Browsing by Subject "binding"

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  • Ahlberg, Sara; Randolph, Delia; Okoth, Sheila; Lindahl, Johanna (2019)
    Aflatoxins continue to be a food safety problem globally, especially in developing regions. A significant amount of effort and resources have been invested in an attempt to control aflatoxins. However, these efforts have not substantially decreased the prevalence nor the dietary exposure to aflatoxins in developing countries. One approach to aflatoxin control is the use of binding agents in foods, and lactic acid bacteria (LAB) have been studied extensively for this purpose. However, when assessing the results comprehensively and reviewing the practicality and ethics of use, risks are evident, and concerns arise. In conclusion, our review suggests that there are too many issues with using LAB for aflatoxin binding for it to be safely promoted. Arguably, using binders in human food might even worsen food safety in the longer term.
  • Laurikkala, Sini (Helsingin yliopisto, 2015)
    The literature review presents general information on fungi and mycotoxins and then deals with aflatoxins, in particular aflatoxin B1 and M1, their occurrence, significance, and current methods for controlling the risk of aflatoxin. Particular emphasis was given to studies on lactic acid bacteria (LAB) in controlling the growth of aflatoxigenic molds and binding of aflatoxins. The aim of the experimental work was to assess the ability of 171 LAB isolates originating from Kenyan naturally fermented traditional milk and maize samples (1) to inhibit the growth of Aspergillus and (2) to bind aflatoxin M1 in vitro. All the LAB isolates (n=171) were screened for their antifungal activity against A. flavus by an overlay method with 100 µl LAB culture on potato dextrose agar (PDA) plate. Out of 171 LAB isolates, mold growth was reduced by 33 isolates, of which 19 isolates were confirmed to retain their activity. These 19 LAB isolates were tested against A. flavus with three different amounts of LAB culture (50 µl, 100 µl and 200 µl). Three LAB isolates performed best against A. flavus by inhibiting the growth with all the tested amounts of LAB culture. The three LAB isolates were identified as Lactobacillus plantarum first by 16S rDNA sequence analysis and later confirmed by recA derived primers and multiplex PCR assay. The ability of 171 LAB isolates to bind AFM1 from phosphate-buffered saline (PBS) in vitro was carried out. LAB isolates were incubated with an amount equivalent to 50 ng AFM1 /ml for 4 h and then centrifuged (10 000 rpm, 10 °C) for 15 min to obtain supernatant containing unbound AFM1. The amount of unbound aflatoxin was analysed by HPLC chromatography from 51 samples. Binding ability of the analyzed isolates varied from 15,4 % to 51,5 %, and six LAB isolates were shown to bind more than 42,4 % of AFM1. The results showed that all tested indigenous LAB isolated from fermented milk and maize products manufactured in Kenya had variable ability to control the growth of A. flavus and bind AFM1 in vitro. It is suggested that such LAB strains could be used for reduction of the risk of aflatoxin contamination in food and feed chains.
  • Guryanov, Ivan; Tennikova, Tatiana; Urtti, Arto (2021)
    Vascular endothelial growth factors (VEGFs) are the family of extracellular signaling proteins involved in the processes of angiogenesis. VEGFA overexpression and altered regulation of VEGFA signaling pathways lead to pathological angiogenesis, which contributes to the progression of various diseases, such as age-related macular degeneration and cancer. Monoclonal antibodies and decoy receptors have been extensively used in the anti-angiogenic therapies for the neutralization of VEGFA. However, multiple side effects, solubility and aggregation issues, and the involvement of compensatory VEGFA-independent pro-angiogenic mechanisms limit the use of the existing VEGFA inhibitors. Short chemically synthesized VEGFA binding peptides are a promising alternative to these full-length proteins. In this review, we summarize anti-VEGFA peptides identified so far and discuss the molecular basis of their inhibitory activity to highlight their pharmacological potential as anti-angiogenic drugs.