МОНОГРАФИИ ВОЗ Т 4

Ramulus cum Uncis Uncariae

Definition

Ramulus cum Uncis Uncariae consists of the dried hook-bearing stem branch of Uncaria rhynchophylla (Miq.) Jacks, U. macrophylla Wall., U. hirsuta Havil., U. sinensis (Oliv.) Havil. or U. sessilifructus Roxb. (Rubiaceae) (1–3).

Synonyms

Uncaria rhynchophylla (Miq.) Jacks, Nauclea rhynchophylla Miq., Ourouparia rhynchophylla Matsum (4).

Selected vernacular names

Choto-ko, chotoko, cho-to-kou, gout eng, kagikazura (1, 4, 5).

Geographical distribution

Indigenous to China and Japan (6, 7).

Description

A deciduous twining shrub up to 10 m long. Branches brownish, glabrous, occasionally bearing compressed, hooked thorns. Young stems slender, square to slightly angular, glabrous. Stipules of the plagiotropic shoot 6–10 mm long, those of the orthotropic shoot considerably larger, up to 30 mm long, inside glabrous with glandular hairs at the base, outside glabrous, margins entire, narrowly triangular, deeply bifid for over two thirds of the length, lobes narrowly triangular to triangular-lanceolate. Leaves opposite, ovate to ovate-oblong or elliptic to elliptic-oblong, 5–12 × 3–7 cm, membranous, glabrous on either side; apex acute to cuspidate; base cuneate to truncate; lateral nerves 4–8 pairs, axils with sparsely hairy domatia, tertiary nerves curved, impressed, ultimate venation reticulate. Inflorescence an axillary or terminal peduncled solitary head. Flowers yellow, subsessile on the receptacle. Hypanthium 1–2 mm, densely hairy. Calyx 1 mm, pubescent; lobes oblong to slightly triangular, 0.5–1 mm, sparsely pubescent. Corolla tube 6–8 (6–10 mm), outside

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glabrous or with a few scattered hairs; lobes oblong, 1.5–2.5 mm, outside glabrous or slightly farinose-pubescent, margins sometimes ciliate. Stamens 5. Ovary 2-celled. Fruiting head 14–18 mm in diameter, fruit a dry capsule. The plant entwines other trees with its hooked thorns (6, 8, 9).

Plant material of interest: dried hook-bearing stem branch

General appearance

Cylindrical or subsquare, 1–4 cm long, 2–5 mm in diameter. Externally reddish-brown to dark brown or yellow-brown with fine longitudinal striations, glabrous, or yellowish-green to greyish-brown, sometimes with white dotted lenticels, covered with yellowish-brown pubescence. Transverse section: square to elliptical. Most nodes of stem branches with two opposite downward curved hooks/prickles (sterile peduncles), some with a hook only on one side and with raised scars on the other side; hooks relatively flattened or rounded, apex acute, base relatively broad; dotted scars of fallen petiole and ring-shaped stipule scars visible on the branch at the hook base; transverse section oblong to elliptical. Texture hard and tenacious, fracture yellowish-brown, bark fibrous, pith yellow- ish-white to light brown or hollowed (1, 2).

Organoleptic properties

Odour: none; taste: slight (1, 2).

Microscopic characteristics

Transverse section of the prickle (hook) reveals vascular bundles in the cortex, unevenly distributed and arranged in a ring. Parenchyma cells in the secondary cortex containing crystals of calcium oxalate (2, 3).

Powdered plant material

To be established in accordance with national requirements.

General identity tests

Macroscopic examination (1–3), microchemical test (1–3), and highperformance liquid chromatography for the presence of characteristic oxindole alkaloids (2, 10–13).

Purity tests

Microbiology

Tests for specific microorganisms and microbial contamination limits are as described in the WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues (14).

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Chemical

To be established in accordance with national requirements.

Foreign organic matter

Not more than 2% (3).

Total ash

Not more than 4% (2, 3).

Acid-insoluble ash

To be established in accordance with national requirements.

Water-soluble extractive

To be established in accordance with national requirements.

Alcohol-soluble extractive

Not more than 6% (1).

Loss on drying

Not more than 12% (2).

Pesticide residues

The recommended maximum limit of aldrin and dieldrin is not more than 0.05 mg/kg (15). For other pesticides see the European pharmacopoeia (15) and the WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues (14) and pesticide residues (16).

Heavy metals

For maximum limits and analysis of heavy metals, consult the WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues (14).

Radioactive residues

Where applicable, consult the WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues (14).

Chemical assay

Not less than 0.03% of total rhynchophylline (rhynchophylline and hirsutine) as determined by high-performance liquid chromatography and calculated on the dried basis (2).

Major chemical constituents

The major constituents are indole alkaloids (1.7%) including the tetracyclic oxindoles rhynchophylline (0.02%), isorhynchophylline (0.05%),

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corynoxeine (0.006%) and isocorynoxeine (0.001%). Other notable alkaloids are hirsuteine (0.001%) and hirsutine (0.001%). Besides ursolic acid, two other triterpenes, the bioactive uncarinic acids A and B as well as the flavonoid, hyperin, have been reported (4, 5, 17). Structures of major tetracyclic indole and oxindole alkaloids and the triterpenes uncarinic acids A and B are presented below.

Medicinal uses

Uses supported by clinical data

None.

Uses described in pharmacopoeias and well established documents

Used orally to treat eclampsia, headache, dizziness, high fevers and hypertension (1, 6). Considering the serious nature of these diseases, the usefulness of the crude drug needs to be confirmed by controlled clinical studies.

Uses described in traditional medicine

Used as a carminative, diuretic, and a muscle relaxant. Also used to treat cardiovascular disease, colic, convulsions, stroke and vertigo (5, 6).

Pharmacology

Experimental pharmacology

Much of the pharmacological work has been performed with pure compounds isolated from the crude drug. These studies used high concentra-

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tions of the pure compounds and thus the applicability of these data to the crude drug and its preparations needs to be further investigated.

Antiarrhythmic activity

The effect of hirsutine, an indole alkaloid isolated from the crude drug, on membrane potentials of rabbit sino-atrial node and guinea-pig right ventricle and left atrium was investigated. Hirsutine at concentrations of 0.1–30.0 μM decreased the maximum rate of rise and prolonged action potential duration in sino-atrial node in vitro, as well as in atrial and ventricular preparations (18). Hirsutine, in concentrations of 1.0–3.0 μM produced a dose-dependent relaxation of the isolated rat aorta precontracted with either norepinephrine or potassium chloride solution, suggesting that the compound dilated blood vessels through the inhibition of volt- age-dependent calcium channels (19). The compound, at a concentration of 30 μM, also decreased intracellular calcium concentrations in isolated vascular smooth muscle cells through the inhibition of norepinephrineinduced calcium influx (20).

Anticonvulsant activity

Intragastric administration of a methanol extract of the crude drug to rats at a dose of 1.0 g/kg body weight (bw) inhibited kainic acid-induced epileptic seizures and reduced the levels of free radicals, as measured by lipid peroxidation in the brain (21).

Intraperitoneal administration of an ethyl acetate or methanol extract of the crude drug to mice at a dose of 70.0 mg/kg bw inhibited pentetra- zole-induced convulsions (22). Hyperin, a chemical constituent isolated from the extract, decreased the elevated activities of Γ-aminobutyric acid-T, xanthine oxidase and lipid peroxide induced by pentetrazole in mouse brain tissue in vitro at a concentration of 25.0 mg/ml (23).

Intragastric administration of an aqueous extract of the crude drug to mice, at a dose of 1.0–3.0 g/kg bw, inhibited glutamate-induced convulsions, but had no effect on convulsions induced by picrotoxin, strychnine or electroshock (24). The active constituents of the crude drug were isolated and identified as indole alkaloids, geissoschizine methyl ether and hirsutine. Intragastric administration of the alkaloids to mice at a dose of 100.0 mg/kg bw also inhibited glutamate-induced convulsions in a dosedependent manner (24).

An aqueous extract of the crude drug at a concentration of 0.1 mg/ml prevented glutamate-induced neuronal death in cultured rat cerebellar granule cells through the inhibition of calcium influx into the cells (25). In cultured mouse cerebral neurons, glucose oxidase-induced toxicity was reduced after treatment of the cells with 100 Μg/ml of the crude drug (26).

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In cultured hippocampal neurons from neonatal mice, hydrogen per- oxide-induced neuronal damage was significantly reduced after treatment of the cells with 80 Μg/ml of the crude drug (27). A methanol extract of the crude drug protected against N-methyl-D-aspartate-induced excitotoxicity in cultured rat hippocampus slices at a concentration of 100 Μg/ ml (28).

Antihypertensive activity

An alkaloid-containing extract of the crude drug reduced blood pressure in rats when administered by gavage at a dose of 50.0 mg/kg bw for 20 days, or when administered by intravenous injection to cats at a dose of 20.0 mg/kg bw for 20 days (29). A 50% methanol extract of the crude drug inhibited the activity of angiotensin-converting enzyme isolated from pig kidney at a concentration of 200.0 μg/ml in vitro (30).

An infusion of the crude drug inhibited norepinephrine-induced contractions of isolated rat aorta at a concentration of 0.12 mg/ml (31). En- dothelium-dependent relaxation induced by the extract of the crude drug was inhibited by N-monomethyl-L-arginine, but not indometacin or atropine, and was decreased when the endothelium was not present. The authors concluded that the extract relaxes the precontracted rat aorta through an endothelium-dependent mechanism involving nitric oxide (31).

Anti-inflammatory activity

A decoction of the crude drug suppressed carrageenan-induced footpad oedema in rats when administered by subcutaneous injection at a dose of 10.0 ml/kg bw (32). An infusion of the crude drug inhibited the activity of prostaglandin synthetase in rabbit microsomes at a concentration of 750.0 μg/ml (33).

Antimicrobial activity

An ethanol extract of the crude drug was not active against Bacillus subtilis, Candida albicans, Escherichia coli or Streptococcus pneumoniae in vitro at concentrations up to 500.0 mg/disc (34).

Antioxidant activity

Intraperitoneal administration of an ethanol extract of the crude drug at a dose of 1.0 g/kg bw to rats inhibited an increase in lipid peroxidation in the ipsilateral cortex induced by the injection of ferric chloride into the lateral cortex (35). The extract also induced an increase in the activity of superoxide dismutase in the mitochondrial fraction of the ipsilateral cortex (35). A methanol extract of the crude drug inhibited kainic acidinduced lipid peroxidation in rat brain tissues in vitro (21). An aqueous extract of the crude drug, at a concentration of 50.0 μg/ml, had strong

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scavenging activity against superoxide anion radicals in vitro, as measured by electron spin resonance spin-trapping techniques (36).

Depressant effects on the central nervous system

Intragastric administration of an aqueous extract of the crude drug (2.0 g/ kg bw), or oxindole alkaloids isolated from the crude drug (10–100 mg/kg bw) to mice, significantly prolonged thiopental-induced sleep time (p < 0.05) (13, 37). Intragastric administration of an aqueous extract of the crude drug to mice at a dose of 2.0 g/kg bw significantly depressed locomotor activity (p < 0.05) (37). Intragastric administration of three indole alkaloids isolated from the crude drug, corynoxine (30.0 mg/kg bw), corynoxine B (100.0 mg/kg bw) or isorhynchophylline (100.0 mg/kg bw) also significantly decreased locomotor activity (p < 0.05) (38).

The suppressant effects on the central nervous system were confirmed by a study in mice of extracts prepared from mixtures of the herb with and without the crude drug. Preparations containing the crude drug prolonged thiopental-induced sleep, but the extract prepared from the mixture of herb without the crude drug was devoid of this activity (39). Intraperitoneal administration of a 90% ethanol extract of the crude drug reduced spontaneous motor activity in mice (34).

Effects on neurotransmitters

An 80% ethanol extract of the crude drug inhibited serotonin reuptake by 97% at a concentration of 10.0 μg/ml in rat brain stem neurons (40). Uncarinic acids A and B, isolated from the crude drug inhibited the activity of phosphatidylinositol-specific phospholipase C, a key enzyme involved in the signal transduction of growth factors, neurotransmitters and hormones, with a median inhibitory concentration of 35.66 and 44.55 μM, respectively (41). Hirsutine, at a concentration of 300 nM to 10.0 μM inhibited dopamine release induced by nicotine in rat pheochromocytoma PC12 cells (42). In a study in rats, dopamine release induced by potassium chloride was also inhibited by hirsutine at a concentration of 10.0 μM (41). Hirsutine also had antagonistic effects on the opioid receptors and, at a concentration of 10.0 μM, reversed the inhibitory effect of morphine on twitch contraction in isolated guinea-pig ileum (43).

Toxicology

Intraperitoneal administration of a 90% ethanol extract of the crude drug to mice had a median lethal dose of 1.0 g/kg bw (34).

Clinical pharmacology

No information was found.

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Adverse reactions

No information was found.

Contraindications

Allergy to the plant material.

Warnings

No information was found.

Precautions

General

No information was found.

Drug interactions

No information was found.

Drug and laboratory test interactions

No information was found.

Carcinogenesis, mutagenesis, impairment of fertility

An aqueous extract of the crude drug was not mutagenic in the Ames test at a concentration of 40.0–50.0 mg/plate in Salmonella typhimurium strains TA98 and TA100 (44, 45). The extract was also not mutagenic when administered by intraperitoneal injection to mice at a dose of 4.0 mg/ kg bw, equal to 10–40 times the amount used in humans (44). An infusion of the crude drug inhibited aflatoxin B1-induced mutagenesis in Salmonella typhimurium strains TA98 and TA100 at a concentration of 40.0 mg/ plate (46). Metabolic activation was required for activity.

Pregnancy: teratogenic effects

No information was found.

Pregnancy: non-teratogenic effects

Use of the crude drug during pregnancy requires the supervision of a health care professional.

Nursing mothers

No safety data are available, thus the use of the crude drug by breastfeeding mothers is not recommended.

Paediatric use

No safety data are available, thus the use of the crude drug in children under the age of 12 years is not recommended.

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Other precautions

No information was found.

Dosage forms

Crude drug (1). Store in a dry place (1).

Posology

(Unless otherwise indicated)

Oral daily dose: 3–12 g of the crude drug, added to a decoction, taken in divided doses (1).

References

1.Pharmacopoeia of the People’s Republic of China. Vol. I (English ed.). Beijing, Chemical Industry Press, 2005.

2.The Japanese pharmacopoeia, 14th ed., Suppl. 1 (English ed.). Tokyo, Ministry of Health, Labour and Welfare, 2004.

3.The Korean herbal pharmacopoeia (English ed.). Seoul, Korea Food and Drug Administration, 2002.

4.Hänsel R et al., eds. Hagers Handbuch der pharmazeutischen Praxis. Vol. 6, 5th ed. Springer, Berlin.

5.Farnsworth NR, ed. NAPRALERT database. University of Illinois at Chicago, IL (an online database available directly through the University of Illinois at Chicago or through the Scientific and Technical Network [STN) of Chemical Abstracts Services) 30 June 2005.

6.Medicinal plants in China. Manila, Philippines, World Health Organization Regional Office for the Western Pacific, 1989 (WHO Regional Publications Western Pacific, Series No. 2).

7.Perry LM, Metzger J. Medicinal plants of east and southeast Asia: attributed properties and uses. Cambridge, MA, MIT Press, 1980.

8.Ridsdale CE. A revision of Mitragyna and Uncaria (Rubiaceae). Blumea, 1978, 24:43–100.

9.Kariyone T, Koiso R. Atlas of medicinal plants. Osaka, Nihon Rinshosha, 1973.

10.Laus G, Keplinger D. Separation of stereoisomeric oxindole alkaloids from Uncaria tomentosa by high performance liquid chromatography. Journal of Chromatography A, 1994, 662:243–249.

11.Laus G, Keplinger D. Radix Uncariae tomentosae (Willd.) DC – Eine monographische Beschreibung. Zeitschrift für Phytotherapie, 1997, 18:122–126.

12.Stuppner H, Sturm S, Konwalinka G. HPLC analysis of the main oxindole alkaloids from Uncaria tomentosa. Chromatographia, 1992, 34:597–560.

13.Sakakibara I et al. Chemical and pharmacological evaluations of Chinese crude drug “Gou-teng”. Natural Medicines, 1998, 52:353–359.

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14.WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues. Geneva, World Health Organization, 2007.

15.European Pharmacopoeia, 5th ed. Strasbourg, Directorate for the Quality of Medicines of the Council of Europe (EDQM), 2005.

16.Guidelines for predicting dietary intake of pesticide residues (revised). Geneva, World Health Organization, 1997 (WHO/FSF/FOS/97.7).

17.Yamanaka E et al. Studies of plants containing indole alkaloids. IX. Quantitative analysis on the tertiary alkaloids in various parts of Uncaria rhynchophylla MIQ. Yakugaku Zasshi, 1983, 103:1028–1033.

18.Masumiya H et al. Effects of hirsutine and dihydrocorynantheine on the action potentials of sino-atrial node atrium and ventricle. Life Sciences, 1999, 65:2333–2341.

19.Yano S et al. Ca2+ channel blocking effects of hirsutine, an indole alkaloid from Uncaria genus, in the isolated rat aorta. Planta Medica, 1991, 57:403–405.

20.Horie S et al. Effects of hirsutine, an antihypertensive indole alkaloid from Uncaria rhynchophylla, on intracellular calcium in rat thoracic aorta. Life Sciences, 1992, 50:491–498.

21.Hsieh CL et al. Anticonvulsive and free radical scavenging actions of two herbs, Uncaria rhynchophylla (MIQ) Jack and Gastrodia elata Bl., in kainic acid-treated rats. Life Sciences, 1999, 65:2071–2082.

22.Kim DY et al. Anticonvulsant effect of Uncariae Ramulus et Uncus. II. Effects of methanol extract and ethyl acetate fraction on neurotransmitters related components of brain. Korean Journal of Pharmacognosy, 1998, 29:179–186.

23.Kim DY et al. Anticonvulsant effect of Uncariae Ramulus et Uncus. III. Effects of ursolic acid and hyperin on neurotransmitters related components in brain tissue in vitro. Korean Journal of Pharmacognosy, 1998, 29:187–192.

24.Mimaki Y et al. Anti-convulsion effects of Choto-san and Chotoko (Uncariae Uncis cum Ramulus) in mice, and identification of the active principles. Yakugaku Zasshi, 1997, 117:1011–1021.

25.Shimada Y et al. Extract prepared from the hooks and stems of Uncaria sinensis prevents glutamate-induced neuronal death in cultured cerebellar granule cells. Journal of Traditional Medicines, 1998, 15:141–146.

26.Kim HS et al. Effect of Ramulus et uncus uncariae on glucose-oxidase- induced toxicity in cultured cerebral neurons. Korean Journal of Oriental Physiology and Pathology, 2002, 16:1016–1019.

27.Lee JK et al. Effect of Ramulus et uncus uncariae on cultured hippocampal neurons damaged by oxidative stress. Korean Journal of Oriental Physiology and Pathology, 2001, 15:677–681 [in Korean].

28.Lee JS et al. Protective effect of methanol extract of Uncaria rhynchophylla against excitotoxicity induced by N-methyl-D-aspartate in rat hippocampus. Journal of Pharmacological Sciences, 2003, 92:70–73.

29.Chang TH et al. Hypotensive effect of rhynchophylla total alkaloids and rhynchophylline. National Medical Journal of China, 1978, 58:408–411.

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