Elicitors have been widely used as biotic and abiotic stimulants in triggering the production of secondary metabolites in plant cell culture. The present study aimed to enhance the production of camphor and phenolic compounds and cell growth using methyl jasmonate (MeJA) and salicylic acid (SA) in the cell suspension culture of Turkish endemic species Achillea gypsicola. Various concentrations (0, 10, 50, and 100 µM) of MeJA and SA were applied to 8-day-old cell cultures. The camphor and phenolic compound contents were determined using a headspace gas chromatographic-mass spectrometer device and spectrophotometer. Increasing doses of MeJA and SA significantly enhanced the accumulation of the camphor and phenolic compounds in general. The highest amount of camphor accumulation occurred in cells treated with 100 µM MeJA (0.3449 µg/g) and 50 µM SA (0.3816 µg/g). Increasing concentrations of MeJA resulted in a significant decrease in the total anthocyanin when compared to the initial culture. The present study showed that MeJA and SA could effectively be used as potent elicitors to enhance the production of camphor and phenolic compounds, along with cell growth, in cell suspension cultures of the endemic Turkish yarrow species Achillea gypsicola.

Since December 2019, humanity has faced an important global threat. Many studies have been published on the origin, structure, and mechanism of action of the SARS-CoV-2 virus and the treatment of its disease. The priority of scientists all over the world has been to direct their time to research this subject. In this review, we highlight chemical studies and therapeutic approaches to overcome COVID-19 with seven different sections. These sections are the structure and mechanism of action of SARS-CoV-2, immunotherapy and vaccine, computer-aided drug design, repurposing therapeutics for COVID-19, synthesis of new molecular structures against COVID-19, food safety/security and functional food components, and potential natural products against COVID-19. In this work, we aimed to screen all the newly synthesized compounds, repurposing chemicals covering antiviral, anti-inflammatory, antibacterial, antiparasitic, anticancer, antipsychotic, and antihistamine compounds against COVID-19. We also highlight computer-aided approaches to develop an anti-COVID-19 molecule. We explain that some phytochemicals and dietary supplements have been identified as antiviral bioproducts, which have almost been successfully tested against COVID-19. In addition, we present immunotherapy types, targets, immunotherapy and inflammation/mutations of the virus, immune response, and vaccine issues.

Background: There has been considerable interest in antimicrobial activity of plant essential oils in recent years. Objectives: This research was carried out to determine morphogenetic, ontogenetic and diurnal variability in antimicrobial activity of bitter fennel essential oil. Methods: To specify morphogenetic variability, leaf and root-bulb-stalk samples taken at pre-, full and post-flowering, flower samples picked at full flowering and seed samples gathered at two seed growth stages were used. For ontogenetic and diurnal variability, whole plant samples were taken at pre-, full and post-flowering and at 9:00 am, 1:00 pm and 5:00 pm. A total of 10 microorganisms have been used to determine antimicrobial activity of essential oils with disc-diffusion and microdilution broth methods. Results: The highest inhibitory effect among leaf essential oils was observed from post-flowering samples, but essential oils of root-bulb-stalk samples of pre-flowering produced the highest antimicrobial activity. Whole plant essential oils of post-flowering samples produced higher antimicrobial activity than those of pre-and full flowering samples. Generally, inhibitory effect of seed essential oils extracted at the beginning of seed formation was higher than those of seed maturity. Daily harvesting time caused no effect on antimicrobial activity of essential oils of whole plant samples. Conclusion:The present study reveals that antimicrobial activity of bitter fennel essential oil significantly vary based on plant parts and growth stages.

Elicitor treatments play an important role in inducing some protective signal transmitter enzymes in cells and regulating phenylalanine ammonia-lyase (PAL) activity. The aim of this study was to determine the effects of elicitors [silver nitrate (AgNO3), salicylic acid (SA) and yeast extract (YE)], which were added individually or in combination to Ocimum basilicum L. cell suspension cultures, on the production and antioxidant activity of secondary metabolites (SMs). Calluses were obtained from the leaves of O. basilicum kept on Murashige and Skoog (MS) medium containing 0.5 mg/l kinetin (KIN) + 2.5 mg/l naphthalene-acetic acid (NAA) and cell suspension cultures were initiated. Then elicitors were applied to the cell suspension cultures individually or in combination, and cells were harvested at the end of the second, fourth, and eighth days. Compared with the control culture, the maximum rosmarinic and chicoric acid production was obtained at the end of the 4th day from SA (24 µM) + YE (80 mg/l) treatment as 20.19 mg/g DW (118%) and 7.55 mg/g DW (123%), respectively. The maximum biosynthesis of isoquercetin and rutin compared with the control culture was 3.88 mg/g DW [YE (80 mg/l)] with a 1.6-fold increase and 6.35 mg/g DW [YE (80 mg/l) + AgNO3 (6 µM)] with a 1.76-fold increase, respectively. Estragole and linalool's highest values compared with the control culture were 4.50 μg/g DW [AgNO3 (6µM) + SA (24 µM)] and 3.02 μg/g DW [SA (24 µM)], respectively. Results clearly show that the elicitor treatment could enhance the biosynthesis of phenolic compounds and terpenoid content in cell suspension cultures of O. basilicum and may be used for commercial supply in the future for therapeutic applications.

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