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Ethnobotanical
Leaflets 12: 1029-34. 2008. Phytochemical Screening and Antibacterial
Activity of Leaf Extracts of Pterocarpus marsupium Roxb. (Fabaceae) 1
Department of Zoology, 2 School
of Biotechnology, CBME, Vellore Institute of 3Department
of Botany, RD Issued Abstract ����������� The
present study was carried out to screen and evaluate the antimicrobial
activity of bark and leaf extracts from Pterocarpus marsupium Roxb.
Hexane, ethyl acetate and methanol extracts were tested against four selected
Gram positive and Gram negative bacteria. Result indicated that phytochemical extracts of P. marsupium exhibited significant
anti-bacterial activity at all dosage tested (1mg/ disc and 5mg/ disc).
However, the inhibitory activity was found to be dose dependent. Ethyl
acetate and methanol extracts were found to be more active towards the
organisms tested than hexane extract. This study depicts that ethyl acetate
and methanol extracts of bark and leaves of P. marsupium can be used as a potential
source of novel antimicrobial agents. Keywords: Pterocarpus marsupium; medicinal
plants; antibacterial agents; phytochemicals. Introduction� Medicinal plants, that form the backbone of traditional
system of medicine in ����������� It has
been pointed out that more than 80% of world�s population depends on plants
to meet their primary health care needs (WHO, 2005). In recent years,
multiple drug/ chemical resistance in both human and plant pathogenic
microorganisms has been developed due to indiscriminate use of synthetic
drugs in the treatment of infectious diseases. This drives the need to screen
medicinal plants for novel bioactive compounds as a basis for pharmacological
studies since the bioactive principles obtained from the plants are
biodegradable, safe and have fewer side effects. Therefore, endemic medicinal
plants should be investigated to better understand their pharmacological
properties and efficacy (Prusti et al., 2008). ����������� According
to a survey conducted by WHO (1998), it has been shown that most of the
modern prescriptions contain plant derived lead molecules as a base in their
drug formulations. Nevertheless, more-than about 42% of 25 top selling drugs
marketed world wide are either directly obtained from natural sources or
entities derived from plant products (WHO, 2007). The value of plant based
prescribed drugs in 2000 was estimated at $35.5 billon which has been on the
raise since then. ����������� Pterocarpus marsupium
Roxb. (Fabaceae)
popularly known as Indian Kino Tree, Malabar Kino Tree. Kino is locally
called as �Vengai� and has restricted distribution
to southern part of ����������� Traditionally,
the plant material has been used as a cooling external application for
inflammations and headache, as antipyretic, anti-helminthic,
aphrodisiac, alexeteic and in biliousness, mental
aberrations and ulcers (Sambathkumar et al., 2006).
Parts of the
Indian Kino (heart wood, leaves and flowers) have long been used for their
medicinal properties in Ayurveda. The heart wood is used as an astringent and
in the treatment of inflammation. The wood
and bark of Pterocarpus
are known for their anti-diabetic activity (Ivorra
et al., 1989; Kameswara et al., 2001). Phytochemical studies on P. marsupium have shown that the plant
contains iso-flavonoids, terpenoids
and related phenolic compounds, -sitosterol, lupenol, epicatechin, and aurone
glycosides (Kumar and Seshadri, 1976; Mitra and Joshi, 1983). In the present study we have
evaluated the antimicrobial potential of
P. marsupium in vitro. Materials and
Methods Collection of
Plant Material ����������� Bark and
mature leaves of P. marsupium
were collected from Sivagangai, Preparation of Phytochemical Extracts ����������� The
powder was extracted by maceration in hexane for 72h. Residuals were further
extracted with ethyl acetate and methanol, following the same procedure. The
plant extracts were concentrated using rotary flash evaporator ( Test organisms ����������� Four strains of Gram-positive bacteria - Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus pyrogens
and four strains of Gram
negative bacteria - Escherichia coli, Salmonella typii,
Serratia marcescens and
Pseudomonas aeruginosa were used for
antibacterial activity (Table 1). All strains were gift from Prof. Rajsekaran, ( Phytochemical screening ����������� Phytochemcial analysis of the
extract was carried out as described by Harborne
(1998). By this analysis, the presence of several phytochemicals
like Sugar, Protein, Alkaloids, Flavonoids, Saponins, Tannins, Cardiac glycoside, Terpenoids
and Lipids were tested (Table 2). Antimicrobial
Activity Test ����������� Antimicrobial
activity was tested using a modified disc diffusion method originally
described by Ncube et al (2008).� Plant extracts were dissolved in 20% DMSO
treated water. The inoculums for each microorganism were prepared from broth
cultures (105 CFU/ml). A loop of culture from the NA slant stock
was cultured in LB medium overnight and spread with a sterile swab into Petri-plates.
Sterile disc (6 mm dia, Hi-media, Results and
Discussion ����������� Plants
are known to have beneficial therapeutic effects documented in Traditional
Indian System of Medicine. Much work has been done on ethnomedicinal
plants in ����������� In the
present study most of the bacteria strains tested were inhibited by the bark
and leaf extracts of P. marsupium and results are given in Table 3-5, the
solvent without extracts served as control were no inhibition zone was
observed. Ethyl and methanol extracts were more sensitive to the bacteria
than extracts made out of hexane. Both the extracts exhibited concentration
dependent variation in their anti bacterial activity. Hexane moderately
inhibited growth of the bacterial strains tested. All fractions showed a
promising activity towards Gram negative bacteria however no inhibition was
observed in hexane fractions of P. marsupium towards Bacillus
species. At a concentration of 1mg/ml all fractions showed less activity.
Similarly methanol extract of P. marsupium (bark) showed maximum activity against Pseudomonas aeruginosa,
Streptococcus pyrogens
and Staphylococcus aureus.
Similar observations have been reported by (Nair et al., 2005; Sambathkumar et al., 2006) where it has been shown that
ethanol extracts of P. marsupium exhibited significant anti-ulcer and
antioxidant properties in rats. Conclusion ����������� In the
present study antibacterial activity of P.
marsupium extracts towards drug resistant/
clinically significant microbes are reported and it was observed that the
active constituents in the plant material seep-out in organic solvents.
Further phytochemical studies for identification
and elucidation of active constituents in the plant materials tested is
expected to serve as lead in the development of novel bioactive antimicrobial
compounds. References 1.
Chakravarthy BK and Gode KD (1985)
Isolation of epicatechin from Pterocarpus marsupium and its pharmacological
action. Planta Medica
1:56-9. 2.
Ebi GC and Ofoefule SI (2000)
Antimicrobial activity of Pterocarpus osun stems. Fitoterapia 71:433-435. 3.
Gamble JS (1935)
Flora of the Presidency of 4.
Harborne JB (1998) Phytochemical
methods: A guide to modern techniques of plant analysis. 3rd
Edition Chapman & Hall Pub., 5.
Ivorra MD, Paya M and Villar A (1989) A review of natural products and plants
as potential antidiabetic drugs J. Ethnopharmacology
27:243-275. 6.
Kameswara RB, Giri R, Kesavulu MM and Apparao CH
(2001) Effect of oral administration of bark extracts of Pterocarpus santalinus L. on blood glucose level
in experimental animals. Journal of Ethnopharmacology 74:69-74. 7.
Kumar N and Seshadri TR (1976) A new triterpene from Pterocarpus santalinus bark. Phytochemistry 9:1877-1878. 8.
Manjunatha BK (2006) Antibacterial activity of Pterocarpus santalinus Indian Journal of Pharmacology Science 68(1):115-116. 9.
Matthew KM (1983) The Flora of Tamil Nadu Carnatic. In The Rapinat
Herbarium. 10. Mitra J and Joshi T (1983) Isoflavonoids
from the heart wood of Pterocarpus marsupiam. Phytochemistry
22:2326-2327. 11. Sambathkumar R, Sivakumar T, Shanmugasundaram R, Sivakumar
P, Nethaji R, Gupta M and Kanti
U (2006) Antimicrobial and antioxidant activities of Caerya arborea Roxb.
Stem and bark. Iranian Journal of
Pharmacology and Therapeutics 5:35-41. 12. Subramanian SV and Madhavan VR
(1983) Heritage of the Siddha Medicine.
International Institute of Tamil Studies, 13. Nair R, Kalariya T and Chanda S (2005) Antibacterial Activity of Some Selected
Indian Medicinal Flora. Turk J Biol 29:41-47. 14. 15. Prusti A, Mishra SR, Sahoo S and Table
1. Phytochemical profile of P. marsupium extracts. �����������
����������������������� Table 2. Bacterial strains used in the
present study.
(+ = Gram positive; - = Gram negative) Table 3. Anti-microbial activity of P. marsupium
hexane extracts.
(Growth analysis: +++ = abundant; ++ = normal; + = less; = no) Table 4.�
Anti-microbial activity of P. marsupium ethyl acetate extracts.
(Growth analysis: +++ = abundant; ++ = normal; + = less; = no) Table 5. Anti-microbial activity of P. marsupium
methanol extracts.
(Growth analysis: +++ = abundant; ++ = normal; + = less; = no) |
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