Cytotoxicity of selected medicinal plants used in Mt. Frere District, South Africa.

BACKGROUND: In South African traditional medicine, some are plants known to combat pediatric diseases and are commonly used by traditional healers. The aim was to evaluate cytotoxicity effects of plants. MATERIALS AND METHODS: The ground plant material was exhaustively extracted using methanol, acetone and water separately for 72 hrs. These organic solvents were removed from filtrates using a rotavapour. Stock solutions were prepared at 40 mg/ml Dimethyl sulfoxide (DMSO) and test solutions were transferred into vials and 10 brine shrimps introduced in each. The number of dead shrimps was counted to ascertain toxicity. Ten A. salina nauplii (larva) were transferred into each sample vial and filtered brine solution was added to make 5 ml. The nauplii were counted macroscopically in the stem of the pipette against a lighted background. A drop of dry yeast suspension was added as food to each vial. Probit analysis was used to determine the concentration at which lethality to brine shrimp represents 50 % (LC50). RESULTS: All the tested extracts showed that the concentration is directly proportional to death of brine shrimps. Fifty percent lethality (LC50) of the tested crude extract ranged between 4.1 and 4.6 µg/ml with methanol extract of B. abyssinica being the lowest and T. acutiloba the highest. CONCLUSION: This study revealed that 100% of plant crude extracts screened for activity against Artemisia salina larvae showed strong cytotoxicity below 10 µg/ml and plant species with LC50 values < 1000 µg/ml may not make good paediatric remedies due to their inherent toxicity.

Cytotoxicity studies of lycorine alkaloids of the Amaryllidaceae.

The plant family Amaryllidaceae is renowned for its unique alkaloid constituents which possess a significant array of structural diversity. Several of these alkaloids are known for their interesting biological properties, of which galanthamine and pancratistatin have acquired a privileged status due to their relevance in the pharmaceutical arena. In particular, galanthamine represents the first prescription drug emanating from the Amaryllidaceae after its approval by the FDA in 2001 for the treatment of Alzheimer's disease. Following on this commercial success there have been sustained projections for the emergence of an anticancer agent related to pancratistatin due to the potency, selectivity, low toxicity and high tolerability typifying targets of this series of alkaloids. The lycorine series of alkaloids have also garnered widespread interest as cytotoxic agents and were amongst the earliest of the Amaryllidaceae constituents to exhibit such activity. To date over 100 of such naturally-occurring or synthetically-derived alkaloids have been screened for cytotoxic effects against a number of cancer cell lines. This survey examines the cytotoxic properties of lycorine alkaloids, highlights the outcomes of structure-activity relationship orientated studies and affords plausible insights to the mechanistic rationale behind these effects.

Alergia al espárrago / Allergy to the asparagus

El espárrago (Asparagus officinalis), ampliamente cultivado a escala mundial, forma parte, junto con el ajo, la cebolla y el puerro de la familia de Liliáceas. Se ha descrito hipersensibilidad al espárrago en forma de reacciones retardadas mediadas por células, y de reacciones inmediatas mediadas por IgE. Mientras que las primeras (dermatitis alérgica de contacto) son una causa relativamente frecuente de patología ocupacional, la literatura sólo muestra casos puntuales de alergia IgE mediada. Las reacciones mediadas por IgE ocurren principalmente en individuos atópicos y se pueden clasificar en alergia alimentaria y reacciones secundarias a la exposición cutánea o inhalada, generalmente ocupacional, a proteínas del espárrago. La manifestación clínica más frecuente de la alergia alimentaria es la anafilaxia mientras que en las segundas, la urticaria de contacto, la rinitis y el asma ocupacional pueden coexistir o aparecer aisladas. La diferente forma de presentación clínica de las reacciones mediadas por IgE es probablemente consecuencia de la sensibilización a diferentes alergenos. La importancia de la detección y el diagnóstico diferencial de estas manifestaciones radica en su diferente tratamiento y pronóstico. En este artículo revisamos nuestra experiencia en los últimos 5 años (AU)

[Anterior rhinomanometry as a diagnostic test in occupational allergy caused by Liliaceae]. / Rinomanometría anterior como test diagnóstico en alergia ocupacional por liliáceas.

UNLABELLED: The Liliacea family has been implicated as a cause of occupational rhinoconjunctivitis and bronchial asthma. We report a patient who presented symptoms when he manipulated spices including garlic and onion dusts. Nasal challenge test with active anterior rhinomanometry was used for the diagnosis. MATERIAL AND METHODS: Skin-prick tests with common inhalants, commercial spices, fresh Liliaceae and powdered spices diluted in saline solution (10 mg/ml) were performed. Immunoblot and specific IgE (CAP-Pharmacia) were determined. Control peak expiratory flow was monitored during a period at work in an area where spices were manipulated and in an area where they were transported. Nasal challenge test with garlic and onion powder was performed. The resulting nasal obstruction was measured as nasal airway resistance and was determined by rhinomanometry. RESULTS: Skin-prick tests were positive for onion, garlic powder and fresh Liliacea. Specific IgE were positive for garlic and onion. IgE immunoblotting showed very strong bands at 14 and 40 kD with garlic extract. Nasal challenge showed an increase in inspiratory nasal resistance which was higher than 100 % of the basal value for both onion extract and garlic.

Occupational allergic contact urticaria to yucca (Yucca aloifolia), weeping fig (Ficus benjamina), and spathe flower (Spathiphyllum wallisii).

BACKGROUND: Occupational contact urticaria (CU) from plants is often reported, but it is less often attributed to decorative houseplants. We present an atopic gardener and caretaker of plants who developed CU when occupationally exposed to weeping fig, spathe flower, and yucca. METHODS: Sensitization was evaluated by skin prick tests (SPT) and analyses for IgE antibodies. RESULTS: SPT were positive to all three plants, and IgE antibodies were found to weeping fig and spathe flower. SPT were also performed with several decorative houseplants in more than 600 patients. Positive SPT was found to weeping fig (12%), African milk tree (8.3%), yucca (5.8%), Chinese rose (4.7%), massangana (4.6%), bird's nest fern (3.2%), and spathe flower (3.2%). CONCLUSION: Our study indicates that SPT and tests for IgE antibody are useful in detecting occupational CU caused by houseplants.

Effect of yam (Dioscorea cayenensis) and dasheen (Colocassia esculenta) extracts on the kidney of streptozotocin-induced diabetic rats.

Streptozotocin-induced diabetic wistar rats were maintained for 4 weeks on a supplement of extracts of yam (Dioscorea cayenensis) or dasheen (Colocassia esculenta). The activities of malic enzyme, NADP+ isocitrate dehydrogenase, Glucose 6-P-dehydrogenase and the transaminases were determined to assess any degree of metabolic alteration caused by diabetic nephropathy. Diabetic rats fed normal diet and those fed yam extract, dasheen extract and commercial linamarin respectively lost weight significantly compared to healthy controls. The diabetic rats fed dasheen extract, maintained near normoglycaemic values compared to diabetic rats on normal diet (P < 0.05). Malic enzyme activity was significantly reduced (P < 0.05) in diabetic rats on the normal diet compared to normal healthy controls. Feeding of yam or dasheen extract raised the activity of this enzyme towards normal. Feeding of dasheen extract or commercial linamarin significantly lowered (P < 0.05) the activity of NADP+ isocitrate dehydrogenase below that of healthy controls. Glucose 6-P-dehydrogenase activity was significantly increased (P < 0.05) in diabetic rats compared to healthy controls. Alanine transaminase in the kidney of diabetic rats fed yam extract was significantly higher than healthy controls (P < 0.05). These results demonstrate an overall aggravation of the diabetic nephropathy by yam and dasheen extracts in the diet. In the Caribbean region where these foods are dietary staples, there may be a correlation with the reported high prevalence of diabetes mellitus and the development of renal disease.

Contact dermatitis to Asparagus officinalis.

A 53-year-old farm worker presented with a 3-year history of an occupational allergic contact dermatitis to asparagus. The dermatitis cleared quickly with courses of systemic corticosteroids but relapsed within days of further exposure to asparagus. The genera Asparagus is made up of some 300 species. It belongs to the family Liliaceae which includes tulips, onions and garlic. Asparagus contains asparagin, coniferin and the glucoside vanillin. The allergen may be a plant growth inhibitor, 1,2,3-Trithiane-5-carboxylic acid, which is present in young shoots.