Résumé
Objective: To investigate the possible protective and/or therapeutic potentials of Dunaliella salina (D. salina) biomass, its carotenoid and polar fractions on cardiac dysfunction associated with D-galactose (D-GAL) induced aging in rats. Methods: Aging associated cardiac dysfunction was induced in rats by injection of D-GAL (200 mg/kg; i.p) for 8 weeks. D-GAL injected rats were treated with two regimens; protective regimen where D. salina biomass (250 mg/kg), its carotenoid (250 μg/kg) and polar (250 μg/kg) fractions were given orally for two weeks concurrently with D-GAL injection as well as treatment regimen where the three treatments were given orally for 28 consecutive days after D-GAL injection. Results: D-GAL injection for 8 weeks was accompanied with dramatic electrocardiographic changes as well as profound elevation in serum levels of homocysteine, creatinine kinase isoenzyme and lactate dehydrogenase in addition to the reduction of the cardiac content of glucose trasporter 4. D-GAL also induced reduction in cardiac superoxide dismutase activity and elevation of inducible nitric oxide synthetase and interleukin-6. On the other hand, oral administration of D. salina carotenoid fraction as well as the total biomass significantly attenuated the D-GAL-induced disturbances in the above mentioned parameters where the protective regimen appeared more successful in controlling the manifestations of cardiac dysfunction. The histopathological examination further emphasized the promising results. Besides, the HPLC analysis of the carotenoid fraction of D. salina revealed the presence of 2.31% β -carotene. Conclusions: D. salina carotenoid fraction as well as the total biomass ameliorate D-GAL-induced aging associated cardiac dysfunction which is attributed to the potent antioxidant activity of β -carotene.
Résumé
Oil slicks are common aspects of pollution that often exist in many littorals of the world. The Lebanese coast is typical to these aspects, thus oil slicks and patches are frequently observed while analyzing different satellite images. This is attributed, in a broad sense, to the oil released from ship tracks as well as from the located refineries, oil tanks and factories along the coast of Lebanon. The most severe event of this kind Lebanon has witnessed occurred on July I3[th] 2006 due to the bombing of the oil tanks at Jiyeh power station by the Israeli army. Consequently, several millions of fuel-oil gallons [-15000 tons] were released into the seawater covering an area of about 3000 km[2]. The prevailing dynamics of the sea currents in the area, which are rather fast in northward direction, controlled the spreading regime of oil and diverted it to the north shoreline where it nearly settled. A couple of days after the event, the spread oil was reduced and restricted to the coastline. Nevertheless, analysis of ASTER images dated on August l0[th] 2006 [25 days after the event] showed an abrupt existence of a huge plume into the sea. It was located south to Ez-Zahrani River outlet [16 km south to Jiyeh] and spread out about 5 km into the sea and not at Jiyeh station as it would have been anticipated. This extended the assumption that another release of unidentified materials has taken place in that area between August 3[rd] and 10[th] 2006. Hence, a release of dense materials, different from fuel oil, was proposed to form the identified plume of August 10[th] 2006, a matter that needs further verification