Isik, Bahar; Ates, Irem; Yucel, Nurinisa; Suleyman, Bahadir; Mendil, Ali Sefa; Sezgin, Esra Tuba; Suleyman, Halis

Linezolid, an antimicrobial agent, has been linked to lactic acidosis, oxidative stress, and liver damage. Oxidative stress is considered to play a key role in this damage. Thiamine pyrophosphate (TPP), the active form of thiamine, may prevent lactate accumulation and enhance aerobic capacity. Therefore, this study aimed to evaluate the protective effect of TPP against possible linezolid-induced liver damage and lactic acidosis in rats. Twenty-four male Wistar albino rats were randomly assigned to four groups (n = 6): healthy control (HG), linezolid (LZD), thiamine plus linezolid (TLZD), and TPP plus linezolid (TPLZD). Thiamine and TPP (20 mg/kg, intraperitoneal (i.p.)) were administered once daily, while linezolid (125 mg/kg, per os (p.o.)) was given twice daily (250 mg/kg/day) for 28 days. Animals were euthanized under high-dose anesthesia (with 50 mg/kg, i.p. thiopental sodium). Liver tissues were analyzed for MDA, tGSH, SOD, and CAT, and examined histopathologically. Blood samples were collected prior to euthanasia to assess lactate, LDH, ALT, AST, and TPP levels. In the LZD group, MDA, lactate, ALT, AST, and LDH levels significantly increased, while tGSH, SOD, CAT, and TPP decreased (p < 0.001). Histopathology showed hydropic degeneration, necrosis, and mononuclear cell infiltration (p < 0.05). Thiamine did not prevent these alterations (p > 0.05), whereas TPP significantly prevented both biochemical and histopathological changes (p < 0.05), indicating its protective efficacy. TPP may offer significant protection against linezolid-induced hepatotoxicity and lactic acidosis.

Tohma, Hatice; Köksal, Ekrem; Kılıç, Ömer; Alan, Yusuf; Abdullah Yılmaz, Mustafa; Gülçin, İlhami; Bursal, Ercan; Alwasel, Saleh H.

The identification and quantification of the phenolic contents of methanolic extracts of three Salvia L. species namely S. brachyantha (Bordz.) Pobed, S. aethiopis L., and S. microstegia Boiss. and Bal. were evaluated using reverse phase high performance liquid chromatography, UV adsorption, and mass spectrometry (RP-HPLC/MS). In order to determine the antioxidant capacity of these species, cupric ions (Cu2+) reducing assay (CUPRAC) and ferric ions (Fe3+) reducing assay (FRAP) were performed to screen the reducing capacity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was employed for evaluation of the radical scavenging activity for both solvents. In further investigation, the antimicrobial activities of Salvia species were tested using the disc diffusion method against three Gram-positive and four Gram-negative microbial species, as well as three fungi species. The results showed that there is a total of 18 detectable phenols, the most abundant of which was kaempferol in S. microstegia and rosmarinic acids in S. brachyantha and S aethiopis. The other major phenols were found to be apigenin, luteolin, p-coumaric acid, and chlorogenic acid. All species tested showed moderate and lower antioxidant activity than standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and ascorbic acid. The ethanolic extracts of Salvia species revealed a wide range of antimicrobial activity. S. brachyantha and S. microstegia showed the highest antimicrobial activities against B. subtilis, whereas S. aethiopis was more effective on Y. lipolytica. None of the extracts showed anti-fungal activity against S. cerevisiae. Thus these species could be valuable due to their bioactive compounds.