Antimicrobial and Cytotoxic Evaluation of Methanolic Extract of Thespesia Populnea (Malvaceae) Flowers

Venkateshwaran, K (2008) Antimicrobial and Cytotoxic Evaluation of Methanolic Extract of Thespesia Populnea (Malvaceae) Flowers. Masters thesis, Nandha College of Pharmacy, Erode.


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In the current approach of Thespesia populnea which have been used therapeutically for various medicinal purpouses, however there had been no reports regarding the methanolic extract of the plant. We therefore decided to study the cytotoxic and antimicrobial properties of the same plant the in-vitro antibacterial activity of Thespesia populnea used by Indian peoples to show that therapeutic properties. The antibacterial activity was expressed at varying degrees with the activity being both strain and dose dependent. Fourteen Bacteria’s were used for antibacterial studies. Medicinal plants are being used by large proportion of Indian population. The reasons for this include a) True improvement of diseases conditions after Herbal treatment b) harmful side effects and high cost of the other forms of treatment. In the present study, the results were encouraging, as the Thespesia populnea appeared to contain substances that had antimicrobial properties because of, the methanolic extract of Thespesia populnea flowers were active against 13 out of 14 Bacteria’s. Five concentrations of the extract were used (1000μg/ml, 500μg/ml, 250μg/ml, 125μg/ml and 62.5μg/ml). It is estimated that if an inhibition is obtained by 250μg/ml-1000μg/ml) of test solution, the extract can be considered worthy of further investigations. Compared to other authors it is relatively low concentration. Regarding antifungal activity the methanolic extract of the plant shows positive results for all fungus. The aqueous and organic extracts from the plants showed different activities. There are no common rules for this, but in most cases, organic extracts showed the same (or) greater activity than aqueous extracts. The plate hole diffusion method showed larger activity than disc diffusion method. Most likely; this is because large amount of solvents may influence Bacterial growth, there by demonstrating that larger doses are required. Since the medicinal plants studied appear to have a broad antimicrobial activity spectrum, they could be useful in antiseptic and disinfectant formulations as well as in chemotherapy. The optimal effectiveness of a medicinal plant may not be due to one main active constituent, but to the combined action of different compounds originally in the plant. In Literature, it has been indicated that the antibacterial activity is due to different chemical agents in the extract, including essential oils (especially thymol), flavonoids and triterpenoids and other compounds of phenolic nature or free hydroxyl group, which are classified as active antimicrobial compounds. A complete study conducted with the purpose of finding these chemicals is worthwhile. These findings can form the basis of further studies to isolate active compounds, elucidate them against wider range of Bacterial strains with the goal to find new therapeutic principles. Under this experimental study the extract was active for Bactericidal action. The findings revealed that the extract capability to penetrate the cell walls with hydrophobic environment (gram negative) and hydrophilic environment (gram positive) Bacteria’s responsible for the Bactericidal action which can be isolated and identified by some analytical techniques. The results of the study supports to a certain degree, traditional medicinal uses of the plants evaluated both for human and animal diseases therapy and reinforce the concept that the concept that ethno botanical approach to screening plants as potential sources of bioactive substances is successful. Plants showing significant activity may be due to the presence of alkaloids, flavonoids, tannins and polyphenols. Among the various microorganisms, the methanolic extract was more active against Rhodococcus terrae. The aqueous extract generally exhibits a high degree of antibacterial activity this seems to confirm the traditional therapeutic claims of this plant. These results suggest the presence of either good antibacterial potency or high concentration of an active principle in the extract. This antibacterial activity would support the folk therapy of infections whose symptoms might involve Bacteria. Plant extracts and phytochemical are becoming popular as potential sources of antibacterial and several reviews have been written. By this ethno botanical knowledge of indigenous as a means to select potentially antibacterial plants, this screening potentially to be more successful than a random screen of plants. Moreover the discriminary effect against specific microorganisms suggests the presence of different chemical compounds. According to many Journals plant extract showing activity between the ranges of 1000 μg/ml to 100μg/ml, for isolated compound 100μg/ml to1μg/ml is an accepted range the values varying this range could not accepted as a good antimicrobial activity. But according to my study the values of these activities are within in these limits, so accepted for good activity. Also, we isolated the particular active principle necessary for the activities by Column chromatography, Preparative thin layer chromatography, and then the preliminary confirmation of the isolated compound was carried out by thin layer chromatography here myself selected and performed for more than 70 solvent systems by changing the ratios of the solvent systems according to the polarity before going for column chromatography but only 60% of solvent systems shows the spots clearly among this only one solvent system n-butanol:aceticacid:water shows clear spots under UV so, I used this solvent for column and the isolated compound was runned in the same solvent system and the same Rf value as that of the extract was thus obtained the samples of same Rf value was collected separately. Then the minimum inhibitory concentration of the isolated compound was carried out which gives the positive results. a. IR Spectrum: 1) The absorption spectrum consists of few bands and the substances are therefore relatively simple. The presence of -OH is indicated by the broad absorption at 3319 cm-1 and at 1065 cm-1. 2) The unsaturation is of an aromatic nature is evident from the characteristic absorption in the regions 1620 cm-1 and 794 cm-1. 3) An aromatic system is indicated by the absorption at 1600 cm-1, 1519 cm-1, and 668cm-1. 4) The strong absorption at 1620 cm-1 is of aromatic absorption. 5) Strong carbonyl absorption at 1696 cm-1 can be interpreted as C=O. b. NMR Spectrum: 1) A chemical shift value at 1.20 indicates the alkane group protons in –CH 3 usually appears at δ = 0.9-1.0. This singlet may be due to CH-C-OH (OR), 2) The other signal at chemical shift value of 2.10 ( singlet) may be due to the keto group bonded to aliphatic alkane group CH- (C=O)R. 3) The shift value at 2.50 may due to keto group attached to an aromatic ring CH-( C=O) Ar. 4) A small singlet at 4.5 indicates HO-Ar hydroxyl group attached to aromatic ring. 5) A triplet is found at the chemical shift value between 3-4 (1:2:1). Proton proton coupling between a single and double bond in a five membered ring system. c. MASS Spectrum: 1) The mass spectrum is the line spectrum. 2) It exhibits m/z at 219 at 45% of relative abundance. 3) The fragmentation patterns are 203 (CH3 -15). 4) Here the peak at 149.46 is the base peak of most intense having 100% of relative abundance. Plant extracts are complex mixtures of many compounds. This study clearly shows that the cytotoxicity and antiviral activity of a extract are not necessary to the same compounds and that the cytotoxicity of some plant compounds may mask the antiviral properties of other plant substances. The result presented here indicates that the cited above methanolic extract of Thespesia populnea possess moderate antiviral and cytotoxic activities, and these effects might be due to their content of flavonoids, specially biflavones and C-glycosyl flavonoids for which antiviral activity was already described. In this work I presented results concerning the antiviral activity of methanolic extract of Thespesia populnea flowers. The final conclusion is that extracts from plants employed in ethno medicine can exhibit antiviral activity. Accordingly medicinal plants can be a source for isolation of pure compounds against HSV-1 and2. Despite the fact that the amount of information on anti-HSV plant extract is very relevant, not all the bioactive anti-HSV molecules responsible for the activity of plant extracts have been identified, isolated, synthesized and tested. This is a crucial point, and is highly advisable that all promising plant extracts should undergo further analysis and purification steps in order to identify active principles and clarify the chemical nature. Synthetic approaches should also be developed for production of larger amounts of bioactive molecules and their analogues for all required preclinical and clinical studies. Finally gene expression profile studies employing microarray technology could help to identify molecular targets of biological activity of anti-viral molecules from natural products, allowing moving for gene-based drugs to be used for anti-viral therapy.

Item Type: Thesis (Masters)
Additional Information: Reg. No. 26063830
Uncontrolled Keywords: Antimicrobial and Cytotoxic Evaluation ; Methanolic Extract ; Thespesia Populnea (Malvaceae) Flowers.
Subjects: PHARMACY > Pharmaceutical Biotechnology
Depositing User: Subramani R
Date Deposited: 27 Jun 2017 11:23
Last Modified: 17 May 2018 16:56

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