It is widely used throughout the tropics for a variety of uses; the dried tubers are used in perfumery and for the preparation of fragrant sticks called 'agarbatties'
Indigenous to India but now found all over the world, it is considered to be among the world's most invasive weeds and is especially prevalent in damp places.
A perennial sedge grass (Plate 23), with slender, scaly creeping rhizomes, bulbous at the base, arising singly from the tubers which are about 1-3 cm long, externally blackish in colour and reddish white inside, with a characteristic odour. The stem is up to 25 cm tall and the leaves linear, dark green and grooved on the upper surface. Inflorescences are small, with 2-4 bracts, consisting of tiny flowers with a red-brown husk. The nut is three-angled, oblong-ovate, yellow in colour and black when ripe.
Tubers or rhizomes.
The tuber and rhizome are used to treat abdominal problems, particularly peptic ulcer, diarrhoea and dyspepsia, and as a carminative, demulcent, analgesic and diuretic, as well as for amenorrhoea and dysmenorrhoea. It is used also for skin conditions including scorpion bite, inflammation, wounds, sores and oedema; cold and congestion, impotence and hypertension. It has anthelmintic, antibacterial and fungicidal activities and has been used for many other complaints.
The tubers are used to treat wounds, tuberculosis, pneumonia, scabies and pox and to help heal cracked tail.
Steam distillation of the tubers and bulbous rhizome yields about 0.5-0.9% of an essential oil consisting mainly of sesquiterpene hydrocarbons (25%), epoxides (12%) and ketones (20%) and monoterpene and aliphatic alcohols (25%). These include isocyperol, cyperone rotundines A-C, cyperene, cyperol, cyperlolonecyperotundone, rotundene, ?-selinene, patchoulenone, isopatchoula-3,5-diene, caryophyllene-6,7 oxide, caryophyllene-a-oxide, caryophylla-6-one, caryophyllene and 10,12-peroxycalamenene,4,7-dimethyl-1-tetralone and many other common monoterpenes such as cineole, limonene and camphene.
?-Sitosterol, oleanolic acid and others.
Flavonoids, sugars and minerals have also been isolated from the tuber.
Antiemetic activity: An ethanolic extract of the rhizome exhibited antiemetic activity in dogs, as shown by antagonism of apomorphine-induced vomiting.
Antiinflammatory and antipyretic activities: Significant antiinflammatory activity against carageenan-induced oedema in albino rats was observed in the petroleum ether extract (75% inhibition), chloroform (60.6%) and methanol extracts (57.7%) of the roots of C. rotundus at doses of 10 mg/kg, compared to hydrocortisone (57.7%). The alcoholic extract of the tubers showed antipyretic action, which compared well with sodium salicylate in suppressing yeast-induced pyrexia. These activities were traced to the ?-Sitosterol content and the antiinflammatory activity of this compound is known to be independent of the pituitary adrenal system. ?-Sitosterol has a wide margin of safety with minimal ulcerogenic activity and may have therapeutic value.
Antimalarial activity: 10,12-Peroxycalamenene, an endoperoxide sesquiterpene, isolated from the tubers of C. rotundus exhibited antimalarial activity7 at ECso 2.33 x 10-6 M.
Antiobesity activity: A pilot study was carried out on 30 obese people who were administered the powdered tuber of C. rotundus for 90 days. A reduction in weight along with a decrease in serum cholesterol and triglycerides were observed.
Cytoprotective activity: A decoction of the rhizome of C. rotundus was evaluated against ethanol-induced gastric damage. The extract, which was orally administered at a dose of 1.25,2.5 and 4.0 g crude drug/kg, exhibited antiulcer activity in a dose-dependent manner. The protective action was related to its inhibition of gastric motility and endogenous prostaglandins may play an important role.
Effects on pigmentation: The Iyophilised methanolic extract of the plant stimulated the growth of cultured melanocytes, substantiating its use in the preparation of several formulations for the treatment of skin and hair pigmentation.
Oestrogenic activity: The essential oil exhibited mild oestrogenic activity.
Tranquillising, hypotensive and muscle relaxant activity: Tranquillising, hypotensive and muscle relaxant activity was observed in the ethanolic extract of the rhizome of C. rotundus.
Antibacterial activity: The essential oil inhibited the growth of Staphylococcus aureus but was ineffective against E.coli, E. typhosum, Vibrio cholerae and various strains of Shigella. Of the fractions, cyperone was completely inert, while the hydrocarbon fractions cyperene I and II were more potent than the oil and cyperol.12 Other types of extract were found to be active on various types of bacteria.
The LDso of ?-Sitosterol is 3 g/kg IP in mice and the minimum ulcerogenic dose 600 mg/kg IP in rats.6 The LD 50 of the ethanolic extract of rhizome was found to be 1500 mg/kg.