Pharmacognostical Study of Salvia merjamie Forssk Growing in Saudi Arabia

Abstract

Salvia merjamie, is a member of Lamiaceae family. It is very leafy herb (including flower stem), up to 25 cm tall; pure white flowers 1cm long with thin lines on the lip, cupped in a hairy calyx with faint aromatic odor. The thesis consists of 240 pages, started with a comprehensive introduction of 38 pages and ended with a list of 200 references, it includes 33 tables and 86 figures. In addition to 3 pages of English summary and 3 pages for Arabic summary. The pharmacognostical study of Salvia merjamie were investigated through the following objectives: 1. Study of the macro and micromorphological characters of the plant both in entire and powdered forms. 2. Preliminary phytochemcial screening. 3. Analysis of the essential oil constituents in the leaves. 4. Investigation of the lipid content. 5. Isolation and characterization of the major compounds. 6. Evaluation of the antimicrobial, antioxidant and antihypertensive activities of different extracts and the major pure compounds. For achievement of these goals, the thesis has been divided into:Introduction, Materials, Equipment and Techniques, Macro- and Micromorphological Study, Preliminary Phytochemical Screening, Essential Oil and Lipid Content, Phytochemical Study and Pharmacological Study. · "Introduction"; includes a brief discussion on the chemical constituents of family Lamiaceae and folk use of different Salvia species. The phytochemistry of genus Salvia was discussed with emphasis on the chemical constituents having biological activities. · "Materials, Equipment and Techniques"; lists all materials, equipment and techniques used in botanical, chemical and biological studies. · "Macro and Micromorphological Study"; embodies the macroscopical and microscopical characters of different organs of the plant (root, stem, leaf and flower). The quantitative values (palisade-ratio, vein-islet number, veinterminal number, stomatal number and stomatal index) of the leaf were determined in addition to the crude fibre, moisture content and ash values. · "Preliminary Phytochemical Screening"; was undertaken for the identification of different types of chemical constituents present in the powdered whole plant and successive extracts of Salvia merjamie Forssk. This study revealed the presence of carbohydrates and/or glycosides, flavonoids, sterols and/or triterpenes, volatile constituents and traces of tannins and absence of alkaloids, anthraquinones, cardiac glycosides and saponins. · "Essential Oil and Lipid Content"; preparation of the essential oil of the leaves of Salvia merjamie Forssk (0.05% v/w) was done by hydrodistillation and GC/MS analysis of it revealed the presence of 32 compounds, 27 were identified representing 99.23% of the total oil composition. α-pinene was the major constituent followed by linalool, cis-β-terpineol, β-pinene and limonene. GLC analysis of the unsaponifiable matter of n-hexane extract of the aerial part of the plant revealed the presence of 30 compounds, 26 compounds were identified constituting 91.93% of the total unsaponifiable matter, octacosane was the major constituent where β-sitosterol was the major steroidal compound. GLC analysis of fatty acids methyl esters proved the presence of 25 fatty acids, 17 were identified (85.53%), where linolenic acid and palmitic acid were the major fatty acids. · "Phytochemical Study"; comprises the details for extraction and solvent partitioning of Salvia merjamie Forssk. In addition, it elaborates on the isolation using different suitable chromatographic techniques, characterization and discussion of each isolated compound and provides rationale for the methodologies used for characterization of all isolated compounds, using all necessary spectroscopic techniques, including IR, UV, MS and 1D and 2D NMR. 19 compounds were isolated and identified; 4 triterpenes; oleanolic acid, β-amyrin, maslinic acid and asiatic acid. 2 steroidal compounds; β-sitosterol and β-sitosterol-3-o-β-glucoside. 2 flavonoids; 5-hydroxy-7,4'-dimethoxyflavone and salvigenin. 2 abietane diterpenes; (+)-ferruginol and (+)-7α-acetylhorminone. 2 nor-diterpenes; 6α- hydroxynorambrienolide and 17-epi-6α-hydroxynorambrienolide. 2 sesterpenes; yosgadensolide A and 6α,14-Dihydroxy-13-epi-manoyloxide- 15,17-dien-16,19-olide. One secoabietane diterpene; 6-epimeric 11, 12- dihydroxy-6, 7-secoabieta-8, 11, 13-trien-6, 7-dial-11, 6-hemiacetals and 2 phenolic compounds; 2, 4-ditert-butylphenol and 3',4'-dihydroxyphenyl caffeate were isolated and identified. In addition to 2 synthetic polypropylene compounds; octadecyl-3-(3,5-ditert-butyl-4-hydroxyphenyl) propanoate and bis(2-ethylhexyl)benzene-1,4-dicarboxylate. · "Pharmacological Study"; includes the acute toxicity test of petroleum ether and ethanol extracts of Salvia merjamie Forssk. Besides, the determination of antimicrobial activity and MIC values of different extracts, essential oil and isolated compounds. Furthermore, the antihypertensive and antioxidant activities of different extracts of Salvia merjamie Forssk were evaluated. Some of the tested extracts and the isolated compounds showed significant antimicrobial activity against the tested microorganisms. The study revealed that the tested extracts possess vasodepressant as well as cardiodepressant activities. Furthermore, some of the tested extracts showed antioxidant activity.