Promising antioxidant activity of crude extract from Calliandra tweedii Benth

The interest in medicinal plants encourages new research studies on plant extracts, as they are sources for treatments in medicine, agriculture, and veterinary. Calliandra tweedii is a native Brazilian species with broad use in folk medicine. This study aimed to examine the leaf crude extract (CE) of C. tweedii and its methanolic (MP) and hexane (HP) phases concerning total phenolic compounds (TPC), proanthocyanidins (PRO), and flavonoid profile, and correlate it to their antioxidant activity (DPPH and FRAP). CE and MP revealed high contents of TPC, PRO and high antioxidant activity (DPPH and FRAP) in relation to HP. Opposite, HP showed reduced antioxidant activity, according to the scarce phenolic constituents obtained from the partition. Five flavonols were detected by HPLC-UV-DAD, being quercitrin the major constituent. Also, one kaempferol derivate, and a series of three quercetin derivates were detected. Strong positive correlations were observed between DPPH, FRAP, and phenolic compounds. These discoveries are important to highlight the promising antioxidant activity of CE of C. tweedii, which could contribute to the expansion of popular herbal medicines and new drug discovery.