Protective effect of alpha-linolenic acid on gentamicin-induced ototoxicity in mice

The fatty acid profiles of the mixed fermented milk and its anti-inflammation properties in LPS-induced Raw 264.7 cell model

Increasing knowledge of probiotics has shown that co-cultures of probiotics can achieve better fermentation and beneficial effects, and adding LAB to fermented milk fat products can increase the production of...

The review of alpha-linolenic acid: Sources, metabolism, and pharmacology

α-linolenic acid (ALA, 18:3n-3) is a carboxylic acid composed of 18 carbon atoms and three cis double bonds, and is an essential fatty acid indispensable to the human body. This study aims to systematically review related studies on the dietary sources, metabolism, and pharmacological effects of ALA. Information on ALA was collected from the internet database PubMed, Elsevier, ResearchGate, Web of Science, Wiley Online Library, and Europe PMC using a combination of keywords including "pharmacology," "metabolism," "sources." The following findings are mainly contained. (a) ALA can only be ingested from food and then converted into eicosapentaenoic acid and docosahexaenoic acid in the body. (b) This conversion process is relatively limited and affected by many factors such as dose, gender, and disease. (c) Pharmacological research shows that ALA has the anti-metabolic syndrome, anticancer, antiinflammatory, anti-oxidant, anti-obesity, neuroprotection, and regulation of the intestinal flora properties. (d) There are the most studies that prove ALA has anti-metabolic syndrome effects, including experimental studies and clinical trials. (e) The therapeutic effect of ALA will be affected by the dosage. In short, ALA is expected to treat many diseases, but further high quality studies are needed to firmly establish the clinical efficacy of ALA.

Comparative evaluation of phosphatidylcholine and phosphatidylserine with different fatty acids on nephrotoxicity in vancomycin-induced mice

Phospholipids reportedly alleviate drug-induced acute kidney injury. However, no study has compared the effect of phospholipids with different fatty acids and polar heads on drug-induced nephrotoxicity. In the present study, we aimed to compare the possible nephroprotection afforded by phosphatidylcholine and phosphatidylserine with different fatty acids in a mouse model of vancomycin-induced nephrotoxicity. Pretreatment with phospholipids rich in docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) doubled the survival time when compared with the model group. Moreover, phospholipids rich in DHA/EPA significantly reduced the serum levels of renal function biomarkers and ameliorated kidney pathologies. In terms of alleviating renal damage, no significant differences were observed between different polar heads in DHA-enriched phospholipids, while phosphatidylserine from soybean was better than phosphatidylcholine in mitigating renal injury. Furthermore, DHA/EPA-enriched phospholipids inhibited vancomycin-induced nephrotoxicity mainly by inhibiting apoptosis and oxidative stress. These results provide a scientific basis for phospholipids as potential ingredients to prevent acute kidney injury.

Palmatine ameliorates nephrotoxicity and hepatotoxicity induced by gentamicin in rats

The aim of this study was to investigate the effects of palmatine on gentamicin toxicity. Rats arranged in four groups: 1- Sham, 2- GM, 3- & 4- GM + palmatine (50 & 100 mg/kg). Gentamicin led to increase in plasma AST, ALT, BUN and creatinine. In addition, fractional excretion of Na and K were increased and urine flow rate and creatinine clearance were decreased in gentamicin group. Liver and renal tissues malondialdehyde were increased, and glutathione was decreased in GM group. TUNEL assay showed induction of apoptosis in liver and kidney in GM group. Palmatine treatment caused reduction in plasma AST, ALT, urine flow rate, creatinine clearance, renal and hapatic malondialdehyde, apoptosis and increase in renal and hapatic glutathione, fractional excretion of Na and K, plasma BUN and creatinine in contrast to GM group. Our data showed palmatine reduced hepatotoxicity and nephrotoxicity by inhibition of oxidative stress and apoptosis.

Royal Jelly and Aliskiren mutually annul their protective effects against gentamicin-induced nephrotoxicity in rats

Background and Aim

Gentamicin (GM) is one of the most effective antibiotics for severe, life-threatening Gram-negative infections. Nevertheless, its clinical use has been restrained because of its nephrotoxic potential. Royal jelly (RJ) and aliskiren (ALK) can individually prevent such toxic effects. The aim of this study was to explore the protective effects of a combination treatment of RJ and ALK on GM-mediated nephrotoxicity.

Materials and Methods

Thirty-two adult female. Wistar rats were divided equally into four groups: (I) Receiving normal saline; (II) GM (100 mg/kg, intraperitoneal [i.p.] injection); GM (100 mg/kg, i.p. injection) plus ALK (50 mg/kg, i.p. injection); and (IV) GM (100 mg/kg, i.p. injection) plus ALK (50 mg/kg, i.p. injection) in combination with RJ (150 mg/kg, orally). All treatments were administered daily for 10 days. The blood levels of creatinine, urea, uric acid, albumin, and total protein were measured. Then, the animals were sacrificed, and the kidneys were taken for histopathology.

Results

Compared to normal control rats, GM-injected rats showed significantly (p<0.001) higher serum concentrations of uric acid, urea, and creatinine as well as evidently (p<0.001) lower blood levels of albumin and total protein. Moreover, GM administration was associated with significant renal histopathological changes. All these alterations were considerably (p<0.05) improved in GM-injected rats receiving ALK compared to rats receiving GM alone. However, when RJ was given in combination with ALK to GM-injected rats, it lessened the beneficial nephroprotective effects of both agents.

Conclusion

The combination treatment of RJ and ALK is not desirable for GM-induced nephrotoxicity. Further studies are crucial to accurately explore the precise mechanism of RJ antagonistic interaction with ALK.

Preparation of high-quality concentrated fragrance flaxseed oil by steam explosion pretreatment technology

In this study, flaxseed was pretreated by steam explosion technology and subsequently pressed to prepare flaxseed oil. GC, UPLC, HPLC, and GC-MS techniques were used to analyze the quality characteristics of the prepared flaxseed oil. These included the food safety risk indices, micronutrient components, and oxidative stability. The effects of different steam explosion pressures on the quality characteristics and relative volatile components of flaxseed oil were also investigated. The results revealed that steam explosion pretreatment technology could significantly increase the oil yield, improve micronutrient content, and strengthen the oxidation stability of the product. Moreover, the food safety risk indices (e.g., benzopyrene) were controlled within a reasonable range, while the fatty acid content remained almost unchanged. Notably, the relative pyrazine content in the total volatile components of flaxseed oil was 68.25% when the steam explosion pressure reached 1.2 MPa. This was considered as the main factor that contributed to the unique concentrated fragrance of the produced flaxseed oil. To prove the superiority of the steam explosion pretreatment, we compared this technique with traditional high-temperature roasting and popular microwave pretreatment techniques. The results revealed that flaxseed oil prepared by steam explosion pretreatment displayed the best quality characteristics and most concentrated fragrance. Thus, steam explosion technology shows great potential for application to produce high-quality concentrated fragrance flaxseed oil. This study provides significant reference and guidance for the preparation process of flaxseed oil.

Housing condition-associated changes in gut microbiota further affect the host response to diet-induced nonalcoholic fatty liver

Diet-induced obesity is the most widely used animal model for studying nonalcoholic fatty liver disease (NAFLD). However, the physiological effects of a high-fat diet (HFD) are inconsistent between different studies. To elucidate this mystery, mice raised with conventional (CONV), specific pathogen-free (SPF) and gentamicin (G) treatments and fed with standard diet (STD) or HFD were analyzed in terms of their physiology, gut microbiota composition, hepatic steatosis and inflammation. Serum biochemistry showed increased levels of cholesterol and aspartate aminotransferase in the G-STD and CONV-HFD groups, respectively. The CONV-HFD group exhibited more inflammatory foci compared to the SPF-HFD and G-HFD groups. Furthermore, immunohistochemistry staining revealed the infiltration of Kupffer cells in the liver, consistent with increased mRNA levels of MCP-1, CD36 and TLR4. Principal coordinate analysis and the cladogram of LEfSe showed that the distinguished clusters of gut microbiota were dependent on housing conditions. The Rikenellaceae, F16 and Desulfovibrionaceae were strongly correlated with hepatic inflammation. Otherwise, higher NAFLD activity score correlated with altered relative abundances of Bacteroidetes and Firmicutes. In conclusion, gut microbiota varying with housing condition may be pivotal for the host response to HFD.

Alpha-linolenic acid confers protection on mice renal cells against cisplatin-induced nephrotoxicity

Cisplatin is an antineoplastic agent used in the treatment of various types of solid tumors. Despite the dose-dependency of its antineoplastic effect, the high risk for nephrotoxicity frequently precludes the use of higher doses. α-Linolenic acid (ALA), a carboxylic acid having three cis double bonds, is an essential fatty acid required for health and can be acquired via foods that contain ALA or supplementation of foods high in ALA. Previous studies have shown that ALA demonstrates anti-cancer, anti-inflammatory, and anti-oxidative effects. In this study, we show the protective effect of ALA on cisplatin-induced renal toxicity associated with oxidative stress in mice using biochemical parameters. The mice were randomly assigned into four experimental groups. Group 1 (control group) were administered physiological saline solution for 9 days; group 2 (ALA group) received 200 mg/kg alpha-linolenic acid via gavage for 9 days; group 3 (CIS group) received 100 mg/kg intraperitoneal (i.p.) CIS for 9 days; and group 4 (ALA + CIS group) received 100 mg/kg i.p. CIS and followed by ALA 200 mg/kg via gavage for 9 days. Alpha-linolenic acid significantly reduced the expression of myeloperoxidase (MPO), phospholipase A2 (PLA2), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the ALA + CIS group compared to the CIS group. Furthermore, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) quantities were significantly elevated in the ALA + CIS group when compared to the CIS group. ALA significantly decreased the levels of Bax and cleaved caspase-3, while significantly increasing the level of bcl-2, an anti-apoptotic protein, in the ALA + CIS group than in the CIS group. Finally, histopathological examination in renal tissue showed that the significant edematous damage induced by CIS administration alone was reduced in ALA + CIS group. In conclusion, our findings show that ALA is beneficial to CIS-induced nephrotoxicity in mice via its anti-inflammatory and anti-oxidative effects.

STK33 alleviates gentamicin-induced ototoxicity in cochlear hair cells and House Ear Institute-Organ of Corti 1 cells

Serine/threonine kinase 33 (STK33), a member of the calcium/calmodulin‐dependent kinase (CAMK), plays vital roles in a wide spectrum of cell processes. The present study was designed to investigate whether STK33 expressed in the mammalian cochlea and, if so, what effect STK33 exerted on aminoglycoside‐induced ototoxicity in House Ear Institute‐Organ of Corti 1 (HEI‐OC1) cells. Immunofluorescence staining and western blotting were performed to investigate STK33 expression in cochlear hair cells (HCs) and HEI‐OC1 cells with or without gentamicin treatment. CCK8, flow cytometry, immunofluorescence staining and western blotting were employed to detect the effects of STK33 knockdown, and/or U0126, and/or N‐acetyl‐L‐cysteine (NAC) on the sensitivity to gentamicin‐induced ototoxicity in HEI‐OC1 cells. We found that STK33 was expressed in both mice cochlear HCs and HEI‐OC1 cells, and the expression of STK33 was significantly decreased in cochlear HCs and HEI‐OC1 cells after gentamicin exposure. STK33 knockdown resulted in an increase in the cleaved caspase‐3 and Bax expressions as well as cell apoptosis after gentamicin damage in HEI‐OC1 cells. Mechanistic studies revealed that knockdown of STK33 led to activated mitochondrial apoptosis pathway as well as augmented reactive oxygen species (ROS) accumulation after gentamicin damage. Moreover, STK33 was involved in extracellular signal‐regulated kinase 1/2 pathway in primary culture of HCs and HEI‐OC1 cells in response to gentamicin insult. The findings from this work indicate that STK33 decreases the sensitivity to the apoptosis dependent on mitochondrial apoptotic pathway by regulating ROS generation after gentamicin treatment, which provides a new potential target for protection from the aminoglycoside‐induced ototoxicity.