The growing demand for natural and sustainable ingredients in dermatology and cosmetics has fueled the exploration of novel bio-resources. Nitric oxide (NO) plays a crucial role in skin health, participating in processes like dermal vasodilation, wound healing, immune response modulation, and protection against UV radiation damage. Conventional approaches increasingly focus on advanced materials that release NO in a controlled manner. However, the need for innovative and eco-conscious alternatives has led researchers to investigate cyanobacteria from unique environments such as the Cape Verde archipelago. Cyanobacteria are photosynthetic organisms known for producing diverse bioactive compounds with antioxidant and anti-inflammatory activities. This study explores the potential of aqueous extracts from Cape Verde cyanobacteria as effective NO donors, aiming to advance the development of innovative ingredients for the cosmetic and dermatological fields.
Methods
Aqueous extracts from ten non-toxic cyanobacteria strains isolated from the Cape Verde archipelago were prepared using sequential extraction. The extracts were then chemically profiled for phycobiliproteins, polysaccharides, phenols, and chlorophylls. In vitro cell assays were conducted using keratinocytes, fibroblasts, and endothelial cells to assess cytotoxicity. The extracts’ ability to act as NO donors was evaluated using the murine macrophage cell line RAW 264.7. Additionally, the environmental safety of the extracts was assessed using the zebrafish embryo acute toxicity test (zFET).
Results and Discussion
•Cytotoxicity:
◦Most of the aqueous extracts from the cyanobacteria strains did not show cytotoxicity in keratinocytes, fibroblasts, and endothelial cells.
◦Neolyngbya sp. LEGE 181188 exhibited cytotoxicity in mouse fibroblasts at a concentration of 25 g mL-1.
•Phytochemical Analysis:
◦The extracts were mainly composed of phycobiliproteins (PBPs) and polysaccharides, with lower amounts of phenols and chlorophylls.
◦Salileptolyngbya sp. LEGE 181184 had the highest total phenolic content (TPC).
◦Salileptolyngbya sp. LEGE 181150 and Salileptolyngbya sp. LEGE 181184 exhibited the highest values for phycocyanin (PC), while Nodosilineales LEGE 181157 and Leptothoe sp. LEGE 181156 showed a higher abundance of phycoerythrin (PE).
◦Neolyngbya sp. LEGE 181188, Baaleninema sp. LEGE 181148 and Salileptolyngbya sp. LEGE 181187 were the strains exhibiting the highest values for the total carbohydrates.
•Antioxidant Capacities:
◦Salileptolyngbya sp. LEGE 181184 was the most effective strain for superoxide anion radical scavenging.
◦Salileptolyngbya LEGE 181150 was the only strain capable of reaching IC50 for •NO elimination.
•Lipoxygenase (LOX) Inhibition:
◦Salileptolyngbya sp. LEGE 181150 presented the lowest IC50 for LOX inhibition, close to that of the positive control quercetin.
◦There was a negative correlation between phycocyanin (PC), allophycocyanin (APC), phycoerythrin (PE) and total chlorophylls and the calculated IC values, suggesting the contribution of these PBPs and Chlorophylls to LOX inhibition.
•Evaluation of NO Levels in RAW 264.7 Cells:
◦All extracts significantly increased NO production by macrophages, with some exceeding the levels produced by LPS-stimulated cells.
◦Salileptolyngbya sp. LEGE 181184, Baaleninema sp. LEGE 181148, Leptothoe sp. LEGE 181156 and Salileptolyngbya sp. LEGE 181158, showed the highest NO production.
◦The increased NO production was linked to iNOS overexpression.
◦Polymyxin B (PB) treatment significantly decreased NO production, indicating the involvement of lipopolysaccharides (LPS) in stimulating NO production.
•Screening of Toxins Production:
◦PCR and LC-MS analyses were negative for genes responsible for cyanotoxin production and the presence of toxins.
◦This suggests that the increased NO production observed was predominantly mediated by cyanobacteria LPS.
•Environmental Safety:
◦The 96h-LC50 determined through zFET was 0.1712 mg mL-1, suggesting that the extracts are environmentally safe.
This study highlights the potential of aqueous extracts from cyanobacteria strains, particularly Salileptolyngbya sp. LEGE 181184 and LEGE 181150, Leptothoe sp. LEGE 181156 and Nodosilineales LEGE 181157, as sources of antioxidant and anti-inflammatory compounds. The extracts can act as potential NO donors and effectively scavenge physiologic free radicals. Their ability to stimulate NO production, combined with their antioxidant properties, positions them as valuable candidates for developing innovative ingredients for dermatological and cosmeceutical applications. The discovery of environmentally safe, non-toxic cyanobacteria strains from Cape Verde that can act as NO donors is particularly novel. Future research should focus on exploring the stability of these extracts in topical release systems and further characterizing the bioactive compounds responsible for their observed effects. The exploration of cyanobacteria to act as natural antimicrobial ingredients against antibiotic-resistant strains is also an important avenue for future studies.
Link to the study: https://tinyurl.com/35mahbsf
