Skripsi

Uji Fitokimia dan Aktivitas Inhibisi Enzim Alfa-Glukosidase In Vitro Oleh Ekstrak Metanol dan Petroleum Eter Bunga Kecombrang (Etlingera elatior) = Phytochemical Profile and In Vitro Alpha-Glucosidase Inhibition by Methanol and Petroleum Ether Extracts of Etlingera elatior.

Latar Belakang Diabetes melitus tipe 2 adalah penyakit metabolik dengan prevalensi dan mortalitas tinggi. Terapi inhibitor enzim alfa-glukosidase, seperti acarbose efektif menurunkan gula darah, tetapi menimbulkan efek samping gastrointestinal. Hal ini mendorong pengembangan terapi alternatif herbal. Kecombrang (Etlingera elatior) diketahui mengandung fitokimia (flavonoid, saponin, triterpenoid) dengan potensi antihiperglikemik, tetapi belum terdapat penelitian yang membandingkan efektivitas ekstrak pelarut metanol (polar) dan petroleum eter (nonpolar) terhadap inhibisi enzim alfa-glukosidase. Metode Penelitian in vitro di Laboratorium Kimia FKUI (Januari–Juli 2025). Sampel bunga kecombrang dari tempat budidaya daerah Gunung Gede diekstraksi dengan maserasi menggunakan pelarut metanol dan petroleum eter. Uji fitokimia dilakukan untuk mengidentifikasi metabolit sekunder. Aktivitas inhibisi enzim diuji menggunakan substrat pNPG dan diukur pada gelombang 410 nm dengan ELISA Microplate Spectrophotometer. Kontrol positif yang digunakan adalah obat acarbose. Data dianalisis melalui persentase inhibisi, nilai IC₅₀, dan uji ANOVA. Hasil Ekstrak metanol bunga kecombrang mengandung saponin, flavonoid, dan triterpenoid, sedangkan petroleum eter mengandung triterpenoid. Nilai IC₅₀ ekstrak metanol 52,490 ± 3,715 ppm, petroleum eter 67,420 ± 6,988 ppm, dan acarbose 17,026 ± 6,027 ppm. Uji ANOVA menunjukkan hasil yang berbeda signifikan dari ketika kelompok sampel sebesar 0,000 (p < 0,05). Terdapat perbedaan bermakna antara kelompok acarbose dengan ekstrak metanol (p = 0,001), acarbose dengan ekstrak petroleum eter (p = 0,000), serta antara ekstrak metanol dengan ekstrak petroleum eter (p = 0,047). Kesimpulan Ekstrak metanol bunga kecombrang memiliki kandungan fitokimia lebih beragam dan aktivitas inhibisi alfa-glukosidase lebih baik dibandingkan petroleum eter. Jenis pelarut yang dipakai dalam proses ekstraksi berdampak nyata dalam kemampuan penghambatan enzim alfa-glukosidase.
Kata Kunci: Diabetes melitus tipe 2, fitokimia, kecombrang, alfa-glukosidase, acarbose


Introduction Type 2 diabetes mellitus is a metabolic disease with high prevalence and mortality. Alpha-glucosidase enzyme inhibitors such as acarbose are effective in reducing blood glucose levels but often cause gastrointestinal side effects. This condition encourages the development of alternative herbal therapies. Etlingera elatior (torch ginger) is known to contain phytochemical compounds such as flavonoids, saponins, and triterpenoids with antihyperglycemic potential. However, studies comparing the effectiveness of methanol (polar) and petroleum ether (nonpolar) extracts on alpha-glucosidase inhibition have not yet been conducted. Method This in vitro study was conducted at the Chemistry Laboratory, Faculty of Medicine, Universitas Indonesia (January–July 2025). Torch ginger flower sample from the cultivation area of the Gunung Gede area were extracted by maceration using methanol and petroleum ether. Phytochemical screening identified secondary metabolites, while enzyme inhibition activity was tested using the pNPG substrate and measured at 410 nm with an ELISA microplate spectrophotometer. Acarbose served as a positive control. Data were analyzed for inhibition percentage, IC₅₀ values, and ANOVA significance. Results Methanol extract contained saponins, flavonoids, and triterpenoids, whereas petroleum ether extract contained triterpenoids only. The IC₅₀ values were 52.490 ± 3.715 ppm (methanol), 67.420 ± 6.988 ppm (petroleum ether), and 17.026 ± 6.027 ppm (acarbose). ANOVA revealed significant differences among groups (p < 0.05). Conclusion Methanol extract exhibited more diverse phytochemical contents and stronger alphaglucosidase inhibition than petroleum ether extract. The extraction solvent significantly influences enzyme inhibitory activity.
Keywords: Type 2 diabetes mellitus, phytochemical, Etlingera elatior, alpha-glucosidase, acarbose.