LC-MS Phytochemical Profiles of Phenolic Compounds and Antimicrobial, Antioxidant, and Antiplasmodial Activities of Ethanol Extracts of Pycnostachys erici-rosenii R.E.Fr and Leucas martinicensis (Jack.) R.Br (Lamiaceae)

This study has been conducted to analyze the chemical composition and antimicrobial, antioxidant and antiplasmodial properties of ethanol extracts of Pycnostachys erici-rosenii R.E.Fr and Leucas martinicensis (Jack.) R.Br that are not yet well known. The HPLC-DAD-MS-ESI+ method was used to investigate the chemical profile, the disc diffusion and microdilution method for the antimicrobial activities, the DPPH and FRAP assays for antioxidant property and SYBR Green I-based growth inhibition assay on Pf 3D7 (CQ-sensitive) strain for antiplasmodial properties. The results indicated significant amounts of hydroxybenzoic acid, flavonol and hydroxycinnamic acid in the two species. The total polyphenols analysis gave 209.0 ± 16.1 mg GAE/100g DW for P. erici-rosenii and 175.3 ± 1.6 mg GAE/100g DW for L. martinicensis while for total flavonoids analysis 33.4 ± 1.8 mg TE/100g DW was found for P. erici-rosenii and 39.6 ± 0.6 mg TE/100g DW for L. martinicensis. Moreover, antimicrobial tests revealed 0.125 mg/mL on E. faecalis ATCC25922 for ethanol extracts P. erici-rosenii and L. martinicensis. The antioxidant assays revealed IC50 56.17 μg/mL and 78.43 μg/mL for DPPH assay, and 112.03 μM TE/100mL and 90.46 μM TE/100mL) for FRAP assay for ethanol extracts of P. erici-rosenii and L. martinicensis respectively. Finally, for Antiplasmodial activity, IC50 was 4.07 μg/mL for P. erici-rosenii and 12.29 μg/mL for L. martinicensis. Therefore, the antimicrobial, the antioxidant, and the antiplasmodial results suggest that the ethanolic extracts of the aerial parts of P. erici-rosenii and L. martinicensis contain compounds with antimicrobial, antioxidant, and antiplasmodial properties, which can be searched in new drug discovery for treatment of infectious diseases.