Effects of L-Arginine Supplementation on Leukogram, Inflammatory Bowel Infiltrates and Immunoglobulins with 5-FU Use in Rats.

This study evaluated the effects of L-arginine supplementation on blood parameters, kidney and liver function, immunoglobulins and noninflammatory infiltrates in the small intestines of rats subjected to chemotherapy with 5-fluorouracil (5-FU). Thirty-two Wistar rats were randomly distributed into 4 groups (8 rats/group): an untreated control group, and test groups receiving one dose of 5-FU (G5-FU group), one dose of 5-FU and 295 mg L-arginine/day (GArg295 group) or one dose of 5-FU and 458 mg L-arginine/day (GArg458 group). Neutrophil count, platelet count, serum IgA, and fibrinogen levels in GArg295 and GArg458 remained within normal limits after chemotherapy. In addition, in GArg458 the inflammatory bowel infiltrates improved in 57% of the rats, which showed mild inflammation. The results suggest that daily supplementation with 295 or 458 mg L-arginine attenuates the side effects of 5-FU, including thrombocytopenia and neutropenia, and modulates IgA production. Supplementation with 458 mg of L-arginine/day can also reduce mucositis levels in the small intestine after 5-FU chemotherapy.

SARS-CoV-2 infection, gut dysbiosis, and heterogeneous clinical results of hydroxychloroquine on COVID-19 therapy-Is there a link?

Clinical manifestations of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can include gastrointestinal signals and symptoms. Individuals with previous clinical conditions that usually enroll gut dysbiosis have been identified as being at high risk to develop more severe infectious phenotypes. Actually, intestinal dysbiosis has been observed in infected patients and potentially linked to systemic hyperinflammation. These observations suggest that a previous gut dysbiosis may be aggravated by SARS-CoV-2 infection and related to progression of the coronavirus disease 2019 (COVID-19) into more severe stages. While COVID-19's pathophysiology is not fully understood, it seems relevant to consider the interactions of candidate therapeutic drugs with the host, gut microbiota, and SARS-CoV-2. Here we summarize scientific evidence supporting the potential relevance of these interactions and suggest that unfavorable clinical data on hydroxychloroquine administration in COVID-19 may have been influenced by the dose provided and its impact on gut dysbiosis. The proposition is based on preliminary data on gut microbiota composition from individuals with inactive systemic lupus erythematosus under exclusive continuous hydroxychloroquine treatment, displaying a direct correlation between drug doses and markers typically associated with gut dysbiosis.