In a recent study published in Scientific Reports, researchers investigated the wound healing and photoprotective properties of Acanthus ebracteatus extracts.
Study: Wound healing and photoprotection properties of Acanthus ebracteatus Vahl. extracts standardized in verbascoside. Image Credit: MODMOD/Shutterstock.com
Background
Sea holly, or Acanthus species, is a prominent herb in traditional Thai medicine due to its ability to treat diseases and heal wounds. It is used in Asian recipes to improve the life quality of cancer patients and cure skin conditions such as wound healing.
The plant is grown commercially and sold in traditional Thai stores due to its anti-inflammatory properties. The white flower cultivar, A. ebracteatus, is more often used than the purple variety, A. illicifolius.
Despite its commercial production and availability, scientific data supporting its dermatological applications is scarce.
About the study
In the present study, researchers explored Acanthus ebracteatus extracts as wound-healing agents.
The team standardized the extracts of A. ebracteatus, a medicinal herb, to their verbascoside content. They cleaned and air-dried the leaves to prepare a powder and macerated them in 95% ethanol (EtOH) for one hour, three hours, and 24 hours.
Subsequently, they concentrated the extracts to dryness, yielding AE1, AE3, and AE24 extracts. They determined the photoactive constituent, verbascoside, using ultra-performance liquid chromatography (UPLC) and calculated the extractive yield for each extraction, repeated multiple times.
The team assessed wound healing using plant extracts and their verbascoside active component, using scratch assays and fibroblasts.
All extracts stimulated fibroblast migration, with the non-cytotoxic concentration of A. ebracteatus plant extracts standardized in verbascoside showing cellular viability exceeding 80%. Cell morphology was visually identical to that of controls, indicating their effectiveness in wound healing.
The team investigated the effects of verbascoside and the extracts against matrix metalloproteinase-9 (MMP-9) in human dermal fibroblast (HDF) and keratinocyte (HaCaT) cocultures.
They assessed the safety of A. ebracteatus extracts in both cells separately and evaluated dose-dependent effects in the cocultures.
The researchers examined the cytotoxicity of ultraviolet light A (UVA) and ultraviolet light B (UVB) exposures on cocultures, assessing their ability to protect cells against photodamage. The plant extracts were deemed safe, like the determined marker constituent, verbascoside.
They evaluated the biological activities of MMP-9 at safety concentrations, monitored MMP-9 levels, and evaluated its activity post-UV-induced expression.
Results
The extracts considerably increased wound healing compared to the control. Wound healing by the extracts improved dramatically as their verbascoside concentration increased. The plant extracts protected HaCaT cells and fibroblast cocultures from photodamage.
The extracts robustly inhibited cellular MMP-9 production after UV exposure, outperforming verbascoside at the same test dose.
The team found that the AE3 extract with the highest verbascoside level had the highest wound-healing impact across all periods (33% and 65% at 24 hours and 84 hours, respectively). Verbascoside dramatically enhanced wound closure as compared to the control.
Although verbascoside and the plant extracts were non-cytotoxic to cells, their efficacy was lower than that of the benchmark (FGF, 0.1 μg/mL) in healing wounds.
The wound-healing effect of AE3 is due to the synergy of verbascoside and other phenolic components, which promote cell migration. The extracts established cutaneous homeostasis and accelerated wound healing.
They were non-toxic to cells at concentrations ranging from 13 to 200 µg/mL. Verbascoside (150 µg per mL) was likewise non-cytotoxic.
The team found that all A. ebracteatus extracts, including verbascoside and dexamethasone, dramatically reduced cellular MMP-9 release in UV-exposed cells.
AE3 and AE24 similarly decreased MMP-9 activity, although they outperformed verbascoside. The extracts prevented ultraviolet light-induced cellular damage by suppressing MMP-9.
Additional phenolic components combined with verbascoside changed the cellular activity of the extracts.
This inhibitory impact would promote the healing of skin wounds while suppressing inflammation, which might delay wound healing by interfering with cellular multiplication and maturation. Treatment against MMP-9 may also help to reduce scar formation caused by elevated MMP-9 levels.
Conclusion
Overall, the study findings showed that A. ebracteatus extract shows promise for wound healing and photoprotection and contains a significant amount of verbascoside. Due to its chemical and biological properties, A. ebracteatus, which is high in verbascosides, may be used to generate revolutionary skincare products.
The herb boosted cell movement and MMP-9-targeted effects, making it appropriate for the healing of wounds in ecosystems with high cell migration efficiency and low scar formation.
The findings add to the scientific body of literature on the traditional applications of the plant and recommend more studies into its mode of action, cell migratory impact, and activities against MMP-9. Further research using human volunteers is required to explore the health benefits of A. ebracteatus.
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