Secondary Metabolite Content in Centella asiatica Based on Altitude and Extraction Solvent

Abstract

Objective: To evaluate the effect of altitude and extraction solvent on secondary metabolites of Centella asiatica, with a focus on total phenols, flavonoids, triterpenoids, and antioxidant activity. Study Design: A factorial experimental design was used to assess two main factors: altitude and solvent type. Place and Duration of Research: The research was conducted at the Laboratory of Botany and Genetics, Universitas Muhammadiyah Purwokerto, Central Java, Indonesia, in January 2025. Methodology: Sample Centella asiatica collected from three areas, namely Cilacap (7 masl), Banjarnegara (450 masl), and Bandung (650 masl). The dried and crushed plant materials were extracted using 96% ethanol, 70% ethanol, and methanol. The extracts were analyzed by spectrophotometric methods to determine the total content of phenols, flavonoids, and triterpenoids; antioxidant activity was measured by the DPPH test. Results: The highest levels of phenols (8.56 × 10⁻³ mg GAE/g) and triterpenoids (2.30 × 10⁻³ mg UAE/g) were found in samples from 650 masl using 70% and 96% ethanol, respectively. The highest flavonoid content (0.36 × 10⁻³ mg QE/g) was recorded in lowland samples extracted with methanol. The best antioxidant activity (lowest IC₅₀ = 2165.15 ppm) was found in the mid-altitude (450 masl) methanol extract. Among solvents, 70% ethanol was optimal for extracting phenols, methanol for flavonoids and antioxidant activity, and 96% ethanol for triterpenoids. Conclusion: Altitude and solvent type influence the secondary metabolite content of Centella asiatica, including phenols, flavonoids, triterpenoids, and antioxidant activity. Higher altitudes (650 masl) yielded the most phenols and triterpenoids, while the most flavonoids were found at lower altitudes (7 masl). The best solvents were 70% ethanol for phenols, methanol for flavonoids, and 96% ethanol for triterpenoids. The strongest antioxidant activity came from methanol extraction at 450 masl. These results highlight the role of environment and extraction methods in enhancing medicinal plant quality.