<![CDATA[Background: Green betel (Piper betle) and red betel (Piper crocatum) leaves are widely reported to contain flavonoids, tannins, alkaloids, and saponins, compounds empirically linked to free-radical scavenging activity, yet a direct, quantitative comparison of their antioxidant strength across two polar solvents remains scarce. Objective: To compare the phytochemical content and antioxidant activity of green and red betel leaf extracts using 70% ethanol and 70% methanol via the DPPH method. Method: This laboratory-experimental study was conducted at the Biomedical Science Laboratory, Universitas Karya Husada Semarang, from 22–28 February 2024 (Ethical Clearance No. 003/KEP/UNKAHA/SLE/2024). Antioxidant activity was measured across a 5–9 ppm concentration range, modeled with the linear regression curve y=ax+b, and compared across the four extract-solvent combinations using the Kruskal-Wallis test. Result: Phytochemical screening revealed a more complete compound profile in 70% ethanol than in 70% methanol for both leaf types. All four combinations exhibited DPPH inhibition above 70% even at the lowest tested concentration (5 ppm; range 72.10–97.46%), placing the true IC50 below 5 μg/mL for every combination — well under the 50 μg/mL “very strong” threshold. The Kruskal-Wallis test detected no significant difference in inhibition percentage among the four combinations (H=3.85, df=3, p=0.279). Conclusion: Both green and red betel extracts, in either solvent, qualify as very strong antioxidants with no statistically meaningful difference in potency, positioning either as an equally promising candidate for further natural antioxidant development.]]>
