5-Fluorouracil rechallenge after 5-fluorouracil-induced hyperammonemic encephalopathy

Synthesis, in silico studies, and in vitro biological evaluation of newly-designed 5-amino-1H-tetrazole-linked 5-fluorouracil analog as a potential antigastric-cancer agent

5-Fluorouracil (5FU) is a chemotherapy drug used to treat various cancers, such as colorectal, prostate, skin, pancreas, and stomach, as an ointment or solution. However, its consumption has several side effects. Therefore, a new derivative of fluorouracil containing 5-Amino-1H-tetrazole was designed and synthesized through multi-step synthesis to reduce urea excretion and toxicity. The effectiveness of the synthesized drug on the Adenocarcinoma gastric cell line (AGS) gastric cancer cell line was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, which showed that the new 5-fluorouracil (5FU) analog, with an IC50 of 15.67 µg/mL, is more effective in inhibiting the proliferation of AGS cells after 24 h compared to both synthesized and reported 5FU. In addition, In-silico studies showed that the new 5FU derivative based on amino tetrazole, with a binding energy of -7.2 kcal/mol, exhibits greater anti-cancer activity against the BCL2 enzyme than 5FU, with a binding energy of - 4.8 kcal/mol. It is predicted that the new 5FU derivative will be effective in treating gastric and colorectal cancers. The new derivative of the 5-fluorouracil drug was characterized and identified using FTIR and NMR spectroscopy.Communicated by Ramaswamy H. Sarma.

5-Fluorouracil-induced leukoencephalopathy

ABSTRACT

The incidence of 5-Fluorouracil (5FU)- induced leukoencephalopathy is <5% among the patients treated with this agent. It may present with disorientation, confusion, agitation, seizure, and coma. It should be suspected when patients present with any of these symptoms during or immediately after 5FU chemotherapy. Early detection of drug-induced leukoencephalopathy is important as the clinical symptoms can be reversed by early discontinuation of the drug. Therefore, clinicians should be aware of the possibility of this adverse neurologic effect of 5FU. We describe the case of a 35-year-old female with carcinoma esophagus with 5FU-induced leukoencephalopathy.

Short-Chain Fatty Acids Attenuate 5-Fluorouracil-Induced THP-1 Cell Inflammation through Inhibiting NF-κB/NLRP3 Signaling via Glycerolphospholipid and Sphingolipid Metabolism

5-Fluorouracil (5-FU) is a common anti-tumor drug, but there is no effective treatment for its side effect, intestinal mucositis. The inflammatory reaction of macrophages in intestinal mucosa induced by 5-FU is an important cause of intestinal mucositis. In this study, we investigated the anti-inflammatory effects of the three important short-chain fatty acids (SCFAs), including sodium acetate (NaAc), sodium propionate (NaPc), and sodium butyrate (NaB), on human mononuclear macrophage-derived THP-1 cells induced by 5-FU. The expressions of intracellular ROS, pro-inflammatory/anti-inflammatory cytokines, as well as the nuclear factor-κB/NLR family and pyrin domain-containing protein 3 (NF-κB/NLRP3) signaling pathway proteins were determined. Furthermore, the cell metabolites were analyzed by untargeted metabolomics techniques. Our results revealed that the three SCFAs inhibited pro-inflammatory factor expressions, including IL-1β and IL-6, when treated with 5-FU (p < 0.05). The ROS expression and NF-κB activity of 5-FU-treated THP-1 cells were inhibited by the three SCFAs pre-incubated (p < 0.05). Moreover, NLRP3 knockdown abolished 5-FU-induced IL-1β expression (p < 0.05). Further experiments showed that the three SCFAs affected 20 kinds of metabolites that belong to amino acid and phosphatidylcholine metabolism in THP-1 cells. These significantly altered metabolites were involved in amino acid metabolism and glycerolphospholipid and sphingolipid metabolism. It is the first time that three important SCFAs (NaAc, NaPc, and NaB) were identified as inhibiting 5-FU-induced macrophage inflammation through inhibiting ROS/NF-κB/NLRP3 signaling pathways and regulating glycerolphospholipid and sphingolipid metabolism.

Transient Coma and Signs of Encephalopathy Related to 5-Fluorouracil and Carboplatin: A Case Report

Chemotherapy-related encephalopathy is a rare but severe side effect of cancer therapy. Few reports exist on the course of encephalopathy due to 5-fluorouracil (5FU)/carboplatin treatment. Here, we report on a patient in his 70s, who received first-line palliative treatment with carboplatin followed by continuous infusion of 5FU against a metastasized cancer of the base of the tongue. During the first 5FU infusion, the patient developed a coma with sudden onset. In contrast to earlier reports of 5FU-induced encephalopathy, serum ammonium levels were near-normal, despite a slightly increased bilirubin. The electroencephalogram showed signs of general encephalopathy, for which no other probable cause than chemotherapy could be identified. Based on historical reports, the patient's encephalopathy was likely due to 5FU treatment rather than carboplatin. While initially in a coma with a Glasgow Coma Scale score of three, the patient regained consciousness within 3 days of supportive therapy. This case highlights the potentially benign clinical course of 5FU-induced encephalopathy, characterized by fulminant clinical deterioration and quick recovery. Such a rapid deterioration in a palliative setting can pose a clinical dilemma, where invasive treatments such as intubation must be weighed against a limited prognosis, for which this case may provide guidance.

Investigating drug delivery of 5-fluorouracil by assistance of an iron-modified graphene scaffold: Computational studies

This computational work was performed to investigate drug delivery of 5-fluorouracil (FU) anti-cancer by assistance of an iron(Fe)-modified graphene (G) scaffold. The models were optimized to reach the minimized energy structures in both of singular and bimolecular models. Two models of FU@G complex were obtained including O2@G and O4@G by relaxation of FU through O2 and O4 atoms towards the Fe-atom region of G surface. The obtained results of energies indicated a higher stability and strength for the O2@G model in comparison with the O4@G model. The quantitative and qualitative features of electronic molecular orbitals indicated the investigated G surface could work as a carrier of FU by reducing the unwanted side effects and also playing the sensor role. As a final remark of this work, the investigated G model could be proposed for employing in the targeted drug delivery of FU in both of carrier and sensor agents.

Cytoprotective effects of spleen-invigorating pill against 5-fluorouracil injury to mouse bone marrow stromal cells

ETHNOPHARMACOLOGICAL RELEVANCE

Spleen-invigorating pills (SIP) are composed of Codonopsis, fried Atractylodes, tangerine peel, Fructus aurantii immaturus (fried), fried hawthorn, and colored malt. SIP strengthens the spleen and increases appetite and is often used as a chemotherapy adjuvant.

AIM OF THE STUDY

We aimed to explore the protective effects and mechanism of action for SIP on mouse bone marrow stromal cells (OP9) injured by 5-fluorouracil (5-FU).

MATERIALS AND METHODS

The effects of SIP on OP9 cells injured by 5-FU were evaluated, and high-performance liquid chromatography (HPLC) was used as a quality control method. The experiments were divided into a control group, a model group, an epidermal growth factor (EGF) treatment group, and an SIP treatment group. The cell survival rate, apoptotic cell morphology, cell apoptosis rate, and the contents of caspase 3 were evaluated to determine the protective effects of SIP in OP9 cells injured by 5-FU. Network pharmacology was used to predict the mechanism through which SIP mediates anti-chemotherapy damage. The nitric oxide (NO) and nitric oxide synthase (iNOS) levels and the expression of nuclear factor erythroid-2 related factor 2 (Nrf2) and p62 protein were detected to explore the mechanism through which SIP mediates anti-chemotherapy damage through the regulation of oxidative stress.

RESULTS

Cell counting kit-8 (CCK8) detection showed that 5-FU reduced OP9 cell survival, and SIP blocked the inhibition of OP9 cell growth induced by 5-FU. When OP9 cells were treated with both SIP (10 g L^-1) and 5-FU (2.5 × 10^-2 g L^-1) for 24 h, compared with the model group, the early apoptosis rates significantly decreased, and the activity of caspase 3 was significantly reduced. The results of network pharmacology and Western blot showed that compared with the model group, in the SIP group, the NO levels decreased, iNOS release decreased, and the expression of Nrf2 and p62 proteins increased.

CONCLUSION

The protective effects of SIP on OP9 cells injured by 5-FU were significant. SIP may play a cytoprotective role by mediating changes in oxidative stress-related proteins. The specific mechanism of action through which SIP mediates these effects remains to be further studied.

Hyperammonemic encephalopathy during XELOX regimen. Is it capecitabine or oxaliplatin responsible?

Hyperammonemic encephalopathy represents a rare adverse effect of several chemotherapeutic agents, occurring in about 0.7% of patients treated with fluoropyrimidines, and it is independent from dihydropyrimidine dehydrogenase deficiency. Instead, its physiopathology is linked to the inhibition of Krebs cycle by fluoroacetate, leading to decreased ATP production, and to the inhibition of the urea cycle. Oxaliplatin seems to induce hyperammonemic encephalopathy in a similar way, acting on mitochondria. Here, we report the intriguing case of acute hyperammonemic encephalopathy in a 65-year-old patient with preserved liver function, who was treated with oxaliplatin and capecitabine for a metastatic, G1, atypical lung carcinoid. We reviewed the literature and found very few reports of oxaliplatin or capecitabine-induced hyperammonemic encephalopathy. Out of five cases of capecitabine-related hyperammonemic encephalopathy analyzed (four plus our case), median time to hyperammonemic encephalopathy onset was 6 days, with median serum ammonia levels of 213 μmol/L. Oxaliplatin-related hyperammonemic encephalopathy analyzed cases were three (two plus ours), with a median time to hyperammonemic encephalopathy of 11 days and median serum ammonia levels of 167 μmol/L. Identified predisposing factors for chemotherapy-induced hyperammonemia, such as dehydration, liver and renal impairment, infections, and sarcopenia were absent in our case. We hypothesize that the combination of a platinum-derivative and a fluoropyrimidine multiplies the risk of hyperammonemic encephalopathy, even in the absence of predisposing factors nor impaired liver function. We therefore suggest to always consider the risk of hyperammonemia when starting fluoropyrimidines-based chemotherapy, especially combined with platinum-derivatives, and to timely investigate neurologic symptoms monitoring ammonia serum levels.

5-Fluorouracil-induced hyperammonaemic encephalopathy: A French national survey

BACKGROUND

5-Fluorouracil (5-FU)-induced hyperammonaemic encephalopathy is a rare but serious 5-FU adverse drug reaction (ADR). Given the growing number of cancers treated with 5-FU and the paucity of data regarding this ADR, we performed a retrospective national survey to better characterise 5-FU-induced hyperammonaemic encephalopathy.

PATIENTS AND METHODS

Since inception of the French pharmacovigilance database, we identified all patients who experienced 5-FU-induced hyperammonaemic encephalopathy. Variables regarding demographics, characteristics, management and outcome of patients were collected.

RESULTS

From 1986 to 2018, 30 patients were included. 5-FU-induced hyperammonaemic encephalopathy started 2 [1-4] days after 5-FU infusion onset. Most common neurological disorders were consciousness impairment, seizures and confusion. hyperammonaemia tended to be higher in patients with the lowest Glasgow score and admitted in intensive care unit (ICU) compared to non-ICU patients (250 [133-522] versus 139 [68-220] μmol/L respectively, p = NS). Dihydropyrimidine dehydrogenase deficiency was found in 27% of tested patients (n = 3/11). Encephalopathy-induced mortality was 17%, 57% of patients were admitted in ICU and 70% had a complete neurological recovery within 5 [2-10] days. A 5-FU rechallenge was considered in 14 (67%) patients with neurological recovery and a relapse was observed in 57% of them. No 5-FU-induced hyperammonaemic encephalopathy relapse was observed as long as 5-FU rechallenge was performed with decreased 5-FU dosage.

CONCLUSION

We report the largest cohort of 5-FU-induced hyperammonaemic encephalopathy cases so far. This ADR should be suspected and ammonaemia measured in all patients experiencing neurological disorders after 5-FU administration. In patients with complete neurological recovery, a 5-FU rechallenge could be cautiously considered.

A 5-Fluorouracil-Induced Hyperammonemic Encephalopathy Challenged with Capecitabine

Cancer patients presenting with altered mental status demand a broad differential with early recognition of the etiology. Failure to do so is associated with increased morbidity and mortality. Causes that must be considered include organ involvement of the cancer, electrolytes abnormalities, and even chemotherapeutic agents. A 32-year-old female patient had been recently started on FOLFOX for metastatic colon cancer. Her initial treatments were uneventful, but she later developed encephalopathy during day three of cycle five. During her evaluation, she was found to have hyperammonemia (84 mcmol/L), without hepatic failure, that resolved with stopping chemotherapy and supportive care. After a trial of home infusion fluorouracil, she developed hyperammonemic encephalopathy again. During both admissions, her symptoms resolved with IV hydration and cessation of chemotherapy. She was then successfully challenged with capecitabine (1000 mg/m² daily), and additional hydration, and continued chemotherapy without recurrence of symptoms. Hyperammonemia is associated with fluorouracil though the mechanism is unclear. Suspected etiologies include either elevated levels of the drug due to slower metabolism or accumulation of certain metabolites. Additionally, risk factors such urease-producing bacterial infections, dehydration, and increased catabolism are thought to increase the risk for hyperammonemia. This case demonstrates the need for greater awareness of fluorouracil as a cause of hyperammonemic encephalopathy. Knowledge of this may allow for earlier recognition and reduced unnecessary testing.