اثر وابسته به غلظت عصاره مخمر بر محتوای برخی از ترکیبات فنلی در کشت سلولی مفرو (dracocephalum polychaetum bornm)

Dracocephalum polychaetum یک گیاه دارویی مهم است که به علّت خواص آنتی اکسیدانی و ضد سرطانی خود مورد توجه قرار گرفته است. در این پژوهش، تاثیر غلظت‌های 0، 25، 50، 100، 150 و 200 میلی گرم بر لیتر عصاره مخمر (ye) بر میزان تولیدی برخی از ترکیبات فنلی در سلول‌های d. polychaetum بررسی شد. آزمایش ها در قالب طرح کامل تصادفی در سه تکرار انجام شد. نتایج به دست آمده نشان دادند تمامی فاکتورهای اندازه گیری شده در سلول های تیمار شده تفاوت معنی داری نسبت به شاهد داشتند. بر این اساس، بالاترین فعالیت آنزیم‌های کلیدی فنیل آلانین آمونیالیاز (pal) و تیروزین آمونیالیاز (tal) در سلول‌های تیمار شده با غلظت 100 میلی‌گرم بر لیتر ye مشاهده شد. در نتیجه، بیشترین محتوای فنل کل، فلاونوئید کل، کوئرستین، کاتچین، کاروکرول و تیمول در سلول‌های تیمار شده با همان غلظت ye یافت شد. علاوه بر این، سلول‌های تیمار شده با غلظت 25 میلی‌گرم بر لیتر ye، بالاترین محتوای رزمارینیک اسید را نشان دادند. بر اساس نتایج، پاسخ سلول به اثر غلظت‌های مختلف ye وابسته به غلظت بود. بنابراین می‌توان نتیجه گرفت محتوای ترکیبات فنلی در سلول های تحت تیمار با ye به عنوان پاسخ دفاعی سلول در برابر تنش ایجاد شده، بود. همچنین، بر اساس نتایج حاصل از بررسی ضریب همبستگی، تجمع ترکیبات فنلی می‌تواند به طور مثبت با فعال شدن آنزیم‌های کلیدی به ویژه آنزیم pal در مسیر بیوسنتز فنیل پروپانوئیدها در سلول‌های تحت تیمار با ye تنظیم ‌شود.

the dose-dependent effect of yeast extract on the content of some phenolics in the cell suspension culture of dracocephalum polychaetum bornm.

dracocephalum polychaetum is a significant medicinal plant known for its antioxidant and anticancer properties. in this study, we assessed the impact of varying yeast extract (ye) doses on the levels of certain phenolic compounds in d. polychaetum cells. the experiments followed a completely randomized design with three replicates. the results indicated that all parameters considered in the treated cells showed a significant difference compared to the control. our results indicated that the highest activities of the key enzymes pal and tal were observed in cells treated with 100 mg/l of ye, suggesting a response to oxidative stress induced by ye. consequently, the highest contents of total phenol, flavonoid, quercetin, catechin, carvacrol, and thymol were found in cells treated with the same ye concentration. in addition, cells treated with 25 mg/l ye showed the highest levels of rosmarinic acid. the response to different ye concentrations was dose-dependent rather than linear. therefore, we conclude that moderate ye concentrations (100 mg/l) effectively increase phenolic contents. moreover, the variations in phenolic compound levels may represent a defense mechanism in d. polychaetum cells exposed to ye. based on the correlation coefficient, the accumulation of phenolic compounds can be positively regulated by activating key enzymes, particularly the pal enzyme, in the phenylpropanoid biosynthesis pathway in cells treated with ye. introductiondracocephalum polychaetum is a medicinal plant known for its potent antioxidant and anticancer properties. extensive research has highlighted this species’ applications in modern and traditional medicine, particularly its anti-inflammatory, antioxidant, antimicrobial, and anticancer properties. phytochemical analyses have revealed a variety of phenolic compounds present in the plant. however, production of these valuable metabolites is often limited, usually making up less than 1% of the dry weight. this production is influenced by the plant’s physiological and developmental stages and environmental conditions.to overcome the limitations in producing secondary metabolites, tissue and cell suspension cultures have emerged as effective biotechnological strategies. the biosynthesis of these metabolites can be significantly enhanced by applying biotic and abiotic elicitors. one commonly used elicitor is yeast extract (ye), which has been demonstrated to substantially increase the production of secondary metabolites compared to untreated controls.despite the medicinal significance of d. polychaetum, there is a lack of experimental studies utilizing biotic elicitors to boost its metabolite production. therefore, this study aims to investigate the effects of various concentrations of ye on the accumulation of specific phenolic compounds, as well as the activity of key enzymes involved in their biosynthetic pathways, namely phenylalanine ammonia-lyase (pal) and tyrosine ammonia-lyase (tal), within d. polychaetum cell cultures. material and method polychaetum seeds were germinated in ms medium supplemented with ga₃ under dark conditions at 25°c. hypocotyl explants were cultured in ms medium containing bap, naa, sucrose, and agar to induce callus formation, also in complete darkness at a temperature of 23±2°c. the resulting calli were then used to establish suspension cultures maintained at 25°c on an orbital shaker and subcultured every 12 days to promote uniform cell growth.on the eighth day of cultivation, during the logarithmic growth phase, the cells were treated with varying concentrations of ye. the cells were harvested on the 13th day. the phenolic and flavonoid content and the activities of the pal and tal enzymes were quantified using uv-vis spectrophotometry, while hplc was utilized for phytochemical analysis. statistical analyses were conducted, including duncan’s test (p ≤ 0.05) and principal component analysis (pca), to identify significant differences and relationships among the physiological parameters. results and discussionthe findings indicated that ye treatment significantly affected all measured parameters in d. polychaetum cells compared to the control group. the highest activities of pal and tal were found in cells treated with 100 mg/l ye. this suggests a strong response to the oxidative stress induced by ye. additionally, this treatment led to the most significant accumulation of total phenols, flavonoids, quercetin, catechin, carvacrol, and thymol. notably, the maximum content of rosmarinic acid was observed in cells treated with 25 mg/l ye.the response to ye was dose-dependent yet non-linear, with moderate concentrations (100 mg/l) proving most effective in enhancing phenolic compound production. these variations imply a defensive mechanism in d. polychaetum cells, which upregulate phenolic biosynthesis as a protective response to ye treatment. correlation analysis further confirmed a positive association between the accumulation of phenolic compounds and the activation of pal, underscoring the enzyme’s critical role in regulating secondary metabolite production.ye is abundant in amino acids, vitamins, and minerals supporting plant growth and development. additionally, it acts as an elicitor by triggering secondary signaling pathways by generating free radicals. these reactive molecules serve as secondary messengers, activating the phenylpropanoid pathway and stimulating the synthesis of phenolic compounds. the increased production of these potent antioxidants likely helps protect plant cells under ye-induced oxidative conditions, highlighting the potential of ye as an effective elicitor for enhancing secondary metabolite production in medicinal plants. conclusionthis study demonstrates that ye is an effective elicitor for enhancing the production of secondary metabolites in d. polychaetum. moderate concentrations of ye (100 mg/l) significantly activated the phenylpropanoid pathway, leading to increased activity of pal and tal. as a result, there was an enhanced accumulation of phenolic compounds such as quercetin, catechin, and thymol. these findings highlight the potential of ye to optimize the biosynthesis of valuable medicinal metabolites, offering a sustainable strategy to address the limitations of natural metabolite production in medicinal plants.