Artepillin C

Propolis is a natural product from honeybee hives traditionally utilized in complementary medicine for the treatment of skin wounds and ulcers. Although the efficacy in skin wound healing has been documented, the specific mechanisms underlying its therapeutic effects remain unclear.

This study aimed to elucidate the mechanisms by which propolis facilitates wound healing and improves ulcer treatment. Specifically, we investigated the impact of Brazilian green propolis and its primary bioactive compound, artepillin C (ARC), on cell behavior and collagen metabolism in human dermal fibroblasts.

In vitro culture models were used to evaluate the effects of propolis and ARC on fibroblast proliferation, migration, differentiation into myofibroblasts, collagen fibril formation, and collagen gel contraction.

Treatment with propolis increased extracellular deposition of type I and V collagen while reducing extracellular type III collagen, without affecting collagen mRNA expressions or Smad2 activation, a critical transcription factor known to regulate collagen synthesis. Additionally, propolis reduced the levels of matrix metalloproteinase (MMP)-2 and MMP-9, enzymes for collagen degradation, and simultaneously elevated tissue inhibitor of metalloproteinase (TIMP)-2, which inhibits MMPs activity. Propolis treatment also restricted collagen gel contraction, fibroblast migration, and differentiation into myofibroblasts. Furthermore, propolis suppressed the activation of signaling pathways involving Akt, NF-κB, p38, and ERK, known regulators of collagen metabolism and apoptosis resistance. Some of these biological effects of propolis were replicated by ARC.

Our findings suggest that Brazilian green propolis and ARC facilitate wound healing and may enhance ulcer treatment by modulating collagen metabolism and regulating fibroblast behavior.

Glioblastoma, an aggressive brain cancer, has limited treatment options and poor prognosis. Taiwanese green propolis, known for its tumor-inhibitory properties, shows promise when combined with photodynamic therapy (PDT), a targeted, low-toxicity treatment. This study investigated a novel Taiwanese green propolis-based compound for inducing apoptosis in glioblastoma cells and its synergistic potential with daylight PDT.

Ethanol extracts of green propolis, wheatgrass, and mulberry leaves were combined and analyzed using High-Performance Liquid Chromatography (HPLC). Apoptosis induction in U87 glioblastoma cells was assessed via the MTT assay following treatment with the compound alone and in combination with daylight PDT at 570 nm.

We identified Artepillin C as the main active component in the compound by HPLC, which significantly induced apoptosis in glioblastoma cells. Combined with daylight PDT, it demonstrated enhanced efficacy, with cell viability reduced from 95.2% at 0.25 µL to 11.3% at 8 µL of the compound extract. The EC₅₀ decreased, indicating greater apoptotic activity compared to the extract alone.

This study provides the first in vitro evidence of synergistic anti-tumor effects of a Taiwanese green propolis-based compound daylight PDT (GPDT), highlighting a promising novel therapeutic approach that warrants further clinical investigation.