Search

In the present study the phytochemical composition and biological activities of the aerial part extracts of Asteriscus graveolens against pathogenic bacteria and leishmania parasite were evaluated. Phytochemical analysis revealed the presence of polyphenols, flavonoids and tannins. The ethyl acetate fraction exhibited high antioxidant potential of 359.72 ± 32.03 μg and 326.76 ± 15.86 μg of ascorbic acid equivalents and 13.32 ± 0.19 μg/mL by PM, FRAP and DPPH assays respectively. This fraction also displayed a moderate antibacterial activity against Listeria monocytogenes ATCC 19115 (MIC = 0.312 mg/mL) and strong antileishmanial activity against both promastigote and amastigote forms with IC50 ranging from 22.93 ± 0.39 μg/mL to 35.23 ± 0.62 μg/mL. Furthermore the ethyl acetate fraction exhibited low cytotoxicity and good selectivity index towards the macrophage cell line Raw 264.7. HPLC analysis of the active fraction revealed the presence of hydroxycinnamic acid as major compound (30.56%). Asteriscus graveolens is a promising source of bioactive compounds that could be potentially used in cosmetic and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Despite the significant developments occurring in the treatment of cancer, multiple myeloma remains the second haematological deadly disease. The aim of this study was to investigate the antiproliferative and apoptotic activities of Olea europaea L. cv Chetoui leaf and stem extracts (OLE and OSE) on human myeloma cells, given that plant compounds provide antitumor drugs. Anti-cancer activity was tested on U266 human multiple myeloma cell line using MTT and trypan blue assays. Cell cycle analysis, cell death mechanism, mitochondrial membrane potential levels and caspases activities were assessed in U266 cells using flow cytometry. The nuclear morphology of U266 cells was observed using Hoechst 33342 using fluorescent microscopy. Our data revealed that treatment with OLE and OSE induced anti-proliferative effects on U266 myeloma cells in dose and time dependent manner. The IC50 of OLE and OSE were 55 and 35 μg/mL, respectively after 48 h of exposure. Interestingly, cell cycle analysis showed significant decrease of U266 cells in G1 phase related to significant increase in sub-G1 population after 24 h of extract treatment. Moreover, OLE and OSE significantly induced apoptosis in U266 cell line after 24 h of treatment by inducing mitochondria dysfunctions and caspase 3/7 expression. To our knowledge this is the first paper to be conducted on olive stem extract. Our study showed that OLE and OSE had potent anti-multiple myeloma properties. This work may form the basis for further investigation on olive extracts as potential therapeutic agent on multiple myeloma. [ABSTRACT FROM AUTHOR]

Abstract Four hundred and fifty bacteria were evaluated for antagonistic activity against bacterial soft rot of potato caused by Pectobacterium carotovorum sp strain II16. A strain Ar10 exhibiting potent antagonist activity has been identified as Bacillus amyloliquefaciens on the basis of biochemical and molecular characterization. Cell free supernatant showed a broad spectrum of antibacterial activity against human and phytopathogenic bacteria in the range of 10-60 AU/mL. Incubation of P. carotovorum cells with increasing concentrations of the antibacterial compound showed a killing rate of 94.8 and 96% at MIC and 2xMIC respectively. In addition, the antibacterial agent did not exert haemolytic activity at the active concentration and has been preliminary characterized by TLC and GC–MS as a glycolipid compound. Treatment of potato tubers with strain Ar10 for 72 h significantly reduced the severity of disease symptoms (100 and 85.05% reduction of necrosis deep / area and weight loss respectively). The same levels in disease symptoms severity was also recorded following treatment of potato tubers with cell free supernatant for 1 h. Data suggest that protection against potato soft rot disease may be related to glycolipid production by strain Ar10. The present study affords new alternatives for anti- Pectobacterium carotovorum bioactive compounds against the soft rot disease of potato. [ABSTRACT FROM AUTHOR]