Antioxidants are vital substances protecting cells from oxidative damage of biological molecules like DNA, proteins, lipids and maintain normal homeostasis in cell by scavenging free radicals. Oxidative stress is one of the major source of free radicals and causing disorders like multiple sclerosis, Alzheimer’s, Parkinsons, cardiovascular diseases, and other degenerative disorders. Antioxidants finds application in medicine as they, act as immunoregulators, fight against ageing and also reported to induce apoptosis, cell cycle arrest against some cancer cell lines. Antioxidant also finds application in cosmetic industry and even as topical formulation. They are used as a preservative and also to increase the shelf life of frozen fish, canned mushrooms, meat, juice and general foods.
Studies suggested that medicinal plants are a potential, inexpensive and safe source of antioxidants as they are enriched with bioactive compounds.
Berberies aristata is commonly called as Daruhaldi or Chitra belongs to family Berberidaceae. The use of root extract as antipyretic, antiseptic, in the treatment of conjunctivitis, ulcers and hepatic disorders have been reported in earlier studies by various workers. The plant has been used for treatment of skin diseases, inflammation, diarrhoea and jaundice.
Medicinal plants in the present study were screened for their antioxidant potential against different radicals like DPPH, superoxide, hydroxyl and peroxide. Among them ethanolic roots extract B.aristata exhibit highest antioxidant ability and least IC50 value.
Thus further, the ethanolic root extract of B.aristata was subjected to activity guided isolation of antioxidants. Upon liquid-liquid fractionation ethyl acetate fraction exhibited highest radical scavenging activity against DPPH and peroxide radicals. In addition, the IC50 for DPPH radical scavenging and inhibition of lipid peroxidation were significantly less compared to crude ethanol extract indicating quality of antioxidants in ethyl acetate fraction.
Contents
Chapter 1 Introduction and review of literature
1.1 Introduction
1.2 Classification of antioxidants
1.3 Applications of antioxidants
1.4 Source of natural antioxidants
1.4.1 Berberis aristata
1.4.2 Carum carvi
1.4.3 Foeniculum vulgare
1.4.4 Glycyrrhiza glabra
1.4.5 Madhuca indica
1.4.6 Myristica fragrans
1.4.7 Nardostacy’s jatamansi
1.4.8 Swertia chirayita
1.4.9 Trachyspermum ammi
1.4.10 Zingiber officinale
1.5 Protoberberine
Chapter 2 Screening of medicinal plant extracts for antioxidant activity and phytochemicals
2.1 Introduction
2.2 Aim and Objectives
2.3 Materials and Methods
2.3.1 Preparation of plant extracts
2.3.2 DPPH radical scavenging assay
2.3.3 Superoxide radical scavenging assay
2.3.4 Hydroxyl radical scavenging assay
2.3.5 In-vitro inhibition of lipid peroxidation
2.3.6 Total antioxidant assay by FRAP method
2.3.7 Screening of medicinal plant extracts for phytochemicals
2.3.7.1 Tests for alkaloids
2.3.7.2 Tests for flavonoids and polyphenolics
2.3.7.3 Test for saponins
2.3.7.4 Test for tannins
2.4 Statistical analysis
2.5 Results and Discussion
2.6 Conclusion
Chapter 3 Activity guided isolation of antioxidants from B.aristata
3.1 Introduction
3.2 Aim and Objectives
3.3 Materials and Methods
3.3.1 Fractionation of ethanolic extract of B.aristata
3.3.2 Antioxidant activity
3.3.3 Phytochemical analysis
3.3.3.1 UV-Visible absorption spectral analysis
3.3.3.2 Qualitative analysis
3.3.3.3 Quantification of total alkaloids
3.3.3.4 Quantification of total phenolics
3.3.3.5 Quantification of total flavonoids
3.4 Statistical analysis
3.5 Results and Discussion
3.6 Conclusion
Chapter 4 Antioxidant potential of ethyl acetate fraction against oxidative stress in E.coli model, on erythrocytes and DNA
4.1 Introduction
4.2 Aim and Objectives
4.3 Materials and Methods
4.3.1 Effect of H2 O2 induced oxidative stress in E.coli model
4.3.2 Effect of AAPH radical induced oxidative stress on RBC
4.3.3 DNA fragmentation assay
4.4 Statistical analysis
4.5 Results and Discussion
4.6 Conclusion
Chapter 5 Purification and characterisation of antioxidant alkaloids from B.aristata
5.1 Introduction
5.2 Aim and Objectives
5.3 Materials and Methods
5.3.1 Purification using silica gel column chromatography
5.3.2 High performance liquid chromatography
5.3.3 Structure prediction
5.3.3.1 UV-Visible absorption spectral analysis
5.3.3.2 IR spectroscopy
5.3.3.3 Nuclear magnetic resonance spectroscopy
5.4 Results and Discussion
5.5 Conclusion
Chapter 6 In silico docking studies of berberrubine, jatrorrhizine and thalifendine with caspase 3, cathepsin B, MMP-9 and telomeric DNA
6.1 Introduction
6.2 Aim and Objectives
6.3 Materials and Methods
6.3.1 Retrieval of receptors from Protein DataBank (PDB)
6.3.2 Designing of ligands
6.3.3 Docking with hex v6.3
6.3.4 Docking with iGEMDOCK v2.1
6.4 Results and Discussion
6.5 Conclusion
Chapter 7 Antiproliferative and protease inhibitory activities of protoberberines
7.1 Introduction
7.2 Aim and Objectives
7.3 Materials and Methods
7.3.1 Antiradical activity of berberrubine, jatrorrhizine and thalifendine
7.3.2 Cell proliferation assay
7.3.3 In vitro inhibition of cathepsin B enzyme activity
7.3.4 In vitro inhibition of MMP-9 enzyme activity
7.4 Statistical analysis
7.5 Results and Discussion
7.6 Conclusion
Bibliography
Research Objectives and Focus
The research primarily aims to identify and isolate potent antioxidant compounds from the medicinal plant Berberis aristata, evaluate their biological activity, and investigate their therapeutic potential against oxidative stress and cancer through in vitro and in silico methods.
- Screening of various medicinal plants for antioxidant properties using diverse free radical scavenging assays.
- Activity-guided isolation and structural characterization of active alkaloids (protoberberines) from B. aristata.
- Assessment of the protective role of isolated compounds against oxidative stress in cellular and DNA models.
- In silico molecular docking studies to predict the interaction of isolated protoberberines with cancer-regulating target proteins.
- Investigation of the antiproliferative and protease inhibitory activities of the purified compounds against cancer cell lines.
Excerpt from the Book
1.4.1 Berberis aristata
Berberis is a genus which belongs to family Berberidaceae with nearly 450-500 species of shrubs or small trees. Berberis aristata is a spinous shrub grown in Himalayas, Nepal and Bhutan. It is commonly called as Daruhaldi or Chitra and is distributed in temperate and sub-tropical parts of Asia, Europe and America (Chopra et al., 1956). These species are well known for their curative properties in folk medicine from several centuries (Sharma et al., 2011).
It is an erect spiny shrub grows upto 2 to 3m in height with hard and yellow coloured wood. The bark appears yellowish brown from outside and dark yellow from inside. The leaves are in tufts, lanceolated, toothed and sessile. The flowers are stalked, yellow coloured, complete and inflorescence is a simple corymbose racemose. The fruits are globose to ovoid with violet colour and contain 2 to 5 seeds (Parmar et al., 1982; Rashmi et al., 2008).
Traditionally, B. aristata is used for the treatment of skin diseases, inflammation, diarrhoea and jaundice (Rashmi et al., 2008). Crude extract from leaves is demonstrated to have hepatoprotective activity (Gilani et al., 1995) and crude extract from fruits have hypocholesterolemic activity (Janbaz et al., 2000). Sharma et al., (2011) reviewed that B.aristata stem have anticancerous activity on HT29 cell lines.
Summary of Chapters
Chapter 1: Provides an introduction and literature review regarding antioxidants, their classification, and the therapeutic applications of various medicinal plants.
Chapter 2: Details the screening of various solvent extracts from medicinal plants for their antioxidant potential against different radicals and qualitative phytochemical analysis.
Chapter 3: Describes the activity-guided isolation process of antioxidants from the ethanolic extract of B. aristata using liquid-liquid fractionation.
Chapter 4: Investigates the antioxidant potential of the ethyl acetate fraction of B. aristata against oxidative stress induced in E. coli, red blood cells, and DNA.
Chapter 5: Covers the purification and structural characterization of antioxidant alkaloids (protoberberines) from the ethyl acetate fraction of B. aristata.
Chapter 6: Presents in silico docking studies to analyze the binding affinity of isolated protoberberines with cancer-relevant targets like caspases, MMP-9, and telomeric DNA.
Chapter 7: Analyzes the antiproliferative and protease inhibitory activities of the purified protoberberines against specific human cancer cell lines.
Keywords
Berberis aristata, antioxidants, protoberberines, oxidative stress, DPPH, lipid peroxidation, DNA fragmentation, docking, caspase 3, MMP-9, cathepsin B, antiproliferative, cancer, alkaloids, medicinal plants.
Frequently Asked Questions
What is the core focus of this research?
The research is dedicated to the study of antioxidant, antiproliferative, and protease inhibitory effects of protoberberine alkaloids derived from the plant Berberis aristata.
What are the primary themes explored?
Key themes include plant-based antioxidant screening, isolation and purification of bioactive compounds, structural characterization via spectroscopy, and the investigation of anti-cancer properties through molecular docking and cell culture assays.
What is the ultimate objective of this thesis?
The primary goal is to validate the traditional medicinal use of B. aristata by identifying its active components and establishing their efficacy as therapeutic agents against oxidative stress and cancer.
Which scientific methods are employed?
The study uses liquid-liquid fractionation, silica gel column chromatography, HPLC, UV-Visible, IR and NMR spectroscopy, in vitro radical scavenging assays, MTT proliferation assays, and in silico molecular docking software like Hex v6.3 and iGEMDOCK.
What is covered in the main section of the work?
The main sections cover the screening of various medicinal plants, activity-guided isolation, the protective effect of B. aristata extracts against oxidative stress, chemical purification, computational docking studies, and final efficacy testing in cancer cell lines.
Which keywords best describe this study?
Key terms include Berberis aristata, antioxidants, protoberberines, oxidative stress, docking, protease inhibition, and cancer treatment.
How does the ethyl acetate fraction contribute to the study's findings?
The ethyl acetate fraction was found to be a rich source of antioxidant alkaloids, exhibiting the highest radical scavenging and lipid peroxidation inhibition activity compared to other solvents.
What conclusions were drawn regarding the protoberberines?
The study concluded that berberrubine, jatrorrhizine, and thalifendine exhibit significant antioxidant and anti-cancer properties, with binding potential comparable to existing drugs like doxorubicin.
- Quote paper
- Seema Kumari (Author), 2012, Isolation and Characterisation of Protoberberines with Antioxidant, Antiproliferative and Protease Inhibitory Activity from Berberis Aristata, Munich, GRIN Verlag, https://www.grin.com/document/302826
