The aminonaphthoquinone, spinamine E (5), was isolated for the first time from the sea urchins Strongylocentrotus pallidus (Sars G.O., 1872) and Mesocentrotus nudus (A. Agassiz, 1864). The structure of 5 was elucidated as 2-amino-3,5,6,7,8-pentahydroxy-1,4-naphthoquinone using 1D 1 H-, 13 C-and 2D NMR procedures, and HR-ESI mass-spectrometric data of 5 and its trimethyl ether. Spinamine E, as well as two other aminonaphthoquinones of sea urchins, echinamines A (2) and B (3), along with their hydroxylated analogues, spinochrome E (4) and echinochrome A (1), were tested for their ability to scavenge the stable DPPH radical and to inhibit lipid peroxidation. All investigated naphthoquinones obtained from the sea urchins showed a high antiradical activity, which was up to 1.5 times higher than that of α-tocopherol. Echinamine B showed the highest scavenging effect (EC 50 = 6.5•10-6 M); this effect decreases in the series 35124α-tocopherol. In a lipid peroxidation inhibition testing model, echinamine B and spinamine E showed the highest inhibitory effect. The stability of compounds 1-5 in weakly alkaline solutions was evaluated.

Echinochrome A (Ech A), a natural pigment extracted from sea urchins, is the active ingredient of a marine-derived pharmaceutical called ‘histochrome’. Since it exhibits several biological activities including anti-oxidative and anti-inflammatory effects, it has been applied to the management of cardiac injury and ocular degenerative disorders in Russia and its protective role has been studied for other pathologic conditions. In the present study, we sought to investigate the therapeutic potential of Ech A for inflammatory bowel disease (IBD) using a murine model of experimental colitis. We found that intravenous injection of Ech A significantly prevented body weight loss and subsequent lethality in colitis-induced mice. Interestingly, T cell proliferation was significantly inhibited upon Ech A treatment in vitro. During the helper T (Th) cell differentiation process, Ech A stimulated the generation regulatory T (Treg) cells that modulate the inflammatory response and immune homeostasis. Moreover, Ech A treatment suppressed the in vitro activation of pro-inflammatory M1 type macrophages, while inducing the production of M2 type macrophages that promote the resolution of inflammation and initiate tissue repair. Based on these results, we suggest that Ech A could provide a beneficial impact on IBD by correcting the imbalance in the intestinal immune system.

On long-term introduction to rats in dosage 100 mg/kg polyphenol complexes from heartwood and callus culture of Maackia amurensis Rupr. et Maxim. had a marked influence on the activity of free radical oxidation. Under conditions of induced oxidant stress both polyphenol complexes inhibited prooxidant activity directly affecting the products of free radical oxidation. Inhibiting influence on the production of oxygen active forms that is characteristic for both phytocomplexes is determined by inhibition of mechanisms both enzymatic and non-enzymatic defense.

Seven isoflavonoids, including a new glycoside, (6aR,11aR)-medicarpin-3-O-gentiobioside (6), were isolated from the roots of Maackia amurensis using repeated column chromatography on a Toyopearl HW-50F sorbent and identified by HPLC-PDA-MS, 1 H NMR, 13 C, 1 H-1 H COSY, HSQC NMR and HMBC NMR analyses as daidzin (1), genistein-7-O-gentiobioside (2), pseudobaptigenin-7-O-gentiobioside (3), formononetin-7-O-gentiobioside (4), (6aR,11aR)maackiain-3-O-gentiobioside (5), and 5-O-methylgenistein-7-O-gentiobioside (7). In the model of oxidative stress induced by formalin injection, the isolated isoflavone and pterocarpan glucosides 1-7 were shown to reduce the formation of malondialdehyde (MDA) and other thiobarbituric acid reactive substances (TBARS), as well as glutathione peroxidase (GPO) activity in rats.

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