Uncover Itchy Leaves Ethnomedicine Usage: A Preliminary Study on Characterization and Bioactivity of Laportea Spp

Abstract

Background: Laportea decumana (Roxb.) Wedd. and Laportea stimulans (L.f.) Miq. (Urticaceae) or itchy leaves are endogenous plants from The Maluku Islands, Indonesia, which are used topically as analgesics by local people. Objective: As part of a preliminary investigation on the itchy leaves, this study was conducted to provide information on their macroscopic and microscopic characteristics, phytochemical profiles, and bioactivities according to the ethnomedicinal usages. Materials and Methods: The macroscopic examination was carried out on fresh leaves. The microscopic examination was carried out on leaf powder under a light microscope. The phytochemical analyses using TLC were conducted on those crude extracts and fractions. The bioactivity assays were conducted in vitro as Cox-2 inhibitory and DPPH radical scavenging activities. Results: reveal similar characteristics in the macroscopic and microscopic properties of both Laportea spp. leaves. Calcium oxalate crystals were observed in L. decumana but not found in L. stimulans. Both species have stomata with anisocytic type. More trichomes are found in the leaves of L. decumana, yet smaller and easily detachable. TLC analyses exhibited slightly different profiles. The crude extracts and fractions at 10 μg/ml showed similar inhibitory percentages on Cox-2. The DPPH scavenging activities of the crude extracts and fractions of L. decumana showed active moderate activity with an IC50 value < 250 μg/ml, while those of L. stimulans showed moderate to weak potency with an IC50 value < 500 μg/ml. Conclusion: Further exploration on Laportea spp. pharmacological activity is recommended to provide stronger evidence for its ethnomedicinal usage. Key words: Laportea decumana (Roxb.) Wedd, Laportea stimulans (L.f.) Gaud, Itchy leaves, Characterization, Phytochemical profiles, Cox-2 inhibitor, DPPH radical scavenging activity.