The use of eucalyptus oils in consumer products

Insect repellents As noted in the introduction, Eucalyptus citriodora oil has been used as a ‘natural’ insect repellent. Depending on the product formulation it is used in, Lemon Eucalyptus (known as Quwenling in China) is up to four or five times more effective and longer-lasting than citronella oil (from Cymbopogon nardus), one of the best known natural insect repellents. p-Menthane-3,8-diol is the main active component of Quwenling and this can be isolated and used as a highly effective insect repellent. Eucalyptus citriodora oil contains up to 80–90 per cent citronellal, along with geraniol, both of which are known to have insect repellent activity but tend to dilute the much higher activity of the p-menthane-3,8-diol. The Mosi-guard Natural insect repellent spray produced by MASTA in the UK contains ‘Extract of Lemon Eucalyptus’ and claims on the label: Approved and recommended by the London School of Hygiene and Tropical Medicine. Field trials have shown effective protection for 6 h after a single application in mosquito infected areas. Also protects against many other biting insects. Mosi-guard Natural is made from a natural and renewable resource. It is kind to your skin and has no adverse effects 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 […]

Tagetes spp. (Marigolds)

Tagetes species were used by ancient civilizations like the Aztecs for various purposes (). The pigments of the flowers were used as a dye and in chicken feed, oil was extracted from the leaves and used as an ingredient of perfumes, and the roots were also assumed to have interesting properties. Field tests in the USA in the 1930s showed that larvae of a root-knot nematode entered the roots of marigolds, but usually failed to develop and neither reached the adult stage nor produced eggs (). In 1953, a Dutch bulb breeder () reported the biological activity of common garden marigolds (Tagetes patula) against root rot in Narcissus caused by free-living nematodes. The latter finding was an incentive for a scientific analysis of the effect of Tagetes plants by the crop protection industry and the academic world. A few years after the initial report by Van de Berg-Smit (), Uhlenbroek and Bijloo () isolated and described some active principles from Tagetes plants. These chemicals belonged to a group of heterocyclic sulphur-containing compounds, the thiophenes. The thiophene oe-terthienyl, which occurs in Tagetes and related species, was first synthesized in 1941 () and isolated from plants in 1947 (). In the past three Read more […]

Polygonum hydropiper L. (Water Pepper)

Distribution and Importance Polygonum hydropiper L. (family Polygonoceae) is a member of a genus of some 175 species. It is a semi-erect (25-75 cm) annual herb with a branched stem and lance-shaped leaves, carrying its greenish-pink flowers in slender racemes (). The species is widespread in most parts of Europe, temperate Asia, and North America, and it also occurs at scattered sites in North Africa. Across its main range it is abundant in the verges of ponds and ditches and on waterlogged grasslands and water meadows. Polygonum hydropiper is not grown commercially but has found an exceptionally impressive range of uses in folk medicine and also as a culinary herb, and this has led to the adoption of a rich variety of apt local names, e.g. fireweed, arsemart and smartweed are examples of some 20 English regional names in addition to the accepted vernacular name of “water pepper“. The flower heads have little odour but all the aerial parts have a bitter acrid taste and contain vesicant compounds that blister the skin upon repeated handling (). Medicinal use of Polygonum hydropiper goes back to Dioscorides (ca. 60 a.d.) and tinctures of foliage are used as diuretics, diaphoretics, and to arrest gynecological bleeding Read more […]

Citrus in Traditional Medicine

Citrus in traditional Asiatic medicine In a comparative study of the use of herbal drugs in the traditional medicines of India and Europe, Pun () found a marked similarity between the drugs used in the two continents. He attributed this not only to the similarity of the vegetation in the two areas, but also to the influence that traditional Indian medicine, in particular the Atherveda, one of the most ancient repositories of human knowledge, had on Egypt, Greece and Rome. He listed the principal uses of a small number of these drugs, including bitter orange peel, which in India is used as an aromatic, stomachic, tonic, astringent and carminative agent, and lemon, which is used as a flavouring and for its carminative and stomachic effects. In the Valmiki-Ramayana, written after the Vedas and one of the most sacred of all religious books which enumerates the virtues of the medicinal plants that Lord Rama (Vishnu) met during his fourteen-year journey around different parts of India, Karnick and Hocking () identified and listed fifty of these drugs with their use as described in the Ayurvedica (or native Indian) system of medicine. The immature fruit of Citrus aurantifolia (Christm) Swingle was used as an fortifier, Read more […]

Artemisia Species in Traditional Chinese Medicine and the Discovery of Artemisinin

Qing hao-an antimalarial herb A herb, named Qing Hao (usually pronounced ching how) in Chinese, sweet Annie or sweet wormwood in English, and properly known as Artemisia annua L. has become well known in western countries during the last 20 years. Herbal companies, which deal with traditional Chinese medicine (TCM), receive several inquiries concerning this herb every day. A. question commonly asked by those about to travel to Africa or S.E. Asia is “Can I take the herb called Qing Hao to prevent malaria during my trip?” Unfortunately, the answer has disappointed many people because although this herb is used for the treatment of malaria in TCM, usually combined with other herbs, it is not recommended for the prevention of the disease or as a deterrent to mosquitoes. However, the leaves of Qing Hao were burned as a fumigant insecticide to kill mosquitoes in ancient China but this practice no longer continues today since the development and marketing of more efficient mosquito-repellant devices. The discovery of artemisinin Qing Hao is a herb commonly used in China with a long history of use as an antipyretic to treat the alternate chill and fever symptoms of malaria and other “heat syndromes” in the traditional Chinese Read more […]

The Medicinal Uses of Thyme

The uses of thyme, Thymus vulgaris and other Thymus species are well known, and extensive parts of the world get benefit from this plant group in medicinal and non-medicinal respects. Following the development of the medicinal uses of thyme we can see that thyme has changed from a traditional herb to a serious drug in rational phytotherapy. This is due to many pharmacological in vitro experiments carried out during the last decades, and even a few clinical tests. The studies have revealed well defined pharmacological activities of both, the essential oils and the plant extracts, the antibacterial and spasmolytical properties being the most important ones. The use of thyme in modern phytotherapy is based on this knowledge, whereas the traditional use of thyme describes only empirical results and often debatable observations. Therefore it seems necessary to present here the data available on the pharmacodynamics of thyme and thyme preparations in order to substantiate the use of thyme in modern medicine. The non-medicinal use of thyme is no less important, because thyme (mainly Thymus vulgaris) is used in the food and aroma industries. It serves as a preservative for foods and is a culinary ingredient widely used as Read more […]

Scutellaria baicalensis Georgi

Distribution of Scutellaria The genus Scutellaria belongs to the family Labiatae and subfam. Scutellarideae. Scutellaria is widely distributed all over the world except for South Africa, and there are about 300 species. The calyx of this genus is remarkably specialized to become two-lip-shaped, and characterized by the upper lip having a flat or dish-shaped upper surface on which a small swelling forms; the dish-shaped part peels offat fruit maturation to allow a seed to fall. The 15 species, such as S. maekawa Hara, S. brachyspica Nakai et Hara, S. laeteviolace Koizumi, S. iyoensis Nakai and others are distributed only in Japan. Further S. indica L., S. indica var. parvi flora Makino, S. sterigillosa Hensl, S. dependens Maxim, and others are distributed over wide areas in Japan, the Korean Peninsula, the northeastern section of China and the Indonesian Peninsula. Furthermore, S. baicalensis Georgi is native to the region from the northern section of China to Siberia. It was introduced into Japan from the Korean Peninsula in the middle period of the Edo era and has been cultured in various parts of Japan for the medicinal uses of the root. In Japanese Pharmacopoeia the root of S. baicalensis Georgi, excepting the Read more […]

Perilla frutescens (L.) Britton

Distribution and Importance of Perilla Plants Perilla frutescens (L.) Britton var. crispa (Thunb.) Decaisne, belonging to the family Labiatae, is distributed widely in Japan, China, and southeast Asia. It is an annual herb about 1 m in height, and includes several forms such as f. purpurea Makino (Chirimen-aka-shiso or Aka-shiso) and f. viridis Makino (Chirimen-ao-shiso or Ao-shiso) having deep red-purple and green leaves, respectively. Perilla plants contain essential oil at about 0.5% of fresh leaf weight and give out a fragrance, principles of which are Perilla-aldehyde (55%), d-limonene (20-30%), and α-pinene (); linoleic, stearic, and palmitic acids are also contained as the major aliphatic acids. According to the extensive study on pigments of Chirimen-aka-shiso, 16 kinds of flavonoids including five anthocyanins, two flavones, and nine flavone glycosides are present in the mature dark-red leaves and seeds. Among these flavonoids, the 3-p-coumaroylglucoside-5-glucoside of cyanidin (shisonin) and the 7-caffeoylglucosides of apigenin and luteolin are the major component in the leaves. In seeds, apigenin and luteolin are present in a ratio of about 1:1. With other phenolics, a large amount of caffeic acid derivatives Read more […]

Pepper in traditional medicine and health care

Pepper is one of the most important and unavoidable drugs in Ayurveda, Unani and Sidha, the Indian systems of Medicine. It is used as single drug or in combination with long pepper (Piper longum) and dry ginger (Zingiber officinale) the combination is popularly known as “Trikatu” — the three acrids which cures the three disordered humours-Vata, Pitta and Kapha and helps to maintain normal health. Maricham, the Sanskrit word for pepper literally means that which facilitates numbness of the tongue (“Mriyate Jihwa Anena Iti Maricham” i.e. the pungent property of the drug obstructs the sensory nerve endings of the taste buds). It also has the property of dispelling poison (“Mriyate Visham Anena”). The various Sanskrit synonyms of the drug given in ayurvedic texts of India describe its characters and different uses. According to these classics, pepper is pungent and acrid, hot, rubefacient, carminative, dry corrosive, alternative, antihelminthic and germicidal. It promotes salivation, increases the digestive power, gives relish for the food and cures cough, dyspnoea, cardiac diseases, colic, worms, diabetes, piles, epilepsy and almost all diseases caused by the disorders of vata and pitta. Pepper is prescribed Read more […]