Anti-Inflammatory Concentrate Enriched with Substituted Oligofucans Derived from Brown Seaweed Turbinaria conoides (J. Agardh) Kützing and Its Safety Assessment on Wistar Rats

ABSTRACT

Aqueous extract of the seaweed Turbinaria conoides was purified to obtain an oligofucan-enriched seaweed concentrate (OESC). Oligofucans isolated were characterized as two types with (→1)-fucose-(2,3-diSO₃⁻)-(1→4)-fucose-(2-SO₃⁻)-(1→3)-fucose-(2,3-diSO₃⁻)-(1→4)-fucose-(2-SO₃⁻, 3-OAc)-(4→) and (→1)-fucose-(3-SO₃⁻)-(1→4)-fucose-(2-SO₃⁻)-(1→4)-fucose-(3-SO₃⁻)-(1→4)-fucose-(2-SO₃⁻)-(4→) motifs. A 90-day accelerated shelf-life study (50°C) showed that OESC maintained its antioxidant properties (free radical scavenging, reducing, lipid peroxidation inhibition, and chelating activities) even after 30 days. In vitro COX-2 and 5-LOX inhibitory properties of OESC (67.2 and 95.2%, respectively) showed no significant variation even at the 30th day. OESC significantly mitigated the carrageenan-induced inflammation in rats at 0–2 h (59.7–70.3% inhibition), which were greater compared to the synthetic NSAID aspirin. The safety of OESC has been assessed by acute (14 days) and subchronic (90 days) oral toxicity studies, which showed no toxicity-related significant changes in renal or hepatic function, hematological indices, and serum biochemical parameters in the OESC-treated Wistar rats. No histopathological alterations were observed in the vital organs of rats treated with OESC. LD₅₀ and sub-chronic no-observed-adverse-effect level (NOAEL) for this concentrate were found to be > 5,000 and 2,000 mg/kg BW, respectively. Hence, oligofucan-enriched seaweed concentrate is safe to consume without any adverse effects in the body.

KEYWORDS:

• Seaweed
• anti-inflammatory
• oligofucans
• acute toxicity
• subchronic toxicity
• hematology

Acknowledgments

The authors are thankful to the Indian Council of Agricultural Research (ICAR), New Delhi for providing the necessary facilities to carry out the work. The authors thank the Director of the Central Marine Fisheries Research Institute for his guidance and support. The authors extend thanks to the Head of Marine Biotechnology Division of the Central Marine Fisheries Research Institute for facilitating the research activity. The authors would also like to acknowledge Dr. Ramadasan Kuttan, Research Director at Amala Cancer Research Centre in Kerala for help.

Funding

This work is supported by funding under the Department of Science and Technology of the Ministry of Science and Technology (Grant Number SR/S1/OC-96/2012) in New Delhi, India.

Additional information

Funding

This work is supported by funding under the Department of Science and Technology of the Ministry of Science and Technology (Grant Number SR/S1/OC-96/2012) in New Delhi, India.