Antimicrobial activity of eucalyptus oils

The preservative properties of the volatile oils and extracts of aromatic and medicinal plants have been recognised since Biblical times, while attempts to characterise these properties in the laboratory date back to the early 1900s (e.g. Hoffman and Evans 1911). Martindale (1910) included ‘Eucalyptus amygdalina’ (probably the phellandrene variant of Eucalyptus dives) and Eucalyptus globulus oils, as well as eucalyptol (1,8-cineole), in his study of the antiseptic powers of essential oils and although the ‘carbolic coefficients’ of eucalyptus oils were not as great as those for oils containing large amounts of phenolics – such as origanum (carvacrol), cinnamon leaf (eugenol) and thyme (thymol) – they did, nevertheless, give some quantitative measure of the antiseptic properties of eucalyptus leaf oils. Many volatile oils – particularly those of herbs and spices, but including those from Eucalyptus – have been used to extend the shelf-life of foods, beverages and pharmaceutical and cosmetic products; their antimicrobial and antioxidant properties have also pointed to a role in plant protection. Such a wide variety of applications, actual or potential, has meant that the antimicrobial properties of 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 […]

Pharmacology of Black Pepper

Many spices used in food seasoning have broad spectrum of antimicrobial activity. Their antioxidant activity against lipid peroxidation enhances the keeping quality of food. Apart from the use as a popular spice and flavouring substance, black pepper as drug in the Indian and Chinese systems of medicine is well documented. In the Ayurvedic descriptions, pepper is described as katu (pungent), tikta (bitter), usbnaveerya (potency, leading to storing up of energy, easy digestion, diaphoresis, thirst and fatigue), to subdue vatta (all the biological phenomena controlled by CNS and autonomic nervous system) and kapha (implies the function of heat regulation, and also formation of various preservative fluids like mucus, synovia etc. The main functions of kapha is to provide co-ordination of the body system and regularization of all biological activities). Pepper is described as a drug which increases digestive power, improves appetite, cures cold, cough, dyspnoea, diseases of the throat, intermittent fever, colic, dysentery, worms and piles; also useful in tooth ache, pain in liver and muscle, inflammation, leucoderma and epileptic fits. Black pepper is called maricha or marica in Sanskrit, indicating its property to dispel Read more […]

Populus Species (Poplars)

Populus species are among the fastest-growing forest tree species and are distributed throughout temperate regions of the northern hemisphere. Because of their fast growth and the ease of propagation, they have been considered ideal species for pulpwoods and lumber production. Particularly hybrid poplars have been studied for use in short rotation and biomass production. Hybrid poplar, Populus alba L. x P. glandulosa Uyeki, has been extensively planted in Korea since it was artificially bred by the Institute of Forest Genetics of Korea in 1956. The superior traits such as drought resistance and faster growth than its parents made the hybrid a promising candidate for lumber production in short rotation in mountainous areas. However, its practical use has been restricted to making chopsticks, match splints, and boxes rather than pulpwoods due to its short fiber length. Another valuable feature of the hybrid is its biomass production capacity. Recently, there has been great interest in biomass production using fast-growing tree species. P. alba x P. glandulosa can be one of the candidates because it has good coppicing and sucker-producing ability. Populus species, especially hybrids, are highly amenable to tissue Read more […]

Euphorbia characias L.

Since antiquity, Euphorbia species have been used for multiple purposes. The leaves and branchlets of Euphorbia lancifolia Schlecht were used by Mayam Indians to produce a tea named Ixbut which is reported to act as a galactogogue, increasing the flow or volume of milk in postpartem women. Some species have been used for treatment of cancer, tumors, and warts for more than 2000 years. This is the case for E.fischeriana Steud., that was used in traditional Chinese medicine as an antitumor drug. Medicinal uses of Euphorbia species include treatment of skin diseases, warts, intestinal parasites, and gonorrhea. Table Some species of Euphorbia used in folk medicine summarizes the uses in folk medicine. The latex of some plants of Euphorbia is toxic, causing poisoning in human beings and livestock, skin dermatitis, and inflammations of mucous membranes, conjunctivitis, tumor promotion, and cancer. Table Some species of Euphorbia used in folk medicine Species Used as treatment of E. antiquorum L. Dyspepsia E. caudicifolia Haines Purgative, expectorant E. fischeriana Steud. Antitumor E. genistoides Berg. Diaphoretic E. helioscopia L. Bronchitis E. hirta L. Antihistaminic E. Read more […]

Anxiety Disorders: Supplements With Possible Efficacy

In addition to supplements discussed above, a few other compounds may also have some efficacy in treating symptoms of anxiety. However, since the data that supports the use of the following supplements is extremely limited, clinicians should proceed with caution, and consider the use of the compounds discussed in this section as experimental. St. John’s Wort As described in site, St. John’s Wort (Hypericum perforatum) is an herb that exists in many species throughout the world, and it is widely used as an antidepressant. It is available in a variety of preparations, including capsules, liquid, oils, and raw herb to be brewed as tea. St. John’s Wort contains a plethora of active ingredients, including flavonoids, naphthodianthrones, phloroglucinols, phenolic acids, terpenes, and xanthones. These exert a variety of psychoactive effects, and several of these are described below. Of all herbal supplements, St. John’s Wort is the one that has been researched most extensively and there is strong support for its efficacy in reducing depressive symptoms. The use of St. John’s Wort as an anxiolytic is more recent, but a few studies suggest that is may be effective. Davidson and Connor (2001) reported case studies of patients Read more […]

Black Cohosh (Cimicifuga Racemosa)

Medical Uses Black cohosh is helpful in relieving menopausal symptoms, including mood swings, hot flashes, profuse sweating, and sleep disturbances. It has been the largest-selling herbal dietary supplement for menopause in the United States. Historical Uses In China, black cohosh root has been used for centuries for menopausal symptoms and women’s health in general. Native Americans and Eclectic physicians used black cohosh for rheumatism, menstrual difficulties, and sore throats. Native American women have used it for menopausal symptoms such as hot flashes, anxiety, and depression. Do not confuse it with blue cohosh. Growth Black cohosh is a member of the buttercup family. It is native to the northeastern U. S. and grows in sunny areas in temperate zones. An at-risk endangered herb, black cohosh can be grown in herb gardens. The roots maybe harvested after 2 years. Black Cohosh: Part Used • Root Major Chemical Compounds • Triterpene • Glycosides Black Cohosh: Clinical Uses Studies show that black cohosh is safe and helpful in relieving menopausal symptoms, particularly mood swings, hot flashes, profuse sweating, and sleep disturbances. It is “a safe, effective alternative to estrogen replacement Read more […]

Herpes Simplex Virus

Herpes simplex virus (HSV) is a member of the human herpes virus group that includes, for example, herpes simplex virus-1, herpes simplex virus-2, and Epstein-Barr virus (EBV). Herpes simplex virus is a recurrent viral infection that remains dormant in the nervous system with periods of reactivation characterized by individual or multiple clusters of fluid-filled vesicles at specifically affected sites. Herpes simplex virus-1 and -2 are the main types of herpes virus seen in general clinical practice. Herpes simplex virus-1 typically manifests above the waist and is referred to as Herpes labialis because of it primarily appearing on the lips in the form of “cold sores.” Herpes simplex virus-2, Herpes genitalis, typically appears on the genitals, although it also produces skin lesions. The vesicles rupture, leaving small, sometimes painful ulcers, which generally heal without scarring, although recurrent lesions at the same site may cause scarring. Coinfection with herpes simplex virus-1 and -2 increases the frequency of herpes simplex virus-2 outbreaks. Orogenital sex can lead to cross-contamination of these sites, with oral herpes being more likely transmitted to the genitals than the other way around. The incubation Read more […]

Herb-Drug Interactions: Coffee

Coffea L. species. (Rubiaceae) Synonym(s) and related species Arabian coffee is from Coffea arabica. Robusta coffee is from Coffea canephora (Pierre ex Froehner) also known as Coffea robusta (Linden ex De Wild.). Other species include Coffea liberica. Constituents The kernel of the dried coffee bean contains xanthine derivatives, the main one being caffeine (1 to 2%), with some theobromine and theophylline. It also contains polyphenolic acids such as chlorogenic acids and various diterpenes (e.g. kahweol, cafestrol). Use and indications Coffee has been used as a stimulant and diuretic. However, when roasted, coffee beans are most commonly used as a beverage. Pharmacokinetics The pharmacokinetics of caffeine are discussed under caffeine. Evidence suggests that chlorogenic acid is hydrolysed in the gastrointestinal tract to free caffeic acid, which is then conjugated to form the glucuronate or sulphate. Interactions overview Coffee contains significant amounts of caffeine, so the interactions of caffeine, are relevant to coffee, unless the product is specified as decaffeinated. By virtue of its caffeine content, coffee may also cause serious adverse effects if used with other drugs or herbs with similar Read more […]

Curcuma longa

Regarded as a ‘Rasayana’ herb in Ayurveda to counteract ageing processes, Curcuma longa L. (Zingiberaceae) has also been used for culinary purposes and in the textile industry. Much research has focused on curcumin, a curcuminoid from C. longa rhizomes, and it has been shown to modulate a variety of molecular targets. In particular, studies have shown that some curcuminoids are associated with antioxidant and anti-inflammatory activities, but in general, studies with particular attention to cognitive disorders and any clinical relevance are lacking. In addition, further evaluation of potentially active compounds from Curcuma longa, other than the curcuminoids, may contribute to the understanding of the traditional uses of this herb. The antioxidant activity of curcumin is well documented, and it is suggested to be the underlying mechanism to explain a number of beneficial effects on cognition. Curcumin was shown to be neuroprotective in vitro and protected against ethanol-induced brain injury in vivo following oral administration, an effect that was related to a reduction in lipid peroxide levels and enhancement of glutathione in rat brain. A neuroprotective action of curcumin was also observed in an animal model of Read more […]