Evaluation of hexane extract of parkia speciosa hassk. pericarp as a potential antimicrobial agent / Nurul Afiqah Ahmad Zaidi

Parkia speciosa Hassk. or locally named as “Petai” in Malaysia, belongs to the family Fabaceae. It is known to have many medicinal benefits. In the present study, the discarded pericarp of Parkia speciosa was extracted with n-hexane solvent for assessment on its antimicrobial activities. Antimicrobial susceptibility testing (AST) of the Parkia speciosa extract was done using five concentrations of hexane extract by using the disc diffusion method on S. aureus, B. cereus, E. coli, and S. thyphimurium. The zone of inhibition for AST was only shown for gram positive bacteria which were S. aureus and B. cereus whereas for gram negative bacteria (E. coli and S. thyphimurium) showed no zone of inhibition. The minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Parkia speciosa pericarp hexane extract were also determined by micro-titer method against the four tested bacteria. The MIC result for S. aureus and B. cereus at three concentrations of hexane extract which were 1000 mg/ml, 500 mg/ml and 250 mg/ml showed that no turbidity was seen. MBC result of the three concentrations of extract also showed that there was no growth the Muller Hinton agar. In conclusion, even though the hexane extract of Parkia speciosa pericarp showed antimicrobial activity towards S. aureus and B. cereus, it may not be a good candidate as a potential antimicrobial agent due to the limitations during the preparation of the extract.