In vitro immunomodulatory activity and in vivo anti-inflammatory and analgesic potential with gastroprotective effect of the Mediterranean red alga Laurencia obtusa.
BACKGROUND
Red algae have been recognized as a rich natural source of compounds possessing interesting biological and pharmacological activities.


OBJECTIVE
This work investigates anti-inflammatory, analgesic and gastroprotective activities of MeOH/CH2Cl2crude extract and its fractions F1 (50% MeOH) and F2 (80% MeOH) from the whole alga plant Laurencia obtusa Hudson (Rhodomelaceae).


METHODS
Anti-inflammatory activity was evaluated in vitro using cytometric bead array (CBA) technology to follow up the secretion of tumour necrosis factor alpha (TNF-α) in lipopolysaccharide activated THP-1 monocytic cells at doses of 10-250 μg/mL and in vivo using carrageenan-induced paw oedema in Wistar rats at doses of 25, 50, 100 and 200 mg/kg. Crude extract and fractions were tested at the doses of 25, 50, 100 and 200 mg/kg for peripheral and central analgesic activity by acetic acid-induced writhing test and hot-plate method, respectively, in Swiss albino mice. Gastroprotective activity was evaluated using HCl/ethanol-induced gastric ulcer test in rats at doses of 25, 50, 100 and 200 mg/kg.


RESULTS
Crude extract, F1 and F2 showed an interesting inhibition of TNF-α secretion with IC50values of 25, 52 and 24 μg/mL, respectively, and a significant anti-inflammatory activity in vivo (p <  0.01), 3 h after carrageenan injection, the oedema inhibition was 55.37%, 52.18% and 62.86%, respectively, at the dose of 100 mg/kg. Furthermore, they showed a significant peripheral analgesic activity with 53.79%, 55.92% and 57.37% (p <  0.01) of writhing inhibition, respectively. However, no significant activity was found in the hot-plate test. An interesting gastroprotective effect was observed with crude extract and its fractions F1 and F2 with a gastric ulcer inhibition of 65.48%, 77.42% and 81.29%, respectively, at the dose of 50 mg/kg.


CONCLUSIONS
These results suggest that L. obtusa might be used as a potential source of natural anti-inflammatory and analgesic agents with gastroprotective effect.
a Laboratoire de Développement Chimique, Galénique et Pharmacologique des Médicaments (LR12ES09) , Unité de Pharmacologie Marine, Faculté de pharmacie de Monastir, Université de Monastir , Monastir , Tunisia.|b UMR 7200 CNRS, Laboratoire d'Innovation Thérapeutique, Faculté de Pharmacie , Université de Strasbourg , Illkirch , France.
Sirine
S
Lajili
a Laboratoire de Développement Chimique, Galénique et Pharmacologique des Médicaments (LR12ES09) , Unité de Pharmacologie Marine, Faculté de pharmacie de Monastir, Université de Monastir , Monastir , Tunisia.
Monia
M
Deghrigue
a Laboratoire de Développement Chimique, Galénique et Pharmacologique des Médicaments (LR12ES09) , Unité de Pharmacologie Marine, Faculté de pharmacie de Monastir, Université de Monastir , Monastir , Tunisia.
Haifa
H
Bel Haj Amor
b UMR 7200 CNRS, Laboratoire d'Innovation Thérapeutique, Faculté de Pharmacie , Université de Strasbourg , Illkirch , France.
Christian D
CD
Muller
a Laboratoire de Développement Chimique, Galénique et Pharmacologique des Médicaments (LR12ES09) , Unité de Pharmacologie Marine, Faculté de pharmacie de Monastir, Université de Monastir , Monastir , Tunisia.
Abderrahman
A
Bouraoui
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D005260:Female; D005419:Flavonoids / Q000032:analysis; D005753:Gastric Mucosa / Q000187:drug effects*; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology*; D044722:Laurencia / Q000737:chemistry; D008297:Male; D051379:Mice; D020011:Protective Agents / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
D000700:Analgesics; D000893:Anti-Inflammatory Agents; D005419:Flavonoids; D007155:Immunologic Factors; D020011:Protective Agents; D014409:Tumor Necrosis Factor-alpha
Flavonoids; TNF-α inhibitory activity; flow cytometry; inflammation; phenolics