, F. margarita liver oil potentiated the antibacterial activity of ciprofloxacin, tetracycline, gentamicin, amoxicillin, and chloramphenicol. Conclusion. These results showed the effectiveness of Fontitrygon margarita liver oil against some bacteria responsible for food poisoning, thus demonstrating their antibacterial properties which could be due to their chemical composition.

Background: The limits of antibiotic prompted researchers to explore foods components as antimicrobial. The present study was initiated to value the oils extracted from the fat tissues of Lutjanus dentatus against food poisoning bacteria.Methods: The oils were extracted from the adipose tissue by drying at 45°C for 24 hours and by cooking in a pressure cooker at 95°C for 20 minutes followed by pressing. Subsequently, the oil extraction yield and the chemical characterization from quality indices according to standard methods and physical analysis by Fourier transform infrared (FTIR) spectroscopy were evaluated. The oils antibacterial activity, their emulsion as well as their interactions with some common antibiotics were evaluated by the broth microdilution method.Results: L. dentatus oil adipose tissue extraction yield obtained by cooking at 95oC was high (66.83%) compared to that obtained after drying at 45oC (55.50%). The oil extracted from L. dentatus adipose tissue by drying at 45oC showed peroxide (9.76±1.19 meqd’O2) and anisidine indices (40.94±0.8) higher than those obtained by cooking at 95°C (6.56±0.40 meq d’O2 and 37.85±0.34 respectively). However, the acid, iodine and thiobarbituric acid value of oils extracted using the two methods were not significantly different P≤0.05. The FTIR profile provided information on the functional groups present in the oil and enable to appreciate the variation of the peaks compared to the quality indicesThe antibacterial test showed that the oils studied all had antibacterial activity. The best spectrum of action (23/23 bacteria tested 16 ≤ MIC ≤ 256 mg / ml) was noted with the oil extracted by cooking at 95oC. Regardless of the extraction method, emulsions have better antibacterial activity compared to the oils (0.39 ≤ MIC ≤ 12.5 mg/ml). Moreover L. dentatus oil adipose tissue potentiated the activity of Ciprofloxacin, Tetracyclin, Gentamicin, Amoxicilin and Chloramphenicol on the bacterial strains tested.Conclusion: These results are a source of motivation for a much more in-depth exploration of the antimicrobial properties of the L. dentatus oil.

The decline in efficiency and the frequent toxicity effects observed with antibiotics urge researchers to investigate medicinal plant-based therapies. This study aimed to evaluate the anti-salmonella activity of the methanol extract of Harungana madagascariensis, a plant commonly used in Cameroon by traditional healers. Thirty Wistar albinos male were divided into six groups (normal control, negative control, positive control and three test groups). Test groups received the plant extract at 75, 150 and 300 mg/kg body weight (b.w). The disease evolution and treatment effectiveness were monitored by feces culture from the second-day post-infection until the end of the treatment. In addition, the effects of treatment on growth performances and feed conversion efficiency of rats were evaluated. The extract significantly affected the number of viable Salmonella typhimurium recovered from feces and could stop salmonellosis after 12 days of treatment. The hematological parameters were assessed after infection and treatment. The biological parameter and some serum and tissue oxidative stress markers were also evaluated. Moreover, the plant extract increased the weight of infected rats and normalized levels of TCMH (3.06; 2.83 and 3.16 Pg), CCMH (30.00; 26.66 and 20.00 g/dL) and lymphocytes (3.20; 3.20 and 3.10 μL). The results indicate that the extract of Harungana madagascariensis could be potentially used in salmonellosis treatment.