Bioactive compounds and antioxidant activity of Rhaponticum acaule (L.) DC.

Rhaponticum acaule (L.) DC. is a medicinal plant commonly used for the treatment of some illnesses such as gastrointestinal infections. In this work, we report the composition of different parts of this plant on phenolic compounds, their quantification, and antioxidant activity. The obtained results reported that methanolic extracts of the three parts studied revealed high phenolic contents. For flavonoid contents, the highest contents were reported in organic extracts of leaf part. In addition, results obtained from the study of the antioxidant activity showed that methanolic extract of root presented the highest activity, in DPPH• scavenging ability test with an IC50 of 0.31 ± 0.04 mg/mL and in FRAP test with an EC50 of 1.06 ± 0.02 mg/mL. The RP-HPLC-PDA analysis revealed the presence of five phenolic acids (sinapic, caffeic, chlorogenic, ferulic and syringic acids), one flavanone (naringenin), one flavonol (rutin) and vanillin.

Screening of biological activities of Polygonum maritimum L. from Algerian coast.

OBJECTIVE: To investigate the antioxidant and the antibacterial activities of crude extract from aerial part of Polygonum maritimum L. (Polygonaceae) (P. maritimum) and to find new actives biomolecules. METHODS: The whole plant was collected from the Rechgoune coast (West of Algeria), and methanolic crude extract of aerial parts of P. maritimum (PMCE) was prepared. The extract was tested against different bacterial strain and tested for his ability to neutralize free radical (DPPH) and to scavenge the H2O2. RESULTS: PMCE had a very high content of total phenol, which was (352.49±18.03) mg/g dry weight, expressed as gallic acid equivalent. PMCE exhibited excellent antioxidant activity, as measured using DPPH and H2O2 scavenging assays. It also showed a high antibacterial activity against gram-positive bacterial strains: Bacillus cereus, Bacillus subtilis and Staphylococcus aureus with an highest MIC of 120 µg/mL. CONCLUSIONS: The antioxidant and antibacterial activity of the PMCE is probably due to phenolic compounds present in the extract. The contemporary presence of antioxidant and antibacterial activities in the PMCE suggests that this plant may be a source of bioactive substances with multifaceted activity.