Hepatocellular carcinoma (HCC) is the third most common cancer in terms of mortality and the sixth in incidence worldwide. Treatment varies by tumor stage, but low survival rates are common across all stages. Due to these poor outcomes, there is a critical need for new treatment options and lead compounds, prompting an active search. Geopropolis has been identified as a source of bioactive compounds with various pharmacological activities, including anticancer effects against different types of cancer. Since stingless bees may be selective for native botanical species, the geopropolis they produce can have an unusual chemical profile. In this study, we report the antioxidant properties and anticancer potential of geopropolis extracts produced by Melipona bicolor, M. marginata, and M. mondury using 2D- and 3D- cell culture models. The chemical profile of these samples using UPLC-QTOF HRMS/MS indicated ferreirin and dihydrokaempferide as the main flavonoids, along with cupressic acid and 15-acetoxyisocupressic acid as the most abundant diterpenoids. Interestingly, artepillin C, a main component of green propolis, was also detected. The geopropolis extracts showed good cell viability inhibition and selectivity indices in comparison to cisplatin used as an HCC treatment option. The antioxidant capacity of the geopropolis extracts was high and correlated with the cytotoxic effect against the HCC cells. Investigations into the mechanisms show the ability of the extracts to induce apoptosis and suppress the clonogenic potential of these cell lines. We also observed an inhibition of spheroid formation, viability, and morphology alterations. This is the first time the effects of geopropolis are described in a panel of HCC cell lines.

Leishmania amazonensis, a cause of cutaneous leishmaniasis in Brazil, is a neglected disease with toxic and inconsistently effective treatments. The parasite’s survival depends on managing oxidative stress, making redox-regulating enzymes potential therapeutic targets. Geopropolis, a resinous product from native stingless bees, shows promising antiparasitic effects. This study aims to evaluate the anti-L. amazonensis activity of geopropolis produced by Melipona bicolor, M. marginara, M. mondury, and M. quadrifasciata (two samples), targeting enzymes responsible for the parasite’s redox balance. Ethanol extracts of geopropolis produced by each bee (BCRL, MRGT, MNDY, MNDA(1), and MNDA(2), respectively) were analyzed for total phenolics and flavonoids. Promastigotes and axenic amastigotes were treated with various extract concentrations, and parasite viability was assessed using the resazurin reduction method. Cytotoxicity was tested on peritoneal macrophages, RAW 264.7, VERO cell lines (MTT assay), and erythrocytes (hemolysis assay). Additionally, mitochondrial dehydrogenase activity, reactive oxygen species (ROS) production, the inhibition of recombinant arginase, and autophagic activity were also evaluated in treated parasites. MRGT showed the highest levels of phenolics (762 mg GAE/g) and flavonoids (345 mg QE/g). MDRY was more effective against promastigote and axenic amastigote forms (IC₅₀ = 168 and 19.7 µg/mL, respectively). MRGT showed lower cytotoxicity against RAW 264.7 and VERO (CC₅₀ = 654 µg/mL and 981 µg/mL, respectively). Erythrocytes exhibited reduced sensitivity to MNDA(2) (HC₅₀ = 710 µg/mL). The activity of dehydrogenases and LiARG was reduced by treating the parasites with the extracts following the induction of ROS and autophagic activity. These results highlight geopropolis extracts as a source of substances with anti-L. amazonensis activity capable of inducing oxidative stress on the parasite.