الفهرس 
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Abstract
This study intended to improve the quality and medicinal value of edible plants. Our interest is to focus on utilizing various plant extracts (Bio-modulators) in the modulation of medicinal plants’ secondary metabolites. This study aimed to modulate the contents of potato (Solanum tuberosum L.) peel to comply with food safety regulations and also open a new horizon for the utilization of toxic compounds in developing new anti-cancer drugs. Specifically, post-harvested potatoes were treated with several modulators (biotic and abiotic) for a certain period and the treated peel metabolites were identified by GC-MS and LC-ESI-MS/MS profiling. α-amylase inhibitory activity, reduced sugar content total phenolic, total flavonoids, total alkaloid content, and antioxidant activity were also evaluated for the treated potato peels. This study included the following chapters: Chapter 1: General Screening of selected plant extracts used as bio-modulators in treating post-harvest Cara potato.Bio-modulators’ phytochemical screening, % antioxidant activity, total flavonoid, and total alkaloid contents were evaluated.Chapter 2: General screening for modulated Cara potato peel.1.The alkaloid content conducted by bromocresol green revealed that treatment with LC 0.01% w/v methanolic extract showed the highest TAC by value 26.69 µg/mL.2.Interestingly, significant elevation in the antioxidant activity of Cara potato peel after 4 weeks from the application of modulators as pomegranate outer peel aqueous and methanolic extracts at different concentrations in comparison to control untreated 42.3%. 3.The total phenolic content for treated potato peel values ranged from 11.2 to 53.87 µL/mg GAE. Control potato peel exhibited the highest TPC by value of 53.87 µL/mg GAE. Furthermore, The total flavonoid content for treated Cara potato peel ranged from 231.6 to 651.6 µg/mg QE. The methanolic extract (0.0025% w/v) of PM retained the highest TFC 651.6 µg/mg QE.4.The effect of the applied modulators on potato peel reduced sugar content by using the dinitro salicylic acid (DNS) was conducted. The reduced sugar content in potato peel treated by red beetroot aqueous extracts indicates a significant reduction three-fold in comparison to the control (4.22 µg/mg).Chapter 3: Biological Screening of the modulated Cara potato peel.Part 1: α-Amylase inhibitory assay : α-Amylase enzyme % inhibition of potato peel, their values varied from 8.4% to 91.7%. The peel treated with red beetroot methanolic extract (0.0025% w/v) effectively exhibited the maximum inhibitory activity of 91.7%.Part 2: Cytotoxic activity and IC50 determination: Concerning cytotoxicity activity against five different cancer cell lines (MDA-MB-231, MCF-7, HepG2, HSF, and RAW264.7), treated peel with MJ 0.50 mM showed the higher cell viability for all tested cells with variation in activity for other used modulators.Chapter 4: chromatographic identification.Part 1: Gas chromatography-mass spectrometry (GC-MS) analysis:The GC-MS profile revealed serious modulations in the potato peel secondary metabolites when comparing the control with the treated group. Interestingly the treatment with LC 0.05% (w/v) aqueous extract, RB 0.0025% (w/v) methanolic extract, and PM 0.05% w/v aqueous extract suppressed the toxic solanidine-5-en-3-ol glycoalkaloid.Part 2: LC-ESI-MS/MS profiling:The LC-ESI-MS/MS analysis revealed major variations between the control and treated samples. Glycoalkaloids tomatidinol and solanidine were suppressed by the applied bio-modulators although their expression in the control untreated potato peel. Our finding interestingly determines the food safety effectiveness of OL (0.1% w/v) aqueous among all applied bio-modulators in the reduction of toxic glycoalkaloid in potato peel.Chapter 5: Isolation, purification, and structural elucidation of compounds from potato peel.α-Chaconine and α-solanine were isolated on normal phase silica gel column and purified over Amberlite® XAD®-2 resin.Chapter 6 : In silico Molecular properties, ADMET, and drug-likeness prediction.Swiss ADME calculation, SwissTargetPrediction web tool, Molsoft Drug-Likness, and admetSAR database calculations revealed the following:•All identified glycoalkaloids showed positive values for drug-likeness values except tomatidinol showed negative values.•Tomatidinol, solanidine, and solanidine-5-en-3-ol showed higher availability to cross the blood-brain barrier (BBB) with a low number of stereocenters.•None of the tested compounds were predicted to be CYP 450 inhibitors.•α-Solanine, α-chaiconine, β-chaconine, solanidine, solanidine-5-en-3-ol, leptinine II, leptinine I, and tomatidinol showed no lead likeness probability.•Tomatidinol, solanidine, and solanidine-5-en-3-ol showed a high bioavailability score (0.55).•Solanidine and solanidine-5-en-3-ol are the only tested compounds exhibiting a positive result with Caco2 cell permeability.•Concerning subcellular localization, all tested compound exhibits mitochondrial localization except solanidine-5-en-3-ol shows lysosomal localization.In conclusion: Biomodulators, phytohormones and chemical elicitors were used for modulating potato peel phytochemicals and biological activities. Potato peel methanolic extract was subjected to several investigations as GC-MS and LC-ESI-MS/MS profiling, α-amylase inhibitory activity, reduced sugar content total phenolic, total flavonoids, total alkaloid content, and antioxidant activity. Isolation of α-Solanine and α-chaiconine by simple economic procedure. Virtual screening and mechanism of action determination were performed for identified glycoalkaloids.Recommendations : 1.Further studies of different bio-modulators and their effects on different plant species’ secondary metabolites and biological activities.2.Study the effect of promising bio-modulators and their fractions on different medicinal and edible plants.3.Study the effect of different bio-modulators during different growth stages of the selected plant.4.Finding an explanation for results by monitoring pathway synthesis of different secondary metabolites and genes expression.