Cancer is a serious health burden on global societies. The discovery and development of new anti-cancer therapies remains a challenging objective. Although it has been shown that lichen secondary metabolites may be potent sources for new anti-cancer agents, the Indonesian- grown folious lichens, Physcia millegrana, Parmelia dilatata and Parmeila aurulenta, have not yet been explored. In this study exhaustive preparative high-performance liquid chromatography was employed to isolate the lichen constituents with spectroscopic and spectrometric protocols identifying nine depsides 9–17, including the new methyl 4-formyl-2,3-dihydroxy-6-methylbenzoate 13. The cytotoxicity of the depsides towards cancer cells was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results indicated lowest toxicity of the depsides towards human A549 lung cancer cells. Importantly, the di-depsides (11, 12 and 17) showed greatest toxicity, indicating that these structures are biologically more active than the mono-depsides against the HepG2 liver cancer, A549 lung cancer and HL-60 leukemia cell lines.

The tropical islands of Indonesia house the second largest biodiversity in the world. For generations, indigenous communities have relied on medicinal plants to treat various ailments, including diabetes. However, no comprehensive systematic review has been conducted to consolidate research progress in this area. This review aims to investigate and summarize the current research landscape on antidiabetic medicinal plants in Indonesia. Data collection, collation and analysis were performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Relevant publications on the antidiabetic evaluation of Indonesian medicinal plants were retrieved from leading scientific databases, including Scifinder® and Garuda , yielding a total of 108 eligible articles. Several notable compound screening studies identified bioactive phytochemicals with significant antidiabetic potential, such as quinine as a SIRT1 activator, prunetin as an aldose reductase inhibitor, gallic acid as a pancreatic α-amylase (PPA) inhibitor, oleanolic acid as a PTP1B inhibitor, and 3,4,5-tri- O -caffeoylquinic acid methyl ester as an α-glucosidase inhibitor. Additionally, clinical investigations and community-based trials reported significant blood glucose-lowering effects from botanical extracts including Piper crocatum , Moringa oleifera , and Curcuma xanthorrhiza in diabetic patients. Recognizing the therapeutic potential of indigenous botanicals, the Indonesian government has intensified its support for the development of scientifically standardized herbal medicines aimed at diabetes treatment, positioning them as part of the country’s integrated healthcare system. Graphical abstract