Antibacterial and Antibiofilm Properties of Kulim Bark (Scorodocarpus borneensis Becc.) Hydrogel on Polymicrobial Biofilms.

Objectives: The study aimed to analyze the antibacterial and antibiofilm activity of hydrogels from Kulim (Scorodocarpus borneensis Becc.) stem bark extract and fraction against polymicrobial biofilms.

Methods: The stem bark extract and fraction of Kulim (Scorodocarpus borneensis Becc.) were formulated into a hydrogel (tween 80glycerin). Antibacterial and antibiofilm activities were assessed using a microdilution test against polymicrobial growth and polymicrobial biofilms, while acute toxicity was evaluated using wader pari (Rasbora lateristriata) embryos.

Results: Kulim extract hydrogel (4 μg/µL) showed 69.16% antibacterial activity and 61.25% biofilm inhibition, with 72.58% and 82.86% biofilm degradation at 24 and 48 hours, respectively. The fraction-based hydrogel (0.22 μg/µL) had 58.10% antibacterial and biofilm inhibition activity, with 81.14% and 79.64% degradation at 24 and 48 hours. MIC50 and MBIC50 values were 2.42 μg/µL (extract) and 0.15 μg/µL (fraction) as well as 2.83 μg/µL and 0.19 μg/µL, respectively. Based on observation, MBEC50 values were 1.09 μg/µL and 0.57 μg/µL (24 h), as well as 0.70 μg/µL and 0.03 μg/µL (48 h), respectively, while the extract's LC50 was 0.143 mg/mL.

Conclusion: The hydrogel made from Kulim stem bark extract exhibited stronger antibacterial and antibiofilm activities than the ethyl acetate fraction against polymicrobial.