Bioavailability of aspirin and salicylamide following oral co-administration in human volunteers

Salicylamide Enhances Melanin Synthesis in B16F1 Melanoma Cells

Salicylamide, a non-steroidal anti-inflammatory drug (NSAID), is used as an analgesic and antipyretic agent. We have previously shown that several NSAIDs have anti-melanogenic properties in B16F1 melanoma cells. In contrast, we have found that salicylamide enhances melanin contents in B16F1 melanoma cells; however, the underlying mechanism is not known. Therefore, we investigated the mechanism through which salicylamide stimulates melanogenesis. Interestingly, salicylamide enhanced diphenolase activity in a cell-free assay. Western blotting and real-time RT-PCR revealed that salicylamide increased tyrosinase expression via transcriptional activation of the Mitf gene. Together, our results indicate that salicylamide could be used as an anti-hypopigmentation agent for skin and/or hair.

Absorption of salicylate powders versus tablets following overdose: a poison center observational study

BACKGROUND

Salicylate absorption following overdose of aspirin (ASA) tablet formulations can be prolonged for greater than 24 h. Accordingly, serial serum concentrations are typically recommended to guide treatment. However, there are little published data on absorption following ingestion of powder ASA formulations, and it is not known if delayed ASA absorption occurs following overdose of powder formulations. The objective of this study is to compare the absorption characteristics of powder and tablet formulations of ASA in patients reported to a single poison center.

METHODS

Electronic records from an accredited poison center were searched for single substance acute or acute on chronic ingestions of ASA in powder form between 1 January 2002 and 31 January 2014. An identical search for ingestions of ASA tablet products between 1 January 2012 and 31 December 2013 was undertaken as the comparator group. Other inclusion criteria were age >12 years, documented time of ingestion, treatment in a health care facility within nine hours of ingestion and at least two detectable serum salicylate concentrations.

RESULTS

16 of 25 powder and 22 of 49 tablet cases met inclusion criteria for analysis. Repeat serum salicylate concentrations following ingestion of tablets increased or insignificantly changed in 11 of 22 (50%) cases, and median serum salicylate concentrations in followed cases remained elevated for up to 12 h in some cases. In comparison, serum salicylate concentrations following powder ingestions declined in 15 of 16 (94%) cases. One patient, who ingested a powder product, underwent hemodialysis pursuant to an initial serum salicylate concentration of 96 mg/dL.

CONCLUSIONS

In contrast to persistent concentrations following overdose of tablets, the majority of serum salicylate concentrations declined following ingestion of powder formulations. In this small study population, these findings suggest that prolonged absorption is unlikely following ingestions of ASA powders.

In vitro screening for compounds that enhance human L1 mobilization

The Long interspersed element 1 (LINE1 or L1) retrotransposon constitutes 17% of the human genome. There are currently 80-100 human L1 elements that are thought to be active in any diploid human genome. These elements can mobilize into new locations of the genome, resulting in changes in genomic information. Active L1s are thus considered to be a type of endogenous mutagen, and L1 insertions can cause disease. Certain stresses, such as gamma radiation, oxidative stress, and treatment with some agents, can induce transcription and/or mobilization of retrotransposons. In this study, we used a reporter gene assay in HepG2 cells to screen compounds for the potential to enhance the transcription of human L1. We assessed 95 compounds including genotoxic agents, substances that induce cellular stress, and commercially available drugs. Treatment with 15 compounds increased the L1 promoter activity by >1.5-fold (p<0.05) after 6 or 24 hours of treatment. In particular, genotoxic agents (benzo[a]pyrene, camptothecin, cytochalasin D, merbarone, and vinblastine), PPARα agonists (bezafibrate and fenofibrate), and non-steroidal anti-inflammatory drugs (diflunisal, flufenamic acid, salicylamide, and sulindac) induced L1 promoter activity. To examine their effects on L1 retrotransposition, we developed a high-throughput real-time retrotransposition assay using a novel secreted Gaussia luciferase reporter cassette. Three compounds (etomoxir, WY-14643, and salicylamide) produced a significant enhancement in L1 retrotransposition. This is the first study to report the effects of a wide variety of compounds on L1 transcription and retrotransposition. These results suggest that certain chemical- and drug-induced stresses might have the potential to cause genomic mutations by inducing L1 mobilization. Thus, the risk of induced L1 transcription and retrotransposition should be considered during drug safety evaluation and environmental risk assessments of chemicals.