Determination of the nutritional content, phytochemical composition and the antibacterial properties of the aqueous extract of Citrus sinensis on some bacterial isolates

Medicinal plants have been used as therapeutics before the introduction of modern medicine. Citrus sinensis, commonly known as sweet orange, has many medicinal properties and is widely used against various ailments such as colic, upset stomach, diuretic, tonic to digestive system, and immune system booster. This study was aimed at determining the nutritional content, phytochemical composition and antibacterial properties of the aqueous extract of Citrus sinensis on some clinical isolates. The method of Association of Official Analytical Chemists (A.O.A.C) was used for the qualitative and quantitative assay. Antibacterial activity of the extract of Citrus sinensis was evaluated using the agar well diffusion technique against five bacterial strains: Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus and Klebsiella spp. The nutritional content of the extract of Citrus sinensis revealed moisture content (51.0837 ± 0.1310%), ash content (4.8953 ± 0.0707 mg/kg), crude fat (8.1967 ± 0.1073 mg/kg), crude fibre (none), protein (7.1567 ± 0.1027 mg/kg), and carbohydrate (33.5629 ± 0.0669 mg/kg). The levels of specific phytochemicals present were total tannins, total phenolics, total flavonoids, total saponins and alkaloids, determined through quantitative analysis. The largest inhibition zone observed for the aqueous extract was 20 mm against Staphylococcus aureus in comparison with 30 mm for the standard antibiotic ciprofloxacin. MIC was observed for Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus and Klebsiella spp. at 100 mg/kg, while MBC was observed at 200 mg/kg for all the bacterial isolates except Klebsiella spp. The nutritional content and the phytochemicals identified are indications of its richness and evidence of its antibacterial activity.