Date of Completion


Document Type

Research Project

Degree Name

Grade 12


Antibacterial agents, Garcinia mangostana, Mangosteen, fruit extracts, Staphylococcus aureus, Escherichia coli, Plant Extract, maceration


The study followed a Randomized Control Trial research design with five (5) treatments, the first two being the positive and negative control treatments and the remaining three treatments for each mangosteen fruit extract (pericarp, pulp, and seed). The positive control group consists of an antibiotic (1 μg Oxacillin for Staphylococcus aureus and 30 μg Amikacin for E.coli) while the negative control group consists of a blank sample-free disc. The plant extraction method utilized was maceration and the antimicrobial assay used in the study is the disc diffusion method. One-way ANOVA (Analysis of Variance) and Multiple Comparisons (Tukey/Post Hoc Test) was used in order to determine the significant difference among the treatments. Results of the test had revealed that the extracts had shown mild inhibitory activity against Staphylococcus aureus, with the mangosteen pericarp extract yielding the largest zone of inhibition, and very mild inhibitory activity against Escherichia coli, with all of the extracts exhibiting the same measurements of the zones of inhibition. Further analysis of the data showed that upon comparison, there is a significant difference between the measurements of the zones of inhibition exhibited by all of the treatments for both bacteria.

First Advisor

Carmellette C. Davila