Antimicrobial and Antioxidant Synergy of Lagnob (Ficus septica) (Nogodula et al., 2012), Romblon (Pandanus sp.) (Hamid et al. (2017), and Balingeweg (Saurauia sp.) (Mazo et al., 2021)

Studies on the antimicrobial and antioxidant synergistic effect of Ficus septica, Pandanus sp., and Saurauia sp are sparingly examined. The main objectives of this study are (1) to determine the secondary metabolites present in the ethanol extracts of the three plant species (Ficus septica, Pandanus sp., Saurauia sp.), (2) to examine the antimicrobial and antioxidant activities of the three plant species, and (3) to identify the synergistic effects of combinations of these plants in terms of antimicrobial and antioxidant activities. The ethanolic extracts of Ficus septica, Pandanus sp., and Saurauia sp. was analyzed for secondary metabolites, antimicrobial (using Kirby-Bauer Susceptibility Testing and the Minimum Inhibitory Concentration (MIC)) and DPPH anti-oxidant activities. Fractional Inhibitory Concentration Index (FICI) was calculated to evaluate the antimicrobial synergy while % Radical Scavenging Activity (RSA) was used as bases for evaluating the anti- oxidant synergistic combinations. The presence of flavonoids and phenols, which demonstrated antimicrobial and anti-oxidant effectivity was detected in Romblon (Pandanus sp.) and Balingeweg (Saurauia sp.) Moreover, results showed that out of the three ethanolic extracts, only Pandanus sp. ethanolic extract exhibited a partially active antimicrobial activity against E.coli. Moreover, out of all the combinations of ethanolic extracts, Treatment 7 has the highest antimicrobial activity against E.coli based on its mean zone of inhibition (25mm). In S. aureus, only the combination of Romblon and Balingeweg showed antimicrobial synergistic activity. Against A. niger, treatment 4 performed a synergistic activity at the concentration of 15.62 µg/mL with the combined FIC of 0.0390. In the test organism S. cerevisiae, treatment 6, exhibited synergistic antimicrobial activity. Further, the antioxidant activity of the plant extracts revealed that Romblon had the highest antioxidant activity. Also, among all the combinations of plant extracts, treatment 6 showed the highest radical scavenging activity (%RSA), suggesting that this has the highest synergistic antioxidant activity.