Sinusoidal obstruction syndrome secondary the intake of Senecio brasiliensis: A case report

Metabolic Toxification of 1,2-Unsaturated Pyrrolizidine Alkaloids Causes Human Hepatic Sinusoidal Obstruction Syndrome: The Update

Saturated and unsaturated pyrrolizidine alkaloids (PAs) are present in more than 6000 plant species growing in countries all over the world. They have a typical heterocyclic structure in common, but differ in their potential toxicity, depending on the presence or absence of a double bond between C1 and C2. Fortunately, most plants contain saturated PAs without this double bond and are therefore not toxic for consumption by humans or animals. In a minority of plants, however, PAs with this double bond between C1 and C2 exhibit strong hepatotoxic, genotoxic, cytotoxic, neurotoxic, and tumorigenic potentials. If consumed in error and in large emouns, plants with 1,2-unsaturated PAs induce metabolic breaking-off of the double bonds of the unsaturated PAs, generating PA radicals that may trigger severe liver injury through a process involving microsomal P450 (CYP), with preference of its isoforms CYP 2A6, CYP 3A4, and CYP 3A5. This toxifying CYP-dependent conversion occurs primarily in the endoplasmic reticulum of the hepatocytes equivalent to the microsomal fraction. Toxified PAs injure the protein membranes of hepatocytes, and after passing their plasma membranes, more so the liver sinusoidal endothelial cells (LSECs), leading to life-threatening hepatic sinusoidal obstruction syndrome (HSOS). This injury is easily diagnosed by blood pyrrolizidine protein adducts, which are perfect diagnostic biomarkers, supporting causality evaluation using the updated RUCAM (Roussel Uclaf Causality Assessment Method). HSOS is clinically characterized by weight gain due to fluid accumulation (ascites, pleural effusion, and edema), and may lead to acute liver failure, liver transplantation, or death. In conclusion, plant-derived PAs with a double bond between C1 and C2 are potentially hepatotoxic after metabolic removal of the double bond, and may cause PA-HSOS with a potential lethal outcome, even if PA consumption is stopped.

Herb-induced liver injury (HILI) with 12,068 worldwide cases published with causality assessments by Roussel Uclaf Causality Assessment Method (RUCAM): an overview

Herbal products including herbal medicines are worldwide used in large amounts for treating minor ailments and for disease prevention. However, efficacy of most herbal products has rarely been well documented through randomized controlled trials in line with evidence-based medicine concepts, which could be used to estimate the benefit/risk ratio. Instead, much better documented are adverse reactions such as liver injury associated with the consumption of some herbal products, so called herb-induced liver injury (HILI), which represents a clinical challenge. In order to establish HILI as valid diagnosis, the use of a diagnostic algorithms such as Roussel Uclaf Causality Assessment Method (RUCAM) is widely recommended, although physicians in some countries are reluctant to use RUCAM for their HILI cases. This review on worldwide HILI and RUCAM, developed as part of the artificial intelligence ideas, reveals that China is the leading country with 24 publications on HILI cases that were all assessed for causality using RUCAM, followed by Korea with 15 reports, Germany with 9 reports, the US with 7 reports, and Spain with 6 reports, whereas the remaining countries provided less than 4 reports. The total number of assessed HILI cases is 12,068 worldwide derived from 80 publications but in each report HILI case numbers were variable in a range from 1 up to 6,971. This figure compares with 46,266 cases of drug-induced liver injury (DILI) published worldwide from 2014 to early 2019 also assessed for causality by RUCAM. The original version of RUCAM was validated and established in 1993 and updated in 2016 that should be used in future HILI cases. RUCAM is an objective, structured, and validated method, specifically designed for liver injury. It is a scoring system including case data elements to be assessed and scored individually to provide a final score in five causality gradings. Among the 11,404/12,068 HILI (94.5%) cases assessable for evaluation, causality gradings were highly probable in 4.2%, probable in 15.5%, possible in 70.3%, and unlikely or excluded in 10.0%. To improve the future reporting of RUCAM based HILI cases, recommendations include the strict adherence to instructions outlined in the updated RUCAM and, in particular, to follow prospective data collection on the cases to ensure completeness of case data. In conclusion, RUCAM can well be used to assess causality in suspected HILI cases, and additional efforts are now required to increase the quality of the reported cases.

Quantification of pyrrolizidine alkaloids in Senecio brasiliensis, beehive pollen, and honey by LC-MS/MS

This article presents the determination of eight pyrrolizidine alkaloids (PAs) by LC-MS/MS in honeys, pollen, and Senecio brasiliensis (Asteraceae) samples, all from Santa Catarina state, Brazil. In addition, the Box-Behnken design was used to perform an optimized sample preparation on pollens and S. brasiliensis parts. Senecionine and its N-oxide, besides retrorsine N-oxide, were determined in six of the seven honeys samples. Pollen from species of the Asteraceae, Fabaceae, and Boraginaceae families were found with greater predominance in three of the seven honeys samples. In these three honeys samples were also found the highest PAs levels. In beehive pollen, flower, and leaf of S. brasiliensis, the total levels of PAs and their N-oxides reached 221, 14.1 × 10⁴, and 14.8 × 10⁴ mg kg^-1, respectively. In honeys, these compounds are chemical contaminants and therefore undesirable when the sum exceeds 71 µg kg^-1, according to EFSA. On the other hand, although PAs are naturally present in plant and pollen of some species (Senecio, Crotalaria, Bacharis, Ecchium, Mimosa scabrella, Vernonia), it is important to monitor their levels in plants but also in honeys, and other beehive products since these compounds are transferred to the final product.

Worldwide Use of RUCAM for Causality Assessment in 81,856 Idiosyncratic DILI and 14,029 HILI Cases Published 1993-Mid 2020: A Comprehensive Analysis

Background: A large number of idiosyncratic drug induced liver injury (iDILI) and herb induced liver injury(HILI) cases of variable quality has been published but some are a matter of concern if the cases were not evaluated for causality using a robust causality assessment method (CAM) such as RUCAM (Roussel Uclaf Causality Assessment Method) as diagnostiinjuryc algorithm. The purpose of this analysis was to evaluate the worldwide use of RUCAM in iDILI and HILI cases. Methods: The PubMed database (1993-30 June 2020) was searched for articles by using the following key terms: Roussel Uclaf Causality Assessment Method; RUCAM; Idiosyncratic drug induced liver injury; iDILI; Herb induced liver injury; HILI. Results: Considering reports published worldwide since 1993, our analysis showed the use of RUCAM for causality assessment in 95,885 cases of liver injury including 81,856 cases of idiosyncratic DILI and 14,029 cases of HILI. Among the top countries providing RUCAM based DILI cases were, in decreasing order, China, the US, Germany, Korea, and Italy, with China, Korea, Germany, India, and the US as the top countries for HILI. Conclusion: Since 1993 RUCAM is certainly the most widely used method to assess causality in IDILI and HILI. This should encourage practitioner, experts, and regulatory agencies to use it in order to reinforce their diagnosis and to take sound decisions.