Pharmacology of Poppy Alkaloids: Minor Opium Alkaloids

The pharmacology and biology of minor opium alkaloids have been surveyed previously in two comprehensive reviews (). Thebaine The pharmacology of thebaine was summarized by Reynolds and Randall in 1957 and studied comprehensively by a WHO Advisory Group in 1980. The pharmacological actions of thebaine in various isolated organs have been studied. Thebaine can induce a temporary decrease in blood pressure in anaesthetized dogs and this depressor effect showed a marked tachyphylaxis. In isolated guinea pig atrium, thebaine decreased the heart rate and contractions depending on the concentration. In isolated rabbit ileum it decreased the peristaltic movement and contractions (). The predominant effect of thebaine is stimulation of the central nervous system. In the mouse, rabbit, cat and dog increases in motor activity and reflex excitability were observed at doses around 2-10mg/kg s.c. or i.m. The Straub-tail response was noted only occasionally. The effects of thebaine on body temperature and respiration have also been studied. Convulsions were observed in almost all species of animals including the frog, pigeon, mouse, guinea pig, cat and dog. Transient tremors, restlessness and convulsions were observed in the Read more […]

Pharmacology of Poppy Alkaloids: Major Opium Alkaloids

 The latex obtained by the incision of unripe seed capsules of Papaver somniferum and which is known as opium is the source of several pharmacologically important alkaloids. Dioskorides, in about AD 77, referred to both the latex (opos) and the total plant extract (mekonion) and to the use of oral and inhaled (pipe smoked) opium to induce a state of euphoria and sedation. Since before the Christian era the therapeutic properties of opium were evident, with the first written reference to poppy juice by Theophrastus in the third century BC. Powdered opium contains more than 40 alkaloids which constitute about 25% by weight of the opium and are responsible for its pharmacological activity. In 1803 the German pharmacist Sertiirner achieved the isolation of morphine as one of the active ingredients of opium. Morphine, codeine, thebaine, papaverine, narcotine and narceine are the most important bases, with many of the remaining (minor) alkaloids occurring only in traces. Morphine Morphine has long occupied an eminent position on the list of useful drugs. As a pure alkaloid, it has been employed for over a century and a half and, as the most important constituent of opium, it has contributed to the comfort of the human Read more […]

The Effects of Tea on the Cardiovascular System

Cardiovascular diseases, together with cancers, are the main killing diseases of humans in the world. Of the cardiovascular diseases, atherosclerosis is one of the most prevalent. Atherosclerosis is primarily caused by hypercholesterolemia in which excess cholesterol accumulates in the blood vessels and oxidation of low-density cholesterol (LDL) leads to foci of endothelial abnormalities associated with the process of atherosclerosis (). It deteriorates further with the oxidation of lipids in the blood. Therefore, in order to maintain the cardiovascular system in good condition, it is very important to prevent not only an excessive increase of cholesterols in the blood, but also the oxidation of lipids in the blood. Hypertension is another major factor that can affect the health of the cardiovascular system. In this article, the antioxidative, hypolipidemic, hypotensive and the obesity-depressing activity of tea will be discussed. Antioxidative Activity of Tea Blood-Pressure Lowering Activity of Tea Blood Lipid and Cholesterol Lowering Effect Excessive lipids in blood is a common disorder of middle aged or old aged men and women. High serum-lipid includes high cholesterol and triglyceride content in blood. The cholesterol Read more […]

Blood-Pressure Lowering Activity of Tea

Hypertension is a common disorder in humans. Te a drinking can lower blood pressure. There are many Chinese traditional prescriptions, with tea as a major constituent, used in the treatment of hypertension and coronary disease in Chinese traditional medicine. A survey on the relationship between hypertension and tea drinking in 964 adults was carried out by Zhejiang Medical University of China during the 1970s. Results showed that the average rate of hypertension was 6.2% in the group who drank tea as habit, and 10.5% in the group who did not. Clinical experiments showed that hot water extract of green tea possessed a degree of blood pressure lowering effect. An experiment in vivo carried out on rats fed with diet supplemented with 0.5% crude catechins showed that the blood pressure in treated rats was 10–20 mm Hg lower than that in the control group (). A clinical experiment using green tea on high blood pressure patients was conducted at the Anhui Medical Research Institute of China. Results showed that a 10 g tea intake daily treatment over half a year, decreased the blood pressure by 20–30% (). A study was conducted to determine whether the effect in vitro is reflected in the lowering of blood pressure of Read more […]

Spasmolytic effects of Thyme

The spasmolytic properties are commonly considered as the major action of thyme preparations. In this regard Thymus vulgaris is the most representative species. Therefore many publications have focused on the effects of thyme preparations on smooth muscles, especially rat and guinea pig intestines, such as duodenum and ileum, guinea pig trachea.. seminal vesicles and rabbit jejunum. Two different protocols are typically followed: (i) The isolated smooth muscle is first contracted using several agonists (acetylcholine, histamine, adrenaline, nicotine and BaCl2) and the thyme preparations are subsequently added until maximum relaxation is achieved. The spasmolytical effect is evaluated by measuring the maximum relaxant effect and the ED50 (contraction that produces 50 per cent of the maximum spasmolytic response), (ii) The isolated smooth muscle is first incubated with the thyme preparations; the modification of the dose-response curves produced by the contracting agents are calculated. In this protocol, the relaxant agent remains in the bath throughout the experiment. The use of various spasmogens with different mechanisms of action causing muscle contraction can provide information on the pharmacological Read more […]

Stevia: Stevioside

Absorption, distribution and metabolism In the rat, stevioside (125 mg/kg; p.o.) has a half-life of 24 hour, and is largely excreted in the feces in the form of steviol. Other metabolites include steviolbioside. In this species, at least, metabolism appears to be mediated primarily by the gut microflora. Thus, [17-14C] stevioside is converted to steviol by suspensions of rat intestinal microflora. Conversion is complete within two days. The distribution of a derivative, [131I]iodostevioside (position of the label not reported), has been studied in rats following i.v. administration. Radioactivity rapidly accumulated first in the small intestine and then in the liver. Within two hours, 52% of the radioactivity administered appeared in the bile. The largest biliary component was [131I]iodosteviol (47% of total radioactivity), followed by [131I]iodostevioside (37%) and an unidentified metabolite (15%). Non-enzymatic conversion of stevioside to steviol does not occur. Acid hydrolysis yields isosteviol, while incubation for up to three months under conditions ranging pH 2–8 and 5 to 90 °C does not result in detectable formation of steviol. Stevioside appears to be poorly transported across the cell membrane. No Read more […]

Malva sp. (Mallow)

Distribution and Importance of the Plant Although about 1000 species are designated with the common name of mallow, approximately 30 species belonging to the genus Malva (of the Malvaceae family) are known for their medicinal value, mostly in a traditional sense. The common (blue or high) mallow (Malva sylvestris L.) is a biennial to short-lived perennial with prostrate to semi-erect stems (10-80 cm long) and long-stalked rounded leaves with a heart-shaped base and five to seven broad shallow-toothed lobes. The leaves of M. sylvestris var. incanescens Gris are hairy. The flowers (appearing from May to September) are pale lilac to bright mauve-purple and the seeds are flat button-like nutlets. The plant is found naturally in marginal or waste lands, hedgerows and roadsides and is approximately 1 m high, with stalked, roundish, five- to seven-lobed leaves. Plant parts abound with a mild mucilage. Malva aegyptia (Egyptian mallow) is an annual species, endemic in the Mediterranean countries, 20-50 cm high with purple-blue flowers. Malva cretica (Crecian mallow) is another Mediterranean species, which is an annual, 10-30 cm high with rose-coloured leaves. Malva ambigua Guss (M. sylvestris var. ambigua) is a Read more […]

Specific Medicinal Uses of Cannabis

The historical and contemporary, medicinal uses of cannabis have been reviewed on several occasions. Perhaps the earliest published report to contain at least some objectivity on the subject was that of O’Shaughnessy (1842), an Irish surgeon, working in India, who described the analgesic, anticonvulsant and muscle relaxant properties of the drug. This report triggered the appearance of over 100 publications on the medicinal use of cannabis in American and European medical journals over the next 60 years. One such use was to treat nausea and vomiting; but it was not until the advent of potent cancer chemotherapeutic drugs that the antiemetic properties of cannabis became more widely investigated and then employed. One can argue that the available clinical evidence of efficacy is stronger here than for any other application and that proponents of its use are most likely to be successful in arguing that cannabis should be re-scheduled (to permit its use as a medicine) because it has a “currently accepted medical use”. Specific Medicinal Uses of Cannabis: Use as an Antiemetic Specific Medicinal Uses of Cannabis: Glaucoma Specific Medicinal Uses of Cannabis: Multiple Sclerosis Spastic Conditions A discussion Read more […]

Scarlet Wisteria Tree, Red Wisteria, Daun Turi

Sesbania grandiflora Pers. (Leguminosae) Sesbania grandiflora Pers. is a tree that can grow to 8-10 m in height. The compound leaves are about 30 cm long with 12 to 20 pairs of rounded, narrow, oblong leaflets, 3-4 cm by 1 cm. Flowers are 5-10 cm by 3 cm, in pale pink, red, purple or white. The pods are 25-50 cm, slender, and cylindrical with many light brown to red brown seeds. Origin Native to Malesia and cultivated in the tropics. Phytoconstituents Grandiflorol, (+)-leucocyanidin, oleanolic acid, lutein, beta-carotene, violaxanthin, neoxanthin, zeaxanthin and others. Traditional Medicinal Uses In the Philippines, the plant is used for its hypotensive properties. It is used in Indian folk medicine for the treatment of liver disorders. The juice of the leaves and flowers are popularly used for nasal catarrh and headache when taken as snuff. Various leaf preparations are used to treat epileptic fits. Applied externally for treatment of leprous eruptions. A poultice of the leaves is used for bruises. The leaf juice is mixed with honey for congenital bronchitis or cold in babies. Pharmacological Activities Antibacterial, Anticonvulsant, Anti-inflammatory, Anxiolytic, Depressant, Diuretic, Hepatoprotective, Hypoglycaemic, Read more […]

Round Leaf Chastetree, Beach Vitex

Vitex rotundifolia L. f. (Verbenaceae) Vitex rotundifolia L. f. is an evergreen woody tree, densely covered with short hairs. Leaves are opposite, simple, ovate, broadly oblong-elliptic, 2-5 cm long by 1.5-3 cm wide, rounded or abruptly acute at the base. Inflorescence panicles are at the terminal, densely flowered, 4-7 cm long with purple corolla. Fruits are globose, 5-7 mm. Origin Native to Temperate and Tropical Asia, Australasia and Pacific. Phytoconstituents Rotundifuran, prerotundifuran, vitexilactone, previtexilactone, vitexicarpin, vitricine, vitetrifolins D-G, vitexifolins A-E, isoambreinolide and others. Traditional Medicinal Uses In Malaysia, various parts of the plants are considered panacea for illnesses ranging from headache to tuberculosis. In China, the plant has been used for the treatment of cancer. A poultice of the leaves is used to treat rheumatism, contusions, swollen testicles and as a discutient in sprains. In Indonesia, leaves have been used in medicinal baths, as a tincture or for intestinal complaints. In Papua New Guinea, sap from crushed heated leaves is diluted with water and drunk to relieve headaches. The fruits are used to expel worms and in Vietnam, a decoction of dried fruits Read more […]