ETHNOMEDICINAL STUDIES OF FLORA OF SOUTHERN PUNJAB AND ISOLATION OF BIOLOGICALLY ACTIVE PRINCIPLES

Abstract

This thesis is divided into three sections, Section A, Section B and Section C. Section A deals with ethnomedicinal studies of flora of Southern Punjab, Pakistan and establishment of a Herbarium in Lahore College for Women University. Section B consists of biological activity (antimicrobial and anticancer) of extracts of some of the plants collected from South Punjab and Section C describes the isolation and characterization of bioactive compounds by chromatographic and spectroscopic techniques. It is for the first time that the flora of Southern Punjab has been searched and reported. Complete ethno medicinal studies of 187 plants belonging to 52 families found in South Punjab is documented and also categorized therapeutically for the first time from this region. A first world class herbarium has been established in Lahore College for Women University by categorizing and preserving 186 voucher specimens of plants collected from all over Pakistan. The herbarium is named after the renowned teacher and pioneer Botanist Miss Prem Madan in dedication to her services in the field of Botany in Lahore College for Women University, Lahore. For biological activity seven popular ethnomedicinal plants collected from Southern Punjab namely Capparis decidua (Capparidaceae), Coronopus didymus (Brassicaeae), Heliotropium strigosum (Boraginaceae), Salsola kali (Chenopodiaceae), Salvadora oleoides (Salvadoraceae), Tamarix aphylla (Tamaricaceae) and Withania coagulans (Solanaceae) were selected for antimicrobial and anticancer activity. Topical anti tumor activity of these seven ethnomedicinal plants have been investigated in detail for the first time and all extracts of the Coronopus didymus, Salsola kali, Salvadora oleoides and Tamarix aphylla showed anti tumor activity and provided a new source of further exploration in this respect. While methanol extracts of Withania coagulans, Capparis decidua and Heliotropium stirgosum had been shown to possess best potential against the topical tumor for the first time. The Pet ether, methanolic and dichloromethane extracts of Withania coagulans, Capparis decidua and Heliotropium strigosum reduced the malignancy and cured the fibrous hyperplasia. The screening of these selected medicinal plants for antibacterial activity against six bacterial strains namely Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus pneumoniae, Bacillus subtilus and Sarcina lutae after fractionation in different solvents (methanol, pet ether, dichloromethane) by agar well diffusion method showed the methanol extracts to be more potent then pet ether and dichloromethane extracts. The antibiotic properties of these seven strains were studied against Sarcina lutae, Streptococcus pneumoniae and Pseudomonas aeruginosa bacterial strains for the first time. Methanol extracts of Capparis decidua and Withania coagulans were found to be best bactericidal against all the tested bacterial strains. While methanolic extract of Heliotropium strigosum was very active against all the bacterial strains except Streptococcus pneumoniae. Synergistically Withania coagulans in combination with Pinus wallichiana, Capparis decidua, Hypericum perforatum, Heliotropium strigosum, Coronopus didymus and Salvadora oleoides showed best activity against Staphylococcus aureus (MIC > 0.1μg/ml) only. The methanolic extract of Salsola kali in equal amounts with Senecio chrysthenoides synergistically inhibited the growth of all bacterial strains except Sarcina lutae. The screening of pet ether, methanolic and dichloromethane extracts of Coronopus didymus, Withania coagulans, Capparis decidua, Salsola kali, Heliotropium strigosum, Salvadora oleoides, and Tamarix aphylla was performed against seven fungal strains namely Trichoderma viridis, Aspergillus flavus, Fusarium laterifum, Aspergillus fumigatus, Candida albicans, Trichophyton mentogrophytes and Microsporum canis . By using ANOVA critical value F.05 (6, 36) = 2.38 the plant extracts were compared with other antifungal drugs and it was found that extracts of Capparis decidua, Withania coagulans and Heliotropium strigosum showed best antifungal activity against all the fungal strains.(F-Table value< F-calculated value). On the basis of ethnomedicinal studies and for showing best biological activity three medicinal plants namely Heliotropium strigosum, Withania coagulans and Calotropis procera were selected for isolation and identification of bioactive principles and some other useful applications so as to explore the potential of these plants on commercial basis. Due to its reported biological activityl, abundance and wild nature and use as heavy metal ion remover Calotropis procera was also selected for the first time for identification of its organic phytochemicals having functional groups responsible of removing Cr (III) by spectroscopic techniques so as to put it to some commercial use. Two Flavonoid aglycones Taxifolin (1) and quercetin (2) had been isolated from Heliotropium stirgosum for the first time and identified by comparison of their spectral data with that given in the literature. Taxifolin (1) Quercetin (2) GC MS studies had resulted in identification of the following compounds in Withania coagulans essential oil for the first time, 1. Cyclohexane (3) (C6H6) 2. Borane carbonyl (4) (CH3BO) 3. 3-methyl, hexane (5) (C7H8) 4. Heptane (6) (C7H16) 5. Hexanoic acid (7) (C6H12O2) 6 Nonanoic acid (8) (C9H18O2) While n-hexane fraction of Calotropis procera was subjected to GC MS analysis following open-chain carboxylic acids and their methyl esters were identified, 1. n-Heptanoic acid methyl ester (9) (C8H16O2) 2. n-Decenoic acid (10): (C10H18O2) 3. n-Nonanoic acid methyl ester (11) (C10H20O2) 4. n-Decenoic acid methyl ester (12) (C11H20O2) The FT-IR spectra before and after adsorption of Calotropis procera roots indicated that bonded –OH groups and /or –NH and carboxyl groups especially played a major role in chromium (III) biosorption which was confirmed by GC MS analysis of Calotropis procera showing the presence of carboxylic acids for the first time.