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In India, the sacred Vedas provide many
references on the utilities and importances of medicinal plants (Behera et al., 2008). Plant materials are of
wide use in traditional systems of medicine, particularly in communities of the
developing world. Medicinal plants are the native heritage of many distinctive
geographical area and they bear significant global importances (Sukhdev et al., 2006). Wild edible tuber species
are important sources of food in India and they play significant role in the dietary habits of
small and marginal families and forest- dwelling communities, most often during
periods of food scarcity (Arora and Pandey 1996). Wild edible tubers refer to
species that are neither cultivated nor domesticated, but available from their
natural habitat and used as sources of food (Beluhan et al., 2010). Tubers, rhizomes and wild edible plants are
collected and consumed from time to time by tribal and rural people over a
period of 4-5 months from May- June to September- October to meet their food
needs during periods of food shortage (Mishra et al., 2013). Edible tubers and rhizomes not only enrich the diet
of the people but also possess medicinal properties. The use of plant based
drugs and chemicals for curing various ailments and diseases are as old as
human civilization. They are the only resources available for the treatment of
different microbial infections among many rural and tribal communities even today
. (Fischbash and Walsh, 2009).
In
Odisha, several tribal communities like Kharia, Kolho, Santhal and Mankirdia
depend on wild food plants using their fruits, flowers, leafs, bulbils, tubers
etc. as food for their daily requirement and also during the periods of food
shortage and famine (Kumar et al.,
2012). Tribals are fond of tuber crops and many of the forests are rich in wild tubers which are used both for
food and medicinal purposes (Nedunchezhiyan et
al., 2012). Many tropical tuber species are used in the preparation of
stimulants, tonics, carminatives and expectorants (Edison et al., 2006). The tuber crops like Ipomoea spp., Colocasia spp. Manihot spp., Dioscorea spp., Amorphophallus
spp. and other rhizomatous crops like
Curcuma spp., Costus spp., Zingiber spp.etc.
are profoundly used by the tribal communities of Odisha as food and
medicines (Mishra et al., 2013). The
genus Costus belonging to the family
Costaceae has species like Costus igneus,
Costus afer, Costus pictus, Costus arabicus, Costus dubius, Costus speciosus,
etc. Among these species, Costus
speciosus is profusely available in the forests of Odisha. It is locally known as Kakaiya, keu, keukand.
C. speciosus is widely used as
therapeutic both in traditional and folk medicines (Saraf, 2010). Costus spp. are not only used as therapeutic
medicines but for other socio- cultural purposes, such as wrapping of
indigenous food items, mat making, treatment of evil repellants (Omukhua,
2011). The rhizome of Costus is used
as an antifertility agent as it is rich in diosgenin, a suitable component for
the synthesis of corticosteroids and oral contraceptives (Choudhury et al., 2012). The rural and tribal
people use the leaves against ear infections, diarrhea, cold, catarrhal fever,
cough, dyspepsia and rhizomes for skin diseases and snake bites (Ariharan et al., 2012). Costus sps. exhibit antibacterial activity due to the presence of
phytochemical compounds like alkaloids, terpenoids, tannins, glycosides and
saponins (Vasantharaj et al., 2013).
The
Genus Costus have long fleshy stem
with tuberous rootstock. The leaves are spirally arranged with silky pubescent
beneath. Flowers are densely arranged which are terminal or spikes. The Calyx
is like short tube, funnel-shaped with ovate teeth. Corolla tube is short, the
segments are large and sub equal. Stamens with broad filament, forming oblong
petaloid process with the connective. The ovary is generally 3- celled, style
is filiform and stigma with a semilunar ciliated depression. Ovules are many
and superposed. Capsule globose or ovoid. Seeds are subglobose or obovoid with
short aril (Haines, 1988). Flowering time of the plant is from August to
October (Bhuyan et al., 2013). The
genus Costus comprises of 175 species
distributed in the humid tropics of both hemispheres. This genus is found in
Indo-China, Malaysia to New Guinea, Taiwan and more or less throughout India (Saxena
and Brahmam, 1994- 96). The plant is generally found in roadside ditches and
low lying areas in the forests. It occurs throughout the foot hills of
Himalayas from Himachal Pradesh to Assam, Vindhya Satpura hills in Central
India, Eastern Ghats of Andhra Pradesh and Western Ghats of Maharashtra,
Karnataka, Tamil Nadu and Kerala upto an altitude of 1220 ft (Sarin et al., 1974). Costus speciosus is the only species of family Costaceae found in Odisha. It is found in different parts of Odisha
like Papadahandi, Gandhamardan, Jagatsinghpur, Cuttack, Rayagarh, Khurda etc.
(Saxena and Brahmam, 1994- 96).
Rhizome
of Costus spp. is rich in
macronutrients like carbohydrate, starch, amylose, protein, lipid etc. and also
good source of micronutrients like Vitamin A. Besides it is rich in
antioxidant, like β- carotene, ascorbic acid (Vitamin C), tocoferol (Vitamin
E), that can prevent coronary disorder and cancer (Nedunchezhiyan et al., 2012). Singh (2011) reported the
tubers of C. speciosus. are consumed
raw or as vegetable. It is highly nutritious with high content of carbohydrate- (44.51%),
starch- (31.65%), amylose- (14.44%), protein- (19.20%) and lipid/oil (3.52%).
The stem of Costus afer Ker Grawl. is
reported to contain moisture (33.6%), crude fat (2.48%), crude protein
(14.02%), carbohydrate (20.14%), crude fibre (15.55%) and ash (14.21%) which
indicates its nutritional aspects (Ukana et
al., 2012). Vishalakshi and Urooj
(2010) reported that the leaves of C.speciosus
and C. igneus contain 18 and 15.3%
protein, 46 and 120mg iron, 81 and 216mg ascorbic acid, 660 and 1833μg β-
carotene, 149 and 25mg α- tocopherol, 75 and 400mmol of GSH and 0.848 and
1.89mg/gm extract of total flavonoids respectively thus, the data revealed that
both the plants are good sources of nutrients and natural antioxidant components.
Karthikeyan et al., (2012)
highlighted the protein and phenolic content of C.speciosus qualitatively and quantitatively and found that high
amount of phenolic content was found in the mature leaf of the plant. Antinutrients are natural or synthetic
compounds that interfere with the absorption of nutrients. Protease inhibitors,
lipase, amylase, phytic acid, oxalic acid etc. are some of the antinutrients. Ukana
et al., (2012) reported the presence
of phytochemicals in the stem of Costus
afer with low toxicity level is beneficial in the field of agriculture and
folk medicine. The anti- nutrients evaluated (in mg/ 100gm) were total oxalate
(314.00), soluble oxalate (200.44), cyanide (24.40) and tannins (7.92). The
saponins collected from Costus species
observed to impair the digestion of protein and the uptake of vitamins and
minerals in the gut of animals (Francis et
al., 2002). Trace elements are the dietary elements that are needed in
minute quantities for the proper growth, development and physiology. Singh
(2011) reported the tubers of Costus
speciosus are rich in minerals like Nitrogen, Calcium, Potassium etc. The tuber
contains 3.14% Nitrogen, 1.72% Calcium, 1.42% Potassium, 0.28% Sodium, 0.19%
Magnesium and 0.06% Phosphorus. Ukana et
al., (2012) determined the mineral elements in the stem of Costus afer, which showed the presence
of minerals (in mg/ 100g) like Potassium (88.00), Sodium (1.94), Calcium
(200.40), Magnesium (191.39) and Phosphorus (6.02). Bioactive compounds are the
compounds or the secondary plant metabolites eliciting pharmacological or
toxicological effects. The rhizome of Genus Costus
is very rich with well known compound Diosgenin Gupta et al., 2008. The rhizome is also rich with prosapogenin B of
dioscin, diosgenone, cycloartanol, 25- en cycloartenol octacosanoic acid,
spirostanol glycoside, (steroidal saponin) and furostanol glycoside 26-O-β-
glucosidase (Rathore and Khanna, 1979; Inoue and Ebizuka, 1996). The rhizome
and roots of Costus spp. contain 5α-
stigmasten-3b-ol, sitosterol-β-D-glucoside, dioscin, prosapogenins A and B of
dioscin, gracillin and quinines (Shrivastava et al., 2011).
Duraipandiyan et al. (2012) isolated two sesquiterpene lactones- costunolide and
eremanthin from hexane extract of Costus
speciosus which inhibited tested pathogens at lowest concentrations. The
possible mechanism of action of Costunolide is that it stimulated the beta
islets to secrete insulin by inhibiting the expression of nitric oxide
synthase. It has been shown that costunolide inhibited the expression of nitric
oxide synthase and thus helped in correcting the secretary defects in diabetes (Achrekar
et al. 1991). Saraf (2010) reported
the in vitro antibacterial activity
of the rhizome of Costus speciosus. The
species has shown efficient results against the bacterial strains like E. coli, S. aureus, K. pneumoniae and P.
aeruginosa. The mature leaves of C.
igneus have proven to be effective against bacterial pathogens like B. subtilis, P. mirabilis, E. coli, P.
aeruginosa. The methanol extract showed maximum zone of inhibition against E. coli whereas least zone of inhibition against P. mirabilis (Vasantharaj et al., 2013). Rhizome extract of C. speciosus was found to be most active
against S. epidermidis and S. typhimurium. Thus, it is used as a
potential bio- bacterialcide (Ariharan et
al., 2012). The antibacterial activity of the different parts (leaf,
flower, stem and root) of C. pictus
exhibited pronounced activity against S.
flexneri, K. pneumoniae, B. subtilis and
E. coli. (Majumdar and Parihar, 2012). Duraipandiyan et al. (2012) isolated two sesquiterpene lactones- costunolide and
eremanthin from hexane extract of Costus
speciosus which showed significant antifungal activity, the MIC values of
costunolide were; 62.5 μg/ml against T.
mentagrophytes, 62. μg/ml against T.
simii, 31.25 μg/ml against T. rubrum,
125 μg/ml against E. floccosum, 250
μg/ml against Scopulariopsis spp.,
250 μg/ml against A. niger, 125 μg/ml
against C. lunata, 250 μg/ml against M. grisea. The ethyl acetate extract of C. speciosus rhizome and leaves has
shown promising antifungal activity against fungal strains like T. rubrum, T. mengagrophytes, T. simii, E.
floccosum, A. nizer, B. cinerea, C. lunata and C. albicans (Duraipandiyan and Ignacimuthu, 2011). The methanol extract of C. speciosus leaves exhibited inhibition
against fungal strains like Penicillium
spp. and Mucor spp. Thus, the plant possesses effective
antifungal activity (Vasantharaj et al.,
2013). The extracts of different parts of two species of Costus – Cheilocostus speciosus and C. pictus was found effective against fungus P. aphanidermatum whereas not effective against two fungi C. capsici and S. rolfsii (Abirami et al.,
2014). Diabetes mellitus is a chronic metabolic disorder affecting
approximately 4% population worldwide and is expected to increase to 5.4% in
2025 (Ignacimuthu 2008). Diabetes mellitus is a chronic disease characterized
by high blood glucose levels due to absolute or relative deficiency of
circulating insulin levels (Vishalakshi and Urooj 2008). Eliza et al.(2008) found that freeze-dried
rhizome juice of C. speciosus had antidiabetic and hypolipidemic effect
on body weight, liver and kidneys of normal and STZ-induced diabetic rats. The
hexane crude extract of C. speciosus
rhizome was effective in decreasing the serum glucose level and normalizing
other biochemical parameters in diabetic rats. Aqueous extract and methanolic
extracts of C. speciosus were highly
effective in bringing down the blood glucose level (Rajesh et al. 2009). Daisy et al.
(2008) investigated the possible protective effects of C. speciosus rhizome
extracts on biochemical parameters in Streptozotocin (STZ)-induced male
diabetic Wistar rats. STZ treatment (50 mg/kg) caused a hyperglycemic state
that led to various physiologic and biochemical alterations. Hexane, ethyl
acetate and methanol crude extracts administered at the dose of 250 mg/kg and
400 mg/kg respectively for 60 days to STZ-induced hypoglycemic and
normo-glycemic rats. Kalailingam et al,
(2011) investigated antihyperglycemic and hypolipidemic activities of methanol
extract of C. igneus rhizome in Streptozotocin
(STZ) induced diabetic albino rats. The results showed that fasting blood
glucose, serum TC, TG, LDL, VLDL levels were significantly (p˂0.05) decreased,
whereas serum HDL level was significantly(p˂0.05) increased in the diabetic
rats.
Bavara et
al. (2008) evaluated the antihyperglycemic, antihyperlipemic and
antioxidant potency of ethanol extract of C.
speciosus root in alloxan-induced diabetic male rats. C. speciosus is known to possess anti- diabetic properties and used
in local health traditions in India (Rajesh et
al., 2009). The methanol extract of C. pictus leaves when administered as
single dose per day to diabetes- induced rats for 21 days elicited significant
(p<0.001) reductions of blood glucose, thus C. pictus leaf is a good anti- diabetic agent (Jothivel et al., 2007).
