Effects of Bougainvillea Leaves on Antibacterial Activity: A clinical study

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by Forest Raga February 24, 2021

The present study was carried out to investigate the efficacy and safety of the Effects of Bougainvillea Leaves on Antibacterial Activity

Treatment Offered

Plant Material
The fresh green leaves of Bougainvillea spectabilis visibly free from disease and weighing 1gm or more were collected locally. The botanical identity of the plant of Bougainvillea spectabilis was authenticated from the botany department of Smt. K. W. College, Sangli(India) by Dr. K. S. Patil.

Preparation of Extract

The leaves were washed thoroughly several times with potable water and then air-dried. Dried leaves were pulverized to fine powder, which was soaked (20 g) separately in 100ml of ethanol, 100ml of acetone, and also in a similar quantity of distilled water for 24 to 48hrs. This was then filtered and centrifuged at 7000 x g for 10mins to remove all insoluble materials. The clear supernatant was stored at 4°C for further studies.

Antibacterial Activity
The growth pattern of the test organisms was checked by growing these in a sterile liquid medium containing meat extract 0.5%, peptone 1%, and NaCl 0.5% at pH 7.0. The organisms were added at a 10% level (v/v), with a cell density of 6 x 108 cells/ml. along with 10 ml of the respective extract. Similarly, the second set of experiments were set, where instead of extracts, the same quantity of the respective solvents was added. This was the solvent control set. The third set of flasks was used where 10 ml of extracts were added but no organism was inoculated. This was essential for adjusting the zero reading of the spectrophotometer. The flasks were incubated for 150 minutes on a rotary shaker at 120 r.p.m. The growth was monitored by measuring absorbance at 540 nm at 30 minutes intervals. The solvent extracts were also subjected to GC MS analysis to identify the compounds showing antibacterial properties.


Figure 1: Growth pattern of E. coli in presence of ethanolic extracts (™¦) and acetone extracts (– ) of the leaves. A positive control (–²) was kept wherein no leaf extracts were added.
<div class=The objective of this study was to find out exactly what was the response of the Escherichia coli NCIM 2832, Micrococcus aureus NCIM 5021 growing in presence of the aqueous and solvent extracts of the leaves of Bougainvillea spectabilis, by studying their growth patterns.
Figure 2: Growth pattern of M. aureus in presence of ethanolic extracts (™¦) and acetone extracts (– ) of the leaves. A positive control (–²) was kept wherein no leaf extracts were added.

It can be noted from the results (Fig.1 and Fig.2) that there is a significant reduction in the growth rate of both the organisms in presence of ethanolic extract and acetone extract but no inhibition was observed. It was not possible to show such effects from agar-well diffusion method.
Figure 3: Growth pattern of E. coli in presence of aqueous extracts (™¦) of the leaves. A positive control (–²) was kept where no leaf extracts were added.
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The GC MS analysis showed the presence of Myristic acid, Palmitic acid, and Phytol in the ethanolic extract of the plant. The reduced growth rate of E. coli and M. aureus was primarily due to the presence of myristic acid and to some extent by palmitic acid. These observations concur with the ones reported by16. Phytol being a diterpene also has antibacterial properties17 and possibly this too had the effect of bringing down the growth rate. However, none of these compounds are soluble in water, and hence, the absence of antimicrobial activity of the aqueous extract probably be due to this reason. The activated growth of E. coli is probably due to the readily available and easily metabolizable carbohydrates from the leaf.


It can be thus concluded that as per the observations, the solvent extracts (other than water) of the leaves of Bougainvillea spectabilis are good enough for use as a first aid disinfectant for minor wound dressings and the injured individual must be shifted to a medical center for proper medication. This is due to the fact that the extracts can only retard the growth rate of any infecting organisms. Such disinfectants could to some extent replace the normal formulations like carbolic acid and cetrimide, especially when these are not available immediately and handy.

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