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 […]

Toxicology and Clinical Applications of Black Pepper

Toxicology of Black Pepper There are no data available on the acute or chronic toxicologic aspects of pepper and/ or its constituents. Pepper constituents are not used therapeutically in the allopathic system. Pepper has been in use since very early times as a spice and food additive. No health hazard or untoward action may arise in the concentrations used. The total contents of piperine and associated phenolic amides are of the order of 7–9 per cent w/w and that of the volatile oil are 2–4 per cent. At this level the actual doses of the different constituents available from the quantity of pepper powder, oleoresin or extractive used, will be very little to elicit any toxic reactions. Moreover, the pungent taste of piperine and flavour of the volatile oil constituents will themselves serve as a limiting factor for the intake of high doses. No acceptable daily intake (ADI) has been prescribed by the Joint FAO/WHO Experts Committee on Food Additives for piperine and/or the volatile principles. The major untoward action of pepper is the gastric mucosal injury at a dose of 1.5 g/kg food. There are a few reports about the carcinogenic potential of piperine. It enhances the DNA adduct formation, and extract of pepper 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 […]

Aloes and the immune system: Specific activities

Anti-inflammatory effects The ability of aloe leaf gels to reduce the severity of acute inflammation has been evaluated in many different animal models. For example, Adler studied inflammation in the hind paw of the experimental rat induced by kaolin, carrageenan, albumin, dextran, gelatin and mustard. Of the various irritants tested, Aloe vera was especially active against gelatin-induced and kaolin-induced edema and had, in contrast, minimal activity when tested against dextran-induced edema. Ear swelling induced by croton oil has also been used as an assay. The swelling induced by croton oil on a mouse ear is significantly reduced by application of an aloe gel. In addition, soluble acemannan-rich extracts administered either orally or by intraperitoneal injection to mice will also reduce this swelling. In another model, the acute pneumonia induced in mouse lungs by inhalation of a bacterial endotoxin solution is significantly reduced by systemic administration of an aloe carbohydrate solution. In both these cases the reduction in inflammation is associated with a significant reduction in tissue infiltration by neutrophils. In general, aloe free of anthraquinones was more effective than aloe with anthraquinone. Some 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 […]

Healing Powers of Aloes

Aloe is a medicinal plant that has maintained its popularity over the course of time. Three distinct preparations of aloe plants are mostly used in a medicinal capacity: aloe latex (=aloe); aloe gel (=aloe vera); and, aloe whole leaf (=aloe extract). Aloe latex is used for its laxative effect; aloe gel is used topically for skin ailments, such as wound healing, psoriasis, genital herpes and internally by oral administration in diabetic and hyperlipidaemic patients and to heal gastric ulcers; and, aloe extract is potentially useful for cancer and AIDS. The use of honey may make the aloe extract therapy palatable and more efficient. Aloe preparations, especially aloe gel, have been reported to be chemically unstable and may deteriorate over a short time period. In addition, hot water extracts may not contain adequate concentrations of active ingredients and purified fractions may be required in animal studies and clinical trials. Therefore it should be kept in mind that, in some cases, the accuracy of the listed actions may be uncertain and should be verified by further studies. There are at least 600 known species of Aloe (Family Liliaceae), many of which have been used as botanical medicines in many countries for Read more […]

Healing Powers of Aloes: Pharmacology and Therapeutic Applications

Constipation Aloe latex possesses laxative properties and has been used traditionally to treat constipation. The old practice of using aloe as a laxative drug is based on its content of anthraquinones like barbaloin, which is metabolised to the laxative aloe-emodin, isobarbaloin and chrysophanic acid. The term ‘aloe’ (or ‘aloin’) refers to a crystalline, concentrated form of the dried aloe latex. In addition, aloe latex contains large amounts of a resinous material. Following oral administration the stomach is quickly reached and the time required for passage into the intestine is determined by stomach content and gastric emptying rate. Glycosides are probably chemically stable in the stomach (pH 1–3) and the sugar moiety prevents their absorption into the upper part of the gastrointestinal tract and subsequent detoxification in the liver, which protects them from breakdown in the intestine before they reach their site of action in the colon and rectum. Once they have reached the large intestine the glycosides behave like pro-drugs, liberating the aglycones (aloe-emodin, rhein-emodin, chyrosophanol, etc.) that act as the laxatives. The metabolism takes place in the colon, where bacterial glycosidases are Read more […]

Coix lacryma-jobi L. (Jobstears)

Geographic Distribution and Importance Jobstears (Coix lacryma-jobi) belongs to the Gramineae and is a diploid species (2n = 20). It is widely distributed in the temperate zones in the world, especially in humid areas of low latitude. In China, it is mainly distributed in the south provinces and there are wild and cultivated types of jobstears. Jobstears is a perennial root species and has strong root system with thick fibrous roots (3 mm in diameter). The stem is straight, 1 -1.5 m high and has ten nodes and some branches. The leaf is conifer-shaped and 30 cm in length and 1.5-3 cm in width, midrib thick and prominent. Unisexual flower, monoexism and axillary or top-growing raceme. Female spikelets are at the base of inflorescence and male spikelets at the top of the inflorescence. The blooming period is July-September and in September-October the grains ripen. The fruit of jobstears is oval with a hard outer shell. The endosperm and embryo of the fruit is called “Job’s tears” and are utilized for both food and medicine. The nutritive value of Jobstears is primarily as a cereal crop and the kernel is reputed to be “the king of cereals”. Jobstears is also a highly waterlogging-, drought- and salt-tolerant and high-productive Read more […]