Speargrass is one of the most dominant and noxious weeds in agricultural and non-agricultural fields. It is a prolific seed producer, when detached from stalks the seeds
are carried by wind at long distances, and difficult
to eradicate because of persistent rhizomes. It is ranked as the world's seventh worse weed. In Nigeria, it is reported to have the potential to invade 260 million hectares of land.
Kogon is an annual,
erect, tufted grass, 30 to 80 centimeters high with a prominent underground
stem. Rhizomes are much extended, equally noded and white. Stems
are solid, rather slender; nodes glabrous or bearded. Leaves are flat, linear-lanceolate, 20 to 50 centimeters long, and
5 to 9 millimeters wide, stiff with scabrous margins. Flowers are in panicles, exserted, dense, subcylindric,
white, 10 to 20 centimeters long, 5 to 15 centimeters in diameter, silvery-silky.
Callus hairs copious, about twice as long as the glumes. Spikelets
1- to 2-flowered, 2 to 4 millimeters long, in pairs, its axis continuous.
Stamens 1 or 2, anthers large.
- Throughout the Philippines,
in open, rather dry lands, often
forming extensive cogon grasslands called cogonales, ascending to 2,300 meters in altitude.
- Propagated through the stoloniferous rhizome or the downy caryopsis
(fruits) from a mature spike.
- Also found
in tropical Asia and Africa to Australia and Polynesia.
- Study isolated a new lignan glycoside, impecyloside, from the rhizome.
- Rhizomes have yielded arundoin, cylindrin, fernenol, cylindol, cylindrene, grminones and imperanene.
- Methanolic extract of aerial parts yielded tannins and saponins. (see study below) (18)
- Study on silicon concentration yielded 13,705 ± 9,607 mg/kg dry weight. Silicon was found as an important constituent of cell walls of the epidermis of the whole plant. (19)
Aerial parts yielded four methoxylated flavonoids 1-4 , β-sitosterol-3-0-β-D-glucopyranosyl-6 '
-tetradecanoate 5 , 3-hydroxy-4-methoxybenzaldehyde 6, together with daucosterol, β-sitosterol and α-amyrin 7-9. (see study below) (11)
- Chemical investigation isolated 13 compounds identified as: three phenylpropanoids, 1-(3,4,5-trimethoxyphenyl)-1,2,3-propanetriol (1), 1-O-p-coumaroylglycerol (2), 4-methoxy-5-methyl coumarin-7-O-β-D-glucopyranoside (3); four organic acids, 4-hydroxybenzene carboxylic acid (4), 3,4-dihydroxybenzoic acid (5), vanillic acid (6), 3, 4-dihydroxybutyric acid (7); one phenolic compound, salicin (8); and five triterpenes, namely, arundoin (9), cylindrin (10), fernenol (11), simiarenol (12), glutinone (13).
- Sweet tasting.
- Considered antifebrile, anthelmintic, antibacterial, diuretic, febrifuge,
restorative, styptic, tonic.
- Grass is known for Fe hyperaccumulation and biomineralization capacities. (19)
- Spikes and roots.
- Collect the underground
portion, remove the roots, and clean.
- Cut into pieces. Fry with a strong fire until the covering turns
yellow, sprinkle with clean water and sun-dry.
- The inflorescence may also be collected and sun-dried for use.
· In many Tagalog provinces, decoction of fresh roots used for dysentery.
· Decoction of fruiting spikes used as vulnerary; used as sedative when taken internally.
· Decoction used as blood purifier and as diuretic.
· For hemoptysis,
hematuria, and nose bleeding (epistaxis): a decoction of 30 to 60 gms
of the herb.
· For urinary tract infections: drink a decoction of 80 to 120
gms of fresh rhizomes.
· Painful outgrowth at the tongue. Use 30 to 90 gms dried rhizome,
or 60 to 120 gms of fresh rhizome in decoction.
· Has also been used for diabetes, wound healing, arthritis.
· Root used in the treatment of nose bleeds, hematuria, edema.
· Decoction of root as anthelmintic.
· Decoction of fruiting spikes used as vulnerary; taken internally, as sedative.
· Decoction used as blood purifier and diuretic.
· In Chinese medicine, used as a
diuretic and anti-inflammatory. Also, runners used to make restorative, haemostatic and antifebrile medications.
· A constituent in many Chinese herbal formulations.
· In Vietnam, fresh roots used as diuretic; leaves used for kidney stones.
· Paper: Used for paper-making.
· Roof thatch: Used for making roof thatches in rural Quezon.
• No Glucose Lowering: Comparative
anti-hyperglycemic potentials of medicinal plants:
Roots of IC has had folkloric use as an antidiabetic agent. The study
showed no significant lowering in blood glucose levels with Imperata
• Neuroprotective / Rhizomes: Fractionation of methanolic extract of rhizomes of Imperata cylindrica yielded a new compound, 5-hydroxy-2-(2-phenylethyl)chromone (1), together with three known compounds, 5-hydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone (2), flidersiachromone (3), and 5-hydroxy-2-styrylchromone (4). Neuroprotective 2-(2-Phenylethyl) chromones
of Imperata cylindrica: Compounds 1 and 2 showed significant neuroprotective activity against glutamate-induced
neurotoxicity in primary cultures of rat cortical cells. (2)
• Immunomodulating activity:
Isolation and partial characterization of immunostimulating polysaccharides
from Imperata cylindrica. Crude extract and some of the purified polysaccharides enhance the proliferation of murine splenocytes. (3)
• Anti-Platelet Aggregation: Antiplatelet Aggregating Activity
of Extracts of Indonesian Medicinal Plants: All eight
Indonesian medicinal plants, including Imperata cylindrica, studied
showed inhibitory effects on platelet aggregation. (4)
• No Diuretic Effect: (1) Study assessed the diuretic effect of four traditional Vietnamese herbal remedies – Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus. The study failed to show any effect on urine output and sodium excretion and indicates the need for critical reviews on the recommendations of empiric traditional use of plant materials. (2) In a study on treatment of dysuria and diuretic effects of five indigenous Thai medicinal plants, the rhizome of IC apparently inhibited the urination of rats.
• Vasodilative Effect: The study yielded two novel lignans, graminones A and B. Graminone B showed inhibitory activity on the contraction of the rabbit aorta. (5)
• Impecyloside: A new lignan, 6-acetyl-1-[4,4'-dihydroxy=3,3'-dimethoxy-B-D-fructofuranosyl]-a-D-glucopyranoside, named impecyloside, was isolated from the rhizomes of IC. (8)
• Toxicity Studies: Study suggests the water extract of Imperata cylindrica does not cause acute and subchronic toxicities in rats. (10)
• Hepatoprotective / Phytochemicals: Study of the methanolic extract of IC yielded four methoxylated flavonoids 1-4 and B-sitosterol-3-O-B-D-glucopyranosyl-6'-tetradecanoate, isolated for the first time from IC, together with four other compounds. Results showed a significant hepatoprotective activity on co-administration of ME of IC with CCl4. (11)
• Paper Product Feasibility Study: Study evaluated the feasibility of cogon grass as substitute for cardboard, food packaging, souvenir making uses. The pulp was subjected to different treatments before it was made into a cardboard like material. Treatment C, with 5% water and 7.5% starch showed to be the best treatment. (14)
• No Uric Acid Lowering Effect: Study evaluating the uric acid (C5H4N4)4) lowering potential of cogon grass showed no hypouricemic effect. (15)
• Antibacterial / Aerial Parts: Study evaluated the antibacterial effect of three extracts of aerial parts against Staphylococcus aureus and E. coli. Results showed the aqueous extract had very potent antibacterial activity compared with the other extracts. Imperata cylindrica showed antibacterial activity as well as effective inhibition of microbial growth. (17)
• Anthelmintic / Aerial Parts: Study evaluated the in vitro anthelmintic activity of methanolic extract of roots of Imperata cylindrica against Indian earthworms Pheretima posthuma. Results showed maximum anthelmintic activity comparable to standard drug albendazole. Extract phytoconstituents—tannins and saponins—might have contributed to the potent anthelmintic activity. (18)
• Vasodilative and Antihypertensive Effects / Leaves: Study evaluated the antihypertensive effect of an ethanolic extract of Imperata cylindrica leaves using cat and rabbit models. The extract exhibited a significant dose-dependent reduction in amplitude of smooth muscle contraction of rabbit jejunum. The heart pressure of cats was significant reduced, with no effect on heart rate. The ethanolic leaf extract exhibited vasodilative antihypertensive properties similar to the mechanism of adrenaline and suggests a potential use in the management of hypertension. (20)
• Anticoagulant: Study evaluated the hematological effect of Imperata cylindrica (cogon grass) as an anticoagulant. Results showed significant anticoagulant activity possibly through action on the extrinsic cascade of clotting probably by binding with the antithrombin. (21)
• Larvicidal / Culex sp. / Roots: Study of Imperata cylindrica root decoction showed a larvicidal effect against Culex sp. larvae. (22)