ABSTRACT
This study aimed at isolation, identification and evaluation of probiotic potential of Lactobacillus isolates from camel's milk. Thirty four Lactobacillus isolates coded M 1 to M 34 were Gram positive, rods, catalase and oxidase negative and nonspore-forming bacteria. These isolates were identified by biochemical tests and API 50 CH kits. From these, 14 different Lactobacillus isolates (M 1, M 2, M 4, M 5, M 9, M 10, M 12, M 14, M 15, M 18, M 20, M 27, M 29 and M 31) which were tolerant to gastric and intestinal juices in a previous study were now tested for antipathogenic activity which varied according to the Lactobacillus species and the challenged pathogen. All 14 isolates demonstrated significant inhibitory effect against methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus and moderate to low activity against Salmonella typhimurium and Escherichia coli. When tested for bile tolerance at the concentration of 0.3 to 2.0%, the growth rate of 8 isolates M 2, M 5, M 9, M 10, M 12, M 14, M 18 and M 20 exceeded 60% in 0.3 and 0.5% bile. M 2 (L. fermentum) and M 12 (L. plantarum) and M 20 (L. paracasei ssp. paracasei) exhibited the highest growth rates of 82, 79.4 and 78.8% respectively. At higher levels of 1 and 2% bile, significant reduction (p < 0.05) was observed for all tested isolates except M 9 (L. plantarum) with growth rate of 66.5% at 2% bile. As for cholesterol reduction, M 10 (L. plantarum) and M 15 (L. paracasei ssp. paracasei) had the highest reduction rate of 58.0 and 53.2% respectively, which is comparable to the reference strain L. reuteri DSMZ 20056. Testing adhesion to intestinal epithelial cells and ileal tissues of BALB/c mouse; M 20 (L. paracasei ssp. paracasei) and M 2 (L. fermentum) exhibited highest attachment rate of more than 15 bacterial cells/epithelial cell. SEM images showed variable degrees of bacterial attachment to ileal tissues. These results suggest that camel milk is a rich source for potential probiotic lactobacilli which may be suitable for food and nutraceuticals industries; however, further in vivo investigations are needed.
ABSTRACT
Aims: to evaluate the potential apoptosis inducing effect of Ducrosia flabellifolia extracts against different cancer cell lines. Methodology: The antiproliferative activity of Ducrosia flabellifolia extracts was tested against three cell lines using MTT assay. The apoptosis induction ability of ethanol extract was determined using TUNEL colorimetric assay while agarose gel electrophoresis was used to detect DNA fragmentation. Morphological changes associated with apoptosis were observed using scanning electron microscopy. LC/MSMS analysis was used to determine the main flavonoids present in the plant extract. Results: Ducrosia flabellifolia ethanol extract showed selective antiproliferative activity against different cell lines. The highest activity was against MCF-7 cell line with IC50 value of 25.34 μg/mL, followed by Hep-2 cell line with IC50 value of 98.01 μg/mL. While the lowest activity was against Vero cell line with IC50 value of 98.01 μg/mL. The antiproliferative effect was exerted by inducing apoptosis as indicted by the presence of DNA fragmentation, nuclear condensation, and formation of apoptotic bodies in treated cancer cells. LC/MS-MS analysis revealed the presence of five flavonoids (quercetin, fisetin, kaempferol, luteolin, and apigenin) and their derivatives in the extract. Conclusion: The apoptosis inducing ability of Ducrosia flabellifolia ethanol extract validate the use of this plant in traditional medicine to treat cancer. The anticancer synergistic effect of Ducrosia flabellifolia compounds has broad implication for understanding the anticancer potential of plant natural products in vivo, where different compounds may act in concert to reduce tumor burden.