Background: New findings on the potential of wild mangoes from the island of Sumatra as a source of antioxidant helps their conservation effort as it introduces their useful compounds to the public. This study aims to analyze the antioxidant profile and quantification of gallic acid and quercetin content from leaves and bark of Sumatran wild mangoes. Exploration and analysis of phytochemical constituents from 11 Sumatran wild mangoes was performed. Methods: Antioxidant activity of wild mangoes was analysed with 1,1- diphenyl-2-picryl hydroxyl (DPPH), and determination of quercetin and gallic acid content was performed by high performance liquid chromatography (HPLC) method. Total flavonoid and phenolic analysis was also performed. Curve fitting analysis used a linear regression approach. Results: The highest level of antioxidant activity, phenolic compound and flavonoid compound was found in the leaves and bark of Mangifera sp1. (MBS), the bark of M. foetida 3 (var. batu) and leaves of M. torquenda, and the bark and leaves of M. sumatrana, respectively. The content of gallic acid in leaves ranged from 5.23-35.48 mg/g dry weight. Quercetin content of wild mangoes leaves ranged from 0.76 to 1.16 mg/g dry weight with the lowest value in M. foetida 2 (var. manis) and the highest in M. laurina. Conclusion: The results obtained are expected to be useful in supporting the development of drugs that have antidegenerative effects.

Background: Lithocarpus bancanus or commonly called as mempening in Talang Mamak Tribe, Indonesia is a plant that is used as a traditional medicine. Objective: This study aim to evaluated antioxidant and antidiabetic activities of L. bancanus leaves extract. Material and Methods: The methanol extract was obtained by maceration of the leaves. The n-hexane, dichloromethane and ethyl acetate fractions were prepared by successive partition process of the methanol extract. Antioxidant activities were evaluated by various antioxidant assays, including DPPH (1,1-diphenyl-2-picrylhydrazyl), FRAP (ferric reducing antioxidant power), CUPRAC (cupric reducing antioxidant capacity), and ABTS (2,2'-azonobis 3-ethylbenzothiazoline-6-sulfonic acid) method. Total phenolics were estimated based on the Folin-Ciocalteu method, while, aluminum chloride methods were employed to estimate total flavonoids. Antidiabetic activies was determined by inhibiting the activity of α-glucosidase method. Results: antioxidant activity assay against DPPH radical as well as the total phenolic and flavonoid content of L. bancanus leaves showed that the methanol extract possessed IC 50 value of 39.469 ± 0.273 μg/mL with total phenol and flavonoid were 11.426 ± 0.432 mg GAE/g dry weight sample and 15.423 ± 0.213 mg QE/g respectively. The FRAP, CUPRAC and ABTS values of methanol extract were 3494.302 ±0.456 , 26665.501 ± 5.940 and 2857.977 ± 0.715 μM TE/g dry weight sample respectively. Antidiabetic activity of methanol extract with IC 50 value of 30.565 ± 0.331 µg/mL. Conclusion: It could be concluded that leaves of L. bancanus have antioxidant and antidiabetic properties.

Background: The roots of tunjuk langit (Helminthostacshys zeylanica) have been used traditionally in some villages in Indonesia, particularly in Riau Province. Objective: In this study we reported two flavonoids and their antidiabetic activity. Material and methods: Isolation of the metabolites was based on polarity fractionation method. Purification processes were conducted by vacuum liquid chromatography (VLC). Chemical structures were elucidated based on spectroscopy characteristics, including FTIR and 1D/2D NMR. Results: The isolated compounds were identified as ugonin J and K. The antidiabetic activity was measured by α-glucosidase inhibitor assay. The antidiabetic activity of ugonin J was found at IC 50 273,13±0,402 ppm and Ugonin K was found at IC 50 138,21±0,263 ppm (moderately active). Conclusion: Therefore this plant can be used traditionally as antidiabetic medicine.

Stenochlaena palustris (Burm.f.) Bedd. (Blechnaceae) or Kelakai is a traditional medicinal plant found in the Indonesian islands of Borneo and Sumatra. It has been used to treat wound healing, infection, and diabetes. This study looked into the free radical scavenging activity, antiplasmodial activity, toxicity, and antibacterial activity against pathogenic bacteria. The species’ aerial part was extracted with methanol, followed by a liquid-liquid extraction against (n-hexane, dichloromethane, and ethyl acetate). The extracts’ free radical scavenging activities were determined using DPPH and NO radicals. The antiplasmodial and toxicity assays were conducted using two Plasmodium falciparum strains (3D7 and W2) and the brine shrimp lethality test. In addition, antibacterial activity was determined using the well diffusion method. The results revealed that ethyl acetate depicted potential activities toward the assay. The ethyl acetate showed potential free radical scavenging activities with an IC50 value of 51.63 ± 0.46 μg/mL (DPPH) and 60.03 ± 0.65 μg/mL (NO). The antiplasmodial activities showed that the ethyl acetate had potential activities among the extracts with an IC50 value of 11.06 ± 0.45 μg/mL. However, all the extracts demonstrated nontoxic toward Artemia salina with LC50 > 1000 μg/mL. Furthermore, the ethyl acetate demonstrated intermediate susceptibility against B. cereus ATCC 10876, V. parahaemolyticus ATCC 17802, L. monocytogenes ATCC 7644, and S. Typhimurium ATCC 14028 at a concentration of 500 μg/disc. According to these findings, the ethyl acetate extract of S. palustris (Burm.f.) Bedd is a promising source of natural antioxidants and antiplasmodial agents.

Background: New findings on the potential of wild mangoes from the island of Sumatra as a source of antioxidant helps their conservation effort as it introduces their useful compounds to the public. This study aims to analyze the antioxidant profile and quantification of gallic acid and quercetin content from leaves and bark of Sumatran wild mangoes. Exploration and analysis of phytochemical constituents from 11 Sumatran wild mangoes was performed. Methods: Antioxidant activity of wild mangoes was analysed with 1,1- diphenyl-2-picryl hydroxyl (DPPH), and determination of quercetin and gallic acid content was performed by high performance liquid chromatography (HPLC) method. Total flavonoid and phenolic analysis was also performed. Curve fitting analysis used a linear regression approach. Results: The highest level of antioxidant activity, phenolic compound and flavonoid compound was found in the leaves and bark of Mangifera sp1. (MBS), the bark of M. foetida3 (var. batu) and leaves of M. torquenda, and the bark and leaves of M. sumatrana, respectively. The content of gallic acid in leaves ranged from 5.2270-35.4763 mg/g dry weight. Quercetin content of wild mangoes leaves ranged from 0.76 to 1.47 mg/g dry weight with the lowest value in M. foetida2 (var. manis) and the highest in M. laurina. Conclusion: The results obtained are expected to be useful in supporting the development of antidegenerative drugs from natural ingredients that have potential as immunomodulatory agents.