Toxicity of the genus Dieffenbachia

Taro raphide-associated proteins: Allergens and crystal growth

Calcium oxalate raphide crystals are found in bundles in intravacuolar membrane chambers of specialized idioblasts cells of most plant families. Aroid raphides are proposed to cause acridity in crops such as taro (Colocasia esculenta (L.) Schott). Acridity is irritation that causes itchiness and pain when raw/insufficiently cooked tissues are eaten. Since raphides do not always cause acridity and since acridity can be inactivated by cooking and/or protease treatment, it is possible that a toxin or allergen-like compound is associated with the crystals. Using two-dimensional (2D) gel electrophoresis and mass spectrometry (MS) peptide sequencing of selected peptides from purified raphides and taro apex transcriptome sequencing, we showed the presence on the raphides of peptides normally associated with mitochrondria (ATP synthase), chloroplasts (chaperonin ~60 kDa), cytoplasm (actin, profilin), and vacuole (V-type ATPase) that indicates a multistage biocrystallation process ending with possible invagination of the tonoplast and addition of mucilage that may be derived from the Golgi. Actin might play a crucial role in the generation of the needle-like raphides. One of the five raphide profilins genes was highly expressed in the apex and had a 17-amino acid insert that significantly increased that profilin's antigenic epitope peak. A second profilin had a 2-amino acid insert and also had a greater B-cell epitope prediction. Taro profilins showed 83% to 92% similarity to known characterized profilins. Further, commercial allergen test strips for hazelnuts, where profilin is a secondary allergen, have potential for screening in a taro germplasm to reduce acridity and during food processing to avoid overcooking.

To report a case of crystalline keratopathy induced by Dieffenbachia plant sap and literature review

Purpose

To report a case of crystalline keratopathy induced the Dieffenbachia plant sap.

Methods

Case report and review of the literature.

Results

A 38-year-old woman presented with redness, irritation, and slightly blurred vision in the right eye after the exposure of Dieffenbachia plant sap to her right eye. The patient's eye was irrigated with copious saline on her admission. On ophthalmic examination, her visual acuity was 20/32 OD and 20/20 OS. Anterior segment examination of the right eye revealed mild eyelid edema, grade 2 conjunctival hyperemia, diffuse punctate corneal epithelial erosions, mild stromal edema, and fine refractile needle-like crystals extending from the subepithelial region to mid-stroma. The crystals were visualized with anterior segment photographs and in vivo corneal confocal microscopy (IVCCM) views. Moxifloxacin 0.5% and preservative-free artificial tears were started. Loteprednol etabonate 0.5% was added once the epithelial erosions had healed. The corneal crystals were completely disappeared and the visual acuity of the patient was 20/20 in the third week's visit.

Conclusions

Patients with a history of contact with plant sap should be irrigated with abundant saline immediately to reduce the effect of chemical trauma and thus reduce mechanical damage by inhibiting crystal penetration. IVCCM offers a non-invasive, fast, and reliable diagnosis of Dieffenbachia-related injury, especially in patients with ocular irritation of unknown etiology. Besides, IVCCM is very valuable to differentiate calcium oxalate crystals from other crystalline corneopathies.

Epipremnum aureum Keratopathy: Case Report and Review of the Literature

OBJECTIVES

To report a novel case of Epipremnum aureum toxicity masquerading as bilateral infectious keratitis and review the literature on ocular manifestations of Epipremnum exposure.

METHODS

Case report and literature review.

RESULTS

A 70-year-old man with a history of photorefractive keratectomy presented with a 3-day history of bilateral eye pain. The patient reported exposure to plant debris while performing yard work and also water exposure while cleaning his coral fish tanks. Clinical examination revealed bilateral epitheliopathy progressing to frank epithelial defects with underlying stromal necrosis 6 days after exposure. Empiric topical antibiotic drops were initiated, but multiple cultures, corneal biopsy, and confocal microscopy were all negative for an infectious agent. Over a 2-week period, the epithelial defects worsened and a suspicion for a toxic etiology was raised. The patient later recalled rubbing his eyes after exposure to Epipremnum aureum (Golden Pothos/Devils Ivy) sap. He was thus treated conservatively with artificial tears, topical corticosteroids, and amniotic membrane. After 3 months, the epithelial defects resolved, but with corneal scarring, prominently in the left eye and underwent penetrating keratoplasty. Five years after presentation, best-corrected visual acuity with hard contact lenses was 20/25 in the right eye and 20/20 in the left eye.

CONCLUSION

Epipremnum aureum toxicity is a rare cause of keratitis. It can mimic acanthamoeba keratitis or anesthetic abuse and should be considered in cases of culture negative nonhealing corneal ulcerations. Eliciting a history of plant sap exposure can facilitate appropriate supportive care for this toxic keratitis.

Mucosal Injury From Calcium Oxalate Crystals Resembling Anaphylaxis and Angioedema

BACKGROUND

There are 215 families of plants that contain insoluble needle-shaped calcium oxalate crystals on the surface of their tissues. Upon mucosal contact, injury can cause extreme pain, soft-tissue swelling, salivation, dysphagia, and even aphonia. This presentation can resemble angioedema or anaphylaxis.

CASE REPORT

A 55-year-old Asian female presented to the emergency department complaining of oral pain, swelling, and numbness. Her family reported that she began to experience sharp pain of the tongue and lips immediately after eating "elephant root." Physical examination revealed a patient sitting in an upright position, leaning forward with pooling secretions. She had few lingual petechiae, a subtle diffuse erythema, and mild edema of the lower lip. Due to pain, she was unable to speak and swallow. Her vitals remained within normal limits. The patient was taking lisinopril for hypertension. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Injury by calcium oxalate crystals is a relatively common occurrence that will present to the emergency department. Although most exposures are benign, patients can develop critical illness, requiring emergent therapies and airway management. Due to the nature of presentation, exposure can easily be misdiagnosed as anaphylaxis or hereditary and drug-induced angioedema. Severe pain and the temporal relationship to plant ingestion distinguish insoluble calcium oxalate crystal exposure from these alternative causes of angioedema. There is minimal evidence-based data evaluating treatment of these injuries. Standard treatment regimen includes a local anesthetic, corticosteroids, opioids, and antihistaminergic agents. Given the relative low cost, ease of administration, and benign adverse effect profile, sodium bicarbonate rinse may have a role as an adjunct therapy, however, research is needed.

Antiprotozoal activity of medicinal plants used by Iquitos-Nauta road communities in Loreto (Peru)

ETHNOPHARMACOLOGICAL RELEVANCE

In the Peruvian Amazon, the use of medicinal plants is a common practice. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point for this work was a set of interviews of people living in rural communities from the Peruvian Amazon about their uses of plants. Protozoan diseases are a public health issue in the Amazonian communities, who partly cope with it by using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help identify new antiprotozoal compounds.

AIMS OF STUDY

to inventory and validate the use of medicinal plants by rural people of Loreto region.

MATERIALS AND METHODS

Rural mestizos were interviewed about traditional medication of parasite infections with medicinal plants. Ethnopharmacological surveys were undertaken in two villages along Iquitos-Nauta road (Loreto region, Peru), namely 13 de Febrero and El Dorado communities. Forty-six plants were collected according to their traditional use for the treatment of parasitic diseases, 50 ethanolic extracts (different parts for some of the plants) were tested in vitro on Plasmodium falciparum (3D7 sensitive strain and W2 chloroquine resistant strain), Leishmania donovani LV9 strain and Trypanosoma brucei gambiense. Cytotoxic assessment (HUVEC cells) of the active extracts was performed. Two of the most active plants were submitted to preliminary bioguided fractionation to ascertain and explore their activities.

RESULTS

From the initial plants list, 10 were found to be active on P. falciparum, 15 on L. donovani and 2 on the three parasites. The ethanolic extract from Costus curvibracteatus (Costaceae) leaves and Grias neuberthii (Lecythidaceae) bark showed strong in vitro activity on P. falciparum (sensitive and resistant strain) and L. donovani and moderate activity on T. brucei gambiense.

CONCLUSIONS

The Amazonian forest communities in Peru represents a source of knowledge on the use of medicinal plants. In this work, several extracts with antiprotozoal activity were identified. This work contributes to validate some traditional uses and opens subsequent investigations on active compounds isolation and identification.

Severe destruction of the upper respiratory structures after brief exposure to a dieffenbachia plant

Dieffenbachia is a common domestic plant. Oral contact with the plant generally causes slight effects, but when chewed it may result in painful oropharyngeal edema. Even though the mechanism through which this plant causes toxicity is not known, calcium oxalate crystals (rhaphides) and protease in the idioblast of the plant are considered to be the causes. Our aim was to show the lethal effects of a common domestic plant named Dieffenbachia.A 70-year-old male patient applied to our clinic with aphasia, dysphagia, sialorrhea, wounds on the lips and tongue, and swelling on the face. There was edema on his tongue, soft palate, uvula, anterior pharyngeal plica, epiglottis and aryepiglottic fold, and ulceration on the right side of his tongue, the right cheek mucosa, right-lower gingival, soft palate, tongue base, epiglottis anterior surface, and free edge.Dieffenbachia toxicity presents both minimal and serious problems, which can be life threatening, as in our case. Toxic cases resulting in serious clinical pictures due to Dieffenbachia are rare.

Tongue angioedema in vivo: antagonist response of anti-inflammatory drugs

INTRODUCTION

The toxicity of Dieffenbachia picta, an ornamental plant, arises from its ability to cause painful edema of oral mucous membranes, buccal ulcerations, and tongue hypertrophy after chewing on the stem or contact with the sap.

OBJECTIVES

We compared the anti-inflammatory effect of eugenol (2-methoxy-4-(2-propenyl)phenol) to different drugs, and investigated the role of oxalate crystals in the development of the inflammation reaction.

METHODS

Tongue edema in live mice were measured with a digital tachymeter, 2 h after topical application (0.1 mL) or tissue injection (0.05 mL) of D. picta sap. The mice were treated by intraperitoneal or topical application of drugs, 15 min after edema induction. Vascular permeability was quantified based on abdominal skin plasma extravasation of Evans blue dye in response to intradermal administration of D. picta sap. The proteolytic assay was carried out as previously described (Kunitz M. Crystalline soybean trypsin inhibitor. General properties. J Gen Physiol 1947; 30:291-310.).

RESULTS

Arachidonate cascade antagonists and eugenol showed anti-edematogenic effects. High doses of eugenol (50 μg/kg) and sodium cromoglycate (100 mg/kg), but not a combination of the two, inhibited plasma extravasations. The sap without crystals, its methanol extract, or the ethanol-washed crystals in saline-reconstituted solution did not reproduce the tongue edema seen with the original sap. Topical application of 10% sodium bicarbonate completely abolished the tongue edema.

CONCLUSIONS

The inflammatory response induced by D. picta may be due to mechanical tissue damage resulting from the physical presence of calcium oxalate crystals. We were, however, unable to exclude the possibility of an insoluble toxicity present within the sap as an etiological agent. We realized that emergency treatment should also aim to inhibit antidromic vasodilation and axon reflex flare, reducing mastocyte degranulation and release of tachykinins from nerve endings. We speculate that eugenol showed better antiedematogenic results because it seems to function not only as a classic non-steroidal anti-inflammatory drug, but also as a local anesthetic, blocking neurotransmission in the damaged tissue.

Toxicities of raw Alocasia odora

Alocasia, the Araceae family, is a genus of more than 100 species of perennial, herbaceous, diminutive to extremely large, usually robust herbs with a clear-to-milky latex. They are distributed throughout subtropical and tropical Asia and in the tropical western pacific as well as eastern Australia. Despite easy access to A odora, there have been no published reports in English regarding the toxic symptoms following the ingestion of raw A odora. Here, the clinical manifestations of 2 patients that ingested raw A odora are described. Two patients experienced oral numbness and intractable tongue pain, and 1 patient required endotracheal intubation because of upper respiratory tract obstruction. Although conservative treatment is the primary approach to A odora poisoning, physicians should be aware of the potential for upper respiratory obstruction in patients exposed to A odora, as well as the need for controlling tongue pain.

Acute airway compromise after brief exposure to a Dieffenbachia plant

Dieffenbachia is a common domestic plant. Oral contact with the plant usually is associated with minimal consequences. However, chewing on the stem or the leaf of the Dieffenbachia can result in painful oropharyngeal edema and the inability to speak or handle secretions. Airway compromise has been reported only in a pediatric ingestion. We report a case of an adult who bit into the stem of the plant thinking it was sugar cane. He instantly spit out the remaining stem and despite this brief exposure, oropharyngeal edema developed refractory to medicinal therapy, requiring surgical airway management. The exact mechanism of edema is not known; therefore, methods of treatment are variable. We recommend caution when presented with a patient exposed to Dieffenbachia. Even the patient who initially seems stable may have an airway that will quickly deteriorate.

The management of Elephant's Ear poisoning

The Araceae family of plants is the major cause of symptomatic plant ingestions in some developed countries (Dieffenbachia and Philodendron) and in Zimbabwe (Elephant's Ear), especially in children. A retrospective case series was carried out to evaluate the management of poisoning due to Elephant's Ear at the largest referral hospital in Zimbabwe for the period January 1995-December 1999. The study revealed inappropriate use of antibiotics, atropine, and antihistamines in the treatment of Elephant's Ear poisoning. This article also reviews the management of poisoning due to the Araceae family of plants as exemplified by Elephant's Ear. There is a need to educate health care workers on the clinical management of Elephant's Ear poisoning especially in developing countries where there are limited resources.

Plant poisonings in children

1. Plant poisonings comprise 5% of all hospitalizations due to poisonings in children and plant inquiries to Poison Information Centre consist about 28% of calls concerning children. 2. A search of 71 cases of hospitalization due to plants in a 5 year period obtained from two children's hospitals in Helsinki were reviewed and 105 plant inquiries concerning poisonings among children to the Poison Information Centre in a 6 month period were studied. 3. The most frequent plant poisonings involved lily-of-the-valley, dumb cane and cotoneaster plant. Only 11% of the cases treated in hospital were evaluated to be unequivocal poisonings. 4. Mezereon, snowberry, cotoneaster plant, honeysuckle, and woody nightshade caused the most serious symptoms. Symptoms in mezereon poisoning were increased saliva excretion, haematuria and diarrhoea in a 1.2-year-old girl. Snowberries caused a semicomatose state and difficulty in urination, cotoneaster caused severe stomach ache, honeysuckle abudant gastrointestinal symptoms and muscle cramps, and nightshade led to prolonged high fever and sweating. 5. It appears that almost all plant poisonings could be treated with medical charcoal. Gastric evacuation is seldom required.

Observations on the idioblasts of Dieffenbachia

The toxicity of the Arum genus, especially the Dieffenbachia, has long been a topic of controversy. Some believe that the injury inflicted is primarily mechanical, the result of needle like crystals of calcium oxalate (raphides) found in the stems and leaves. Others cite evidence supporting the existence of enzymatic and allergic injury. This paper describes a hitherto neglected third factor, specialized cells which can forcibly shoot the raphides and which may be necessary for the toxic effect since raphide containing plants devoid of these cells are not toxic. The effects of physical and chemical factors on the behavior of these cells are described.