Medicinal Uses (Roselle) —
Writing this at 6:00 a.m., January 1, 2001, starting the new millennium, I couldn’t help but be delighted at my new hangover remedy, possibly aphrodisiac, that just might prevent cancer, lower blood pressure and blood sugar, and could be a cosmetic for face peels. I call it “Kharkarindo,” reflecting its major ingredients, kharkadi (dried-flowers minus-ovary) and tamarindo, also covered in this spice topic. Yes, both kharkadi and tamarindo are loaded with tasty hydroxycitric “fruit” acids. Calling it “sour tea,” Haji Faraji and Haji Tarkhani (1999) studied ca. 50 patients with moderate essential hypertension. Patients with secondary hypertension or consuming more than two drugs were excluded. Statistical findings showed 11.2% lowering of the systolic blood pressure and a 10.7% decrease of diastolic pressure in the experimental group 12 days after beginning the sour tea treatment, as compared with the first day, proving the “public belief in hypotensive activity of sour tea (X10404421). Adegunloye et al. (1996) demonstrated an antihypertensive effect of aqueous roselle extracts, which caused a dose-dependent decrease in mean arterial pressure of rats.
Reported to be antipyretic, antiseptic, aphrodisiac, astringent, cholagogue, demulcent, digestive, diuretic, emollient, laxative, resolvent, sedative, stomachic, and tonic. The flowers contain gossy-petin, anthocyanin, and glucoside hibiscin, which may have diuretic and choleretic effects, decreasing the viscosity of the blood, reducing blood pressure, and stimulating intestinal peristalsis. A drink, made by placing the calyx in water, is even a folk remedy for cancer. Medicinally, leaves are emollient and are much used in Guinea as a antipyretic, diuretic, and sedative. Fruits are antiscorbutic. Leaves, seeds, and ripe calyces are diuretic and antiscorbutic, and the succulent calyx, boiled in water, is used as a drink in bilious attacks. In Burma, the seed are used for debility, the leaves as emollient. Angolans use the mucilaginous leaves as an emollient and as a soothing cough remedy. Central Africans poultice the leaves on abscesses. Taiwanese regard the seed as diuretic, laxative, and tonic. Philippines use the bitter root as an aperitif and tonic. Alcoholics might consider one item: simulated ingestion of the plant extract decreased the rate of absorption of alcohol, lessening the intensity of alcohol effects in chickens (DAD).
Sachdewa et al. (2001) demonstrated the hypoglycemic activity of the leaf extract in glucose and streptozotocin induced hyperglycemic rats. Administration of the extract once a day for seven days, at an oral dose equivalent to 250 mg/kg, significantly improved glucose tolerance in rats. The peak blood glucose level was obtained at 30 min of glucose load (2 g kg(-1)), thereafter a decreasing trend was recorded up to 120 min. At 250 mg/kg, the efficacy of the extract was 51.5% of tolbutamide at 100 mg/kg. The data suggest that the hypoglycemic activity is comparable to tolbutamide and not to glibenclamide treatment.
Chewonarin et al. (1999) found the 80% ethanol extract of roselle was antimutagenic and chemopreventive in several colon cancer models. Tseng et al. (2000) reported that hibiscus proto-catechuic acid induced apoptosis in human leukemia cells. This phenolic compound from the dried flower also had antioxidant and antitumor promotion effects in their studies (Tseng et al., 2000).
If we can believe Kasture et al. (2000), the ethanolic extracts of the flowers have anticonvulsant, anxiogenic, CNS-depressant, and serotoninergic activities. The extracts protected animals from induced convulsions in mice and raised brain contents of gamma-aminobutyric acid (GABA) and serotonin. They were found to be anxiogenic and to depress the central nervous system. Wang et al. (2000) showed that the floral anthocyanins protected against hepatic toxicity in rats. They quenched free radicals at 100 to 200 ng/ml. Oral pretreatment of the anthocyanins (100 and 200 mg/kg) for 5 days significantly lowered serum levels of hepatic enzyme markers (alanine and aspartate aminotransferase) and reduced oxidative liver damage, inflammatory liver lesions, necrosis. Hansawasdi et al. (2000, 2001) reported on three alpha-amylase inhibitors from roselle tea extract which strongly inhibits porcine pancreatic alpha-amylase (citric acid, hibiscus acid and its 6-methyl ester).
Indications (Roselle) —
Abscess (1; CRC; WBB); Anorexia (f; APA; CRC; KOM; PH2); Aphtha (1; FNF); Atherosclerosis (1; CRC); Bacteria (1; HHB); Biliousness (f; CRC); Calculus (1; FNF); Cancer (f; JLH); Cancer, colon (1; X10478827); Carbuncle (f; PH2); Cardiopathy (f; APA); Catarrh (f; KOM); Chill (f; APA; PED); Circulosis (f; PH2); Cold (1; FNF; PHR; PH2); Conjunctivosis (f; PH2); Constipation (f; APA; KOM); Convulsion (1; X10904147); Cough (1; CRC; WBB); Cramp (1; APA; HHB; PED); Debility (f; CRC); Diabetes (1; X11495291); Dyspepsia (1; CRC; FNF; PHR); Dysuria (f; CRC); Enterosis (1; CRC); Fever (f; CRC; HHB); Fungus (1; FNF); Gastrosis (f; PH2);
Hangover (f; CRC); Heart (f; CRC); Herpes zoster (f; PH2); High Blood Pressure (1; CRC;
X10457797); Infection (1; APA; CRC; FNF); Inflammation (f; PH2); Intoxication (f; CRC; WBB);
Kidney Stone (1; APA; FNF); Neuropathy (1; APA); Neurosis (f; CRC); Ophthalmia (f; PH2);
Respirosis (f; APA; PED; PH2); Scurvy (f; CRC); Seborrhea (1; FNF); Strangury (f; CRC); Swelling (f; PH2); Tuberculosis (1; HHB); Virus (f; PH2). (Commission E list it as unapproved; KOM.)
Roselle for cardiopathy:
• ACE-Inhibitor: gossypetin
• Antiarrhythmic: protocatechuic-acid
• Antiischemic: protocatechuic-acid
• Antioxidant: delphinidin; delphinidin-3-glucoside; gossypetin; protocatechuic-acid
• Diuretic: glycolic-acid
• Sedative: benzaldehyde; benzyl-alcohol
Roselle for cramp:
• Anesthetic: benzaldehyde; benzyl-alcohol
• Antiinflammatory: protocatechuic-acid
• Antispasmodic: benzaldehyde; protocatechuic-acid
• Lipoxygenase-Inhibitor: gossypetin
• Sedative: benzaldehyde; benzyl-alcohol
Other Uses (Roselle) —
Source of a red beverage known as “jamaica” in Mexico (said to contain citric acid and salts, serving as a diuretic). Calyx is what gives the red to my favorite commercial tea, Red Zinger (lemongrass, hibiscus flowers, rose hips, orange peel, and peppermint leaves). Calyx is called “karkade” in Switzerland, a name not too different from the Arabic kharkadi. Karkade is used in jams, jellies, sauces, and wines. In the West Indies and elsewhere in the tropics, the fleshy calyces are used fresh for making roselle wine, jelly, syrup, gelatin, refreshing beverages, pudding and cakes, and to color and flavor rum. The dried roselle is used for tea, jelly, marmalade, ices, ice cream, sherbets, butter, pies, sauces, tarts, and other desserts. Tender leaves and stalks are eaten as salad and as a pot-herb and are used for seasoning curries. Fruits are edible. Seeds, containing an edible oil, have been used as an aphrodisiac coffee substitute. Seed has properties
similar to those of cotton seed oil and is used as a substitute for crude castor oil. Seed can be eaten or made into an oily sauce (Bown, 2001). Sudanese ferment the seeds to make a meat substitute called “furundu.” Roselle is also cultivated for the bast fiber obtained from the stems. The fiber strands, up to 1.5 m long, are used for cordage and as a substitute for jute in the manufacture of burlap. Residues can be used as a cheap fuel (DAD).
For more information on activities, dosages, and contraindications, see the CRC Handtopic of Medicinal Herbs, ed. 2, et al., 2002.
Cultivation (Roselle) —
Bown (2001) suggests well-drained but moist, circumneutral to alkaline soils, in full sun in warm climates (zone 9-11). Soil should be tilled deep, about 20 cm, and thoroughly. Seed, 10-22 kg/ha depending upon the soil, is drilled about 15 cm by 15 cm at beginning of rainy season, mid-April in India, planting to a depth of about 0.5 cm. Seed at 5.5-7.5 kg/ha for a population of 60,000 plants/ha. Broadcasting results in uneven stand and hence lack of uniformity in fiber. Seeds can be started in flats and transplanted. When grown for its fiber, it is planted closely to produce long stems with little foliage. Weed carefully during first month. A dressing of NPK before sowing or planting may promote early growth on soils that are marginally fertile. Roselle responds favorably to nitrogen, and 45 kg/ha is a safe level in India, applied in the form of compost or mineral fertilizer with a small quantity of phosphate. In Java, green-manure (Mimosa invisa) is plowed under before it matures seeds. Javanese recommend 80 kg N/ha, 36-54 kg P2O5/ha, and 75-100 kg K2O/ha. Rotations are sometimes used, since the root-knot nematode is a pest. A sequence of a legume green-manure crop, then roselle, and then corn is suggested. For home gardens of roselle, seeds are sown directly in rows about May 15. After germination, seedlings are thinned to stand 1 m apart. For larger plantings, seeds are sown in protected seedbeds and the seedlings transplanted to 1.3-2.6 m apart in rows 2-3.3 m apart. Applications of manure or commercial fertilizers are beneficial. The red calyces ripen about 3 weeks after the onset of flowering (some 100-160 days after transplanting). The fruit consists of the large reddish calyces surrounding the small seed pods (capsules). Capsules are easily separated but need not be removed before cooking. Calyx production ranges from ca. 1.5 kg (California), to 2 kg (Puerto Rico), and to 7.5 kg/plant in South Florida. Production yields are 8-10 MT/ha calyces, 10 MT leaves, 200 kg/ha seed. Dual-purpose plantings can yield 17,000 kg of herbage in three cuttings and later 6300 kg of calyces. Average fiber production is 1700 kg/ha, with as much as 3500 kg/ha reported (Malaya) (DAD).
Chemistry (Roselle) —
Wrobel et al. (2000) compared aluminum, chromium, copper, iron, manganese, and nickel contents in teas of black tea, green tea, mate, and roselle. Roselle contained (272 ± 19 |Jg/g), mate (369 ± 22 |Jg/g) as compared to black tea (759 ± 31 |Jg/g) or green tea (919 ± 29 |Jg/g). The authors suggested that mate could be a good dietary source of manganese (total content 2223 ± 110 |Jg/g, 48.1% leached to the infusion). The roselle tea could supply more iron (111 ± 5 |jg/g total, 40.5% leached) and copper (5.9 ± 0.3 |jg/g total, 93.4% leached). The lower the tannins level, the better the mineral extraction into the tea (X11314985). Here are a few of the more notable chemicals found in roselle. For a complete listing of the phytochemicals and their activities, see the CRC phytochemical compendium, and , 1993 (DAD) and the USDA database.
Anthocyanins — Antiarthritic 120 mg/man orl; Anticollegenase; Antielastase; Antimutagenic; Anti-myopic 600 mg/man orl; Antinyctalopic 600 mg/man orl; Antioxidant; Antitumor 120 mg/man orl; Antiviral; Hemostat; Goitrogenic; NO-Scavenger; Vasoactive; Vasodilator.
Citric-Acid — Alpha-Amylase-Inhibitor; Antiaggregant; Antiaphthic 20,000 ppm; Anticalculic; Antimutagenic; Antioxidant Synergist; Antipyretic; Antiseborrheic; Antiseptic; Antitumor; Hemo-stat; Irritant; Laxative?; Litholytic; Odontolytic; LD50 = 975 ipr rat; LD50 = 6730 mg/kg orl rat.
Gossypetin — ACE-Inhibitor IC60-90 = 333 | g/ml; Antibacterial; Antimutagenic; Antioxidant; Pigment.
Hibiscin-Chloride — Antiseptic. Hibiscus-Acid — Alpha-Amylase-Inhibitor.
Malic-Acid — Antibacterial; Antimycobacterial; Antioxidant Synergist; Antiseborrheic; Antiseptic; Antitubercular; Antitumor; Bruchiphobe; Hemopoietic; Laxative?; Sialagogue; LDlo = 1600 orl rat.
