The potency of selected ethnomedicinal plants from East Kalimantan, Indonesia as antidiabetic agents and free-radical scavengers

RICO RAMADHAN (Department of Chemistry, Faculty of Science and Technology, Universitas Airlangga. Jl. Mulyorejo, Surabaya 60115, East Java, Indonesia)
PREECHA PHUWAPRAISIRISAN (Center of Excellent in Natural Products, Department of Chemistry, Faculty of Sciences, Chulalongkorn University. 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand)
RUDIANTO AMIRTA (Laboratory of Forest Products Chemistry and Renewable Energy, Faculty of Forestry, Universitas Mulawarman. Jl. Penajam, Gunung Kelua, Samarinda 75123, East Kalimantan, Indonesia)
MUHAMMAD FADIL BAGAS DARMAWAN (Department of Chemistry, Faculty of Science and Technology, Universitas Airlangga. Jl. Mulyorejo, Surabaya 60115, East Java, Indonesia)
KAUTSAR UL-HAQ (Department of Chemistry, Faculty of Science and Technology, Universitas Airlangga. Jl. Mulyorejo, Surabaya 60115, East Java, Indonesia)
IRAWAN WIJAYA KUSUMA (Laboratory of Forest Products Chemistry and Renewable Energy, Faculty of Forestry, Universitas Mulawarman. Jl. Penajam, Gunung Kelua, Samarinda 75123, East Kalimantan, Indonesia)
HERY SUWITO (Division of Exploration and Synthesis of Bioactive Compounds, University CoE-Research Center for Bio-Molecule Engineering, Universitas Airlangga. Jl. Mulyorejo, Surabaya 60115, East Java, Indonesia)
NURLITA ABDULGANI (Department of Biology, Faculty of Sciences and Data Analytics, Institut Teknologi Sepuluh November. Jl. Raya ITS, Keputih, Sukolilo, Surabaya 60117, East Java, Indonesia)
AHMAD MUKHDLOR (Department of Forest Products Technology, Faculty of Forestry, Universitas Gadjah Mada. Jl. Agro, Bulaksumur, Sleman 55281, Yogyakarta, Indonesia)
SAPARWADI SAPARWADI (Yayasan Biosfer Manusia (BIOMA). Jl. A. Wahab Syahranie, Sempaja, Samarinda 75119, East Kalimantan, Indonesia)

Biodiversitas Journal of Biological Diversity
Vol. 23 No. 4 (2022)

Abstract. Ramadhan R, Phuwapraisirisan P, Amirta R, Darmawan MFB, Ul-Haq K, Kusuma IW, Suwito H, Abdulgani N, Mukhdlor A, Saparwadi. 2022. The potency of selected ethnomedicinal plants from East Kalimantan, Indonesia as antidiabetic agents and free-radical scavengers. Biodiversitas 23: 2225-2231. Ten ethnomedicinal plant extracts from East Kalimantan flora, traditionally used to treat blood sugar levels and other diabetes-related diseases, were examined in vitro for their antidiabetic and free radical scavenging activities by inhibiting rat alpha-glucosidase and several free radicals such as DPPH, ABTS, and Nitric oxide respectively. Out of the ten plant species investigated for their antidiabetic activity against maltase and sucrase rat alpha-glucosidase, three exhibited the strongest ?-glucosidaseinhibitory activity with maltose as a substrate, namely extracts of Garcinia nervosa, Syzygium caudatilimbum, and Shorea balangeran with IC50 values of 0.046; 0.037; 0.045 mg/mL. Meanwhile, quercetin as a positive control appeared to have a comparable IC50value. Furthermore, among the ten extracts, Syzygium caudatilimbum, Shorea balangeran, and Ixora javanica showed good inhibition against sucrase rat alpha-glucosidase. Moreover, the antioxidant test showed that the ten methanol extracts of plants from East Kalimantan have an antioxidant activity indicated by IC50values. The present study confirms that the ethnopharmacological use of selected plants from East Kalimantan might have potential as an antidiabetic and natural antioxidant.