Phytochemical, antioxidant and antimicrobial properties of Litsea angulata extracts.

Background:Litsea angulata is a plant species belonging to Lauraceae family that is distributed throughout Indonesia, Malaysia, and New Guinea. The seeds have been traditionally used by local people in Kalimantan, Indonesia for the treatment of boils; however, there is no information about the potency of its branch, bark and leaves yet. This study aimed to determine the antioxidant, antimicrobial activity as well as the phytochemical constituent of Litsea angulata branch, bark, and leaves. Methods: Extraction was performed by successive maceration method using n-hexane, ethyl acetate, and ethanol solvent. Antioxidant activity was evaluated by DPPH radical scavenging assay. The antimicrobial activity using the 96 well-plate microdilution broth method against Staphylococcus aureus and Streptococcus mutans. Results: Based on the phytochemical analysis, it showed that extract of L. angulata contains alkaloids, flavonoids, tannins, terpenoids, and coumarin. The results showed that all extracts of plant samples displayed the ability to inhibit DPPH free radical formation and all tested microorganisms. Conclusions:L. angulata contains secondary metabolites such as alkaloids, flavonoids, tannins, terpenoids, carotenoids, and coumarin. The antioxidant activity on different plant extracts was a range as very strong to weak capacity. All extracts in this study could inhibit the growth of S. aureus and S. mutans.

Validation of Eupatorium triplinerve Vahl leaves, a skin care herb from East Kalimantan, using a melanin biosynthesis assay.

In searching for a new material made from natural resources that could be used as a whitening agent, we focused on the plants used for skin treatment by the native people of East Kalimantan. The methanol extract of the leaves of Eupatorium triplinerve Vahl showed antimelanogenesis activity in a melanin biosynthesis assay. By activity-guided fractionation, 7-methoxycoumarin (1) was isolated as an active compound. The IC50 of 1 on mushroom tyrosinase was 2360 µM (L-tyrosine was used as the substrate) and above 2840 µM (L-DOPA was used as the substrate), respectively. Regarding melanin formation inhibition in B16 melanoma cells, the IC50 of 1 was 1780 µM with 83% cell viability at IC50. Based on these results, we validated that the leaf extract is in line with the traditional use of the Dayak tribe in East Kalimantan.

Biological activity and phytochemical analysis of three Indonesian medicinal plants, Murraya koenigii, Syzygium polyanthum and Zingiber purpurea.

Extracts of Indonesian medicinal plants, Murraya koenigii, Syzygium polyanthum, and Zingiber purpurea were investigated for their biological activity. The presence of phytochemicals, cytotoxicity, and antimicrobial and antioxidant activities were investigated. Parts of M. koenigii, S. polyanthum, and Z. purpurea were extracted with ethanol. The extracts were evaluated for antimicrobial activity using the disc diffusion method, while antioxidant activity was determined with a 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. Cytotoxicity was investigated using the brine shrimp lethality test, and phytochemical screening was performed using a standard method. M. koenigii leaf extract exhibited the most activity in the test microorganism activity index (AI), 0.38-1.25, when compared with standard drugs. S. polyanthum ripened fruit displayed significant antioxidant activity (90%) in comparison to ascorbic acid (95%). Z. purpurea rhizome extract possessed the highest cytotoxic effect with a LC(50) of 52 µg/mL. Phytochemical analysis revealed that carbohydrate, tannin, alkaloid, steroid, triterpenoid, and flavonoid were present in the extracts of M. koenigii leaves and twigs, S. polyanthum leaves and ripened and unripe fruits, and Z. purpurea rhizome, while saponin was only present in the S. polyanthum ripened fruit extract. Our work revealed that the M. koenigii leaves, S. polyanthum ripened fruit, and Z. purpurea rhizome extracts have potential as sources of new antimicrobial, antioxidant, and cytotoxic compounds, respectively.

Antidermatophyte and antimelanogenesis compound from Eleutherine americana grown in Indonesia.

An active compound from the bulb of Eleutherine americana L. Merr. (Iridaceae) collected from East Kalimantan, Indonesia, was tested for its antidermatophyte and antimelanogenesis activity. Antifungal assay-directed fractionation of the n-hexane-soluble fraction of the methanolic extract of the bulb of E. americana led to the isolation of 1 as an active compound. The compound was identified as the naphthoquinone eleutherin by EI-MS and (1)H-, (13)C-, and two-dimensional NMR analyses. Antidermatophyte assay of 1 at concentrations of 10, 20, 40, 60, and 80 microg/disk and myconazole, a commercial antidermatophyte, at 10 microg/disk displayed 7, 8, 13, 16, 17, and 14 mm of inhibition zone against Trichophyton mentagrophytes, respectively. In a melanin formation inhibition assay, compound 1 displayed potent antimelanogenesis activity at 5 ppm with low toxicity compared with arbutin, a commercial skin-whitening agent. The results showed the high potential of 1, an active compound from E. americana, to be applied as an antidermatophyte and antimelanogenesis agent.