Antioxidant properties and safety of Paederia bojeriana (A.Rich. ex DC.) Drake used by traditional herbal practitioners to manage asthma in Malawi

This study assessed the phytochemical composition, antioxidant activity and safety of Paederia bojeriana (A.Rich. ex DC.) Drake claimed to manage asthma by Malawian traditional herbal practitioners. Crude extracts were analysed for total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP) and 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) using standard assays. The TPC and TFC ranged from -1.67 ± 0.01 mg GAE/g to -22.60 ± 0.20 mg GAE/g DW and 13.49 ± 0.01 mg QE/g to 64.37 ± 0.06 mg QE/g DW, respectively. FRAP values ranged from 6.00 ± 0.08 mg TEAC/g DW to 9.42 ± 1.00 mg TEAC/g DW, while the scavenging activity (SA50) of the extracts ranged from 0.13 ± 0.01 μg/mL to 2.65 ± 0.01 μg/mL of extract. The extracts exhibited the Brine shrimp lethality in vitro LC50 value of 11.09 μg/mL whilst acute oral toxicity in vivo LC50 category of > 2000 mg/kg - 5000 mg/kg. SA50 values of less than 50 ug/mL imply that Paederia bojeriana (A.Rich. ex DC.) Drake has strong DPPH antioxidant activity. Based on the levels of phenolic compounds and antioxidant activity, Paederia bojeriana (A.Rich. ex DC.) Drake seems to scave and antioxidants in the management of asthma.