Antioxidant and Anti-inflammatory Extracts From Sea Cucumbers and Tunicates Induce a Pro-osteogenic Effect in Zebrafish Larvae

Abstract

Bone metabolic disorders such as osteoporosis are characterized by the loss of mineral from the bone tissue leading to its structural weakening and increased susceptibility to fractures. A growing body of evidence suggests that inflammation and oxidative stress play an important role in the pathophysiological processes involved in the rise of these conditions. As the currently available therapeutic strategies are often characterized by toxic effects associated with their long-term use, natural antioxidants and anti-inflammatory compounds such as polyphenols promise to be a valuable alternative for the prevention and treatment of these disorders. In this scope, the marine environment is becoming an important source of bioactive compounds with potential pharmacological applications. Here, we explored the bioactive potential of three species of holothurians (Echinodermata) and four species of tunicates (Chordata) as sources of antioxidant and anti-inflammatory compounds with a particular focus on polyphenolic substances. Hydroethanolic and aqueous extracts were obtained from animals’ biomass and screened for their content of polyphenols and their antioxidant and anti-inflammatory properties. Hydroethanolic fractions of three species of tunicates displayed high polyphenolic content associated with strong antioxidant potential and anti-inflammatory activity. Extracts were thereafter tested for their capacity to promote bone formation and mineralization by applying an assay that uses the developing operculum of zebrafish (Danio rerio) to assess the osteogenic activity of compounds. The same three hydroethanolic fractions from tunicates were characterized by a strong in vivo osteogenic activity, which positively correlated with their anti-inflammatory potential as measured by COX-2 inhibition. This study highlights the therapeutic potential of polyphenol-rich hydroethanolic extracts obtained from three species of tunicates as a substrate for the development of novel drugs for the treatment of bone disorders correlated to oxidative stress and inflammatory processes.

Antioxidant Potential of Sea Cucumbers and Their Beneficial Effects on Human Health

“…Likewise, the ethyl acetate fraction of H. scabra extracts, rich in phenolic compounds, inhibited pro-inflammatory cytokine synthesis at both the transcriptional and translational levels, mainly inducible nitric oxide synthase (iNOS), nitric oxide (NO), interleukin-1β (IL-1β), prostaglandin E 2 (PGE 2 ), and tumor necrosis factor-α (TNF-α) [ 37 ]. Carletti et al [ 35 ] demonstrated that polyphenol-rich sea cucumber ( H. forskali , H. arguinensis , and H. mammata ) extracts, mainly hydroethanolic extracts, exhibited anti-inflammatory activity via COX-2 inhibition and osteogenic activity in a zebrafish ( Danio rerio ) model. However, phenolic-rich Holothuria atra extracts were used to determine the antioxidant efficacy against 7,12-dimethylbenz[a]anthracene (DMBA)-induced hepatorenal dysfunction [ 31 ].…”

Investigation of the effects of bovine collagen peptides and mixed berries on rheological properties and biological activity of egg white-based beverage via central composite design

“…The total antioxidant capacity was obtained by FRAP (Ferric Reducing Antioxidant Power) method described by Moure et al ( 63 ). The method reported by Carletti et al ( 64 ) was slightly modified for the measurement of FRAP of the egg white-based beverage samples.…”

Levels of contaminant metals in three species of holothurians from Portugal: Seasonal, sex and tissues variations

“…A total of 370 sea cucumber were used for toxic metal analyses, H. arguinensis (n = 123), H. forskali (n = 124) and H. mammata (n = 123). The phylogenetic identi cation was made in accordance to the methodology described by Carletti et al (2022). The animals were classi ed for each season and species, and after sorted by sex (male and female).…”