Antimicrobial activity of medicinal plants thesis

The phytochemical analysis of the different leaf extracts from the various extractants, aqueous, methanol and ethanol showed the presence of tanins, saponnins, terpenoids and flavonoids. Petroleum ether and ethyl acetate were devoid of tanins and flavonoids, probably resulting in low inhibitory activity against the pathogens. Most of these phytochemicals are the basis for plants medicinal properties and these are starting materials for production of new drugs today.

The extracts were found to be effective against the pathogens used in this study, which highlight the potential of herbal drugs and their possible use as local medicine. The ethyl acetate extract exhibited relatively lower inhibitory activity against the bacterial strains, with zones of The ethanol extract showed a significant higher inhibitory activity against P. The antimicrobial activities of methanol, aqueous and ethanol extracts were comparable with that of amoxicillin, the standard antibiotic Additional file 3 whilst the negative control DMSO— The high antibacterial activity in the methanolic extract may be due to the presence of high amount of tannins, flavonoids, and terpenoids.

Tannins and flavonoids possesses similar mechanism by providing a source of stable free radical and also forms complex with nucleophilic amino acids in protein leading to the inactivation of the protein and loss of function, their potential antimicrobial effect is great as they probably target microbial cell of surface-exposed adhesins, cell wall polypeptides and membrane bound enzymes [ 15 ].

Terpenoids are for dissolution of the cell wall of microorganisms by weakening the membranous tissue [ 16 ]. Saponins have the ability to cause leakage of proteins and certain enzymes from the cell [ 17 ]. Both petroleum ether and ethyl acetate extracts were devoid of the phytochemicals mentioned above, justifying their lower inhibitory activity against the tested strains employed in the current research. The minimum inhibitory concentration MIC and minimum bactericidal concentration MBC of Ricinus communis leaf extract on the isolated pathogens ranged from 3. The MICs depending on the microbe and the extract, greater sensitivity was observed in methanol, ethanol and aqueous extracts and the least sensitive was petroleum ether and ethyl acetate extracts where most of their MBCs were undetected.

Another research group reported that methanol extract of Ricinus communis was found to be more active against S. In this study the more susceptible test organisms to the methanol extract were P. A similar study conducted by Kensa and Yasmin showed that the more susceptible organism was E. The differences observed may be due to the different extraction process and the difference in the susceptibilities of the clinical strains used. Interestingly, the fungus, C. The results of this current research are in agreement with other findings supporting that most compounds in medicinal plants are more extracted in methanol [ 22 ].

The data shown represent the average of three wells treated on the same day. The experiment was repeated twice and day-to-day variation was found to be within onefold of the presented data. The extractants used have a major impact on inhibitory activity of the bioactive agents. In this study, methanol extract showed maximum antimicrobial activity, followed by ethanol and aqueous extracts. Petroleum ether and ethyl acetate showed the least antibacterial activity, suggestive of the active compounds having antimicrobial potential be extracted using appropriate solvent.

This research gives a scientific validation to the fact that bioactive components in the plant Ricinus communis are extracted substantially in methanol and exhibited highly promising antibacterial and antifungal inhibitory activity. Acquisition of reagents and chemicals was difficult and that caused hindrance in conducting other test of interest. Chanda S, Baravalia Y.

Thesis on antimicrobial activity of medicinal plants - write my english paper

Novel leads from herbal drugs for infectious skin diseases. Begum D, Nath SC. Ethnobotanical review of medicinal plants used for skin diseases and related problems in Northeastern India. J Herbs Spices Med Plants.

Table of contents

Ricinus communis L. Int J PharmTech Res. Assessment of phytochemical screening, antioxidant and antibacterial potential of the methanolic extract of Ricinus communis l. Asian J Pharm Technol. Antioxidant activity of the methanolic extract of Ricinus communis leaves. Asian J Chem.

Table of contents

Evaluation of anti-inflammatory potential of Ricinus communis Linn leaves extracts and its flavonoids content in Wistar rats. J Chem Pharm Res. Food Chem Toxicol. Hepatoprotective effect of an active constituent isolated from the leaves of Ricinus communis Linn. Drug Dev Res.

Prakash E, Gupta D. In vitro study of extracts of Ricinus communis Linn on human cancer cell lines.


J Med Sci Public Health. Jena J, Gupta AK. Ricinus communis Linn : a phytopharmacological review. Int J Pharm Pharm Sci. No reports on M. This is the first report on B. The MIC was 2. Bonellia flammea showed antifungal activity against C. In our study the AE of B. Finally, R. From the twelve medicinal plants screened, only four have the potential to be used in controlling fungi diseases of economically important crops, such as those caused by M. The losses caused by these phytopathogenic fungi occur mainly as a direct reduction in the quality and quantity of the harvested product, and due to the use of synthetic fungicides to control them for many years in the field it is common to find fungal isolates that are less sensitive or even resistant to these fungicides [ 13 ].

Mycosphaerella fijiensis is responsible for black streak disease in banana and plantains, and C. For this reason, and to eliminate or reduce the negative impact of synthetic fungicides on the environment, it is very important to find an alternative to control fungi using natural products.

In our case, the botanical knowledge obtained from people of the villages of the coastal dune and mangrove of the Yucatan peninsula opens a window of opportunities to search for compounds with antifungal activity to control crop pathogens. Searching a chemical backup of the twelve medicinal plants, the HPLC chromatographic profiles of the twelve aqueous extracts were obtained using a previously published technique [ 18 ].

The analysis of these chromatograms is based on the results shown in S2 Table. Several solvent systems were tested until peaks were well separated, with gradient mixtures of acidified water pH 2. When comparing chromatograms at both wavelengths, we observed a major abundance of compounds at nm in all the aqueous extracts. The chromatogram window was conveniently divided into three zones to classify peaks according to their polarity and retention time [high 0—15 min , medium 15—40 min , and low 40—65 min ].

The aqueous extract of B. Peaks with a high concentration This species only showed activity against C. In the chromatogram of M. They were concentrated in the medium polar region This species only showed good activity against E. The chromatographic profile of aqueous extract of M.

This plant showed antioxidant, antihypertensive, and antimicrobial activities against crop and human pathogens.

Antibacterial and Antifungal Properties of Brahmi

The chromatogram of R. This plant showed antimicrobial activity against M. The chromatogram of S. This plant showed great antihypertensive activity and moderate antimicrobial activity against V. It is not frequent to find in the literature reports on chromatographic profiles using HPLC of aqueous extracts of medicinal plants with any biological activity.

At least, not any profile is reported on the twelve aqueous extracts here studied, and we consider this analysis necessary to have a chromatographic backup of the samples with biological activity that will allow us, in the future, to compare with other active samples of the same species collected in different years or seasons.

These results showed the biotechnological potential value of native, wild, and medicinal plant species. Also, they are significant enough to make them known to the society, which, we believe, will reduce the negative impact that exists on these species that are under the risk of disappearing, because they are not considered useful to our society, regardless of its ecological value, also unknown or unimportant nowadays. These species might have several applications as food and pharmaceutical products.

For this, additional studies should be carried out to isolate and identify the compounds involved in the biological activities of the aqueous extracts. Browse Subject Areas? Click through the PLOS taxonomy to find articles in your field. Abstract Looking for a biotechnical potential, aqueous extracts of leaves of 12 native species used in the Mayan traditional medicine of the coastal dune and mangrove of Yucatan Mexico were selected to evaluate their biological activities. Introduction Natural products coming from plants have been an axis of the Mayan traditional medicine, and they remain regularly in use today.

Plant material For this study we selected 12 species because they are wild and native plants from the Yucatan coast. Determination of phenolic compounds and flavonoid content Phenolic compounds were determined using the Folin-Ciocalteu reagent Sigma-Aldrich, St. Free radical scavenging activity The method of Meda et al. Angiotensin-converting enzyme inhibitory assay Inhibitory activity of aqueous extracts was analyzed following a method by Hayakari et al.

Antimicrobial activity Human pathogenic microbial material. Phytopathogenic fungal material. Assessment of human antimicrobial activity. Detection of anti-phytopathogenic fungal activity. Statistical analysis All experiments were performed, at least, twice with three replicates.

Download: PPT.


Table 1. Native medicinal plants of coastal dune and mangrove of Yucatan selected in this study. Antioxidant activity The 12 aqueous extracts showed the presence of polyphenols, which was expected because all the plant species produce these secondary metabolites to protect themselves from other organisms [ 28 ].

Table 2. Total phenol and flavonoid content of aqueous extracts 1. Fig 1.