Improvement and prediction of the extraction parameters of lupeol and stigmasterol metabolites of Melia azedarach with response surface methodology.

BACKGROUND: Melia azedarach is known as a medicinal plant that has wide biological activities such as analgesic, antibacterial, and antifungal effects and is used to treat a wide range of diseases such as diarrhea, malaria, and various skin diseases. However, optimizing the extraction of valuable secondary metabolites of M. azedarach using alternative extraction methods has not been investigated. This research aims to develop an effective, fast, and environmentally friendly extraction method using Ultrasound-assisted extraction, methanol and temperature to optimize the extraction of two secondary metabolites, lupeol and stigmasterol, from young roots of M. azedarach using the response surface methodology. METHODS: Box-behnken design was applied to optimize different factors (solvent, temperature, and ultrasonication time). The amounts of lupeol and stigmasterol in the root of M. azedarach were detected by the HPLC-DAD. The required time for the analysis of each sample by the HPLC-DAD system was considered to be 8 min. RESULTS: The results indicated that the highest amount of lupeol (7.82 mg/g DW) and stigmasterol (6.76 mg/g DW) was obtained using 50% methanol at 45 °C and ultrasonication for 30 min, and 50% methanol in 35 °C, and ultrasonication for 30 min, respectively. Using the response surface methodology, the predicted conditions for lupeol and stigmasterol from root of M. azedarach were as follows; lupeol: 100% methanol, temperature 45 °C and ultrasonication time 40 min (14.540 mg/g DW) and stigmasterol 43.75% methanol, temperature 34.4 °C and ultrasonication time 25.3 min (5.832 mg/g DW). CONCLUSIONS: The results showed that the amount of secondary metabolites lupeol and stigmasterol in the root of M. azedarach could be improved by optimizing the extraction process utilizing response surface methodology.

Improvement and prediction of secondary metabolites production under yeast extract elicitation of Azadirachta indica cell suspension culture using response surface methodology.

Neem is a medicinal plant used as antimalarial, antibacterial, antiviral, insecticide, and antimicrobial drug. This study aimed to investigate and predict the effect of yeast extract and sampling time on cell growth, secondary metabolites synthesis, SQS1 and MOF1 genes expression by response surface methodology. The highest fresh and dry cell weights were 580.25 g/L and 21.01 g/L, respectively obtained 6 days after using 100 mg/L yeast extract. The highest azadirachtin accumulation and production were 16.08 mg/g DW and 219.78 mg/L obtained 2 and 4 days, respectively after using 25 mg/L yeast extract. Maximum mevalonic acid accumulation (1.75 mg/g DW) and production (23.77 mg/L) were observed 2 days after application of 50 mg/L yeast extract. The highest amount of squalene accumulation (0.22 mg/g DW) and production (4.53 mg/L) were achieved 4 days after using 50 mg/L yeast extract. Prediction results exhibited the highest azadirachtin accumulation (13.61 mg/g DW) and production (190.50 mg/L), mevalonic acid accumulation (0.50 mg/g DW) and production (5.57 mg/L), and squalene accumulation (0.30 mg/g DW) by using 245 mg/L yeast extract for 2 days, 71 mg/L yeast extract for 2 days, 200 mg/L yeast extract for 4.96 days, without yeast extract for 6.54 days and 4 days, respectively. Also, it was predicted that the highest squalene production is achieved by long-term exposure to high concentrations of yeast extract. The qRT-PCR analysis displayed the maximum relative gene expression of SQS1 and MOF1 by using 150 and 25 mg/L yeast extract for 4 and 2 days treatment.

New biological trends on cell and callus growth and azadirachtin production in Azadirachta indica.

Azadirachtin is an important secondary metabolite from Azadirachta indica used as a natural biopesticide. This study is the first comprehensive report concerning the influence of plant growth regulators on callus induction, cell suspension growth, and azadirachtin accumulation and production in cell suspension cultures of A. indica. We investigated the effect of plant growth regulators including different types of auxins and cytokinins and their combinations on callus induction, cell suspension growth, and azadirachtin accumulation and production. The highest percentage of callusing (100%) obtained at different combinations of plant growth regulators on MS medium supplemented with 1 mg/L picloram and 2 mg/L kinetin and the highest fresh weight of callus (264.50 mg) was observed in MS medium containing 1.5 mg/L NAA and 3 mg/L kinetin. In cell suspension cultures, the maximum cell density, SCV, and PCV were 2.44 × 106 cells per mL, 97.95%, and 81.46%, respectively, obtained in the MS medium containing 1.5 mg/L 2,4-D and 3 mg/L zeatin riboside. The highest average growth rate (0.25 days) was on MS medium containing 1.5 mg/L NAA and 3 mg/L zeatin riboside. The MS medium supplemented with 1 mg/L picloram and 2 mg/L kinetin produced the highest amount of fresh cell weight (493.02 g/L), dry cell weight (77.27 g/L), azadirachtin accumulation (3.69 mg/gDW), and azadirachtin production (285.64 mg/L). The results showed that all measured indices had positive correlation with together except FCW and DCW with azadirachtin accumulation.

Enhanced thebaine production in Papaver bracteatum cell suspension culture by combination of elicitation and precursor feeding.

In this study, the effect of methyl jasmonate (MJ) and ultrasound (US), individually and in combination with L-tyrosine, on the stimulation of thebaine production in Papaver bracteatum cell suspension cultures was studied. The addition of L-tyrosine did not significantly affect the cell biomass, but significantly increased the thebaine yield of cells compared with the control. The synergistic effects of MJ and L-tyrosine in the combined treatment of 100 µM MJ and 2 mM L-tyrosine increased the thebaine yield of cells up to 84.62 mg L(- 1) at 6 days after treatment. Sonication of the cells for 20 s caused a significant decrease in cell growth and biomass, whereas the thebaine yield increased up to 39.60 mg L(- 1) at 6 days after treatment. The combination of US (10 s) and L-tyrosine feeding (2 mM) significantly increased the production of thebaine in comparison to individual utilisation of 2 mM L-tyrosine and US (10 s).