Date of Completion
2025
Document Type
Thesis
Degree Name
Bachelor of Science in Pharmacy
Keywords
Rice husk, RC 534, Ballatinao rice, phenolic compounds, antimicrobial activity, antibiofilm activity, Staphylococcus aureus, ethanolic extract, biofilm inhibition, maceration, thin-layer chromatography, total phenolic content, growth curve kinetics, resazurin microplate assay, crystal violet assay, Philippine rice industry, natural bioactive compounds
Abstract
This study evaluated the phytochemical composition, antimicrobial activity, and antibiofilm potential of ethanolic extracts derived from pigmented (Ballatinao) and non-pigmented (RC 534) rice husks against Staphylococcus aureus ATCC 29213. Crude extracts were obtained through maceration using 95% ethanol, yielding 12.36 g (1.24%) for RC 534 and 11.11 g (1.02%) for Ballatinao. Phytochemical screening confirmed the presence of phenols, carbohydrates, and alkaloids in both samples. Thin-layer chromatography (TLC) and total phenolic content (TPC) analysis revealed a higher TPC in RC 534 (143.62 mg GAE/g) than in Ballatinao (89.29 mg GAE/g). However, the pigmented extract exhibited stronger antimicrobial activity in the Resazurin Microplate Assay (REMA), achieving a minimum inhibitory concentration (MIC) at approximately 80 mg/mL, while the non-pigmented extract did not reach the MIC threshold. The Crystal Violet assay showed moderate antibiofilm activity at 50 mg/mL, with Ballatinao and RC 534 extracts reducing biofilm biomass by 23.34% and 25.66%, respectively, compared to the untreated control. The stronger bioactivity of the Ballatinao extract, despite its lower TPC, suggests that antimicrobial efficacy may depend on specific phytochemicals such as anthocyanins and alkaloids rather than total phenolic content alone. It is recommended that future studies isolate and identify individual active compounds using advanced analytical techniques and test higher concentrations of RC 534 extract to determine its true MIC. Investigating synergistic effects with antibiotics, as well as the influence of environmental factors on phytochemical content, may further optimize the use of rice husks as cost-effective natural antimicrobial agents.
First Advisor
Darwin Japheth L. Eusebio, RPh
APA Citation
Chugani, C. C.,
Mabini, M. B.,
Ramirez, E. J.,
Regala, E. G.,
&
Salvador, R. M.
(2025).
Evaluation of the antimicrobial and antibiofilm activity of non-pigmented RC 534 and pigmented ballatinao rice (Oryza sativa) husk ethanolic extract against staphylococcus aureus via resazurin and crystal violet assay.
Bachelor of Science in Pharmacy.
Retrieved from https://greenprints.dlshsi.edu.ph/bsp/129