Mad honey of Nepalese origin-related grayanatoxin intoxication

The relationship between oxidative stress and apoptosis of histopathological changes in the ovary made by mad honey containing grayanotoxin

The purpose of this study is to determine the effects of grayanotoxin in mad honey on ovarian tissue folliculogenesis in terms of cell death and nitric oxide expression. Three groups of 18 female Sprague-Dawley rats were formed. The first group received mad honey (80 mg/kg), the second group received normal honey (80 mg/kg), and the third group was the control. The first and second groups received normal and mad honey by oral gavage for 30 days before being sacrificed under anesthesia. Caspase 3 immunostaining showed a moderate to strong response, particularly in the mad honey group. In the mad honey group, immunostaining for caspase 8 and caspase 9 revealed a moderate immunoreaction in the granulosa cells of the Graaf follicles. The majority of Graaf follicles exhibited TUNEL positive in the mad honey group. The iNOS immunoreaction revealed a high level of expression in the mad honey group. In all three groups, eNOS immunostaining showed weak reactivity. According to the findings of apoptotic and nitric oxide marker expression, it was determined that mad honey may result in an increase in follicular atresia in ovarian follicles when compared to normal honey and control groups.

Worldwide distribution and clinical characteristics of mad honey poisoning cases

OBJECTIVES

Mad honey poisoning is a common public health problem that can be seen in many parts of the world. In this study, the symptoms and clinical findings of mad honey poisoning cases and their distribution worldwide were investigated based on current data.

METHODS

PubMed, Scopus, Web of Science and Google Scholar databases were searched. The demographic characteristics of the cases, clinical findings, amount of consumed honey, duration of hospitalization, and data of the region where mad honey was produced were recorded.

RESULTS

900 cases were identified. The majority of poisoning cases (91.44%) were reported from mad honey produced in Turkey, Nepal (4.67%) came second and Korea (1.56) third. The majority of cases in Turkey were due to honey produced in the Black Sea Region. It was also determined that the mad honey was produced in the west Black Sea Region in most of the cases (35.22%), followed by the east Black Sea Region with a rate of 33.22%. In poisonous cases, it was determined that the mad honey was mostly produced in Rize, followed by Trabzon and Kastamonu, respectively. The most common signs of mad honey poisoning were bradycardia (88.48%) and hypotension (76.04%).

CONCLUSION

The majority of cases have been reported from Turkey. When examining where the mad honey was produced in Turkey, it was seen that the western Black Sea Region came first, and the eastern Black Sea Region came second. Rize came first among the provinces, followed by Trabzon and Kastamonu. There is a parallelism between the distribution of mad honey poisoning cases and the distribution areas of Rhododendron species. However, although Rhododendron species show a widespread distribution throughout the world, why the majority of the cases were reported from Turkey draws attention as an issue that needs to be investigated.

Risks for human health related to the presence of grayanotoxins in certain honey

The European Commission asked EFSA for a scientific opinion on the risks for human health of the presence of grayanotoxins (GTXs) in 'certain honey' from Ericaceae plants. The risk assessment included all structurally related grayananes occurring with GTXs in 'certain' honey. Oral exposure is associated with acute intoxication in humans. Acute symptoms affect the muscles, nervous and cardiovascular systems. These may lead to complete atrioventricular block, convulsions, mental confusion, agitation, syncope and respiratory depression. For acute effects, the CONTAM Panel derived a reference point (RP) of 15.3 μg/kg body weight for the sum of GTX I and III based on a BMDL10 for reduced heart rate in rats. A similar relative potency was considered for GTX I. Without chronic toxicity studies, an RP for long-term effects could not be derived. There is evidence for genotoxicity in mice exposed to GTX III or honey containing GTX I and III, showing increased levels of chromosomal damage. The mechanism of genotoxicity is unknown. Without representative occurrence data for the sum of GTX I and III and consumption data from Ericaceae honey, acute dietary exposure was estimated based on selected concentrations for GTX I and III reflecting concentrations measured in 'certain' honeys. Applying a margin of exposure (MOE) approach, the estimated MOEs raised health concerns for acute toxicity. The Panel calculated the highest concentrations for GTX I and III below which no acute effects would be expected following 'certain honey' consumption. The Panel is 75% or more certain that the calculated highest concentration of 0.05 mg for the sum of GTX I and III per kg honey is protective for all age groups regarding acute intoxications. This value does not consider other grayananes in 'certain honey' and does not cover the identified genotoxicity.

Wild honey poisoning: A case report from western Nepal

Wild honey has been used for several purposes in South-Asia and Eastern Europe since long ago. One of the commonest is medicinal purposes, especially for gastrointestinal disorders (peptic ulcer disease, dyspepsia, and gastritis), hypertension, and an aphrodisiac (sexual stimulant). However, honey produced from the nectar of few rhododendron species contains a toxin known as grayanotoxin, which acts on the sodium channel and prevents its inactivation leading to vagal activation, causing hypotension and bradycardia. Here, we report a case of 55 years woman who reported to our Emergency Department with complaints of dizziness and vomiting as well as bradycardia and hypotension. Most of the cases of wild honey poisoning resolve within the first 24 h, but in our case, the symptoms persisted for 72 h. So, we must observe patients for 72 h as some cases may last longer. Timely management of the patient can prevent fatal complications.

Natural plant toxins in honey: An ignored threat to human health

Consumers often believe that "natural food" is harmless, however naturally occurring toxins in food represent a health risk to humans. Honey as a natural, nutritious sweetener, is one of the most commonly consumed foods throughout the world. However, food safety concerns for honey arise when honeybees collect nectar from poisonous plants such as Rhododendron sp., Coriaria arborea, and Tripterygium wilfordii Hook F. Such honey contains natural plant toxins. Humans may develop intoxication symptoms after consuming toxic honey; in some cases, it can be fatal. As a result, toxic honey poses an often-ignored threat to public health. Typical plant toxins such as grayanotoxins, triptolides, tutin and pyrrolizidine alkaloids, have been identified in toxic honey. Although different toxic honeys elicit similar symptoms, such as vomiting, nausea, and dizziness, the mechanism of toxicity may be different. Thus, it is necessary to determine the exact toxicity mechanism of different toxins to further develop effective antidotes and cures. Another important challenge is preventing toxic honey from entering the food chain. Liquid chromatography-mass spectrometry has a wide range of applications in the detection of different toxins due to its accuracy and simplicity. More methods, however, are urgently needed to detect multiple plant-derived toxins in honey and its derivatives. Developing uniform international standards for toxin detection during quarantine using advanced techniques is critical for preventing human consumption of toxic honey.