ABSTRAKPenelitian ini bertujuan mengetahui efektivitas ekstrak daun jamblang (Syzygium cumini) sebagai antidiabetik pada gambaran mikroskopis pankreas tikus putih (Rattus norvegicus) yang diinduksi streptozotosin. Induksi diabetes dilakukan dengan pemberian steptozotosin 40 mg/kg bb. Sebanyak 15 ekor tikus putih jantan diadaptasi selama 7 hari, kemudian dibagi kedalam 5 kelompok dan 3 ulangan. Kelompok kontrol negatif (KN) hanya diberikan akuades, kelompok kontrol positif (KP) diberikan streptozotosin dan akuades, dan kelompok perlakuan diberikan ektrak daun jamblang dosis 100 mg/kg bb (K1), 150 mg/kg bb (K2) dan 200 mg/kg bb (K3). Pemberian ektrak daun jamblang diberikan secara oral selama 14 hari. Gambaran histologi jaringan pankreas dilakukan dengan menggunakan metode pewarnaan hemotoksilin dan eosin. Data hasil penelitian dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa pemberian ektrak daun jamblang dengan dosis 100 mg/kg bb, 150 mg/kg bb, dan 200 mg/kg bb berpengaruh terhadap perbaikan jaringan pulau Langerhans pankreas dengan bertambahnya jumlah sel β pankreas, ruang intersel semakin berkurang, sel-sel β tersebar ke seluruh pulau Langerhans, dan ukuran pulau Langerhans lebih besar. Dosis 200 mg/kg bb ekstrak daun jamblang menunjukkan perbaikan histopatologi pankreas yang lebih baik.Kata kunci : Jamblang, streptozotosin, diabetes, pankreas ABSTRACTThis study aimed to determine the effectiveness of jamblang (Syzygium cumini) leaf extract as an antidiabetic on histopathological lesion of rat (Rattus norvegicus) pancreas induced by streptozotocin. Diabetic induction was performed by giving steptozotosin 40 mg/kg BW. 15 male rats were adapted for 7 days, divided into 5 groups and 3 replications. Negative control group (NC) was given only aquadest, positive control group (PC) was given streptozotocin and aquadest, and the treatment groups was given jamblang leaf extract dose of 100 mg/kg BW (K1), 150 mg/kg BW (K2) and 200 mg/kg BW (K3). Jamblang leaf extract were given by oral for 14 days. The histological of pancreatic tissue were performed using the Hematoxylin-Eosin staining. Data of research result was analyzed descriptively. The results showed that the extract of jamblang leaves with dose of 100 mg/kg BW, 150 mg/kg BW, and 200 mg/kg BW have an effect on the improvement islet of Langerhans pancreas proven by the increasing number of pancreatic β cells, decreasing of intercellular space, β cells were spread throughout islet of Langerhans, increasing the size islet of Langerhans. Doses of 200 mg/kg BW of jamblang leaf extract showed better improvement in histopathological pancreatic.