Comparison of Total Tannin Levels in Extracts of Pegagan Leaves (Centella asiatica), Alang-Alang Roots (Imperata cylindrica), and Neem Leaves (Azadirachta indica) Using The UV-Vis Spectrophotometric Method

Tannins are polyphenolic compounds that possess a variety of important biological activities, such as antioxidant, antimicrobial, anti-inflammatory, and antidiabetic properties. Gotu kola leaves (Centella asiatica), cogon grass roots (Imperata cylindrica), and neem leaves (Azadirachta indica) are plants widely used in traditional medicine. However, information about the comparison of total tannin content of the three is limited. This study aimed to compare total tannin contents in the aqueous extracts of these three plants using UV-Vis spectrophotometry with the Folin-Ciocalteu and galic acid standard. The extracts were produced by maceration using distilled water, then reacted with the Folin-Ciocalteu and 7.5% sodium carbonate, incubated for 60 minutes, and their absorbance measured at the wavelength of 760.4 nm. The results show that the gotu kola leaf extract had the highest total tannin content (57.78 ± 0.34 mgGAE/g), followed by the neem leaf extract (49.33 ± 0.01 mgGAE/g), and cogon grass root extract (39.41 ± 0.69 mgGAE/g). Statistical analysis with One-Way ANOVA shows a significant difference among the three extracts (p < 0.05). In conclusion, gotu kola leaves have the highest tannin content among the three plants tested. Further research is recommended to identify specific types of tannins and test their biological activities.