EFEK HIPOTENSIF FRAKSI KLOROFORMIK EKSTRAK ETANOLIK DAUN PEGAGAN (Centella asiatica (L.) Urban) PADA TIKUS TERINDUKSI FENILEFRIN

HARWOKO, Prof. Dr. Suwijiyo Pramono, DEA., Apt.

2013 | Tesis | S2 Ilmu Farmasi

Sebesar 75,8% kasus hipertensi di Indonesia belum terdiagnosis dan belum terjangkau pelayanan kesehatan. Ramuan antihipertensi yang dikembangkan dari program saintifikasi jamu berisi daun pegagan (Centella asiatica (L.) Urban). Pegagan mengandung senyawa triterpenoid, flavonoid, fenolik, tanin, dan resin. Fraksi triterpenoid total pegagan dilaporkan dapat mengobati mikroangiopati hipertensi vena, sedangkan fraksi etil asetat daun pegagan berefek hipotensif pada kucing. Penelitian ini bertujuan untuk memisahkan fraksi triterpenoid ekstrak etanolik 70% daun pegagan dari fraksi flavonoid, menetapkan kadar asiatikosida, dan menguji efek hipotensif pada tikus terinduksi fenilefrin. Preparasi sampel dilakukan dengan maserasi daun pegagan dalam etanol 70%, kemudian difraksinasi dengan kloroform untuk mendapatkan fraksi kloroformik ekstrak etanolik daun pegagan (FKDP). Pemisahan senyawa triterpenoid dibuktikan secara kualitatif dengan KLT dan penetapan kadar asiatikosida dilakukan dengan KLT densitometri. Sebanyak 40 ekor tikus putih jantan galur Wistar dibagi menjadi 8 kelompok, yaitu kontrol normal (Na-CMC 0,5%), kontrol negatif (fenilefrin 0,9 mg/kgBB), dan kontrol positif (kaptopril 2,5 mg/kgBB), serta perlakuan FKDP dosis 5, 10, 15, 20 mg/kgBB, dan ekstrak daun pegagan dosis 400 mg/kgB. Parameter kardiovaskular yang diukur meliputi tekanan darah sistolik, diastolik, tekanan arteri rata-rata, dan denyut jantung, dengan metode tail-cuff secara non-invasif. Perbedaan respon antar kelompok diuji secara statistik dengan analisis varian satu jalan dan dilanjutkan uji LSD pada taraf kepercayaan 95%. Hasil penelitian menunjukkan bahwa fraksi triterpenoid ekstrak etanolik 70% daun pegagan dapat dipisahkan dari fraksi flavonoid dengan cara fraksinasi menggunakan kloroform. Kadar asiatikosida dalam FKDP sebesar 0,402 ± 0,02%. FKDP dapat berefek hipotensif pada tikus terinduksi fenilefrin dengan persentase daya antihipertensi terbesar, yaitu 134% pada dosis 20 mg/kgBB. Nilai ED50 sebagai parameter potensi FKDP pada tekanan darah sistolik, diastolik, dan tekanan arteri rata-rata tikus berturut-turut sebesar 7,79; 10,11; dan 8,63 mg/kgBB.

The hypertension cases in Indonesia that had not been diagnosed and reached yet by health care system were 75.8%. Antihypertensive herbs in scientification of “jamu” contains Centella asiatica (L.) Urban. The leaf contains several compounds such as triterpenoids, flavonoids, phenolics, tannins, and resins. Reportedly, the total triterpenic fraction of C. asiatica can treat venous hypertensive microangiopathy, while ethyl acetate fraction of C. asiatica leaf has hypotensive effect in cats. This study aims to separate triterpenoid fraction of C. asiatica leaf from flavonoid fraction, to analyze asiaticoside contents, and to examine the hypotensive effect on phenylephrine-induced hypertensive rats. Ethanolic extract of C. asiatica leaf (EECA) was fractionated by chloroform to separate between triterpenoid fraction in the chloroformic fraction of C. asiatica leaf (CFCA) and flavonoid fraction in the chloroform insoluble fraction. Asiaticoside contents were then determined by TLC densitometry. As many as 40 male Wistar rats were grouped into 8 treatment groups: normal control (CMC-Na 0.5%), negative control (phenylephrine 0.9 mg/kg), positive control (captopril 2.5 mg/kg), CFCA doses of 5, 10, 15, 20 mg/kg, and EECA 400 mg/kg. Cardiovascular parameters such as systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate were measured by non-invasive tail-cuff method. The respon differences between groups were tested with one way ANOVA then followed by LSD at 95% level of confidence. The result showed that triterpenoid fraction of EECA could be separated from flavonoid fraction by fractionation with chloroform. The TLC-densitometric data showed that asiaticoside contents of CFCA were 0.402 ± 0.02%. The CFCA showed hypotensive effect on phenylephrine-induced hypertensive rats. The highest hypotensive effect was 134% at dose 20 mg/kg. The ED50 values, a parameter of drug potency, of these effects on SBP, DBP and MAP were 7.79, 10.11, and 8.63 mg/kg, respectively.

Kata Kunci : Centella asiatica (L.) Urban, triterpenoid, asiatikosida, antihipertensi