Antibacterial activity and mechanism of chloroform fraction from aqueous extract of mugwort leaves (Artemisia argyi L.) against Staphylococcus aureus.

In this work, the antibacterial activity and mechanism of chloroform fraction obtained from aqueous extract of mugwort leaves against Staphylococcus aureus were investigated. The extract showed obvious antibacterial activity against S. aureus which the minimum inhibitory concentration and minimum bactericidal concentration were determined to be 3·0 and 6·0 mg ml-1 respectively. The mechanism study suggested that the extract could destroy the integrity of the S. aureus cell walls and increase the permeability of cell membrane in a certain concentration, but it could not kill S. aureus in a short time. Instead, the extract could make bacteria in a state of apoptosis for a long time, interfere with the normal physiological metabolism of bacteria, and eventually make bacteria die, which was confirm by scanning electronic microscope.

Identification of 17 novel major histocompatibility complex-A alleles in a population of Chinese-origin rhesus macaques.

Rhesus macaques (Macaca mulatta) serve as important animal models for human disease and vaccine research. Although Chinese rhesus macaques are the same species as those of Indian origin, they are from a geographically separated population and possess divergent major histocompatibility complex (MHC) class I A alleles. In an analysis of 65 Chinese rhesus macaques, 17 novel Mamu-A alleles were identified and deposited under the following accession numbers: EU252155-158, EU262737-741, EU418504-505, EU422996, EU418506, EU753185-187, and EU828528. The discovery of these additional MHC class I A sequences indicates a greater diversity and polymorphism of Chinese rhesus macaques in different geographic locations. As the set of Mamu-A alleles in Chinese rhesus macaques differs from the alleles of Indian animals, more work still needs to be carried out to identify these new allele-restricted immune responses with regard to vaccine studies.

Chemical pattern recognition of three Chinese herbal medicines from the genus Stephania lour.

Chemical pattern recognition was applied to three Chinese herbal medicines from the genus Stephania Lour., viz. S. kwangsiensis Lo, S. viridiflavens Lo and M. Yang and S. mashanica Lo and B.N. Chang. Based on the chemical features obtained from HPLC, SIMCA program was carried out and the results showed that the classification accuracy was 100%. In addition, the obtained features showed three major classes by NLM. The results of both methods were consistent with those of plant taxonomical identification. It suggested that chemical pattern recognition could be a helpful method to classify and identify Chinese herbal medicines.