Studies on the activity of the standardized extracts of Piper betle L. and Piper nigrum L. on Mycobacterium tuberculosis : cellular and metabolomics approaches
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Date
2012
Authors
Patilaya, Popi
Journal Title
Journal ISSN
Volume Title
Publisher
Pusat Pengajian Sains Perubatan, Universiti Sains Malaysia
Abstract
The rising of drug-resistance tuberculosis (TB) cases has prompted an urgent
need for a new anti-TB drug preferably from local medicinal plants. However, in the
last decade not much attention has been given to the microbiology and metabolomics
aspects of these plants regarding to their anti-TB activity.
This study was carried out to test the antimycobacterial activity of
standardized extracts and fractions of Piper betle and Piper nigrum. The extracts and
fractions were prepared with maceration and liquid-liquid partition method,
respectively. The activity was tested using tetrazolium microdilution assay. The
effects of the active fraction on the growth of Mycobacterium tuberculosis was also
studied under light and scanning electron microscopy observation. HPLC and FTIR
spectroscopy in combination with PCA were used to profile the extract and fraction.
Toxicity testing of the active extracts and fraction was performed using Brine Shrimp
method. The results indicated that extracts of P. betle and P. nigrum exhibited
antimycobacterial activity with MIC values ranging from 100 μg/ml to 500 μg/ml
while the MIC of the fractions was 25-100 μg/ml. Evaluation under light microscopy
showed that the active fractions affected the growth of mycobacterial cells causing
loss of acid-fastness and morphological changes. Under scanning electron
microscopy the affected cells appeared wrinkled and empty due to release of
cytoplasmic materials from ruptured cells. HPLC analysis showed that the extract
and fraction of P. betle contain 0.065% and 0.010% eugenol, respectively.
Meanwhile extract and fraction of P. nigrum contain 1.215% and 0.060% piperine,respectively. Principal component analysis (PCA) was able to differentiate the leaf
ethanol/water (1:1) extract of P. betle, the leaf ethanol extract of P. nigrum, and its
ethyl acetate fractions based on the FT-IR spectra. Toxicity test indicated that the
active extract had low toxicity with LD50 >1000 μg/ml while the LD50 of the ethyl
acetate fractions of P. betle and P. nigrum were 90.78 μg/ml and 137.90 μg/ml,
respectively. This study indicated that both P. betle and P. nigrum have potential
antimycobacterial activity.
Description
Keywords
Mycobacterium tuberculosis