Estimation of phytochemical constituents and in vitro antioxidant potencies of Brachychiton populneus (Schott & Endl.) R.Br.

Plants either in raw form or their isolated bioactive constituents are utilized as complementary and alternative medicine in various disorders. The present study was designed to evaluate chief phytochemical constituents of various fractions of Brachychiton populneus leaves and its antioxidative aptitude against free radicals.

Various fractions of B. populneus were prepared through solvent-solvent extraction technique based on their polarity and screened for phytochemical classes, total phenolic (TPC), flavonoid (TFC) and total tannin (TTC) content. Antioxidant effects of the extracts were manifested by in vitro multidimensional assays i.e. DPPH, hydroxyl radical scavenging, iron chelating, nitric oxide scavenging, β-carotene bleaching, phosphomolybdenum and reducing power assay.

Qualitative screening of various fractions of B. populneus ensured the presence of alkaloids, saponins, terpenoids, phenols, tannins, triterpenoids and flavonoids. Quantitative analysis revealed that aqueous fraction (BPA) showed maximum quantity of TPC and TFC followed by BPE and BPB. In terms of IC₅₀ values BPA exhibited minimum values in all the in vitro antioxidant assays. However, the phytochemicals and yield did not accumulate in various fractions on polarity.

Our results indicated the presence of various polyphenolics, flavonoids, alkaloids etc. The yield of various fractions and qualitative phytochemical analysis did not correlate with polarity of solvents. Various antioxidant assays exhibited significant (p < 0.05) correlation with TPC and TFC and renders B. populneus with therapeutic potential against free-radical-associated oxidative damages and this effect was significant with BPA.