Biofilms infections are a huge concern in the medical field due to increased antibiotic resistance. Plants may be a potential solution because they possess a variety of phytochemicals that have several biological activities. They also act as antioxidants an important property in preventing biofilm formation in wounds. This study aims to investigate the antioxidant and antibiofilm potential of Ageratum conyzoides L, and Bidens pilosa L. Plants were investigated for quantitative phytochemistry screening, antioxidant activity using DPPH scavenging assay, and antibiofilm activity using microtiter plate assay. All plants contained tannins, flavonoids, polyphenols, and alkaloids of which alkaloids were abundant in all plants. The antioxidant activity (IC50) of A. conyzoides was 50.52 µg and B. pilosa 45.94 µg. The minimum concentration to inhibit 50% of the biofilms (MBIC50) of P. aeruginosa was 24.9 mg/ml, for B. Pilosa and 28.3 mg/ml for A. conyzoides respectively. The MBIC90 was 147.7 mg/ml for A. conyzoides and 139.5 mg/ml for B. pilosa. For S. aureus biofilms, MBIC50 was 11.4 mg/ml for B. pilosa and 18.6 mg/ml for A. conyzoides. The MBIC 90 was 69.3 mg/ml for B. pilosa and 97 mg/ml for A. conyzoides. In the biofilm removal assay for P. aeruginosa, the minimum concentration to remove 50% of the formed biofilms (MBEC50) was 38.1 mg/ml, for A. conyzoides, and 200 mg/ml for B. Pilosa. The MBEC90 was 151.7 mg/ml for A. conyzoides and 261 mg/ml for Bidens Pilosa. For S. aureus, MBEC50 was 96.93 mg/ml for A. conyzoides and 195 mg/ml for B. Pilosa. MBEC 90 was 334 mg/ml and 250 mg/ml for A. conyzoides and B. pilosa respectively. The study confirms that plant extracts have antioxidant activity and the potential to inhibit biofilm formation and disrupt mature biofilms. The antibiofilm activity of these plants shows their potential as a solution to antibiotic resistance in further research.

Keywords: Antibiofilm activity, antioxidant activity, A. conyzoides, B. pilosa, S. aureus, P. aeruginosa.