<![CDATA[ABSTRACT Worm infections caused by ascariasis remain a public health problem in Indonesia due to their high prevalence and their impact on nutritional status and growth. The use of synthetic anthelmintics as the primary treatment has limitations in the form of side effects and the potential for resistance, making natural alternatives necessary. Sappan wood (Caesalpinia sappan L.) is known to contain flavonoids, saponins and tannins that have potential as anthelmintics. This was an experimental study with six treatment groups: a negative control (distilled water), a positive control (0.25% pyrantel pamoate), and secang wood ethanol extracts at concentrations of 4%, 8%, 12%, and 15%. The study was conducted from October 2025 –May 2026 at the Parasitology Laboratory of the Department of Medical Laboratory Technology, Poltekkes Kemenkes Surabaya. The ethanol extract of secang wood was prepared at the Faculty of Veterinary Medicine, Airlangga University, whilst the Ascaris suum worms were obtained from the Surabaya Slaughterhouse. The results of the study showed that all concentrations of the ethanol extract of secang wood were capable of causing the death of all worms by the 10th hour. In the positive control, all worms died by the 2nd hour, whilst in the negative control, no worm mortality was observed. Based on the results of the study, it can be concluded that ethanol extract of secang wood exhibits anthelmintic activity against Ascaris suum at all test concentrations. The 12% concentration was the lowest effective concentration capable of causing the death of 50% of the worm population (LC50) with a time to 50% mortality (LT50) of 6 hours, although its efficacy was still lower than that of 0.25% pyrantel pamoate. ABSTRAK Infeksi kecacingan akibat askariasis masih menjadi masalah kesehatan di Indonesia karena prevalensinya tinggi serta berdampak pada status gizi dan pertumbuhan. Penggunaan antelmintik sintetik sebagai terapi utama memiliki keterbatasan berupa efek samping dan potensi resistensi sehingga diperlukan alternatif berbasis bahan alam. Kayu secang (Caesalpinia sappan L.) diketahui mengandung flavonoid, saponin, dan tanin yang berpotensi sebagai antelmintik. Metode penelitian ini adalah eksperimental dengan enam kelompok perlakuan, yaitu kontrol negatif (aquadest), kontrol positif (pirantel pamoat 0,25%), serta ekstrak etanol kayu secang konsentrasi 4%, 8%, 12%, dan 15% yang dilaksanakan pada Oktober 2025–Mei 2026 di Laboratorium Parasitologi Jurusan Teknologi Laboratorium Medis Poltekkes Kemenkes Surabaya. Ekstrak etanol kayu secang dibuat di Fakultas Kedokteran Hewan Universitas Airlangga, sedangkan cacing Ascaris suum diperoleh dari Rumah Pemotongan Hewan Surabaya. Hasil penelitian menunjukkan bahwa seluruh konsentrasi ekstrak etanol kayu secang mampu menyebabkan kematian seluruh cacing pada jam ke-10. Pada kontrol positif, seluruh cacing mati sejak jam ke-2, sedangkan pada kontrol negatif tidak ditemukan kematian cacing. Berdasarkan hasil penelitian dapat disimpulkan bahwa ekstrak etanol kayu secang memiliki aktivitas antelmintik terhadap Ascaris suum pada seluruh konsentrasi uji. Konsentrasi 12% merupakan konsentrasi efektif terendah yang mampu menyebabkan kematian 50% populasi cacing (LC50) dengan waktu kematian 50% populasi (LT50) selama 6 jam, meskipun efektivitasnya masih lebih rendah dibandingkan pirantel pamoat 0,25%.]]>
