Comparative studies on the antibacterial properties of extracts obtained from medicinal plants were carried out by two different methods. The plants selected were Emblica officinalis Gaertn. (fruit-Euphorbiaceae), Glycyrrhiza glabra Linn. (rhizome-Papilionaceae), Eclipta alba (L.) Hassk. (whole plant-Compositae), Tinospora cordifolia (Willd.) Micrs (stem-Meninspermaceae), Asparagus racemosus Willd. (root-Liliaceae) and Centella asiatica (L.) Urb. (whole plant, Apiaceae). The solvents used were petroleum ether, chloroform, methanol and water. The antibacterial screening was conducted by agar-well diffusion method against nine bacterial strains. The most active extracts were compared by Minimum Inhibition Concentration (MIC) and their chemical constituents were separated through High Performance Thin Layer Chromatography (HPTLC). The separated plant metabolites on HPTLC plate were again evaluated for antibacterial property through bioautography. The results obtained indicated that the chloroform extracts were most active against tested bacterial strains. Chemical nature of the separated active antibacterial compounds through HPTLC was detected by various detecting reagents and marked by corresponding Rf values. The qualitative phytochemical analysis was carried out for active extracts for the presence of falvonoids, terpenes, steroids, and alkaloids.
Due
to an increase in the side effects of synthetic products,
herbal products are gaining importance in the world market
(Raina, 1997; Lemmens et al., 2001; and Dubey et
al., 2004), resulting in the acceptance of traditional
medicine as an alternative form of healthcare. The development
of microbial resistance to the available antibiotics has
led scientists to investigate the new antibacterial compounds
from plants (Bisignano et al., 1996; Lis-Balchin
and Deans, 1996; Mazon and Neeman, 1998; and Hammer et
al., 1999). The plants selected in the present investigation
are basically components of many ayurvedic preparations
and are also used by the cosmetics, food, and pharmaceutical
industries. The aim of this study is to investigate the
antibacterial activity of extracts from the plants mentioned
which is used in Indian folk medicine. A comparative study
on the antibacterial properties of the extracts obtained
by two different methods in order to choose the one which
gives the most efficient antibacterial compounds is reported.
The
plant materials used in this study were obtained from Petalad
Mahal Arogya Mandal (PMAM) Pharmacy, Nadiad, Gujarat. The
plants selected were Emblica officinalis Gaertn.
(fruit-Euphorbiaceae), Glycyrrhiza glabra (Linn.)
(rhizome-Papilionaceae), Eclipta alba (L.) Hassk
(whole plant-Compositae), Tinospora cordifolia (Willd.)
Micrs (stem-Meninspermaceae), Asparagus racemosus (Willd.)
(root-Liliaceae), and Centella asiatica (L.) Urb.
(whole plant, Apiaceae). Extractions were carried out by
two methods designated in the subsequent text as method-A
and method-B. In method-A extractions were carried out by
leaching known amount of powdered drug (10 gm) at room temperature
with distilled water, methanol, chloroform, and petroleum
ether, individually. |
