Oxidative stress, excess generation of Reactive Oxygen Species (ROS), is a common event in many pathological conditions including cancer. The generation of reactive oxygen species (ROS) is an inevitable aspect of life under aerobic conditions. ROS are continuously produced as byproducts of certain metabolic pathways and also by some specific systems under fine cellular control. At the same time, ROS are degraded via several specific and nonspecific mechanisms. These two processes are usually under tight cellular control and very low (<10-8 M) steady-state levels are maintained. However, under some special conditions, the balance between ROS production and elimination is disturbed and leading to generation of super oxides (O2-), hydroxyl radical (OH-) and hydrogen peroxide (H2O2).
H2O2, a common intermediate of various enzymatic and non-enzymatic reactions including electron transport chain, peroxisomal oxidases, flavoproteins as well as D-amino acid oxidases, L-hydroxy acid oxidases and fatty acyl oxidases. In endoplasmic reticulum, cytochrome P-450, P-450 reductase and cytochrome b-5 reductase generate superoxide anion and hydrogen peroxide during their catalytic cycles. The catalytic cycle of xanthine oxidase has emerged as an important source of O2 – and H2O2. During phagocytosis, the phagocytic cells such as neutrophils generate O2– and H2O2 by NADPH oxidase. Inflammation is also one of the major sources of ROS. Spontaneous dismutation of O2– at neutral pH or dismutation by superoxide dismutase also results in H2O2 production. Substantial evidence has indicated that H2O2 play a key role in wide range of diseases including CNS , autoimmune, cardiac, alveolar and hepatic disorders. The pathological role of H2O2 is well established in many acute and chronic disorders such as ischemia, atherosclerosis, diabetes, aging, immuno suppression and neuro degeneration.
H2O2 is an important metabolite produced in cells during metabolic reactions, plays an important role in cell death (or) apoptosis. Accumulating data suggest that an increase in the cellular concentrations of H2O2 associated with DNA damage and mutations which leads to the prevalence of various disorders. H2O2 induced DNAf damage seems to be mediated by OH.- generated from H2O2. Several studies have also demonstrated that increased levels of H2O2 can induce cell death.
Table of Contents
CHAPTER-I INTRODUCTION AND REVIEW OF LITERATURE
1.1. INTRODUCTION
1.2. REVIEW OF LITERATURE
CHAPTER-II PHYTOCHEMICAL ANALYSIS OF Semecarpus anacardium STEM BARK FOR FREE RADICAL SCAVENGING, ANTIOXIDANT AND CYTOPROTECTIVE ACTIVITIES
2.1. INTRODUCTION
2.2. OBJECTIVES
2.3. MATERIALS AND METHODS
2.3.1. Preparation of Plant Extract
2.3.2. DPPH Radical Scavenging Activity
2.3.3. Total Antioxidant Activity by FRAP Method
2.3.4. Hydroxyl Radical Scavenging Activity
2.3.5. Superoxide Radical Scavenging Activity
2.3.6. Hydrogen Peroxide Scavenging Assay
2.3.7. Inhibition of Lipid Peroxide Formation
2.3.8. HRB Membrane Stabilization Test
2.3.9. Preliminary Phytochemical Analysis of Methanolic Extract of S.Anacardium Stem Bark
2.3.9.1. Tests for Polyphenolics
2.3.9.2. Tests for Flavonoids
2.3.9.3. Tests for Alkaloids
2.3.9.4. Test for Saponins
2.3.9.5. Test for Tannins
2.3.9.6. Quantification of Total Phenolics
2.3.9.7. Quantification of Total Flavonoids
2.4. STATISTICAL ANALYSIS
2.5. RESULTS AND DISCUSSION
2.6. CONCLUSION
CHAPTER-III PURIFICATION AND CHARACTERIZATION OF ANTIOXIDANT COMPOUND(S) FROM METHANOLIC EXTRACT OF Semecarpus Anacardium STEM BARK
3.1. INTRODUCTION
3.2. OBJECTIVES
3.3. MATERIAL AND METHODS
3.3.1. Chemicals
3.3.2. Activity Guided Isolation of Antioxidant Compounds Using Soxhlet Extractor
3.3.3. Purification of Antioxidant Compound(s) using Silica Gel Chromatography
3.3.4. Thin Layer Chromatography
3.3.5. High Pressure Liquid Chromatography (HPLC)
3.3.6. UV-Visible Absorption Spectroscopy
3.3.7. Liquid Chromatography Electrospray Ionization Mass Spectroscopy (LC- ESI-MS)
3.3.8. FT-IR Spectroscopy
3.3.9. NMR Spectroscopy
3.4. RESULTS AND DISCUSSION
3.5. CONCLUSION
CHAPTER IV PROTECTIVE EFFECT OF ISOLATED FLAVONOIDS ON H2O2 INDUCED CYTOTOXICITY IN LUNG AND LIVER CELLS
4.1. INTRODUCTION
4.2. OBJECTIVES
4.3. MATERIALS AND METHODS
4.3.1. Chemicals and other Reagents
4.3.2. Cell Culture and Treatments
4.3.3. Determination of Cytotoxicity Effect of H2O2 on L-132 and L02 Cell Lines
4.3.4. Protective Effect of Isolated 3-O-Methyl quercetin and Kaempferol against H2O2 Induced Cytotoxicity
4.3.5. Protective Effect of Isolated 3-O-Methyl quercetin and Kaempferol on H2O2 Induced Morphological Changes in L132 and L02 cells.
4.3.6. Lactate Dehydrogenase (LDH) Release Assay
4.4. STATISTICAL ANALYSIS
4.5. RESULTS AND DISCUSSION
4.6. CONCLUSION
CHAPTER-V PROTECTIVE EFFECT OF ISOLATED 3-O-METHYL QUERCETIN AND KAEMPFEROL ON H2O2 INDUCED CELL DEATH OF LUNG AND HEPATIC CELLS
5.1. INTRODUCTION
5.2. OBJECTIVES
5.3. MATERIALS AND METHODS
5.3.1. Chemicals and Other Reagents
5.3.2. Cell culture and Treatments
5.3.3. Estimation of Intracellular ROS using DCFH-DA
5.3.4. Measurement of Mitochondrial Membrane Potential (MMP)
5.3.5. DNA damage by Comet Assay
5.3.6. DNA laddering Assay
5.4. STATISTICAL ANALYSIS
5.5. RESULTS AND DISCUSSION
5.6. CONCLUSION
CHAPTER-VI EFFECT OF ISOLATED FLAVONOIDS ON ACTIVATION OF STRESS MARKERS : AN IN SILICO AND IN VITRO ANALYSIS
6.1. INTRODUCTION
6.2. OBJECTIVES
6.3. MATERIALS AND METHODS
6.3.1. Chemicals and other Reagents
6.3.2. Cell culture and Treatments
6.3.3. In Silico Analysis of Stress Marker Proteins p38α, ERK1, JNK1 and Nrf2 by Docking Process
6.3.3.1. Retrieval of Proteins from Protein Data Bank (PDB)
6.3.3.2. Designing of Ligand
6.3.3.3. Docking with GOLD Suite
6.3.4. RT-PCR Analysis
6.3.5. Western-blot Analysis
6.4. STATISTICAL ANALYSIS
6.5. RESULTS AND DISCUSSION
6.6. CONCLUSION
CHAPTER-VII SUMMARY
Research Objectives and Focus Areas
The primary research objective of this thesis is to evaluate the antioxidant and cytoprotective properties of the stem bark extract of Semecarpus anacardium, specifically focusing on the characterization of its isolated flavonoids and their protective mechanism against hydrogen peroxide-induced oxidative stress in human lung and liver cell lines.
- Phytochemical screening and quantification of phenolic and flavonoid compounds in Semecarpus anacardium.
- In vitro evaluation of antioxidant activity using radical scavenging assays and membrane stabilization models.
- Isolation and structural elucidation of antioxidant flavonoids using chromatographic and spectroscopic techniques (HPLC, NMR, FT-IR).
- Investigation of the cytoprotective effects of isolated flavonoids on hydrogen peroxide-induced cell damage in lung and liver cell lines.
- In silico molecular docking studies and gene expression analysis (RT-PCR, Western blot) of stress markers such as Nrf2 and p38.
Excerpt from the Book
1.1. INTRODUCTION
Oxidative stress, excess generation of Reactive Oxygen Species (ROS), is a common event in many pathological conditions including cancer. The generation of reactive oxygen species (ROS) is an inevitable aspect of life under aerobic conditions. ROS are continuously produced as byproducts of certain metabolic pathways and also by some specific systems under fine cellular control. At the same time, ROS are degraded via several specific and nonspecific mechanisms. These two processes are usually under tight cellular control and very low (<10-8 M) steady-state levels are maintained (Halliwell and Gutteridge, 1989). However, under some special conditions, the balance between ROS production and elimination is disturbed and leading to generation of super oxides (O2-), hydroxyl radical (OH-) and hydrogen peroxide (H2O2).
H2O2, a common intermediate of various enzymatic and non enzymatic reactions including electron transport chain, peroxisomal oxidases, flavoproteins as well as D-amino acid oxidases, L-hydroxy acid oxidases and fatty acyl oxidases. In endoplasmic reticulum, cytochrome P-450, P-450 reductase and cytochrome b-5 reductase generate superoxide anion and hydrogen peroxide during their catalytic cycles. The catalytic cycle of xanthine oxidase has emerged as an important source of O2 – and H2O2. During phagocytosis, the phagocytic cells such as neutrophils generate O2 – and H2O2 by NADPH oxidase. Inflammation is also one of the major source of ROS. Spontaneous dismutation of O2 – at neutral pH or dismutation by superoxide dismutase also results in H2O2 production (Bandyopadhyay et al., 1999). Substantial evidence has indicated that H2O2 play a key role in wide range of diseases including CNS , autoimmune, cardiac, alveolar and hepatic disorders (Rahal et al., 2014). The pathological role of H2O2 is well established in many acute and chronic disorders such as ischemia, atherosclerosis, diabetes, aging, immuno suppression and neuro degeneration (Saeed et al., 2012).
Summary of Chapters
CHAPTER-I INTRODUCTION AND REVIEW OF LITERATURE: Provides an overview of oxidative stress and the importance of natural antioxidants, specifically highlighting the medicinal potential of Semecarpus anacardium.
CHAPTER-II PHYTOCHEMICAL ANALYSIS OF Semecarpus anacardium STEM BARK FOR FREE RADICAL SCAVENGING, ANTIOXIDANT AND CYTOPROTECTIVE ACTIVITIES: Details the methodologies and findings of the antioxidant and cytoprotective capabilities of various solvent extracts of the plant stem bark.
CHAPTER-III PURIFICATION AND CHARACTERIZATION OF ANTIOXIDANT COMPOUND(S) FROM METHANOLIC EXTRACT OF Semecarpus Anacardium STEM BARK: Focuses on the isolation and structure determination of specific antioxidant compounds using advanced spectroscopic methods.
CHAPTER IV PROTECTIVE EFFECT OF ISOLATED FLAVONOIDS ON H2O2 INDUCED CYTOTOXICITY IN LUNG AND LIVER CELLS: Evaluates how the isolated compounds protect normal lung and liver cells from damage caused by oxidative stress.
CHAPTER-V PROTECTIVE EFFECT OF ISOLATED 3-O-METHYL QUERCETIN AND KAEMPFEROL ON H2O2 INDUCED CELL DEATH OF LUNG AND HEPATIC CELLS: Examines specific cellular mechanisms, including ROS levels, mitochondrial integrity, and DNA damage, influenced by the isolated compounds.
CHAPTER-VI EFFECT OF ISOLATED FLAVONOIDS ON ACTIVATION OF STRESS MARKERS : AN IN SILICO AND IN VITRO ANALYSIS: Investigates the signaling pathways involved in the antioxidant response through molecular docking and gene expression analysis.
CHAPTER-VII SUMMARY: Concludes the thesis by synthesizing the research findings regarding the antioxidant and cytoprotective nature of the isolated compounds.
Keywords
Semecarpus anacardium, Oxidative stress, Reactive Oxygen Species (ROS), Flavonoids, 3-O-methyl quercetin, Kaempferol, Cytoprotection, Antioxidant enzymes, Nrf2, p38 MAPK, Molecular docking, Lipid peroxidation, Apoptosis, Comet assay, Cell line studies.
Frequently Asked Questions
What is the core subject of this research thesis?
The thesis investigates the antioxidant and cytoprotective properties of the methanolic extract of Semecarpus anacardium stem bark and specifically studies the efficacy of isolated flavonoid compounds in protecting human lung and liver cells from hydrogen peroxide-induced oxidative damage.
What are the primary thematic fields addressed?
The key themes include plant biochemistry, natural product isolation, cellular signaling pathways, oxidative stress biology, and pharmacological evaluation of medicinal plants.
What is the primary objective of this work?
The goal is to provide scientific evidence for the traditional medicinal uses of Semecarpus anacardium by identifying active antioxidant constituents and demonstrating their protective effects on human cell models through both experimental and computational analyses.
Which scientific methods are primarily utilized?
The study employs chromatographic techniques (column, TLC, HPLC), spectroscopic characterization (NMR, FT-IR, Mass spectrometry), in vitro cell culture models (MTT, LDH, comet assays), and in silico molecular docking simulations.
What does the main body of the work encompass?
The main chapters cover the systematic extraction and analysis of phytochemicals, the purification of active flavonoids (3-O-methyl quercetin and kaempferol), and the evaluation of their cytoprotective activities against oxidative insults in lung and liver cell lines.
How can this work be described in terms of key topics?
The work is defined by the study of plant-derived flavonoids, the cellular defense mechanisms against oxidative stress, and the role of transcriptional regulators like Nrf2 and MAPK signaling in mediating antioxidant responses.
Which compounds were isolated and identified in this study?
The study successfully isolated and characterized two key flavonoid compounds: 3-O-methyl quercetin and kaempferol, which were shown to possess potent antioxidant activity.
How does the research validate the protective effect of these flavonoids?
The research uses various biomarkers of cellular injury—including cell viability tests (MTT), membrane damage (LDH release), mitochondrial membrane potential assays, and DNA fragmentation analyses—to demonstrate the reduction of cellular stress in the presence of the isolated flavonoids.
- Arbeit zitieren
- Dr. A.D. Naveen Kumar (Autor:in), 2014, Studies on Antioxidant and Cryoprotective Flavonoids from the Stem bark of Semecarpus anacardium, München, GRIN Verlag, https://www.grin.com/document/380764
