ANTIBACTERIAL
EFFICACY OF CURCUMA
CAESIA FROM BASTAR DISTRICT OF CHHATTISGARH, INDIA
Dhananjay Pandey* and A.K. Gupta
Microbiology Research Laboratory, School of Studies in Life
Sciences, Pt. Ravishankar Shukla University, Raipur- 492010, Chhattisgarh,
India
ABSTRACT: Bio-efficacy of
plants and their derivatives have been reemphasized in recent times. The
present investigation was carried out to study the antibacterial efficacy of Curcuma
caesia (family:
Zingiberaceae) commonly known as kali haldi. The root, stem and leaf of Curcuma
caesia were
extracted successively with polar (aqueous, methanol), dipolar (acetone) and
non-polar (chloroform) solvents, and their physical characteristics were
explored which revealed the presence of more phytocompounds in case of root
followed by stem and leaf. The extracts were assessed for their potential
antibacterial activity against gram positive and gram negative bacteria viz., Bacillus
cerus, Bacillus
subtilis, Staphylococcus
aureus, Staphylococcus
epidermidis,Escherichia
coli, Proteus
vulgaris, Pseudomonas
aeruginosa and Klebsiella
pneumoneae. The gram positive
bacteria were found to be more sensitive than gram negative bacteria. The
inhibition of both gram positive and gram negative bacteria by the extracts
indicates the presence of broad spectrum antibacterial potentiality of the
plant. The root extracts of the plant were found to be more effective in
inhibiting the bacterial growth as compared to stem and leaf. The root extracts
of the plant showed inhibition against all gram positive and gram negative
bacteria except Pseudomonas aeruginosa. The highest
activity index was recorded in root methanol and chloroform extracts in case of Bacillus
cerus and Klebsiella
pneumoneae respectively. The results were promising and justified the
use of Curcuma caesia root by tribal
community of Bastar and traditional healers in combating several bacterial
diseases
Keywords:
|
Curcuma caesia,solvents, Extracts,
Percentage yield, Antibacterial efficacy, Activity index
INTRODUCTION:
Medicinal plants are one of the emerging and best sources for the discovery and
development of novel bioactive compounds for combating several bacterial
diseases 1.The plant based
herbal therapy is widely explored in the traditional system of medicine and
their curative potentials are well documented 2.
The
medicinal properties of plants are due to their antioxidant, antimicrobial,
antipyretic, anti-inflamatory and antitumour activity of the phytochemicals
present in them 3.
The
use of plant extracts for the treatments of several bacterial diseases have
become popular because the effective life span of antibiotic is limited and
over prescription as well as misuse of antibiotics is causing antimicrobial
resistance 4.
Many reports have documented
the effective activity of traditional herbs against microorganisms, so plants
are one of the bedrocks for the discovery of modern medicines 5.
Several
types of antibiotics are available, but a large number of factors such as, drug
toxicity, low potency, emergence of resistant bacterial strains, high cost of
new generation antibiotics with limited effective span have resulted in
increased death rate 6. However, over the past few decades the health
benefits are under threat as many commonly used antibiotics and their extensive
use against bacterial diseases has led to the emergence of multidrug resistance 7. The bacterial
species have developed the genetic potentiality to acquire and transmit
resistance 8.
Herbal medicines are in great demand in the developed as well as developing
countries due to their wide medicinal and biological applications.
So
the identification of bioactive compounds in plants, their isolation,
purification and characterization of active ingredients in crude extracts by
various analytical methods is greatly significant. Thus, the documentation of
the plants phytochemicals to treat and prevent infectious bacterial diseases
has attracted the attention of scientist’s worldwide 9.
Curcuma species have a great importance for its
medicinal value. Curcuma
caesia is a member of family Zingiberaceae and popularly known
askali haldi. It has been used by various tribal communities in curing several
ailments since traditional times. C. caesia is a
perennial herb with bluish-black rhizome native to North-East and Central
India. In India it is found in Chhattisgarh, Madhya Pradesh, Uttar Pradesh,
Orissa and West Bengal. Black Turmeric is also sparsely found in Papi Hills of
East Godavari, West Godavari and Khammam Districts of Andhra Pradesh. The
rhizomes of kali haldi have a high economic importance because of its putative
medicinal properties. The rhizomes are used in the treatment of smooth muscle
relaxant activity, leprosy, dirrhoea, wound, asthma, haemorrhoids, cancer,
epilepsy, fever, vomiting, menstrual disorder, antihelmentic, aphrodisiac,
inflammation and gonorrhoeal discharges 10, 11. The antimicrobial activities of this plant
have not yet been explored. In this context present study was carried out to
screen the antibacterial efficacy of Curcuma caesia against
both gram positive and gram negative bacteria viz., Bacillus cerus, Bacillus
subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli,
Proteus vulgaris, Pseudomonas aeruginosa and Klebsiella pneumoneae.
MATERIALS
AND METHODS:
Selection of medicinal plant:
Plant of Curcuma caesia was
selected based on its traditional usage by the tribal community of Bastar
district of Chhattisgarh in healing several diseases and its ethno-medicinal
significance as herbal drug. Apparently healthy and disease free plants were
selected for antibacterial screening.
Collection of the sample:
The fresh and healthy root,
stem and leaves of Curcuma
caesia were collected and identified at Department of
Horticulture, Shahid Gundadhoor College of Agriculture and Research Station,
Kumhrawand, Jagdalpur from Bastar district, Chhattisgarh, India. The plant
samples were washed under running tap water to remove debris and shade dried
for about three weeks to attain a constant weight. The dried samples were
mechanically grinded by using a mortar and pestle and finally powdered by
laboratory grinder machine and stored in separate air tight bottles till use (Fig. 1).
FIG.
1: SAMPLE COLLECTION OF DIFFERENT PARTS OF CURCUMA CAESIA
Extraction procedure: 15g
powdered material was extracted with 150 ml of different solvents according to
their increasing polarity successively for 8-10 hours in the Soxhlet apparatus
at a temperature not exceeding the boiling point of the respective solvents.
After extraction excess solvent was removed by distillation and the
concentrated extracts so obtained were further dried in incubator at 40oC. The percentage
yield and other physical properties were recorded. The residual extracts after
drying were dissolved in 50% DMSO and stored in refrigerator at 4oC in small and
sterile glass tubes.
Microorganisms
used for the test: The present study was carried
out with the bacterial strainsprocured from IMTECH, Chandigarh, India. The
bacterial strains used for antibacterial screening were Bacillus cereus (MTCC-430), Bacillus subtilis (MTCC-441), Staphylococcus aureus (MTCC-96), Staphylococcus epidermidis (MTCC-435), Escherichia coli (MTCC-1687), Proteus vulgaris (MTCC-744), Pseudomonas aeruginosa (MTCC-741)
and Klebsiella
Pneumoniae (MTCC-3384). The bacterial strains were maintained
on nutrient agar slants, sub cultured regularly and stored at 4oC for further
use.
Inoculum preparation: One
loop full of overnight grown bacterial culture was inoculated in 25 ml nutrient
broth at 37oC on a rotary
shaker incubator for 16-18 h. The inoculum size of each bacterial strains were
standardized by adjusting the optical density of the culture broth to a
turbidity corresponding to 0.08 at 620 nm using a spectrophotometer which is
equivalent to 108 cfu/ml 12.
Assessment of antibacterial activity: The
antibacterial activity of the crude extracts was determined by the agar-well
diffusion method13.
200 µl of the standardized cell suspension were spread on Muller Hinton Agar
(Hi-media) plate using a sterile swab and air dried to remove the surface moisture.
Wells were then bored into the agar using a sterile 6 mm diameter cork borer.
The crude extract was introduced into the well at a concentration of 2mg/20µl,
allowed to stand at room temperature for about 1 h as a period of
pre-incubation diffusion to minimize the effect of variation in time between
the application of different solutions and later the plates were incubated at 37oC for 24 h.
Controls were also set up in parallel and the effects were compared with
penicillin and streptomycin at a concentration of 10µg/20µl. The plates were
observed for the zone of inhibition after 24 h. The experiment was conducted in
triplicates and the results are expressed as mean ± SE.
RESULT
AND DISCUSSION:
The various parts of Curcuma caesia viz., root,
stem and leaf were extracted successively using four different solvents based
on their polarity index as chloroform, acetone, methanol and aqueous for
assessment of their antibacterial efficacy as the antibacterial phytochemical
compounds of the plant origin may occur mostly in root, stem and leaf of the
plants 14. The physical
properties of the root, stem and leaf extracts of Curcuma caesia were
studied and the result revealed that the root extracts were almost sticky to
viscous in nature with brown to yellowish in color and the percentage yield was
found to be highest in root extracts in case of polar aqueous solvent (6.33%)
followed by methanol (4.80%), acetone (1.93%) and chloroform (1.40%).
The
highest percentage yield in aqueous solvent might be due to the fact that water
is a universal solvent and extracts most of the compounds 15. The stem
extracts were greenish to brown in color and leaf extracts were almost waxy to
viscous in nature with dark green to brown in color and the percentage yield of
the stem and leaf extracts were found to be maximum in case of polar organic
solvents (5.06%) and non-polar solvents (4.73%) respectively (Table 1). The above study clearly illustrates the
presence of varied phytochemical in different parts of the plants and their
affinity towards different solvents according to their polarity index.
The efficacy in crude extract
of root, stem and leaf of Curcuma caesia in four different solvents based
on their polarity as polar (aqueous, methanol), dipolar (acetone) and non-polar
(chloroform) were assessed against both gram positive and gram negative
bacteria viz. Bacillus cerus, Bacillus
subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus vulgaris Pseudomonas
aeruginosa and Klebsiella pneumoneae.
The study revealed that the root extracts were found to be more effective to
these bacteria followed by stem and leaf.
The
antibacterial activity in case of gram positive bacteria was found to be
maximum in methanolic root extracts followed by acetone and chloroform. The
methanolic root extract exhibited significant zone of inhibition against all
the four gram positive bacteria with maximum against Bacillus cerus (15.06±0.06)
followed by Staphylococcus
epidermidis (14.20±0.20), Staphylococcus aureus (12.93±0.17), and Bacillus subtilis (12.33±0.33).
The stem and leaf extract showed activity against Bacillus cerus followed
by Staphylococcus
epidermidis and Staphylococcus aureus,
whereas no significant activity was observed in case of their aqueous extract.
These results clearly indicate that organic solvents were more suitable for the
extraction of the active principles responsible for antibacterial activity 16, 17.
The
decline in activity of aqueous extract might be due to the excessive heating of
the aqueous soluble active constituents during the extraction process which
often affect biologically active substances such as flavonoids, essential oils
and other heterogeneous phytoconstituents present in the extract 18, 19, 20. The
phytochemical analysis of Curcuma caesia showed the presence of alkaloids,
flavonoids, tannins, polyphenolics, terpenoids, phytosterols, resins and
saponin which might be responsible for the antimicrobial activity of plant
extracts 21. The potential
sensitivity of the extracts against gram positive bacteria and the zone of
inhibition were recorded and are presented in Table 2 and Fig. 2.
TABLE 2: ANTIBACTERIAL ACTIVITY OF CURCUMA
CAESIA AGAINST GRAM POSITIVE BACTERIA (ZONE OF INHIBITION IN MM, MEAN
± SE)
Bacterial
Species
|
B.
cerus
|
B.
subtilis
|
S.
aureus
|
S.
epidermidis
|
ROOT
|
||||
Chloroform
|
09.73±0.26
|
08.46±0.24
|
08.80±0.20
|
11.80±0.11
|
Acetone
|
11.86±0.13
|
09.46±0.24
|
12.00±0.23
|
13.13±0.06
|
Methanol
|
15.06±0.06
|
12.33±0.33
|
12.93±0.17
|
14.20±0.20
|
Aqueous
|
ND
|
ND
|
ND
|
ND
|
Penicillin
|
11.86±0.13
|
10.33±0.24
|
26.40±0.40
|
29.33±0.33
|
Streptomycin
|
26.93±0.06
|
22.86±0.13
|
27.93±0.06
|
26.20±0.11
|
STEM
|
||||
Chloroform
|
07.13±0.06
|
ND
|
07.06±0.17
|
07.46±0.24
|
Acetone
|
8.46±0.24
|
ND
|
08.20±0.20
|
11.20±0.11
|
Methanol
|
13.86±0.13
|
ND
|
10.40±0.30
|
12.33±0.33
|
Aqueous
|
ND
|
ND
|
ND
|
ND
|
Penicillin
|
11.86±0.13
|
10.33±0.24
|
26.40±0.40
|
29.33±0.33
|
Streptomycin
|
26.93±0.06
|
22.86±0.13
|
27.93±0.06
|
26.20±0.11
|
LEAF
|
||||
Chloroform
|
06.46±0.29
|
ND
|
06.93±0.06
|
07.33±0.33
|
Acetone
|
08.06±0.06
|
ND
|
08.20±0.20
|
08.26±0.26
|
Methanol
|
13.66±0.33
|
ND
|
10.26±0.26
|
12.13±0.24
|
Aqueous
|
ND
|
ND
|
ND
|
ND
|
Penicillin
|
11.86±0.13
|
10.33±0.24
|
26.40±0.40
|
29.33±0.33
|
Streptomycin
|
26.93±0.06
|
22.86±0.13
|
27.93±0.06
|
26.20±0.11
|
Standard antibiotics: Penicillin and
Streptomycin; ND- Not detected
The antibacterial
activity in case of gram negative bacteria was found to be comparatively less
than that of gram positive bacteria against all the extracts tested. The
chloroform extract of root exhibited maximum zone of inhibition against Klebsiella pneumoneae (11.80±0.11)followed by Proteus vulgaris(09.73±0.06), Escherichia coli (09.00±0.00) and no significant
activity was observed in case of Pseudomonas aeruginosa.
However, the stem and leaf extracts showed activity against Klebsiella pneumoneae and Proteus vulgaris.
Amongst gram negative
bacteria, Klebsiella pneumoneae showed
the highest inhibition whereas Pseudomonas aeruginosa were
found to be resistant against all the extracts tested (Table 3 and Fig. 3). In the present
investigation the gram positive bacteria were found to be more susceptible as
compared to gram negative bacteria against the plant extracts tested. The
higher resistance of gram-negative bacteria to plant extracts is due to thick
murein layer in their outer membrane, which prevents the entry of inhibitory
substances into the cell and have outer phospholipid membrane carrying the
structural lipopolysaccharides components, this makes the cell wall impermeable
to antimicrobial substances whereas, gram positive bacteria have single layered
cell wall with peptidoglycan constituting the outer layer, which is not an
effective permeability barrier 22, 23.
The activity index was
calculated to express the relationship between zones of inhibition of the
extracts with the standard antibiotics 24. Among the
root, stem and leaf extracts of Curcuma caesia, the
highest activity index of 0.55 was recorded in methanol extract of root in gram
positive bacteria as B. ceruswhereas,
activity index of 0.59 was observed for gram negative bacteria as K. pneumoneae against streptomycin (Table 4).
Higher activity index
(>0.5) in the crude extract indicates potential antibacterial activity in
the plant. The findings of present study offers a scientific validation for the
usage of Curcuma caesia root by the tribal community of
Bastar as their food, medicine, cosmetics and traditional healers in curing
different diseases.
TABLE 3: ANTIBACTERIAL
ACTIVITY OF CURCUMA CAESIA AGAINST GRAM NEGATIVE BACTERIA
(ZONE OF INHIBITION IN MM, MEAN ± SE)
Bacterial
Species
|
E.
coli
|
P.
vulgaris
|
P.
aeruginosa
|
K.
pneumoneae
|
ROOT
|
||||
Chloroform
|
09.00±0.00
|
09.73±0.06
|
ND
|
11.80±0.11
|
Acetone
|
08.13±0.13
|
08.20±0.20
|
ND
|
9.46±0.24
|
Methanol
|
06.80±0.11
|
07.20±0.20
|
ND
|
8.06±0.06
|
Aqueous
|
ND
|
ND
|
ND
|
ND
|
Penicillin
|
09.93±0.29
|
ND
|
ND
|
ND
|
Streptomycin
|
20.80±0.20
|
17.66±0.24
|
14.60±0.23
|
19.73±0.37
|
STEM
|
||||
Chloroform
|
ND
|
8.93±0.06
|
ND
|
11.00±0.00
|
Acetone
|
ND
|
08.20±0.11
|
ND
|
09.13±0.13
|
Methanol
|
ND
|
07.06±0.66
|
ND
|
07.73±0.26
|
Aqueous
|
ND
|
ND
|
ND
|
ND
|
Penicillin
|
09.93±0.29
|
ND
|
ND
|
ND
|
Streptomycin
|
20.80±0.20
|
17.66±0.24
|
14.60±0.23
|
19.73±0.37
|
LEAF
|
||||
Chloroform
|
ND
|
ND
|
ND
|
10.20±0.11
|
Acetone
|
ND
|
ND
|
ND
|
08.86±0.13
|
Methanol
|
ND
|
ND
|
ND
|
06.93±0.06
|
Aqueous
|
ND
|
ND
|
ND
|
ND
|
Penicillin
|
09.93±0.29
|
ND
|
ND
|
ND
|
Streptomycin
|
20.80±0.20
|
17.66±0.24
|
14.60±0.23
|
19.73±0.37
|
Standard antibiotics: Penicillin and
Streptomycin; ND- Not detected
FIG. 3: ANTIBACTERIAL
ACTIVITY OF CHLOROFORM EXTRACTS OF ROOT OF C. CAESIA AGAINST
GRAM NEGATIVE BACTERIA (KLEBSIELLA PNEUMONEAE)
TABLE 4: ACTIVITY INDEX OF THE EXTRACT OF CURCUMA CAESIA IN DIFFERENT SOLVENTS WITH RESPECT TO STREPTOMYCIN
TABLE 4: ACTIVITY INDEX OF THE EXTRACT OF CURCUMA CAESIA IN DIFFERENT SOLVENTS WITH RESPECT TO STREPTOMYCIN
Bacterial
Species
|
Chloroform
|
Acetone
|
Methanol
|
||||||
Root
|
Stem
|
Leaf
|
Root
|
Stem
|
Leaf
|
Root
|
Stem
|
Leaf
|
|
B.
cerus
|
0.36
|
0.26
|
0.23
|
0.44
|
0.31
|
0.29
|
0.55
|
0.51
|
0.50
|
B.
subtilis
|
0.37
|
-
|
-
|
0.41
|
-
|
-
|
0.53
|
-
|
-
|
S.
aureus
|
0.31
|
0.25
|
0.24
|
0.42
|
0.29
|
0.29
|
0.46
|
0.37
|
0.36
|
S.
epidermidis
|
0.45
|
0.28
|
0.27
|
0.50
|
0.42
|
0.31
|
0.54
|
0.47
|
0.46
|
E.
coli
|
0.43
|
-
|
-
|
0.39
|
-
|
-
|
0.32
|
-
|
-
|
P.
vulgaris
|
0.55
|
0.50
|
-
|
0.46
|
0.46
|
-
|
0.40
|
0.39
|
-
|
P.
aeruginosa
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
K.
pneumoneae
|
0.59
|
0.55
|
0.51
|
0.47
|
0.46
|
0.44
|
0.40
|
0.39
|
0.35
|
CONCLUSION: The present
investigation was carried out to study the antibacterial potentiality in the
root, stem and leaf extracts of Curcuma caesia in
four different solvents against four gram positive and four gram negative
bacteria. The results were promising and revealed that the methanol root
extracts exhibited significant antibacterial activity against gram positive and
chloroform root extracts against gram negative bacterial species under study
except for P. aeruginosa followed by stem
and leaf extracts. The above findings reveals that the plant based
antimicrobials have enormous therapeutic potentials and can serve the purpose
with lesser side effects that are often associated with synthetic
antimicrobials. The present study would be a primary platform to explore local
potential medicinal plants possessing antimicrobial efficacy and their further
exploration proves to be the bedrock for future medicine.