ABSTRACT
The thalli of the red alga, Jania rubens [L.] Lamx. were phytochemically and biologically investigated. The alga yielded 22.56% of neutral mucilage when successively extracted with cold and hot water. Chromatographic study of the ethanolic [80%] extract and mucilage hydrolysates of the thalli using paper chromatography [PC], thin layer chromatography [TLC] and gas liquid chromatography [GLC] revealed that galactose, mannose, xylose, rhammose and glucose were detected in both the ethanolic extract and the mucilage hydrolysates. Galacturonic acid was only detected in the mucilage hydrolysates. In addition, arabinose was detected only in the extract prepared on cold water. Mannitol was separated from the concentrated ethanolic extract of Jania rubens [L.] Lamx. [yield 0.8%]. The thalli of the red alga Jania rubens [L.] Lamx. were biologically investigated for their toxic and therapeutic effects. The alcoholic and aqueous extracts of Jania rubens [L.] Lamx. showed significant analgesic, antipyretic and anti-inflammatory effects. Both the alcoholic and aqueous extracts had an inhibitory effects on the intestinal motility of rabbits, uterine motility of rats and guinea pigs' ileum. It exhibited no histaminic nor antihistaminic effects on isolated guinea pigs' tracheal strips. Both the alcoholic and aqueous extracts caused a significant increase of urine volume in the rats. The ethanolic extract had a more significant diuretic effect than the aqueous extract. Both extracts had a transient hypotensive effect