Antioxidant, anti-inflammatory, and anti-Staphylococcal activities of Albizia lucidior (Steud.) I. C. Nielsen wood extracts

Abstract

Albizia lucidior (Steud.) I. C. Nielsen is a leguminous tropical hardwood tree that is of great interest as a herbal medicine. In this study, both ethanolic and aqueous extracts of A. lucidior wood were investigated. The phenolic and flavonoid contents of the extracts were measured, and the antioxidant and anti-inflammatory activities were evaluated by inhibition of tumor necrosis factor α and nitric oxide production. Cytotoxic activity against macrophages was determined by the MTT assay, and antimicrobial activities were tested against Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA), and Staphylococcus epidermidis, measuring the minimum inhibitory and bactericidal concentrations. The chemical composition of the extracts was analyzed by GC-MS. The aqueous extract had higher total phenolic content than the ethanolic extract. Both extracts had strong antioxidant activity in the DPPH assay, with respective IC50 values of 7.12 and 9.02 µg/ml. In the ABTS assay, the aqueous extract had a lower IC50 (9.50 µg/ml) than the ethanolic extract. The ethanolic extract significantly inhibited NO, but the aqueous extract showed no inhibitory activity. However, neither extract significantly inhibited TNF-α production. Significant antibacterial activity was found only in the ethanolic extract with an MIC and an MBC against S. aureus of 2.5 mg/ml and 5.0 mg/ml, respectively. From our knowledge, this is the first study of the antioxidant, anti-inflammatory, and anti-Staphylococcal activities of A. lucidior wood extracts. The significant anti-Staphylococcal activity should be further explored in preclinical studies.