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 […]

Neem in Agriculture

Earlier Reports on Pesticide Activities The activity of neem against locusts, though not well documented, has been well known to Indian farmers since very early times and some information about it is available in the earlier publications (). It was mentioned that locusts avoided feeding on leaves sprayed with crude extracts of neem and China berry. It was Robert Larson of Vikwood Botanicals, USA, who during his many business trips to India, brought to the notice of American scientific workers the property of neem against insects. This was the era when the use of synthetic pesticides was widespread, and more and more health hazards about them were coming to light, but no alternative was in sight. There was a need for safer and effective biodegradable pest control compounds with greater stability. The Problems Created by Synthetic Pesticides It was seen that the continuous and indiscriminate use of synthetic chemicals for the control of insects led to the following problems: Environmental pollution, as the chemicals brought about biochemical changes in the various organisms. Health hazards due to high residue levels. Indiscriminate destruction of insects, without any consideration of their beneficial or harmful Read more […]

Solanum dulcamara L. (Bittersweet)

Biology and Distribution Solanum dulcamara L. (=Dulcamara flexuosa Moench) (), known as dogwood or bittersweet (Solanaceae), is a clambering or prostrate, perennial shrub which may grow to a height of 2 m (Hegi 1927). Its stem is angular and woody with the exception of the herbaceous top and ranges in diameter between 0.25 and 2 cm, rarely up to 5-6 cm. The leaves are alternate, long-stalked, sparsely pubescent on both sides, and quite variable in shape. The oval- to egg-shaped leaf blade is pointed at the tip. Its base, however, may also be cordate, arrow-shaped, or may consist of one or two lobes. Different leaf forms may be found on the same plant. The flowers emerge axillary in panicle-like loose clusters. The calyx bears five narrow teeth; the five joint petals are bright purple and their tips are somewhat reflexed when fully expanded. The five stamens have yellow anthers which form a conspicuous column. The fruit is a round- to egg-shaped berry, green when young and becoming bright red when mature. In Europe, the flowering season is May to September. It is distributed throughout Europe and is also a native to North Africa, West Asia, India, the USSR, China, and Japan. It is not clear whether its occurrence in Read more […]

Leontopodium alpinum Cass. (Edelweiss)

Distribution of the plant The genus Leontopodium (Compositae; Inulae; Gnaphaliinae sensu amplo) consists of between 30 and 40 species () found growing in mountainous areas of Japan (), Asia () and Europe (). A single species, Leontopodium alpinum Cassini, is considered to represent the genus in Europe () and the once separate Leontopodium nivale (Ten) Huet ex Hand.-Mazz. is now regarded as a subspecies, i.e. Leontopodium alpinum subsp. nivale (Ten) Tutin, stat. nov. (). The plant is protected by national legislation in Austria, Germany, Italy and Liechtenstein. Leontopodium alpinum, commonly known as edelweiss, is a perennial plant with a branching rootstock and fibrous roots (). Aerial structures exhibit wide morphological diversity (). Foliage leaves are linear to lanceolate in shape, 3-8 mm wide and pubescent. Inflorescence stalks develop from June to August and grow 2-45 cm high. The characteristically star-shaped “flower” varies in diameter from 1.5-10.5 cm and consists of an inflorescence made up of up to 12 densely aggregated capitula, which are subtended by an involucre of hairly leaves (). Leontopodium alpinum is traditionally found growing on limestone formations at altitudes up to 3140 m but can be easily 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 […]

Aloes and the immune system

There is a moderate scientific literature on the immunological effects of extracts from plants of the genus Aloe. Unfortunately, it is difficult to assess the significance of many of these studies because of two problems. First, most studies have been undertaken using many different, poorly characterized, complex aloe extracts. Second, studies have been performed using several different Aloe species, making comparisons impossible. Although anecdotal reports describe a wide variety of both immunostimulating and immunosuppressive effects, controlled scientific studies have substantiated very few of these. Most studies that have been performed have focused on the clear mesophyll gel of the Aloe vera leaf and on its major storage carbohydrate, acetylated mannan (acemannan). Recently a unique pectin has been isolated from aloe mesophyll cell walls and appears to have unique and important properties. Some consistent properties have, however, been noted. Thus aloe gel extracts and partially purified acemannan preparations have mild anti-inflammatory activity and multiple possible pathways for this activity have been investigated. Aloe extracts also have some limited macrophage activating properties. These include the release Read more […]

Aloe vera in wound healing

Aloe vera gel is a powerful healer that has been successfully employed for millennia. It acts in the manner of a conductor, orchestrating many biologically active ingredients to achieve the goal of wound healing. Aloe can penetrate and anesthetize tissue, it is bactericidal, virucidal, and fungicidal. It possesses anti-inflammatory and immunomodulatory properties and it serves as a stimulant for wound healing, a fuel for proliferating cells and a dressing for open wounds. Although some of the independent fractions of aloe have shown unique and impressive activity by themselves, the number of different substances acting in concert serves to confirm the relative complexity of aloe’s actions. Aloe vera certainly gives scope to the phrase, ‘the whole is more than the sum of its parts.’ Since it has been difficult to postulate, separate and isolate one substance that is responsible for aloe’s capabilities, many more controlled, scientific studies must be completed before all the secrets associated with the wound-healing abilities of aloe are unlocked. Future research may be directed at further investigation of the gel’s ability to stimulate cell growth in tissue culture and its antimicrobial, antifungal, antiviral Read more […]

Aloe vera in wound healing: Gel components

Saccharides Mono- and polysaccharides form about 25% of the solid fraction of the aloe gel. Mannose and glucose are the most significant monosaccharides found in the gel. These sugars most commonly serve as fuels and building blocks. For example, mannose-6-phosphate is required to initiate glycoprotien and glycolipid synthesis in the endoplasmic reticulum of all nucleated cells. Optimal nutrition is required for the growth, regulation, reproduction, defense, regeneration and repair during wound healing. In addition, saccharides such as mannose are essential in the golgi apparatus of all cells to complete synthesis of all structural and functional molecules. Lastly, the mannose-6-phosphate of Aloe vera has been shown to activate the insulin-like growth factor receptor of the fibroblast, stimulating it to increase collagen and proteoglycan synthesis. This activity has been shown to increase wound tensile strength. The polysaccharide component of aloe gel is primarily glucommannans that are comprised of glucose and mannose (β1→ 4 linked acetylated mannan). These polysaccharides, unlike other sugars, are absorbed complete and appear in the bloodstream undigested. Here, they have many activities. It has been very Read more […]

Solanum khasianum

Distribution and Importance of the Plant Solanum khasianum () which originates from India, is a widespread plant in Asia. The stem and leaves of this bushy annual or short-lived perennial plant are packed with spines. The plant is of commercial and medicinal importance because of its high content of steroidal alkaloids such as solasodine and its triglycosides solasonine and solamargine. For the pharmaceutical industry, solasodine has become increasingly interesting as a valuable starting compound for the synthesis of steroid hormones, such as cortisone and oral contraceptives. It can be readily converted to 16-dehydropregnenolone acetate, a key intermediate in the synthesis of steroid drugs, and therefore might serve as an alternative to the hitherto extensively used diosgenin. In addition to the use of solasodine as raw material for the synthesis of steroid hormones, the solasodine glycosides, solamargine and solasonine, show biological activities, which might be of medicinal value. The antitumoral effects of a Solarium sodomaeum glycoalkaloid extract, mainly consisting of the glycoal-kaloids solamargine and solasonine, have been described and this preparation has been recently used for treatment of certain skin 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 […]