Vitamin C in disease prevention and therapy

Vitamin C je esencijalan sastojak hrane uključen u mnoge biološke i biokemijske procese kao antioksidans. S obzirom da je oksidacijsko oštećenje povezano s nastankom različitih bolesti, vitamin C ima potencijalno preventivan, ali i terapijski učinak. Voće i povrće su preporučeni izvori vitamina C koji imaju preventivnu ulogu u razvoju malignih tumora i bolesti krvožilnog sustava, premda ne isključivo zbog vitamina C. Povrh toga, sintetski vitamin C uzet u količinama većim od preporučenog dnevnog unosa (RDA) djeluje povoljno na za rastanje rana, ublažavanje simptoma prehlade, ali i u prevenciji prehlade u osoba izloženih prekomjernom fizičkom stresu. Također, vitamin C je učinkovit u smanjivanju koncentracije fibrinogena pove zanog s povećanim rizikom od nastanka bolesti krvožilnog sustava. Pozitivni učinci mogu se također ostvariti intravenskim unosom vitamina C kod bolesnika s šećernom bolesti i nekim oblicima malignih tumora. Međutim, pozitivni učinci vrlo često ovise o mno gim čimbenicima, kao što su doza, dob, zdravstvene navike i dr.Vitamin C is an essential nutrient involved in many biological and biochemical processes as an antioxidant. As oxidative damage is implicated in the development of various diseases, vitamin C could have a preventive or even therapeutic effect. Fruits and vegetables are the recommended sources of vitamin C. Five servings of fruits and vegetables are protective against cancer and cardiovascular disease, however not because of vitamin C alone. On the other hand, oral vitamin C supplements in amounts higher than Recomended Daily Allowance (RDA) are beneficial in wound healing, reducing the duration of common cold symptoms, but also in prevention of common cold in heavily physically stressed persons. Furthermore, vitamin C is effective in decreasing serum fibrinogen, which is related to increased cardiovascular risk. Positive effects may be also achieved by intraarterial or intravenous administration of vitamin C in patients with diabetes mellitus and cancer. However, positive effects frequently depend on many factors, such are dose, age, health habits, etc

Hepatoprotective activity of phytochemicals

Jetra je središnji organ u detoksikaciji ksenobiotika i proizvoda metabolizma i kao takav podložan je oštećenju. Brojni čimbenici mogu dovesti do oštećenja jetre, prije svega egzogeni čimbenici kao što su lijekovi, alkohol, neki sastojci hrane, hepatotropni virusi i dr. Zbog ponovljenog izlaganja hepatotoksičnom agensu, akutno oštećenje može prerasti u kronični hepatitis, što često zahtijeva presađivanje organa. Danas još uvijek ne postoji uspješni način liječenja hepatitisa, te se naglasak stavlja na prevenciju. U terapiji oštećenja jetre, uz klasične lijekove kao što je interferon kod virusnog hepatitisa, raste spoznaja o mogućnosti korištenja iscrpaka nekih biljaka i njihovih najaktivnijih komponenti kao dopuna postojećoj terapiji. Brojna su istraživanja pokazala hepatoprotektivan učinak fitokemikalija kao što su silimarin, glicirizin, luteolin, kvercetin i drugi prirodni spojevi, kako u prevenciji, tako i u terapiji nekih oblika bolesti jetre. Njihov pozitivan učinak pripisuje se prvenstveno antioksidativnom djelovanju, no antioksidansi nisu „magični spojevi” koji mogu nespecifično liječiti bilo koji poremećaj ili bolest. Istraživanja na životinjama i staničnim kulturama ukazuju na to da mnoge fitokemikalije ulaze u interakciju sa staničnom signalizacijom i ekspresijom gena, što može predstavljati osnovu za njihovo selektivno korištenje u specifičnim patološkim procesima.Liver is the central organ in detoxification of xenobiotics and metabolism products, and as such is subject to damage. Many factors can lead to liver damage, primarily exogenous factors such as drugs, alcohol, some food ingredients, hepatotrophic viruses, etc. As a result of repeated exposure to a hepatotoxic agent, acute damage can develop into chronic hepatitis, which may require organ transplantation. Today, there is still no successful treatment for hepatitis, and thus the emphasis is on prevention. In the treatment of liver damage, in addition to classic drugs such as interferon for viral hepatitis, there is a growing awareness of the possibility of using some plant extracts and their most active components as a complement to existing therapies. Numerous studies have shown hepatoprotective effects of phytochemicals such as silymarin, glycyrrhizin, luteolin, quercetin and other natural compounds, both in prevention and in treatment of some forms of liver disease. Their positive effect is primarily attributed to antioxidant activity, but antioxidants are not “magic compounds” that can non-specifically treat any disorder or disease. Research in animals and cell cultures show that many phytochemicals interact with cell signalling and gene expression, which could be the basis for their selective use in specific pathological processes

Osteoporosis and Nutrition — Nutrition, Anthropometry and Bone Mineral Density in Women

Relationship between nutrition and bone mineral density with respect to the risk of osteoporotic fracture

LIPID PEROXIDATION - CAUSES AND CONSEQUENCES

SAŽETAK U normalnim biološkim uvjetima, molekula kisika neenzimatskom oksidacijom povremeno oduzima elektrone drugim molekulama, što uzrokuje nastanak slobodnih radikala. Višestruko nezasićene masne kiseline (PUFA) često su meta stvorenih slobodnih radikala, što posljeduje lipidnom peroksidacijom. Unutarstanični i izvanstanični antioksidansi uklanjanjem reaktivnih spojeva kisika i dušika smanjuju mogućnost oksidacijskoga oštećenja lipidnih molekula, u prvom redu PUFA-e, ali i drugih spojeva. Enzimska kataliza jest najučinkovitiji postupak uklanjanja reaktivnih kisikovih vrsta (ROS). U organizmu postoji nekoliko skupina antioksidacijskih enzima uključujući superoksid dismutazu (SOD) za uklanjanje superoksidnoga radikala i katalaza (CAT), te glutation peroksidazu (GPx) za uklanjanje vodikova peroksida i organskih peroksida. Oštećenje lipida može se odrediti mjerenjem količine malondialdehida (MDA), 4-hidroksinonenala (HNE), izoprostana, te drugih produkata lipidne peroksidacije. Povećana lipidna peroksidacija povećava rizik za razvoj ateroskleroze i drugih upalnih bolesti.ABSTRACT Occasionally, under normal biological conditions, oxygen does manage to steal away electrons from other molecules by nonenzymatic autoxidations, which results in the free radical formation. Polyunsaturated fatty acids frequently serves as the target for generated free radicals, inducing lipid peroxidation. Intracellular and extracelular antioxidants attenuate oxidative damage of lipid molecules, primarily PUFA, but also other molecules. The most efficient way to eliminate undesirable toxic species is by means of enzyme catalysis. Families of antioxidant enzymes have evolved for this purpose, including superoxide dismutases (SOD) for the elimination of the superoxide radical, and catalases (CAT) and glutathione peroxidases (GPx) for the elimination of hydrogen peroxide and organic peroxides. Lipid damage could be determined by measuring the amount of malondialdehyde (MDA), 4-hydroxynonenal (HNE), isoprostanes and other products of lipid peroksidation. Increased lipid peroxidation increase the risk of atherogenesis and other inflammatory diseases

Hepatoprotective effects of Micromeria croatica ethanolic extract against CCl4–induced liver injury in mice

Abstract BACKGROUND: Micromeria croatica (Pers.) Schott is an aromatic plant from Lamiaceae family previously found to possess potent in vitro antioxidant activity which is mainly attributed to the high level of polyphenolic substances. The aim of this study was to investigate the hepatoprotective activity and possible underlying mechanisms of Micromeria croatica ethanolic extract (MC) using a model of carbon tetrachloride (CCl4)-induced liver injury in mice. METHODS: Male BALB/cN mice were randomly divided into seven groups: control group received saline, MC group received ethanolic extract of M. croatica in 5% DMSO (100 mg/kg b.w., p.o.), and CCl4 group was administered CCl4 dissolved in corn oil (2 mL/kg, 10% v/v, ip). MC50, MC200 and MC400 groups were treated with MC orally at doses of 50, 200 and 400 mg/kg once daily for 2 consecutive days, respectively, 6 h after CCl4 intoxication. The reference group received silymarin at dose of 400 mg/kg. At the end of experiment, blood and liver samples were collected for biochemical, histopathological, immunohistochemical and Western blot analyses. In addition, major phenolic compounds in MC were quantified by HPLC-DAD. RESULTS: CCl4 intoxication resulted in liver cells damage and oxidative stress and triggered inflammatory response in mice livers. MC treatment decreased ALT activity and prevented liver necrosis. Improved hepatic antioxidant status was evident by increased Cu/Zn SOD activity and decreased 4-hydroxynonenal (4-HNE) formation in the livers. Concomitantly, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were overexpressed. The hepatoprotective activity of MC was accompanied by the increase in nuclear factor-kappaB (NF-κB) activation and tumor necrosis factor-alpha (TNF-α) expression, indicating amelioration of hepatic inflammation. Additionally, MC prevented tumor growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) expression, suggesting the potential for suppression of hepatic fibrogenesis. CONCLUSION: These results of the present study demonstrated that MC possesses in vivo antioxidant and anti-inflammatory activity and exhibits antifibrotic potential, which are comparable to those of standard hepatoprotective compound silymarin

Hepatic Expression of Metallothionein I/II, Glycoprotein 96, IL-6, and TGF-β in Rat Strains with Different Susceptibilities to Experimental Autoimmune Encephalomyelitis

In a search of peripheral factors that could be responsible for the discrepancy in susceptibility to EAE in Albino Oxford (AO) and Dark Agouti (DA) rats, we estimated the expression of metallothioneins I/II (MT), heat shock protein-gp96, interleukin (IL)- 6, and transforming growth factor (TGF)- in the livers of these animals. Rats were immunized with bovine brain homogenate (BBH) emulsified in complete Freund adjuvant (CFA) or only with CFA. Western blot and immunohistochemical analyses were done on day 12 after the immunization, as well as in intact rats.The data have shown that during the first attack of EAE only the EAE prone-DA rats markedly upregulated the hepatic MTs, gp96, IL-6, and TGF-. In contrast, AO rats had a significantly higher expression of MT I/II, IL-6, and TGF- in intact liver ( < 0, 001), suggesting that the greater constitutive expression of these proteins contributed to the resistance of EAE. Besides, since previously we found that AO rats reacted on immunization by an early upregulation of TGF- on several hepatic structures (vascular endothelium, Kupffer cells, and hepatocytes), the data suggest that the specific hepatic microenvironment might contribute also to the faster recovery of these rats from EAE

Modulacijsko djelovanje prehrane maslinovim i kukuruznim uljem na sadržaj minerala u submandibularnoj žlijezdi nakon parcijalne hepatektomije

To estimate the role of the submandibular gland (SMG) in liver regeneration, i) the tissue mineral dynamics in SMG after 1/3 partial hepatectomy (pHx) and ii) the influence of olive (OO) and corn-oil (CO) enriched diets on these events were investigated. Different nutrition of BALB/c mice lasted 3 weeks, and the minerals in SMG were determined by microwave digestion and ICP spectrometry. The diet containing CO initially suppressed liver regeneration (after 24 h) and then, similarly to OO, increased liver growth (on day 7). In mice fed standard food, Zn2+ and Ca2+ accumulated in SMG and the concentration of Mg2+ decreased in the early phase of liver regeneration. These changes were, however, significantly less expressed in mice fed CO and OO enriched diets, suggesting that monounsaturated oleic acid (C18:1n-9) and polyunsaturated linoleic acid (C18:2n-6) might interfere with some metal-dependent activities of SMG that participate in the control of liver regeneration