Microscopic Characters, Phytochemical Screening Focus on Alkaloid and Total Phenolic Content of Uncaria gambir Roxb. and Uncaria sclerophylla Roxb. Leaves

Objective: Uncaria gambir Roxb. and Uncaria sclerophylla Roxb. are medicinal plants widely grown in Indonesia. Genus Uncaria is well known for catechin content that has potent antioxidant activity. Uncaria also was reported containing alkaloid that has antihypertensive action. This study aims to provide microscopic characters and phytochemical profiles associated with the phenolic and alkaloid compounds contained in these two species of Uncaria. Methods: Microscopic characteristics were performed on fresh leaf samples using a microscope. Presence of alkaloids from ethanol and chloroform extract of U. gambir and U. sclerophylla leaf were performed using Dragendorff reagents. Thin Layer Chromatography profile was developed in the mobile phase that consisted of acetone: chloroform (8:2). Total Phenolic Content was determined according to the Folin-Ciocalteu method using microplate reader spectroscopically at λ = 765 nm. Results: Microscopy of U. gambir leaf revealed the presence of vascular bundle fragment, oil fragments, parenchyma cells, midrib transverse-section and lower epidermis with paracytic stomata. Whereas in U. sclerophylla can be observed midrib transverse-section and lower epidermis unicellular with trichomes. Both U. gambir and U. sclerophylla positively contain alkaloids. Chloroform extract showed the presence of alkaloids while ethanolic extracts showed negative results. The TLC profile shows the presence of catechin compound in the ethanolic extract, whereas in the chloroform extract does not show the presence of catechin. The total phenolic content of U. gambir and U. sclerophylla leaf ethanolic extract and chloroform extract was 7.309; 5.734 and 0.437; 0.161 mg of gallic acid equivalents each gram sample, respectively. Conclusion: Microscopic characteristics, TLC and phytochemicals obtained can be used for the authentication of Uncaria gambir Roxb. and Uncaria sclerophylla Roxb leaf.