Callitris spp. (Cypress Pine)

Distribution and Morphology The name Callitris is derived from the Greek word kallistos, and means most beautiful (). It was first named by Ventenat in 1808 (), and is a relatively small genus that belongs to the division of Gymnospermae, order Coniferales, family Cupressaceae (). Appreciable nomenclature complexities occur and therefore the reports on the number of Callitris species varies. In the Index Kewensis the names of 39 species are listed (Hooker and Jackson 1895). Although present in North Africa with two species, Callitris quadrivalvis and Callitris articulata (), most species are found in Australia, New Caledonia, Tasmania, and New Zealand (). Callitris, vernacularly named cypress pine, is found in all states of Australia and covers approximately 4300000 ha of forest (). The most common and most important species is C. columellaris, also known as the white cypress pine (). Therefore, the greater part of the literature on Callitris deals with this species. Confusingly enough, previously used names for C. columellaris are: C. glauca, C. intratropica, C. arenosa and C. hugelii (). In addition, recently another new name, C. glaucophylla, has been introduced for this species by Thompson and Johnson (), while Read more […]

Cultivation of Artemisia

The genus Artemisia includes a large number of species and some have been cultivated as commercial crops with a wide diversity of uses. Some better known examples include antimalarial (Artemisia annua – annual or sweet wormwood), culinary spices (Artemisia dracunculus – French tarragon), liquor flavouring (Artemisia absinthium – absinthe), garden ornamental (A. abrotanum – southernwood) and insect repellent (Artemisia vulgaris – mugwort). However this review will concentrate on the cultivation of Artemisia annua because of its contemporary importance as a source of new and effective antimalarial drugs. During World War II and in the years immediately following, the world wide incidence of malaria was dramatically reduced. On the one hand the Anopheles mosquito vector was successfully controlled by the advent of the insecticide DDT and on the other the organisms causing human malaria – the single celled Plasmodium species: falciparum, vivax, malariae and ovale – were effectively controlled by the use of synthetic derivatives of quinine. The specific statistics for India illustrate this dramatic reduction. In 1961 the incidence of malaria had fallen to about 100,000 reported cases, however by 1977 the number of reported Read more […]

Artemisia: Plant Cultural Techniques

Plant Establishment Natural stands In China Artemisia annua traditionally has been harvested from wild natural self seeded stands. Although no specific crop production statistics are available, because of a confidentiality policy of Chinese authorities, it is believed that the bulk of Chinese production still comes from wild stands. These stands are the source of much of the artemisinin derived drugs used in China and probably the bulk of those drugs exported elsewhere (WHO, 1994) although some selected lines of Artemisia annua are cultivated as a row crop in Szechwan Province (). Ideally the harvesting of raw material for medicinal drug production from wild stands is not a good policy (). The plant material in wild stands is typically very variable in its content of the required medicinal constituents and this has an impact on the economics of drug extraction. Added to this the continual encroachment and elimination of wild stands will ultimately limit the source of genetic variability which is vital to the development of improved seed lines (). Another negative factor against utilisation of wild stands is that transport distances often become uneconomic with a crop such as Artemisia annua with a relatively low artemisinin Read more […]

Non-Medicinal Uses of Cannabis Sativa

The plant Cannabis sativa has been providing man with a range of his most basic needs for centuries (). We know that hemp — the fibrous extract of C. sativa, was used for clothing in ancient Egypt, at least as early as 1,200 years BC and the use of the plant as a source of rope is well documented in many cultures down the centuries (see «Cannabis Use and Abuse by Man: An Historical Perspective»). The seeds from the plant have been subjected to various treatments to provide food and the fibre has also been used from early times as a major paper making material; indeed, early editions of the Gothenburg and King James Bibles were published on such paper and much later, the first two drafts of the American Declaration of Independence. The new president of the United States, George Washington was to be found exhorting his head gardener to: “Make the most of the Indian hemp seed…and sow it everywhere” (Washington, 1794). These peaceful uses were not the only ones however. From the 17th century onwards, the British Royal Navy — at the time the most powerful navy in the world — relied heavily on hemp for ropes, rigging and caulking. In the mid-1800s, a typical 44-gun man of war might inventory some 60 tons Read more […]

Chamomile: Plant Selection And Breeding

Breeding Targets and Techniques The composition of the essential oil with varying percentages of bisabolol, bisabololoxide, bisabolone, and matricine is fixed genetically. Schick and Reimann-Philipp remarked in 1957: “As far as breeding is concerned Matricaria Chamomilla has not yet been worked on.” In 1950 only the two group varieties “Quedlinburger Groβblütige Kamille” (Quedlinburg large-flowered chamomile) and “Erfurter Kleinblütige Kamille” (Erfurt small-flowered chamomile) were mentioned. Often the stability, the resistance against diseases, the germinability, the flower yield, the fact that the individual flower heads are ripe at the same time, the homogeneous flowering horizon, the stability of the flower head, and consequently the suitability for a mechanical harvest are not sufficient. Since then a rapid development has been experienced. A number of chemotypes with a varying content of matricine / chamazulene, (–)-α-bisabolol, spiroethers, and the bisabolol oxides A and B as well as bisabolone oxide A were selected. Varieties with very different breeding targets were bred. The content, especially the composition of the active principles, was worked on by precise selections. For nondestructive Read more […]

Strophanthus Species (Members of the Dogbane Family)

The cardiac glycosides are pharmaceutically potential drug groups that are available to medicine today for the treatment of congestive heart failure. Clinically availabilities are derived from the leaves and seeds of plant in the genera Digitalis and Strophanthus. In vitro culture, regeneration, and production of Digitalis (foxglove) cardenolides and other secondary metabolites were reviewed in detail (). Strophanthus, belonging to the family Apocynaceae (the dogbane family), is from the Greek meaning “a turn or twist” and “a flower” and refers to the twisted lobes of the corolla. About 40 species of Strophanthus native to Africa and Asia, chiefly tropical, are perennial trees, shrubs or climbers up to 3 m tall. The leaves are feathery or leathery and opposite. The cymose inflorescence is terminal. Members of this genus have a variety of fragrant flowers, ranging in color from white, through the yellows and reds, to purple. The calyxes is glandular, the corolla funnel-shaped, with five lobes tapering into attenuated, long tails. The two carpeled ovaries develop into capsular fruits having two diverging free follicles, which enclose the hairy seeds. Strophanthus seeds have long been used by the native Africans in Read more […]

Post-harvest handling and processing of Capsicums

The genus Capsicum encompasses a number of species differing in size, shape, colour and pungency. Due to these differences some of them are used as vegetables, while most others are valued as condiments and culinary supplements. The post-harvest handling and processing technologies for Capsicum have developed considerably as a consequence of the increased production and newer applications of this crop. Bell peppers and a sizable quantity of chillies are consumed fresh and their harvesting indices and scientific handling protocols have been standardized. Chillies and paprika are initially dried and stored in preparation for processing. The accumulated scientific evidence shows the role of various processing factors on the quality of the processed products like chilli powder, oleoresin and colour extract. In keeping with this knowledge, process parameters have been modified to develop new technologies for obtaining superior products. The emergence of the industrial food processing sector along with newer food applications requiring tailor-made ingredients have also introduced more stringent demands for Capsicum products. R&D and the industry are poised to face the challenges. Tropical South America is believed to Read more […]

Pharmacological Effects of Thyme

Antimicrobial effects of thyme essential oils and thyme preparations Antibacterial effects The first researcher who attributed antibacterial properties to thyme (without specifying the species) was Chamberlain in 1887, after observing the antibacterial effect of its “vapours” on Bacillus anthracis. Since then, numerous studies with essential oils of different species of Thymus have been carried out. They were shown to inhibit a broad spectrum of bacteria, generally Gram-positive bacteria being more sensitive than Gram-negative bacteria. This became obvious in some screening studies administering Thymus oils to a variety of bacteria. Recently the antibacterial activity of thyme (Thymus vulgaris) oil against some important food-borne pathogens, namely Salmonella enteritidis, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Campylobacter jejuni, was tested. The latter was found to be the most resistant of the bacteria investigated. In another study it was shown that the essential oil of thyme and especially its phenols, thymol and carvacrol, have antibacterial acivity against periodontopathic bacteria including Actinobacillus, Capnocytophaga, Fusobacterium, Eikenella, and Bacteroides species, and Read more […]

Hypericum canariense L.

Hypericum L. Shrubs or herbs of Hypericum L. species are distributed throughout the world. They are found in the Mediterranean region, Portugal, Spain, Canary Islands [Spain], Africa, Turkey, Australia, Tasmania, New Zealand, New Caledonia, Papua New Guinea, parts of South-East Asia, Sri Lanka, and from North to South America. Etymologically, the name Hypericum L. was first used by Linnaeus. It comes from hyper (over) and eikon (image), on account of the image that appears on the petals. According to other botanists, the name comes from hypo and ereikn or erikn meaning “plant that grows under heathers”; it could also come from hyper and eikon meaning “plant resembling a ghost’s image or plant with an air of mystery”. Chemistry Many authors reported on the chemical composition and the variability of the main components in different species of Hypericum L.. However, the chemical study of this genus began with Hypericum perforatum L. in 1830 with the pioneering isolation of hypericin by Bruchner, who named the compound “hypericum red”. About one century later, in 1911, the compound was identified and renamed hypericin by Cerny, who also isolated other similar constituents without a proven structure determination, because Read more […]

Artemisia annua L.

Malaria, one of the oldest known diseases, was referred to in Egyptian writings of the 16th century B.C. In the 17th century, Italians believed that breathing bad air (mal aria) arising from swamps was responsible for the disease, and the term malaria first entered the English medical literature in the first half of the 19th century. Each year, this disease afflicts over 300 million people worldwide, killing up to 2.7 million, mostly children. Most of these cases occur in Africa, but large areas of Asia, Central, and South America have high incidences of the disease. Out of 37 countries and territories, which are members of the Pan American Health Organization (PAHO), World Health Organization (WHO), 21 still have active malaria transmission (PAHO/WHO 1998). Malaria has been treated for over 40 years with quinine-derived drugs. However, Plasmodium falciparum has developed resistance against these drugs in several areas of the world. Artemisinin (qinghaosu) (), a sesquiterpene lactone belonging to the cadinane series, is an antimalarial compound first isolated from Artemisia annua L. by Chinese scientists in 1972. In addition to a lactone group, artemisinin contains an endoperoxide bridge, which is rarely found in Read more […]