Melatonin ameliorates renal dysfunction in glyphosate- and hard water-treated mice.

Chronic interstitial nephritis in agricultural communities (CINAC) is a severe and widespread disease that has been associated with environmental and occupational exposure to glyphosate and hard water. However, the potential underlying mechanisms remain incompletely understood. Melatonin is reported to exert protective effects on the kidney, but whether melatonin can attenuate renal tubular injury in mice exposed to glyphosate combined with hard water is unclear. Here, mice were treated with high doses and environmentally relevant doses of glyphosate (100 mg/kg·bw and 0.7 mg/L, respectively) and/or hard water (2500 mg/L CaCO3 and 250 mg/L Ca2+, respectively) via their drinking water for 12 weeks. We found that high-dose glyphosate or hard water treatment significantly increased the levels of biomarkers of renal damage, including ß2-microglobulin, neutrophil gelatinase-associated lipid carrier protein, and/or albumin, in the urine; these increased biomarker levels were correlated with obvious morphological changes, and all of these changes were also observed in animals exposed to environmentally relevant doses of glyphosate and/or high Ca2+ water. Melatonin (10 mg/kg·bw, intraperitoneal injection, daily for 12 weeks) administered concomitantly with high doses of glyphosate and hard water inhibited the glyphosate- and hard water-induced increases in the levels of kidney injury biomarkers and changes in morphology; this result was intriguing. Additionally, glyphosate combined with hard water at both high and environmentally relevant doses significantly upregulated the expression of the endoplasmic reticulum (ER) stress marker proteins Bip, ATF6, and PERK as well as the pyroptosis-related proteins (NLRP3 and caspase 1 signaling proteins) in renal tissues. Similarly, melatonin significantly attenuated the increased ER stress and pyroptosis induced by high doses of glyphosate and hard water. In summary, we conclude that exposure to glyphosate and hard water at both high doses and environmentally relevant doses causes renal dysfunction in mice, and this dysfunction can be attenuated by melatonin, possibly through the inhibition of ER stress and pyroptosis. Our results support the notion that melatonin may have therapeutic potential for the treatment of chronic kidney diseases.

Involvement of mitochondrial fission in renal tubular pyroptosis in mice exposed to high and environmental levels of glyphosate combined with hard water.

Chronic interstitial nephritis in agricultural communities (CINAC) has reached epidemic proportions. The combination of glyphosate and hard water has been postulated to play a potent aetiological role in CINAC. Therefore, dynamin-related protein 1 (Drp1)-mediated aberrant mitochondrial fission and subsequent activation of the nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (Nlrp3)/caspase1 pathway may be involved in the pathogenesis of nephropathy. In the present study, mice were sub-chronically exposed to high doses and environmental levels of glyphosate (100 mg/kg body weight (mg/kg·bw) glyphosate in Roundup and 0.7 mg/L pure glyphosate, respectively) and hard water (2500 mg/L CaCO3 and 250 mg/L Ca2+, respectively) in drinking water. Moreover, Mdivi-1 (Md-1, 10 mg/kg·bw) was intraperitoneally injected to inhibit Drp1 on the basis of the high-dose experiment. Histopathological examination, biochemical analysis, ELISA, western blotting and fluorescent staining were used to analyse renal structure, renal tubular pyroptosis and mitochondrial fission/fusion alterations. The results showed dramatic proximal tubular injury, particularly in the combined groups. Moreover, significant increases in the protein expression levels of calmodulin (CaM), calmodulin-dependent protein kinase II (CaMKII), Drp1/p-Drp1-Ser616 and the Txnip/Nlrp3/caspase1 signalling pathway, and alterations in oxidative stress were observed in the combined groups, and these effects were attenuated by the Drp1 inhibitor Md-1. Intriguingly, there may be a synergistic effect of glyphosate and hard water on renal injury. Taken together, these results suggest that the combination of glyphosate and hard water, even at environmental exposure levels, enhances pyroptosis and ongoing tubulointerstitial inflammation through excessive Drp1-mediated mitochondrial fission.

Effects of Commercially Available Mineral Waters on Decoction of Kampo Medicines / 日本東洋医学雑誌

Kampo medicines containing Bupleuri Radix (Sho-saiko-to and Sho-saiko-to plus Fossilia ossis mastodi and Ostreae testa) were decocted with four kinds of mineral waters and tap water, and the extracts were analyzed for saikosaponin contents by HPLC. The results indicated that the yield of the extracted materials was the largest when Kampo medicines were decocted with the hard water compared with other mineral water extracts. However, the same extract contained the smallest amount of saikosaponin b₂ of those tested. Extractions made with the mineral waters having a weakly acidic or weakly alkaline nature gave similar yields of the extracted materials and saikosaponin b₂ contents.<br>Present results suggest a possibility that decoction using a hard water significantly affects extraction of certain ingredients in Kampo medicine.