Intraspecific Variation of Phytochemicals, Antioxidant, and Antibacterial Activities of Different Solvent Extracts of Albizia coriaria Leaves from Some Agroecological Zones of Uganda

Abstract

Albizia coriaria Welw ex. Oliver is a customary African medicinal plant, which has a long history of utilization in the management of oxidative stress-induced and bacterial diseases. However, there is no report on the phytochemicals, antioxidant, and antibacterial activities of its leaves. The aim of this study was therefore to compare the phytochemicals, antioxidant, and antibacterial potential of A. coriaria leaves from Jinja, Kole, and Mbarara districts of Uganda. Shade-dried leaf samples were ground into powder and successively extracted with ethyl acetate, ethanol, and distilled water. Phytochemical screening indicated the presence of alkaloids, phenols, saponins, flavonoids, cardiac glycosides, tannins, and terpenes as the major secondary metabolites in the extracts. Total phenolic and flavonoid contents and total in vitro antioxidant activity were found to be the highest for ethanolic extracts, with the highest contents (101.72 ± 0.22 mg GAE/g DW; 13.23 ± 0.03 mg QE/g DW) and antioxidant potential (IC50 = 18.65 ± 0.06 mg/mL) being for leaves from Mbarara district. Antibacterial activity of the extracts determined by agar disc diffusion method revealed that ethanolic extracts had higher antibacterial activities with mean zones of inhibition of 6.00 ± 1.73 to 10.00 ± 1.73 mm, 5.00 ± 1.00 to 12.30 ± 1.53 mm, 17.00 ± 0.00 to 25.00 ± 2.65 mm, and 9.00 ± 1.73 to 16.00 ± 1.73 mm for Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhi, respectively. Ethyl acetate extracts of A. coriaria leaves from Kole and Mbarara had lower antibacterial activities, while aqueous extracts and ethyl acetate extract of leaves from Jinja showed no antibacterial activity. The current study for the first time established that A. coriaria leaves possess therapeutic phytochemicals with significant in vitro antioxidant and antibacterial activities, which lend credence to their use in traditional management of oxidative stress-induced conditions and bacterial diseases in Uganda. Structural elucidation of the responsible pure compounds for the observed bioactivities as well as toxicity studies of the extracts is recommended.

Phytochemical, Cytotoxicity, and Antimycobacterial Activity Evaluation of Extracts and Compounds from the Stem Bark of Albizia coriaria Welw ex. Oliver

“…The results, therefore, suggest that the stem bark of A. coriaria contains more polar extractable phytochemicals than their nonpolar counterparts. In a related study, ethanol, a solvent of comparable polarity to methanol had the highest yield in the extraction of phytochemicals from the leaves of A. coriaria [ 13 ].…”

“…The phytochemicals present are secondary metabolites of various pathways that occur in many plant species of family Fabaceae. Some of these phytochemicals have been reported to possess good pharmacological activities against TB and hence could be responsible for the antimycobacterial properties of this plant [ 13 ]. The diverse phytochemical composition of acetone extracts is due to its intermediate polarity that allows acetone to extract a wide range of phytochemicals of intermediate and slightly high polarity [ 19 ].…”

“…Apart from its use in the management of TB, the stem bark of this tree is also used in the preparation of herbal remedies for the management of symptoms of bronchial infections, dysentery, malaria, jaundice, and skin infections [ 7 , 8 , 10 ]. The ethanol extract from the leaves of A. coriaria showed good antibacterial activity against several bacteria strains ( Escherichia coli , Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhi ) with minimum inhibitory concentrations ranging between 62.5 and 250 μ g/mL [ 13 ]. However, there was no published scientific study that has validated the claimed antimycobacterial activity of A. coriaria .…”

Synergistic Antibacterial Activity of Ethanolic Extracts of Mondia whytei Roots and Physalis peruviana Leaves against S. aureus and E. coli

“…The MIC was evaluated for the two selected bacteria using the broth microdilution method labelled by Omara et al [28]. The initial concentration was defined as 100%, while other concentrations were prepared using successive dilutions (0.1-100) µg/ml using Dimethyl sulfoxide (50 mg/ml) for all the samples and the concentration for the reference Antibiotic was 500 µg/ml.…”

Phytochemical Composition and Antioxidant Activities of Phosphate Buffered Saline and Aqueous Extracts of Aloe barbadensis Miller Leaf Latex and Gel from Three Counties of Kenya

“…The secondary metabolites screened for included phenols, saponins, flavonoids, anthraquinones, cardiac glycosides, alkaloids, quinones, glycosides, steroids, sterols, tannins and terpenes and coumarins. The screening results were reported in terms of the relative abundance of the secondary metabolites identified based on colour or foaming intensities [29][30][31]. The total phenolic content (TPC) of A. barbadensis extracts were determined using the Folin-Ciocalteau method [32] with some modifications [31].…”