Carrageenans-Sulfated Polysaccharides from Red Seaweeds as Matrices for the Inclusion of Echinochrome

Abstract

The possibility of using different types of carrageenans (CRG) as matrixes for incorporating of echinochrome A (Ech) was investigated. Ech interacts with carrageenans and is incorporated into the macromolecular structure of the polysaccharide. The inclusion of Ech in carrageenan matrices decreased its oxidative degradation and improved its solubility. The changing in the charge and morphology of CRGs during binding with Ech was observed. The rate of Ech release from CRG matrices depended on the structure of the used polysaccharide and the presence of specific ions. The gastroprotective effect of CRG/Ech complexes was investigated on the model of stomach ulcers induced by indomethacin in rats. Complexes of CRG/Ech exhibited significant gastroprotective activity that exceeded the activity of the reference drug Phosphalugel. The gastroprotective effect of the complexes can be associated with their protective layer on the surface of the mucous membrane of a stomach.

Liposomal Form of the Echinochrome-Carrageenan Complex

“…We tried to incorporate Ech in phosphate buffer into liposomes, but in this case, the Ech oxidized rapidly and the obtained liposomes contained a non-native, but oxidized form of Ech. According to our earlier results, CRGs protected the Ech from its oxidative degradation and improved its solubility [ 27 ]. So it was not possible to incorporate the Ech without carrageenan into the liposomes.…”

“…The red pigment of water-insoluble Ech from sea urchins is the active substance of the drug Histochrome and exhibits high antioxidant activity [ 30 , 31 ]. Recently, we have shown that the incorporation of Ech into the CRG matrix improves its water solubility and prevents Ech from oxidation [ 27 ]. In the present work, we included CRG/Eсh in the liposomes and examined the properties of these liposomes.…”

“…Previously, we found that Ech A included in kappa-CRG has a moderate antiulcer effect. The activity of the CRG/Ech A complexes exceeded the activity of the Phosphalugel reference drug by three times the amount [ 27 ]. The liposome form of Escher carrus can enhance this effect.…”

“…However, compared with commonly used mucoadhesive polymers, such as hydroxypropyl methylcellulose, chitosan, pectin and alginate, the utilization of CRG to coat liposomes has not been reported frequently. Recently, we showed that a water-insoluble sea urchin pigment, echinochrome (7-ethyl-2,3,5,7,8-pentahydroxy-1,4-naphthoquinone) (Ech), interacts with CRGs and is incorporated into the macromolecular structure of the polysaccharide [ 27 ]. Ech exhibits a wide range of pharmacological activities; it protects the mitochondrial functions of rat cardiac myoblast H9c2 cells from cardiotoxic agents and ROS initiators, such as doxorubicin, sodium nitroprusside and tert-butyl hydroperoxide, and it decreases the ROS level and mitochondrial membrane potential [ 28 , 29 ].…”

“…Ech with registration number P N002362/01 is the active substance in the cardioprotective and antioxidant drug Histochrome ® , which is produced in Russia from the sand dollar [ 30 ] and is used for the treatment of ocular diseases, diabetic retinopathy, dystrophies, central retinal vein thrombosis, and post-traumatic haemorrhages [ 31 ]. The inclusion of Ech in complexes with CRGs decreased its oxidative degradation and improved its solubility [ 27 ]. This work is devoted to the inclusion in liposomes of the sulfated polysaccharides of CRGs that contain Ech.…”