Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
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Article Optimization of Precursor and Elicitor Utilization in Batch Cultures of Astragalus Trojanus Stev.(2018) Nartop, Pınar; Gürel, Aynur; Akgün, İsmail Hakkı; Bedir, ErdalElicitor and precursor applications are commonly used to induce secondary metabolism in plant cell cultures. In this study, methyl jasmonate, jasmonic acid, salicylic acid and pectin were used as elicitors and ?-sitosterol was used as a precursor in batch cultures of Astragalus trojanus in order to trigger astragaloside IV and cycloastragenol productions. Growth parameters (fresh and dry weights and dry weight percentages) of batch cultures were also evaluated in order to understand the effects of elicitors and precursor on primary metabolism. All elicitors and precursor used in this study triggered metabolite production at different stages of culture period. The highest astragaloside IV accumulation (0.9435 µg/mg) was detected in medium supplemented with 50 µM methyl jasmonate at the 14th day of culture period, whereas the highest cycloastragenol concentration (0.3626 µg/mg) was found in medium supplemented with 50 µM jasmonic acid at the 28th day of culture period. Large scale cultivation was also performed and 0.3759 µg/mg astragaloside IV was detected in medium supplemented with 50 µM methyl jasmonate at the 14th day.Article Astragalus Trojanus Stev. Batch Cultures: Cycloartane-Type Metabolite Accumulation in Response To Ph, Sucrose and Casein Hydrolysate(Hacettepe Üniversitesi, 2019) Nartop, Pınar; Gürel, Aynur; Akgün, İsmail Hakkı; Bedir, ErdalI n this study, two grams of callus regenerated from stem and leaf explants of Astragalus trojanus Stev. were cultured in Woody Plant Medium (WPM) supplemented with 1 mg/L 2,4-D for four weeks and used as inoculum in order to investigate the effects of working volume and media composition. The highest biomass was obtained in 250 mL flask with astragaloside IV (1.66 µg/mg) and cycloastragenol (0.19 µg/mg) accumulation. Different concentrations of sucrose and casein hydrolysate (1 and 2 g/L) were also tested and the effect of pH was also investigated. Biomass accumulation cannot be enhanced, however, astragaloside IV and cycloastragenol content was ascended. The highest astragaloside IV (95.23 µg/mg) and cycloastragenol (5.93 mg/mg) accumulations were obtained at pH 6.8 and 2 g/L casein hydrolysate, respectivelyArticle Citation - WoS: 13Citation - Scopus: 13Cycloartane-Type Sapogenol Derivatives Inhibit Nf?b Activation as Chemopreventive Strategy for Inflammation-Induced Prostate Carcinogenesis(Elsevier Ltd., 2018) Debeleç Bütüner, Bilge; Öztürk, Mert Burak; Tağ, Özgür; Akgün, İsmail Hakkı; Yetik Anacak, Günay; Bedir, Erdal; Korkmaz, Kemal SamiChronic inflammation is associated to 25% of cancer cases according to epidemiological data. Therefore, inhibition of inflammation-induced carcinogenesis can be an efficient therapeutic approach for cancer chemoprevention in drug development studies. It is also determined that anti-inflammatory drugs reduce cancer incidence. Cell culture-based in vitro screening methods are used as a fast and efficient method to investigate the biological activities of the biomolecules. In addition, saponins are molecules that are isolated from natural sources and are known to have potential for tumor inhibition. Studies on the preparation of analogues of cycloartane-type sapogenols (9,19-cyclolanostanes) have so far been limited. Therefore we have decided to direct our efforts toward the exploration of new anti-tumor agents prepared from cycloastragenol and its production artifact astragenol. The semi-synthetic derivatives were prepared mainly by oxidation, condensation, alkylation, acylation, and elimination reactions. After preliminary studies, five sapogenol analogues, two of which were new compounds (2 and 3), were selected and screened for their inhibitory activity on cell viability and NFκB signaling pathway activity in LNCaP prostate cancer cells. We found that the astragenol derivatives 1 and 2 as well as cycloastragenol derivatives 3, 4, and 5 exhibited strong inhibitory activity on NFκB signaling leading the repression of NFκB transcriptional activation and suppressed cell proliferation. The results suggested that these molecules might have significant potential for chemoprevention of prostate carcinogenesis induced by inflammatory NFκB signaling pathway.