Antioxidant and Antityrosinase Activity of Flemingia macrophylla and Glycine tomentella Roots.

The antioxidant and antityrosinase activities of the water extract of Flemingia macrophylla root (WEFM) were investigated. The results showed that WEFM exhibited radical scavenging and reducing activities, as well as ferrous ion chelating property. In addition, WEFM also protected phospholipids against oxidation, indicating that WEFM could protect biomolecules from oxidative damage. Meanwhile, in the range of 50-100 µg/mL, the tyrosinase inhibitory activity of WEFM increased with an increase in sample concentration and was superior to that of the water extract of Glycine tomentella root (WEGT). A high performance liquid chromatography analysis was used to determine the phenolic components, revealing that daidzin, daidzein, genistin, and genistein were present in WEFM and WEGT. Acting as an antioxidant and a tyrosinase inhibitor, these bioactive constituents could contribute to the protective effects of WEFM. Overall, the results showed that WEFM might serve as a natural antioxidant and tyrosinase inhibitor.

Mitochondrial DNA alterations in blood of the humans exposed to N,N-dimethylformamide.

N,N-Dimethylformamide (DMF) has been widely used in industries because of its extensive miscibility with water and solvents. Its health effects include hepatotoxicity and male reproductoxicity, possibly linked with mitochondrial DNA (mtDNA) alterations including mtDNA common deletion (DeltamtDNA(4977)) and mtDNA copy number. The relationship between DMF exposure and mtDNA alterations, however, has not been postulated yet. The purposes of this study were to investigate whether the DMF exposure is associated with DeltamtDNA(4977) and mtDNA copy number and to evaluate the DMF-derived mtDNA alterations are more associated with exposure to the airborne DMF concentrations or to the levels of two urinary DMF biomarkers of N-methylformamide (NMF) and N-acetyl-S-(N-methylcarbamoryl) cysteine(AMCC). Thirteen DMF-exposed workers and 13 age and seniority-matched control workers in a synthetic leather factory were monitored on their airborne DMF, NMF and AMCC in the urine as well as DeltamtDNA(4977) and mtDNA copy number in blood cells. We found that the frequencies of relative DeltamtDNA(4977) in DMF-exposed group were significantly higher than those in the control group. Moreover, elevation in the proportion of DeltamtDNA(4977) of individuals with high urine AMCC (U-AMCC) and airborne DMF levels were significantly higher than those without. We conclude that long-term exposure to DMF is highly associated with the alterations of mtDNA in urine and blood cells. The DeltamtDNA(4977) was more significantly related to repeated exposure to DMF and mtDNA copy number was more closely related to short-term DMF exposure. We also confirmed that U-AMCC is more appropriate to serve as a toxicity biomarker for DMF exposure than U-NMF. Further study with a larger number of subjects is warranted.

Simultaneous determination of p-aminobenzoic acid and its metabolites in the urine of volunteers, treated with p-aminobenzoic acid sunscreen formulation.

p-Aminobenzoic acid (PABA) and its metabolites (p-aminohippuric acid, p-acetamidobenzoic acid, and p-acetamidohippuric acid) were detected using high-performance liquid chromatography with an electrochemical (carbon paste) detector (HPLC-ECD). For direct current (dc) mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.125 to 1.80 microg/ml was found. The detection limit was approximately 2.0 ng/ml. A carbon paste coulometric detector was used to demonstrate that PABA and its metabolites are electrochemically oxidized in acidic media, and to determine, by analyzing human urine, the percutaneous absorption of PABA and its metabolites. Findings using HPLC-ECD and HPLC with an ultraviolet detector (HPLC-UV) were comparable.

Inhibitory effects of water extract of Flos Inulae on mutation and tyrosinase.

In this study, the effects of a water extract of Flos Inulae (WFI) on antioxidant, antimutation and antityrosinase were investigated. The results showed that WFI inhibited the mutagenicity of 2-aminoanthracene (2-AA), an indirect mutagen; and 4-nitroquinoline-N-oxide (4-NQO), a direct mutagen toward Salmonella typhimurium TA 98 and TA 100. In addition, WFI, in the range of 0.2-0.6 mg/ml, showed radical scavenging, reducing activities and chelating activity as well as decreased lipid oxidative damage. Meanwhile, WFI also inhibited tyrosinase activity and NO generation in lipopolysaccharide (LPS) stimulated macrophages. High performance liquid chromatography analysis suggests that the major phenolic constituents in WFI are chlorogenic acid, rutin, quercetin, luteolin and kaempferol. These bioactive components may contribute to the protective effects of WFI. The obtained data suggests that Flos Inulae can be applied to antimutation, antityrosinase and anti-inflammation.

Antioxidant and anti-inflammatory activities of aqueous extracts of Schizonepeta tenuifolia Briq.

This study investigated the antioxidative and anti-inflammatory activities of aqueous extracts of Schizonepeta tenuifolia Briq. (STE). The results showed that STE displayed radical scavenging and reducing activity, as well as liposome protection activity. In addition, the implementation of an HPLC with a photodiode array detector helped to identify polyphenolic components including hesperidin, luteolin, and diosmetin. STE administration in the range of 125-500 mg/kg showed concentration dependent inhibition on carrageenan induced inflammatory response in mice. The anti-inflammatory effects of STE could be related to tissue NO and tumor necrosis factor a (TNF-α) suppression, and associated with the reduction of lipid peroxidation and an increase in antioxidant enzyme activities including catalase, superoxide dismutase, and glutathione peroxidase in vivo. Overall, the results showed that STE might serve as a natural inhibitor of oxidation and inflammation.

Antioxidant and antityrosinase activity of mulberry (Morus alba L.) twigs and root bark.

The antioxidant and antityrosinase activities of the ethanolic extract of mulberry twigs (EEMT) were investigated. The results showed that EEMT exhibited radical scavenging and reducing activity, as well as ferrous ion-chelating activity. In addition, EEMT also protected phospholipids against free radicals, indicating that EEMT could protect biomolecules from oxidative damage. Meanwhile, in the range of 0-60 µg/ml, the tyrosinase inhibitory activity of EEMT increased with increase in sample concentration, and was superior to that of the ethanolic extract of mulberry root bark (EEMR). High-performance liquid chromatography (HPLC) analysis was employed to determine the phenolic components, revealing that maclurin, rutin, isoquercitrin, resveratrol, and morin were present in EEMT. Acting as an antioxidant and a tyrosinase inhibitor, these bioactive constituents could contribute to the protective effects of EEMT. Overall, the results showed that EEMT might serve as a natural antioxidant and tyrosinase inhibitor.

Regioselective reduction of 3-sulfonyl glutarimides to 3,4-dihydro-5-sulfonylpyridin-2-ones. Formal synthesis of the indolizidine 8a-epi-dendroprimine.

Sodium borohydride regioselectively reduced various 3-sulfonyl glutarimides 1 to hydroxy piperidones 2, which were further dehydrated to 3,4-dihydro-5-sulfonylpyridin-2-ones 3 in the presence of boron trifluoride. Formal synthesis of 8a-epi-dendroprimine (4) possessing an indolizidine ring system has been accomplished via intramolecular radical cyclization of cyclic vinyl sulfone 5.