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Abstract:The study aimed to evaluate the hepatic antioxidant capacity of embelin (from Embelia ribes) using different antioxidant tests, free radical scavenging activity and lipid peroxidation in albino rats. Carbon tetrachloride (CCl 4 ) treatment to rats has been more susceptible to peroxidative damage through production of reactive metabolites, namely trichloromethyl-free radicals (CCl as measured by thiobarbituric acid reactive species. After the induction of liver damage by CCl 4 intoxication to rats, the concentration of lipid peroxidation was significantly (P £ 0.001) higher in liver and serum, along with concomitant decrease in the levels of antioxidants and cytochrome P450 enzyme in liver as compared to vehicle controls. The activities of marker enzymes -transaminases (AST, ALT), alkaline phosphatase (ALP), c-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH) -along with the total bilirubin and total protein levels were altered significantly (P £ 0.001) in the serum of CCl 4 -treated rats. When these rats received embelin orally (25 mg/kg) from day 1 to day 15, peroxidative damage was minimal in both liver and serum along with effectively inducing the antioxidant potential in CCl 4 -treated rats. The biochemical results were compared with the standard drug silymarin -a combination of flavonolignans of Silybum marianum and histology of liver sections. In conclusion, this study suggests that embelin acts as a natural antioxidant against hepatotoxicity induced in rats.

Predicting the activation of sub-micron particles into cloud droplets in the atmosphere remains a challenge. The importance of surface tension,  (mN/m), in these processes has been evidenced by several works but information on the "surfactants" lowering  for atmospheric particles remains scarce. In this work, PM1 aerosols from urban, coastal and remote regions of Europe (Lyon, France, Rogoznica, Croatia, and Pallas, Finland, respectively) were investigated and found to contain amphiphilic surfactants in concentrations up to 2.8 g m -3 in the air and 1.3 M in the particle volume. In Pallas, correlations with the PM1 chemical composition showed that amphiphilic surfactants were present in the entire range of particle sizes, thus confirming recent works. This implied that they were present in hundreds to thousands particles cm -3 and not only in a few large particles, as it has been hypothesized. Their adsorption isotherms and Critical Micelle Concentration (CMC) were also determined. The low CMC obtained (3  10 -5 -9  10 -3 M) imply that surface tension depression should be significant for all the particles containing these compounds, even at activation (Growth Factor = 10). Amphiphilic surfactants are thus likely to enhance the CCN ability of sub-micron atmospheric particles.

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The antioxidant and hepatoprotective activities of the extract of Moringa oleifera leaves were investigated against CCl4-induced hepatotoxicity in rats. Hepatotoxic rats were treated with ethanol extract of Moringa oleifera for a period of 60 days at the following three dose levels; 100, 200 and 400 mg/kg body weight/day, orally. The activities were studied by assaying the serum marker enzymes like SGOT, SGPT, GGT, LDH, ALP, ACP, as well as total bilirubin, total protein and albumin in serum concomitantly with the activities of LPO, SOD, CAT, GSH, GR and GPx in liver. The activities of all parameters registered a significant (p ≤ 0.001) alteration in CCl4 treated rats, which were significantly recovered towards an almost normal level in rats co-administered with M. oleifera extract in a dose-dependent manner. All the biochemical investigations were confirmed by the histopathological observations and compared with the standard drug. silymarin. Results suggest that the antioxidant and hepatoprotective activities of M. oleifera leaves are possibly related to the free radical scavenging activity which might be due to the presence of total phenolics and flavonoids in the extract and/or the purified compounds β-sitosterol, quercetin and kaempferol, which were isolated from the ethanol extract of M. oleifera leaves.

The distributions, correlations, and source apportionment of aromatic acids, aromatic ketones, polycyclic aromatic hydrocarbons (PAHs), and trace metals were studied in Canadian high Arctic aerosols. Nineteen PAHs including minor sulfur-containing heterocyclic PAH (dibenzothiophene) and major 6 carcinogenic PAHs were detected with a high proportion of fluoranthene followed by benzo[k]fluoranthene, pyrene, and chrysene. However, in the sunlit period of spring, their concentrations significantly declined likely due to photochemical decomposition. During the polar sunrise from mid-March to mid-April, benzo[a]pyrene to benzo[e]pyrene ratios significantly dropped, and the ratios diminished further from late April to May onward. These results suggest that PAHs transported over the Arctic are subjected to strong photochemical degradation at polar sunrise. Although aromatic ketones decreased in spring, concentrations of some aromatic acids such as benzoic and phthalic acids increased during the course of polar sunrise, suggesting that aromatic hydrocarbons are oxidized to result in aromatic acids. However, PAHs do not act as the major source for low molecular weight (LMW) diacids such as oxalic acid that are largely formed at polar sunrise in the arctic atmosphere because PAHs are 1 to 2 orders of magnitude less abundant than LMW diacids. Correlations of trace metals with organics, their sources, and the possible role of trace transition metals are explained.

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