In this study four plants (Chrozophora hierosolymitana Spreng, Chrysanthemum leucanthemum L., Ephedra gerardiana Wall. ex Stapf and Quercus dilatata L.) collected from different regions of Pakistan were screened to identify any chemotherapeutic agents
present in them. Seven crude extracts of these plants (leaf, stem and root extracts of C. hierosolymitana, aerial parts of C. leucanthemum, stem and root extracts of E. gerardiana and aerial parts of Q. dilatata) were examined for antimicrobial activity using agar diffusion method and agar tube dilution method, cytotoxicity using brine shrimp assay, antitumor activity using potato disc assay, phytotoxic activity using radish seed bioassay
and antioxidant activity by using DPPH radical scavenging assay and free radical induced oxidative DNA damage assay.
Two plant extracts of C. hierosolymitana and Q. dilatata showed antibacterial activity. Two plant extracts of E gerardiana and C. leucanthemum showed antifungal activity. Two plant extracts i.e., leaf extract of C. hierosolymitna and root extract of E.gerardiana showed significant brine shrimp cytotoxicity activity (IC50 171.55 to 523.8 ppm). Six of the seven extracts exhibited tumor inhibition at all the three concentrations tested ranging from 10 to 80%. All extracts showed significant plant growth and seed
germination inhibition at higher concentrations against radish seeds. Two extracts of C.hierosolymitana and Q. dilatata showed growth stimulating effects at lower concentrations. Two extracts of C hierosolymitana and Q. dilatata showed significant DPPH radical scavenging activity (IC50 10.52 to 45.9 ppm). Three of the seven extracts i.e., (R) E. gerardiana, (A) Q. dilatata and (A) C. leucanthemum showed DNA protection activity at 100 and 10 ppm while at 1000 ppm showed no DNA protection activity while rest of the four extracts showed DNA protection activity at all the three concentrations tested. Phytochemical tests showed presence of alkaloids, saponins, anthraquinones, terpenoids, flavonoids, flavones, tannins, phlobatannins and cardiac glycosides at varying
levels in these extracts.
[...]
Table of Contents
Chapter 1 Introduction
1.1 Chrozophora hierosolymitana Spreng
1.2 Chrysanthemum leucanthemum
1.3 Ephedra gerardiana Wall. ex Stapf
1.4 Quercus dilatata
1.5 Bioassay guided fractionation:
1.6 Bioassays
1.6.1 Antimicrobial assay
1.6.2 Toxicity testing against brine shrimp
1.6.3 Potato disc antitumor assay
1.6.4 Phytotoxicity assay
1.6.5 Antioxidant assays
1.7 Phytochemicals:
1.7.1 Primary metabolites
1.7.2 Secondary metabolites
1.8 Separation and purification techniques:
Chapter 2 Biological assays of crude plant extracts
Materials and methods
2.1 Plant material
2.2 Extraction
2.3 Antibacterial assay
2.4 Antifungal assay
2.5 Toxicity testing against brine shrimp
2.6 Antitumor assay
2.7 Radish seed bioassay
2.8. DPPH radical scavenging assay
2.9 Free radical induced oxidative DNA damage analysis
2.10 Phytochemical analysis
Results
2.11 Antibacterial activity of crude plant extracts
2.12 Antifungal assay
2.13 Toxicity testing against brine shrimp
2.14 Antitumor assay
2.15 Radish seed bioassay
2.16 DPPH free radical scavenging assay
2.17 Free radical induced oxidative DNA damage analysis
2.18 Phytochemical analysis
Chapter 3 Fractionation by solvent partitioning
Materials and methods
3.1 Preparation of fractions
3.2 Antibacterial assay
3.3 DPPH radical scavenging assay
3.4 Free radical induced oxidative DNA damage analysis
3.5 Phytochemical Analysis
Results
3.6 Antibacterial activity of partitioned fractions
3.7 DPPH free radical scavenging assay
3.8 Free radical induced oxidative DNA damage analysis
3.9 Phytochemical analysis
Chapter 4 HPLC analysis of ethanol fraction
Materials and methods
4.1 HPLC analysis of ethanol fraction
4.1.1 Anaytical HPLC
4.1.2 Preparative HPLC
4.2 Antibacterial assay
4.3 DPPH radical scavenging assay
4.4 Free radical induced oxidative DNA damage analysis
4.5 Characterization of the purified active component
Results
4.6 HPLC Fractionation
4.7 Antibacterial activity of the fractions
4.8 DPPH free radical scavenging assay
4.9 Free radical induced oxidative DNA damage analysis
4.10 HPLC analysis of active fractions
4.10.1 AM2 Fraction
4.10.2 AM3 Fraction
4.11 Antibacterial activity
4.12 DPPH Free Radical Scavenging Assay
4.13 Characterization of purified active component
Chapter 5 Discussion
Research Goals and Key Topics
The primary research objective is to identify and isolate pharmacologically active components from four selected Pakistani plant species—Chrozophora hierosolymitana, Chrysanthemum leucanthemum, Ephedra gerardiana, and Quercus dilatata—by utilizing bioassay-guided fractionation to investigate their potential as chemotherapeutic agents.
- Screening of crude plant extracts for antimicrobial, cytotoxic, antitumor, and antioxidant activities.
- Application of bioassay-guided fractionation to isolate active compounds from the most effective extract.
- Characterization of purified bioactive fractions using high-performance liquid chromatography (HPLC) and spectrophotometric analysis.
- Evaluation of protective effects of plant extracts against free-radical induced oxidative DNA damage.
- Detailed phytochemical screening to correlate biological activity with chemical constituents.
Excerpt from the Book
1.1 Chrozophora hierosolymitana Spreng
Chrozophora hierosolymitana (Fig 1.1) is commonly known as Dyer's croton. Synonyms are Chrozophora tinctoria (L.) Raf, Chrozophora verbascifolia Baill (Nasir and Ali, 1972). Chrozophora is genus of the family Euphorbiaceae. The Euphorbiaceae (spurge family) is among the larger families of flowering plants with c. 300 genera and 8000 species (Webster, 1994). Chrozophora is sole genus comprised in the subtribe Chrozophorinae. It comprises 11 or 12 species, which are monoecious herbs or undershrubs. They are found from Africa and the Mediterranean to Southeast Asia.
Summary of Chapters
Chapter 1 Introduction: Provides a comprehensive overview of the role of medicinal plants in drug discovery, the importance of traditional remedies in Pakistan, and the specific biological and chemical characteristics of the four selected plant species.
Chapter 2 Biological assays of crude plant extracts: Details the methodologies used for screening the crude extracts for antibacterial, antifungal, cytotoxic, antitumor, and antioxidant activities, including detailed procedures for each bioassay.
Chapter 3 Fractionation by solvent partitioning: Describes the process of partitioning the most active crude extract of Quercus dilatata into various solvent fractions and evaluating the biological activity of these partitioned fractions.
Chapter 4 HPLC analysis of ethanol fraction: Documents the purification of the highly active ethanol fraction from Quercus dilatata using analytical and preparative HPLC, followed by the isolation and characterization of pure active subfractions.
Chapter 5 Discussion: Integrates the research findings, discusses the observed biological activities in relation to the phytochemical profiles of the plants, and provides a conclusion regarding the identification of potentially new bioactive compounds.
Keywords
Medicinal plants, Pakistan, Quercus dilatata, Bioassay-guided fractionation, Antimicrobial activity, Antioxidant activity, DPPH, HPLC, Oxidative DNA damage, Phytochemical analysis, Cytotoxicity, Antitumor, Secondary metabolites, 1,1-Diphenyl-2-picrylhydrazyl, Plasmid pBR322.
Frequently Asked Questions
What is the core focus of this research?
The research focuses on the screening and pharmacological evaluation of four selected plant species native to Pakistan to identify their therapeutic potential, particularly regarding antimicrobial, antitumor, and antioxidant activities.
What are the primary plant species investigated?
The study examines Chrozophora hierosolymitana, Chrysanthemum leucanthemum, Ephedra gerardiana, and Quercus dilatata.
What is the main goal of this thesis?
The primary goal is the isolation and characterization of pharmacologically active chemical components from these plant species using a bioassay-guided fractionation approach.
What specific scientific methods are utilized?
The research employs various biological assays, including antimicrobial, brine shrimp cytotoxicity, potato disc antitumor, radish seed phytotoxicity, DPPH radical scavenging, and free radical-induced oxidative DNA damage assays, followed by HPLC for purification.
What does the main body of the work cover?
The main body covers the preparation of plant extracts, a detailed biological evaluation of these extracts, the systematic fractionation of the most active candidate (Q. dilatata), and the subsequent analytical characterization of purified fractions via HPLC.
What are the key terms that define this work?
The key terms include bioassay-guided fractionation, phytochemical screening, antioxidant activity, and pharmacological screening of medicinal plants.
How was Quercus dilatata selected for further purification?
Quercus dilatata was selected for further study because the crude extract of its aerial parts demonstrated the most significant antibacterial and antioxidant activity during the initial screening phase.
What significance does the study attribute to its HPLC findings?
The study suggests that the compounds successfully isolated from the Quercus dilatata ethanol fraction are chemically distinct from standard known compounds found in the same genus, indicating they could potentially be newly identified compounds.
- Arbeit zitieren
- Maryam Jamil (Autor:in), 2010, Screening of selected plant species of Pakistan for their pharmacological activities, München, GRIN Verlag, https://www.grin.com/document/175245
