Podophyllum spp.

Lignans, as natural products, are distributed widely in the plant kingdom. More than 200 compounds in this general class have been identified. Lignans have aroused considerable interest because some of them display antitumor activities. This is particularly true of the podophyllotoxin group of lignans, which are constituents of the medical resin extracted from Podophyllum species. Podophyllotoxins are a particularly instructive class of natural products for consideration in the design and synthesis of potential anticancer agents based upon natural product prototypes. History The medical use of Podophyllum species dates back over 1000 years. At that time the roots of wild chervil were used in a salve for treating cancer in England. About 400-600 years ago, the natives of the Himalayas and the American Indians independently discovered that the aqueous extracts of the roots (podophyllin) from Podophyllum species was a canthartic and poison. After the American Indians introduced the use of podophyllin to the American colonists, it became such a popular drug that it was included in the US Pharmacopoeia in 1820 as a canthartic and cholagog and remained until 1942, when it was removed because of its severe toxicity. However, 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: 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 […]

Stephania

Importance and Distribution of the Genus The genus Stephania (Menispermaceae) comprises approximately 50 species distributed from Africa through Asia to Australia. The importance of the genus in traditional medicine in Asia and Africa is well documented. The underground tubers of the vines are generally characterized by powerful pharmacological effects. Stephania abyssinica is a creeper indigenous to southern and eastern Africa. The leaves of this plant are used as a purgative and emetic, whereas the roots are employed in the treatment of roundworm, menorrhagia and boils. Stephania bancroftii is used by the aboriginal communities of Australia both as a treatment for diarrhea and as a fish poison. Stephania cepharantha (), a perennial plant native to mainland China known by the vernacular name “bei-yan-zi”, is commonly used as a folk medicinal herb. Decoctions from the tuber of Stephania cepharantha are traditionally used in China to treat a number of diseases including parotiditis, gastric ulcer, leukopenia, alopecia areata and alopecia androgenetica. The major components of this crude drug, known as Cepharanthin preparations, are the bisbenzylisoquinoline (BBI) alkaloids cepharanthine, isotetrandrine and cycleanine. Stephania 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 […]

Chamomile: Traditional Use and Therapeutic Indications

Traditional Use Chamomile has been known for centuries and is well established in therapy. In traditional folk medicine it is found in the form of chamomile tea, which is drunk internally in cases of painful gastric and intestinal complaints connected with convulsions such as diarrhea and flatulence, but also with inflammatory gastric and intestinal diseases such as gastritis and enteritis. Externally chamomile is applied in the form of hot compresses to badly healing wounds, such as for a hip bath with abscesses, furuncles, hemorrhoids, and female diseases; as a rinse of the mouth with inflammations of the oral cavity and the cavity of the pharynx; as chamomile steam inhalation for the treatment of acne vulgaris and for the inhalation with nasal catarrhs and bronchitis; and as an additive to baby baths. In Roman countries it is quite common to use chamomile tea even in restaurants or bars and finally even in the form of a concentrated espresso. This is also a good way of fighting against an upset stomach due to a sumptuous meal, plenty of alcohol, or nicotine. In this case it is not easy to draw a line and find out where the limit to luxury is. Clinic and practice Preliminary remark The suitability of the empirical Read more […]

Sempervivum spp. (Houseleek)

Distribution and Importance of Sempervivum The genus Sempervivum (Crassulaceae) contains approximately 80 species and several subspecies. The name is indicative of their evergreen, sempervirent nature (semper = always, vivum = living). Houseleeks (Sempervivum spp.) grow mainly on sunny, barren hillsides, mostly at 1000-2000 m. They are favourite plants in rock-gardens, because they grow on walls and roofing tiles. One of the most important species, Sempervivum tectorum L. is native to the Alps, but it can be found sporadically as far as the Pyrenees and the northern regions of the Balkan Peninsula, in central Anatolia. It grows well under extreme conditions, usually in calcareous soil. It is a cosmopolitan species living in dry circumstances (Hegnauer 1964). It can be used on extreme sites (notably in urban environments), if its basic ecological and growth requirements are respected. One of the most important ecophysiological features of Sempervivum – in which it is similar to other members of Crassulaceae family – is nocturnal C02 fixation; this physiological adaptation to a dry environment enables tolerance of water deficiency. This metabolism, known as CAM (crassulacean acid metabolism), is an alternative Read more […]

Specific Medicinal Uses of Cannabis: Use as an Antiemetic

Many agents used in cancer chemotherapy produce severe nausea and vomiting in most patients. Symptoms can last for hours or days and have a major impact on patient nutrition and electrolyte status, body weight and physical and mental resilience to both the disease and its treatment. The current choice of available anti-emetics is limited and most are only partially effective, which may lead patients to refuse therapy all together, or for clinicians to use chemotherapeutic regimens which are less than optimum. For these reasons, the search for more effective antiemetics continues. Cannabis In the late 1960s and early 1970s, patients receiving various cancer chemotherapy regimes (including mustine, vincristine, prednisone and procarbazine) noted that smoking cannabis from illicit sources, before and during chemotherapy, reduced the incidence of nausea and vomiting to a variable degree. Only since the isolation of THC have formal clinical trials on the safety and efficacy of cannabis derivatives been conducted. As far as crude cannabis is concerned, we have only anecdotal evidence that inhaling its smoke is effective in a variable percentage of patients who vomit, despite supposedly adequate doses of standard antiemetics. There 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 […]