Free Phenolic Acids from the Seaweed Halimeda monile with Antioxidant Effect Protecting against Liver Injury

Abstract

Phenolic compounds are found in seaweed species together with other substances presenting antioxidant activity. The objective of this work was to evaluate the antioxidant activity of the free phenolic acids (FPA) fraction from the seaweed Halimeda monile, and its activity to protect the expression of hepatic enzymes in rats, under experimental CCl4 injury. The antioxidant activity was measured by the DPPH method. The FPA fraction (80 mg/kg, p.o.) was administered during 20 consecutive days to rats. The peroxidation was performed by thiobarbituric acid reactive substances (TBARS). The SOD and CAT enzymatic expressions were measured by RT/PCR. The histology technique was used to evaluate liver injuries. The expression of both, CAT and SOD genes, was more preserved by FPA. Only partial injury could be observed by histology in the liver of rats receiving FPA as compared with the control group; and CCl4 administration induced 60% more peroxidation as compared with the rats receiving FPA. These data suggest that FPA could modulate the antioxidant enzymes and oxidative status in the liver through protection against adverse effects induced by chemical agents

Seaweeds from Halimeda Genus as Sources of Natural Antioxidants

“…Direct antioxidants that have the function of eliminating formed free radicals before they can start a specific damage, and this is done with endogenous antioxidant biomolecules located in the cell membrane and in the cytosol or exogenous compounds provided by the diet. Halimeda spp extracts exhibited a high free radical scavenging activity which could be explained by its polyphenolic compounds content [7][8][9][10][11][12][13][14][15]21].…”

“…We observed that the treatment with the seaweed Halimeda spp led to a significant increase in the activity of these enzymes, which in turn resulted in an enhanced antioxidant defense. Mancini-Filho et al [12] reported an over-expression of catalase genes by treatment with FPA from Halimeda monile, while de Oliveira e Silva et al [14] by RT/PCR analysis showed an increase in the catalase gene expression in the group treated with free phenolic acid (FPA) fractions from Halimeda opuntia, suggesting the inductor effect of these compounds on the enzyme genes. Accordingly, Vidal et al [21] demonstrated similar effect with Halimeda incrassata.…”

“…The antitumour effect was detected by induction of apoptosis in leukemia cells, using extracts from H. discoidea [41]. Moreover, the genus Halimeda has been studied for antioxidant properties; animal studies carried out in our laboratory have shown that Halimeda spp effectively attenuates oxidative stress exhibiting neuroprotective and hepatoprotective activities [8,9,[12][13][14]21,37,39,42] In the quest for more potent antioxidants from natural sources, our group has been especially interested in studying the beneficial properties of seaweed from the Halimeda genus for an application in biomedicine in hepato-, neuro-and athero-protection.…”

“…It has been shown that Halimeda spp has a high phenolic content [10][11][12][13] together with low amounts of other antioxidants, such as ascorbate, β-carotene, chlorophylls, and selenium; taken together the ensemble of these compounds can explain its antioxidant properties. In our laboratory, we have identified and quantitated phenolic acids as major component of Halimeda spp such as salicylic, cinamic, galic pyrogalic, ferulic and caffeic acids and it has been suggested that the significant antioxidant activity displayed by Halimeda extract is at least partly related to its high levels of total phenolic compounds and particularly due to the phenolic acids content [10][11][12].…”

“…In our laboratory, we have identified and quantitated phenolic acids as major component of Halimeda spp such as salicylic, cinamic, galic pyrogalic, ferulic and caffeic acids and it has been suggested that the significant antioxidant activity displayed by Halimeda extract is at least partly related to its high levels of total phenolic compounds and particularly due to the phenolic acids content [10][11][12].…”