An experimental model of peripheral neuropathy induced in rats by Karwinskia humboldtiana (buckthorn) fruit

Intoxication by Karwinskia humboldtiana (buckthorn) fruit presents a neurological picture similar to that of Guillain-Barré syndrome. In this report, we describe an experimental animal model of peripheral neuropathy induced by buckthorn fruit. Four groups of Wistar rats received one oral dose of 1.5 g/kg followed by oral doses of 0.5 g/kg at days 3, 7, 10, and 14 of dried and ground buckthorn fruit in aqueous suspension. Rats were sacrificed at 24, 48, 58, and 112 days after initial dose. Treated animals developed progressive paralysis through 58 days, then completely recovered by 112 days. Sciatic nerves showed segmental demyelination and cellular infiltrates until 58 days after exposure and then remyelinating changes at 112 days. This experimental model for peripheral neuropathy is reproducible and easy to handle. Its manipulation is relatively innocuous and allows us to study reversible peripheral nerve damage. This model can be developed in other animal species and may be useful to test new therapies for peripheral neuropathy.

Olfactory shifts parallel superspecialism for toxic fruit in Drosophila melanogaster sibling, D. sechellia

Olfaction in the fruit fly Drosophila melanogaster is increasingly understood, from ligand-receptor-neuron combinations to their axonal projection patterns into the antennal lobe . Drosophila thus offers an excellent opportunity to study the evolutionary and ecological dynamics of olfactory systems. We compared the structure and function of the generalist D. melanogaster with that of specialist D. sechellia, which oviposits exclusively on morinda fruit . Our analyses show that whereas the fruit's headspace was dominated by acids, antennae responded most strongly to hexanoates. D. sechellia exhibited an extraordinarily strong response to methyl hexanoate (MeHex). Behaviorally, D. sechellia was much more attracted to these morinda fruit volatiles than was D. melanogaster. The high sensitivity to MeHex was paralleled by a 2.5x-3 x overrepresentation of MeHex neurons on the antenna and a concordant 2.9 x increase in volume of the corresponding glomerulus as compared to D. melanogaster. In addition, the MeHex neuron exhibited an extreme sensitivity down to femtograms of its ligand. In contrast, no peripherally mediated shift was found paralleling D. sechellia's increased attraction to acids. These findings are a demonstration of evolution acting at several levels in the olfactory circuitry in mediating a fruit fly's unique preference for fruit toxic to its sibling species .

Safety and whole-body antioxidant potential of a novel anthocyanin-rich formulation of edible berries

Edible berry extracts rich in anthocyanins possess a broad spectrum of therapeutic, pharmacologic and anti-carcinogenic properties. Six berry extracts (wild blueberry, bilberry, cranberry, elderberry, raspberry seeds and strawberry), singly and in combination, were studied in our laboratories for antioxidant efficacy, cytotoxic potential, cellular uptake and anti-angiogenic properties. Combinations of edible berry extracts were evaluated to develop a synergistic formula, OptiBerry, which exhibited high oxygen radical absorbance capacity (ORAC) value, low cytotoxicity and superior anti-angiogenic properties compared to the other combinations tested. The current study sought to determine the broad spectrum safety and antioxidant potential of OptiBerry in vivo. Acute oral LD(50) of OptiBerry was greater than 5 g/kg in rats. Acute dermal LD(50) of OptiBerry was greater than 2 g/kg. No changes in the body weight or adverse effects were observed following necropsy. Primary skin and eye irritation studies were conducted in New Zealand albino rabbits. OptiBerry was classified as slightly irritating to the skin (primary skin irritation index 0.3) and minimally irritating to the eye (maximum mean total score 6.0). The antioxidant potential of OptiBerry was investigated in rats and mice by assessing GSH redox status in tissues as well as by a unique state-of-the-art electron paramagnetic resonance (EPR) imaging of whole-body redox status. A clinically relevant hyperbaric oxygen (HBO) exposure system (2 atm, 2 h) was employed to study the antioxidant properties of OptiBerry. OptiBerry feeding (8 weeks) significantly prevented HBO-induced GSH oxidation in the lung and liver of vitamin E-deficient Sprague Dawley rats. Furthermore, OptiBerry-fed mice, when exposed to HBO, demonstrated significant protection in whole-body HBO-induced oxidation compared to the unfed controls by EPR imaging. Taken together, these results indicate that OptiBerry is reasonably safe and possess antioxidant properties.

Experimental phytophotodermatitis

BACKGROUND/AIMS

Phytophotodermatitis (PPD) is defined as a phototoxic reaction of the skin after contact with substances derived from plants and subsequent exposure to sunlight. It is a frequent disease in our outpatient clinics during summer because of contact with Tahitian lemon. Our objectives were to experimentally reproduce PPD in rats, to identify whether PPD is induced by minimal exposure periods to sunlight, to find what kinds of lemons and which parts of the lemon (the fruit juice or the peel juice) may trigger the disease; to know whether the use of sunblock prevents the reaction; and to perform light microscopy of the lesions to describe their histology.

METHODS

Adult rats (Rattus norwegicus), three in each experiment, were used. After painting the rats with the fruit juice or the peel juice they were exposed to sunlight for 2.5, 5, 7.5, and 10 min. Tahitian and Sicilian lemons were used in the experiments. Biopsies with 3-mm punches of different times of exposure were performed.

RESULTS

The peel juice of both lemons reproduced PPD, which was clinically evident after 48 h. When the peel juice was alone applied there was no reaction; moreover, exposure to sunlight alone triggered no reaction. Two and a half minutes of exposure time was sufficient to induce phototoxic reaction, which was time dependent (the longer the exposure the more intense the reaction). Histopathological studies showed epithelial time-dependent vacuolar degeneration. The use of sunblock diminished the intensity of the reaction but did not prevent it.

CONCLUSION

PPD can be reproduced in an animal model. It may be caused by the peel juice of Tahitian and Sicilian lemon. Because of an extremely short time of exposure (2.5 min) is sufficient to induce PPD it is necessary to alert the population, of the need for caution when handling lemons, especially outdoors despite using sunblock.

Poisoning by Coriaria myrtifolia Linnaeus: a new case report and review of the literature

Coriaria myrtifolia should be recognized as one of the most neurotoxic plants in western Mediterranean area. This shrub produces a toxin, coriamyrtin, that is present in high concentrations in the berries. Ingestion of few fruits similar to blackberries may induce digestive and neurological manifestations including seizures, coma and apnea. The authors present a new case report that took place in the French Catalonia: an 8 year-old boy developed vomiting and generalized recurrent convulsions after ingestion of C. myrtifolia berries. He needed repeated diazepam administrations and was managed in the hospital. He recovered after one day of benzodiazepine treatment. In order to evaluate the consequences of C. myrtifolia poisoning, 83 cases of the literature were analyzed: the cases occurred in three countries (Spain, France and Morocco); the mean delay of the symptom development was 150 min; the neurological disturbances were the most frequent signs and 11 patients died (6 children, 5 adults) mainly in old reports.

The genetics of adaptation in Drosophila sechellia

Drosophila sechellia is an island endemic of the Seychelles. After its geographic isolation on these islands, D. sechellia evolved into a host specialist on the fruit of Morinda citrifolia--a fruit often noxious and repulsive to Drosophila. Specialization on M. citrifolia required the evolution of a suite of adaptations, including resistance to and preference for some of the toxins found in this fruit. Several of these adaptive traits have been studied genetically. Here, I summarize what is known about the genetics of these traits and briefly describe the ecological and geographical context that shaped the evolution of these characters. The data from D. sechellia suggest that adaptations are not as genetically complex as historically thought, although almost all of the adaptations of D. sechellia involve several genes.

Colocynth toxicity. A possible cause of bloody diarrhea

Five cases of toxicity due to consumption of an uncommon wild fruit called Colocynth are described. These cases were seen over a period of 2 years. Severe bouts of bloody diarrhea were encountered in these patients. The plant, its ingredients, the medicinal and other uses, features of toxicity and the management is discussed. Doctors are advised to be aware of this uncommon clinical problem.

Cytotoxic major saponin from tomato fruits

A major novel steroidal alkaloid glycoside, possessing cytotoxic activity has been isolated from the fruits of Lycopersicon esculentum.

Cytotoxicity and apoptotic inducibility of Vitex agnus-castus fruit extract in cultured human normal and cancer cells and effect on growth

A crude extract was prepared with ethanol from dried ripened Vitex agnus-castus fruits growing in Israel (Vitex extract). Cytotoxicity of the extract against human uterine cervical canal fibroblast (HCF), human embryo fibroblast (HE-21), ovarian cancer (MCF-7), cervical carcinoma (SKG-3a), breast carcinoma (SKOV-3), gastric signet ring carcinoma (KATO-III), colon carcinoma (COLO 201), and small cell lung carcinoma (Lu-134-A-H) cells was examined. After culture for 24 h (logarithmic growth phase) or 72 h (stationary growth phase), the cells were treated with various concentrations of Vitex extract. In both growth phases, higher growth activity of cells and more cytotoxic activity of Vitex extract were seen. The cytotoxic activity against stationary growth-phase cells was less than that against logarithmic growth-phase cells. DNA fragmentation of Vitex extract-treated cells was seen in SKOV-3, KATO-III, COLO 201, and Lu-134-A-H cells. The DNA fragmentation in Vitex extract-treated KATO-III cells was inhibited by the presence of the antioxidative reagent pyrrolidine dithiocarbamate or N-acetyl-L-cysteine (NAC). Western blotting analysis showed that in Vitex extract-treated KATO-III cells, the presence of NAC also inhibited the expression of heme oxygenase-1 and the active forms of caspases-3, -8 and -9. It is concluded that the cytotoxic activity of Vitex extract may be attributed to the effect on cell growth, that cell death occurs through apoptosis, and that this apoptotic cell death may be attributed to increased intracellular oxidation by Vitex extract treatment.

Neurotoxic effects of carambola in rats: the role of oxalate

BACKGROUND AND PURPOSE

Carambola (star fruit) has been reported to contain neurotoxins that cause convulsions, hiccups, or death in uremic patients, and prolong barbiturate-induced sleeping time in rats. The constituent responsible for these effects remains uncertain. Carambola contains a large quantity of oxalate, which can induce depression of cerebral function and seizures. This study was conducted to investigate the role of oxalate in carambola toxicity in rats.

MATERIALS AND METHODS

The effects on barbiturate-induced sleeping time and death caused by intraperitoneal administration of carambola juice were observed in Sprague-Dawley rats. To obtain a dose-dependent response curve and evaluate the lethal dose, rats were treated with serial amounts of pure carambola juice diluted with normal saline in a volume of 1:1. To test the role of oxalate in the neurotoxic effect of carambola, either 5.33 g/kg carambola after oxalate removal or 5.33 g/kg of pure carambola juice diluted with normal saline were administered intraperitoneally, while the control group was given normal saline before pentobarbital injection. The effects of carambola and oxalate-removed carambola on barbiturate-induced sleeping time were compared with those of saline. To assess the lethal effect of oxalate in carambola, we gave rats chemical oxalate at comparable concentrations to the oxalate content of carambola.

RESULTS

Carambola juice administration prolonged barbiturate-induced sleeping time in a dose-dependent manner. The sleeping time of rats that received normal saline and 1.33 g/kg, 2.67 g/kg, 5.33 g/kg, and 10.67 g/kg of carambola juice were 66 +/- 16.6, 93.7 +/- 13.4, 113.3 +/- 11.4, 117.5 +/- 29.0, and 172.5 +/- 38.8 minutes, respectively. The three higher-dose groups had longer sleeping times than controls (p < 0.05 or 0.005). This effect was eliminated after the removal of oxalate from carambola juice. Four of eight rats in the 10.67-g/kg group and all rats in the 21.33 g/kg and chemical oxalate groups died after seizure. Lethal doses of carambola juice were rendered harmless by the oxalate removal procedure.

CONCLUSIONS

Oxalate is a main constituent of carambola neurotoxicity. This finding suggests that patients with carambola intoxication should be treated for oxalate toxicosis.

Evaluation of the cytotoxicity, mutagenicity and antimutagenicity of emerging edible plants

This study evaluates the toxic, mutagenic and antimutagenic effects of emerging edible plants that are consumed as new leafy vegetables in Taiwan. Among eight plant extracts, only the extracts of Sol (Solanum nigrum L.) showed cytotoxicity to Salmonella typhimurium TA100 in the absence of S9 mix. The toxicity of extracts from different parts of the Sol plant, such as leaf and stem, immature fruit and mature fruit, towards S. typhimurium TA100 and human lymphocytes was also assayed. The immature fruit extracts of Sol exhibited strong cytotoxicity with dose dependence and induced significant DNA damage in human lymphocytes based on the comet assay. However, no mutagenicity was found in eight plant extracts to TA98 or TA100 either with or without the S9 mixture. Sol and Sec [Sechium edule (Jacq.) Swartz] extracts showed the strongest inhibitory effect towards the mutagenicity of 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ) in S. typhimurium TA98 and TA100; the ID(50) was less then 1 mg/plate. Cra [Crassocephalum creidioides (Benth.) S. Moore] extracts also expressed moderate antimutagenic activities towards IQ and benzo[a]pyrene (B[a]P) either in TA98 or in TA100; the ID(50) was 1.63-2.41 mg/plate. The extracts from Bas (Basella alba L.), Bou (Boussingaultia gracilis Miers var. pseudobaselloides Bailey), Cen (Centella asiatica L. Urban), Cor (Corchorus olitorius L.) and Por (Portulaca oleracea L.) showed weak to moderate inhibition of mutagenicity of IQ. However, the potential antimutagenicity of these plant extracts towards B[a]P was weaker than that towards IQ. For a direct mutagen, 4-nitroquinoline-N-oxide (NQNO), only the Sol extracts showed strong inhibitory effects in the TA100 system. The antimutagenic activity of water extracts of Sec was partly reduced by heating at 100 degrees C for 20 min. The heat-stable antimutagens in Sec extracts could be produced in the plant extract preparation process. Fractions with molecular weights above 30,000 showed the strongest antimutagenicity and peroxidase activity in all the fractions of the Sec extracts.

Should home ipecac-induced emesis be routinely recommended in the management of toxic berry ingestions?

Poison center (PC) management of toxic berry ingestions may include recommendations to administer syrup of ipecac (SI) regardless of the number of berries ingested. We investigated whether the routine use of SI in the home management of asymptomatic single or few (< 6) berry ingestions may be unnecessary. A prospective, randomized clinical trial compared SI + home observation (HO) to HO alone for management of pediatric toxic berry ingestions. Subjects were children 9 mo to 5 y who ingested a small number (< 6) of Taxus sp (yew), Solanum americanus (nightshade), Ilex sp (holly) or unknown potentially toxic berries. Exclusions were symptomatic subjects, ingestion of more than 1 type of berry or other plant part, or contraindication to SI. Outcome variables consisting of symptom assessment and disposition were assessed 24 h following the ingestion. Over a 27-mo period 103 subjects were entered into the study; 45 received SI/HO and 51 received only HO. While 100% of the SI/HO group experienced vomiting, none of the HO group vomited. Diarrhea and sedation were more common in the SI/HO group. Use of SI in the home management of young children who ingest fewer than 6 toxic berries (yew, nightshade, holly or unknown) and who are asymptomatic when the PC is contacted may be responsible for the majority of symptoms. Ingestion of small amounts of berries may require no intervention beyond observation. Methodological limitations of this study included the lack of confirmed identification of the berries and the inability to confirm ingestion and absorption.

Safety evaluation of wild apricot oil

Wild apricot, a variety of Prunus armeniaca, grows in the hilly regions of India. The seeds yield 27% of kernels. The potential availability of the kernels is 40,000 tons/year and these yield 47% of oil. The oil has 94% unsaturated fatty acids, rich in oleic and linoleic acids. Systemic effects and nutritional quality of wild apricot oil (WAO) were assessed in a 13-wk feeding study in weanling albino rats using a diet containing 10% WAO as the sole source of dietary fat. A similar diet containing groundnut oil (GNO) was used as the control. WAO did not manifest any toxic potential. The food consumption, growth rate and food efficiency ratio of rats fed WAO were similar to those fed GNO. The digestibility of this oil was found to be comparable to that of GNO. There were no macroscopic or microscopic lesions in any of the organs that could be ascribed to WAO incorporation in the diet. The results of this study indicate that WAO could be used for edible purposes without any overt toxic signs or symptoms. However a long-term study may be needed to confirm its innocuousness further.

Mutagenicity of white grape juice in the Ames test

The mutagenicity of commercially available white grape juice was evaluated in the Ames mutagenicity test. Grape juice elicited a positive mutagenic, response in Salmonella typhimurium strain TA104 and a weaker response in strains TA97, TA98, TA100 and TA1530. The mutagenic response was evident in the absence of an activation system and inclusion of such a system did not influence mutagenicity. The grape juice-mediated mutagenic response was not due to histidine residues in the juice or likely treatment with sulfite. Moreover, freshly prepared grape juice displayed a similar mutagenic response. Three different brands of commercially available white grape juice were investigated in the Ames test; they all provoked a clear positive mutagenic response, but the degree of mutagenicity differed and could not be attributed to differences in the content of solids. It is concluded that grapes contain direct-acting genotoxic component(s).

Effect of Momordica charantia on key hepatic enzymes

The effect of Momordica charantia on certain key hepatic enzymes was investigated using male Sprague-Dawley rats as the animal model. Fruit juice and seed extract of Momordica charantia were administered orally at a daily dose of 1 ml/100 g body weight for 30 days under light ether anaesthesia while the control group received equivalent amounts of distilled water under identical conditions (n = 10 in each case). Serum gamma-glutamyl transferase (P < 0.001) and alkaline phosphatase (P < 0.01-0.001) concentrations were found to be significantly elevated following oral administration of both the fruit juice and the seed extract. Consistent significant histopathological changes in the liver were not observed in either treatment group although the prevalence of dilatation and/or congestion of the central vein sinusoidal system appeared to be twice as high following fruit juice treatment than in the other 2 groups. Thus, Momordica charantia may either contain hepatotoxins capable of causing cellular damage at the molecular level without causing significant histopathological changes or the plant may have an enzyme inducing effect.

Genetics of a nonoptimal behavior: oviposition preference of Drosophila mauritiana for a toxic resource

Among three sibling species of the D. melanogaster subgroup, two are generalists (D. simulans and D. mauritiana), while the third, D. sechellia, specializes on a single toxic resource, the fruit of Morinda citrifolia. D. sechellia, resistant to the toxics, prefers to oviposit on morinda; D. simulans, which is very sensitive, is strongly repelled. D. mauritiana exhibits an aberrant behavior since it prefers to lay its eggs on morinda, where its embryos are killed. Oviposition behavior, studied in parental species, F1 hybrids, and backcrosses, was mostly an additive genetical trait. Further investigations were made with D. mauritiana and D. simulans carrying recessive markers. The X and second chromosomes had no effect, while a clear effect was found for chromosome 3. Since the toxicity of morinda is due to middle-length fatty acids, the behavior of the three species toward various acids was investigated. We found that D. sechellia exhibited a general oviposition preference for acids, while D. simulans was repelled by acids with at least four carbons. Surprisingly D. mauritiana exhibited behavior quite similar to that of D. simulans. Preference for morinda in D. sechellia and D. mauritiana could be mediated by different chemicals.

Blood cholinesterase in rats fed an insect resistance apple clone containing a natural cholinesterase inhibitor

A crab apple clone (Malus brevipes 1021), highly resistant to the apple maggot, is being used in breeding programs developing commercial apple cultivars. This study has discovered that this crab apple contains a natural cholinesterase (ChE) inhibitor that caused a 17.5% in vitro inhibition of rat blood ChE activity. This crab apple also showed a relatively high total (titratable) acidity of 1.28%. The commercial, nonresistant, apple cultivar McIntosh was capable of causing a 7.9% inhibition of blood ChE in vitro. The total acidity in McIntosh was 0.45%. A 4-wk feeding study compared 2 groups of 5-wk-old Fischer 344 male rats fed diets containing 45% of either M. brevipes or McIntosh freeze-dried apples to a third (control) group of rats fed a semipurified diet. In vivo blood ChE activities were similar in all groups of rats, as well as hemoglobin, hematocrit, and red blood cell counts. The liver mixed-function oxidase activity through aminopyrine N-demethylase in the rats fed the apple diets was higher than the controls, but p-nitroanisole O-demethylase activity was induced only in the animals fed the maggot-resistant crab apple. Lowered growth with concomitant lowered food intake, in the otherwise healthy rats fed the maggot-resistant crab apple diet, was attributed to the less palatable, highly acidic fruit. This study indicates that the natural ChE inhibitor in the insect-resistant apple M. brevipes is apparently detoxified upon ingestion.

Experimental Azadirachta indica toxicosis in chicks

Brown Hisex chicks were fed Azadirachta indica ripe fruit at 2, 5 or 10% of basic diet from their 7th to 35th d of age. Decreased body weight gain and efficiency of feed utilization and hepatonephropathy were most severe in chicks fed the 10% A indica diet. These changes were accompanied by anemia and increases in LDH, GOT and ALP activities and uric acid concentration and by decreased serum total protein. Hepatocytes and renal tubular cells did not completely revert to normal 2 w after removal from the test diets.

Clinical and pathological effects on the rabbit's eye of some plant-derived ophthalmic swabs

The stems of corn, millet, sugar cane and the banana leaf frond excite some clinical and pathological effects in the rabbit's eye when implanted either into the anterior chamber (AC) or subconjunctivally. These effects have not been sight threatening. The materials can either be left to be cleared by the body's phagocytes when they produce mild inflammatory reaction or removed surgically if the inflammatory response is moderate when fragments have been left intraocularly.

A toxicological investigation of the garden shrub Brunfelsia calcyina var. floribunda (yesterday-today-and-tomorrow) in three species

Brunfelsia calcyina var. floribunda is an ornamental evergreen shrub found in the United States. A diagnosis of the fatal intoxication of a canine due to consumption of plant material (primarily berries) was made. The significant features of the clinical constellation were similar to those seen with substances interfering with the neurotransmission process, such as lathyrus or strychnine. Necropsy findings on the canine were unrevealing. Toxicologic studies performed on mice and rats with ground shrub material demonstrated that all parts of this plant are toxic, but unequally so. All plant preparations produced signs similar to those of a spinal convulsant. There were no distinguishing gross pathologic or histopathologic findings associated with the toxicoses induced in the laboratory animals with preparations from this plant. The toxic principles from this shrub are water soluble and very stable. The ability of aqueous extracts stored at 4 C to produce the clinical syndrome and subsequent lethality remained unchanged over a period of 4 months. Exposures are not always fatal. They most often occur in the canine and there is a significant hazard for small children.

Effects of toxin T-544 from the Karwinskia humboldtiana (buckthorn) plant upon mouse embryos explanted at 11 days

Eleven-day mouse embryos were exposed to the K. humboldtiana toxin T-544 for 24 hr. At the end of the culture period, embryos were examined grossly for malformations and biochemically for altered protein levels. There was a significant difference in malformations in those embryos exposed to 0.05 and 0.2 microgram/ml of toxin compared with controls. Embryo protein content was significantly lower in those embryos exposed to 0.1 microgram/ml of T-544 compared with control group.

Subchronic feeding study of grape colour extract in beagle dogs

The effect of feeding Welch's Special Grape Color Powder Type BW-AT at dose levels of 7.5 and 15% w/w in the diet for 90 days was studied in beagle dogs. Body-weight gain of male and female dogs at the high dose level was significantly decreased compared with control dogs. No other treatment-related effects were seen in food consumption, haematology, clinical chemistry, ophthalmology or gross and histopathological findings.