Influence of viscous Rhodella grisea (Rhodophyceae) proteoglycan on chemically induced cough reflex

Area of Science:

• Marine biotechnology
• Pharmacology
• Biochemistry

Background:

• Algal extracellular biopolymers are complex macromolecules with diverse biological activities.
• Rhodella grisea, a red alga, produces a mucilaginous substance with potential therapeutic applications.

Purpose of the Study:

• To isolate and characterize an algal extracellular biopolymer from Rhodella grisea.
• To evaluate the pharmacological effects of this biopolymer on cough and airway smooth muscle reactivity in vivo.

Main Methods:

• Isolation of the biopolymer via concentration, alcohol precipitation, dialysis, and freeze-drying.
• Chemical composition analysis of the isolated biopolymer.
• In vivo testing in guinea pigs to assess cough suppression and airway smooth muscle reactivity.

Main Results:

• An algal extracellular biopolymer (over 8.5 × 10^5 Da) was successfully isolated, rich in carbohydrates (52%) and protein (13%).
• The biopolymer's sugar profile was dominated by xylose derivatives (63%), with significant amounts of galactose and glucuronic acid.
• In vivo studies showed a significant cough suppressing effect in guinea pigs, with no adverse impact on airway smooth muscle reactivity.

Conclusions:

• The isolated algal biopolymer from Rhodella grisea possesses notable antitussive properties.
• The biopolymer's ability to suppress cough without compromising expectoration makes it a promising candidate for pharmaceutical development.