In vitro and in vivo determination of antioxidant activity and mode of action of isoquercitrin and Hyptis fasciculata.

Reactive oxygen species (ROS) are thought to underline the process of ageing and the pathogenicity of various diseases, such as neurodegenerative disorders and cancer. The use of traditional medicine is widespread and plants still present a large source of natural antioxidants that might serve as leads for the development of novel drugs. In this paper, the alcoholic extract from leaves of Hyptis fasciculata, a Brazilian medicinal plant, and isoquercitrin, a flavonoid identified in this species, showed to be active as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavengers. The extract of Hyptis fasciculata and isoquercitrin were also able to increase tolerance of the eukaryotic microorganism Saccharomyces cerevisiae to both hydrogen peroxide and menadione, a source of superoxide. Cellular protection was correlated with a decrease in oxidative stress markers, such as levels of ROS, protein carbonylation and lipid peroxidation, confirming the antioxidant potential of Hyptis fasciculata and isoquercitrin.

High HPV genetic diversity in women infected with HIV-1 in Brazil.

The present study on genetic diversity of human papillomaviruses in women infected by HIV in Brazil describes the frequency, the genotypes, and five new variants of HPV. One hundred fifty cervical smears of HIV-positive women were subjected to cytological examination, and the DNA samples obtained were assayed by MY09/MY11 amplification, followed by RFLP typing. The overall HPV-DNA-positive rate was 42.7%. One hundred twenty-two samples (81.3%) had benign cellular alterations or normal cytological results, and HPV DNA frequency among them was 30.3%. Otherwise, 96.4% of samples with altered cytology were positive for HPV DNA. A high diversity of genotypes was observed. HPVs-16 and 81 were the most prevalent (14.1%) and were followed by HPVs 52, 35, 62, 33, 53, 56, 66, 70, 18, 58, 6b, 11, 31, 39, 40, 61, 71, 32, 54, 59, 67, 68, 85, and 102. Five new variants of the high-risk HPVs 18, 33, 53, 59, and 66 were detected. Possible associations between the detection of HPV genotypes and the cytological classification, HIV viral load, CD4 count, and antiretroviral treatment were also examined. We observed that a high proportion of HIV-infected women are infected with HPV and may carry oncogenic genotypes, even when cytological evaluation shows normal results.

Evaluation of antioxidant activity of Brazilian plants.

In this work, 22 alcoholic extracts, obtained from 14 species of plants belonging to four families, used for different food and medicinal purposes in Brazil, were evaluated for their capacity to inhibit the reduction of the free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and to protect Saccharomyces cerevisiae cells, an eukaryotic cell model, against the lethal oxidative stress caused by tert-butylhydroperoxide (TBH). Five extracts, two from Lamiaceae family (ethanol and butanol extracts from aerial parts of Hyptis fasciculata) and three from Palmae family (Copernicia cerifera leaves and mesocarp of fruits and the endocarp/mesocarp of fruits from Orbignya speciosa) were able to increase the tolerance of S. cerevisiae to TBH and showed to be active as DPPH radical scavengers, thus indicating that these plant extracts could be considered as potential sources of antioxidants. With the exception of ethanol extract of H. fasciculata, the remainder four extracts exhibited a DPPH radical scavenging activity higher than that obtained from Ginkgo biloba, a reference plant with well documented antioxidant activity. Interestingly, the ethanol extract of G. biloba were not effective for yeast cell protection, reinforcing the antioxidant potential of these extracts.

L1 sequence of a new human papillomavirus type-58 variant associated with cervical intraepithelial neoplasia.

The present study on molecular characterization of a human papillomavirus (HPV) isolated in Central Brazil describes the L1 gene sequence from a new variant of HPV-58, the isolate Bsb-02. The sample was from a smear obtained from a woman with cervical intraepithelial neoplasia grade II. The whole L1 gene from isolate Bsb-02 was sequenced automatically, showing 99.1% nucleotide identity with the gene from the HPV-58 reference. The clustering between Bsb-02 and HPV-58 reference sequence was also supported by phylogenetic analysis. Fourteen nucleotide substitutions were observed: eight were synonymous and six were associated with amino acid substitutions. A10V and V144I have not been previously described. At GenBank, the only complete L1 sequence from HPV-58 in addition to the HPV-58 reference one is that of Bsb-02. These data provide information that may be relevant to HPV diagnosis and to rational vaccine strategies. HPV variants may also be associated with host immune responses and with the risk of cervical neoplasia.

L1 sequence of a new human papillomavirus type-58 variant associated with cervical intraepithelial neoplasia

The present study on molecular characterization of a human papillomavirus (HPV) isolated in Central Brazil describes the L1 gene sequence from a new variant of HPV-58, the isolate Bsb-02. The sample was from a smear obtained from a woman with cervical intraepithelial neoplasia grade II. The whole L1 gene from isolate Bsb-02 was sequenced automatically, showing 99.1 percent nucleotide identity with the gene from the HPV-58 reference. The clustering between Bsb-02 and HPV-58 reference sequence was also supported by phylogenetic analysis. Fourteen nucleotide substitutions were observed: eight were synonymous and six were associated with amino acid substitutions. A10V and V144I have not been previously described. At GenBank, the only complete L1 sequence from HPV-58 in addition to the HPV-58 reference one is that of Bsb-02. These data provide information that may be relevant to HPV diagnosis and to rational vaccine strategies. HPV variants may also be associated with host immune responses and with the risk of cervical neoplasia.