Raman spectroscopy: A novel experimental approach to evaluating cisplatin induced tissue damage

Quantitative Raman chemical imaging of intracellular drug-membrane aggregates and small molecule drug precipitates in cytoplasmic organelles

Raman confocal microscopes have been used to visualize the distribution of small molecule drugs within different subcellular compartments. This visualization allows the discovery, characterization, and detailed analysis of the molecular transport phenomena underpinning the Volume of Distribution - a key parameter governing the systemic pharmacokinetics of small molecule drugs. In the specific case of lipophilic small molecules with large Volumes of Distribution, chemical imaging studies using Raman confocal microscopes have revealed how weakly basic, poorly soluble drug molecules can accumulate inside cells by forming stable, supramolecular complexes in association with cytoplasmic membranes or by precipitating out within organelles. To study the self-assembly and function of the resulting intracellular drug inclusions, Raman chemical imaging methods have been developed to measure and map the mass, concentration, and ionization state of drug molecules at a microscopic, subcellular level. Beyond the field of drug delivery, Raman chemical imaging techniques relevant to the study of microscopic drug precipitates and drug-lipid complexes which form inside cells are also being developed by researchers with seemingly unrelated scientific interests. Highlighting advances in data acquisition, calibration methods, and computational data management and analysis tools, this review will cover a decade of technological developments that enable the conversion of spectral signals obtained from Raman confocal microscopes into new discoveries and information about previously unknown, concentrative drug transport pathways driven by soluble-to-insoluble phase transitions occurring within the cytoplasmic organelles of eukaryotic cells.

Ameliorative effect of nebivolol in doxorubicin-induced cardiotoxicity

This study aimed to investigate the potential of nebivolol in preventing doxorubicin-induced cardiotoxicity by targeting the inflammatory, oxidative, and apoptotic pathways. Twenty-eight male rats were randomly divided into four groups, each consisting of seven rats. The control group received standard diets and unrestricted access to water. The rats in the normal saline (N/S) group were administered a 0.9% normal saline solution for two weeks. The doxorubicin group (the "induced group") received doxorubicin at a dosage of 2.5 mg/kg three times per week for two weeks. The nebivolol group received an oral dose of 4 mg/kg of nebivolol for the same duration. The cardiac tissues of rats treated with doxorubicin exhibited increased levels of tumor necrosis factor, interleukin-1, malondialdehyde, and caspase-3 compared to the normal saline control group (p<0.05), along with decreased levels of total antioxidant capacity and Bcl-2. These results show that doxorubicin is harmful to the heart. The administration of nebivolol significantly reduced the cardiotoxic effects induced by doxorubicin, as indicated by a statistically significant decrease in the levels of inflammatory markers, specifically tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) (p<0.05). The nebivolol group exhibited a significant decrease in malondialdehyde levels, which serves as a signal of oxidation, in cardiac tissue compared to the doxorubicin-only group (p<0.05). Additionally, the nebivolol group showed a significant increase in overall antioxidant capacity. Nebivolol dramatically attenuated doxorubicin-induced cardiotoxicity in rats, likely by interfering with oxidative stress, the inflammatory response, and the apoptotic pathway.

The neuroprotective effect of mesenchymal stem cells in colistin-induced neurotoxicity

Colistin is an effective antibiotic against multidrug-resistant gram-negative bacterial infections; however, neurotoxic effects are fundamental dose-limiting factors for this treatment. Stem cell therapy is a promising method for treating neuronal diseases. Multipotent mesenchymal stromal cells (MSC) represent a promising source for regenerative medicine. Identification of neuroprotective agents that can be co-administered with colistin has the potential to allow the clinical application of this essential drug. This study was conducted to assess the potential protective effects of MSC, against colistin-induced neurotoxicity, and the possible mechanisms underlying any effect. Forty adult female albino rats were randomly classified into four equal groups; the control group, the MSC-treated group (A single dose of 1 × 106/mL MSCs through the tail vein), the colistin-treated group (36 mg/kg/d colistin was given for 7 d) and the colistin and MSC treated group (36 mg/kg/d colistin was administered for 7 d, and 1 × 106/mL MSCs). Colistin administration significantly increased GFAP, NGF, Beclin-1, IL-6, and TNF-α immunreactivity intensity. MSC administration in colistin-treated rats partially restored each of these markers. Histopathological changes in brain tissues were also alleviated by MSC co-treatment. Our study reveals a critical role of inflammation, autophagy, and apoptosis in colistin-induced neurotoxicity and showed that they were markedly ameliorated by MSC co-administration. Therefore, MSC could represent a promising agent for prevention of colistin-induced neurotoxicity.

The role of autophagy in paclitaxel and cremophor induced damage to rat testis

The anticancer drug, paclitaxel (PTX), is used to treat a variety of solid tumors, but its effects on normal tissues remain unclear. We investigated the effects of different doses of PTX and its vehicle, cremophor EL, on testis using histochemical, immunohistochemical and biochemical methods. We used 30 adult Wistar albino rats divided randomly into five groups: physiological saline was administered to the control group; the sham 8 group received 8 mg/kg cremophor EL; the sham 16 group received 16 mg/kg cremophor EL; 8 mg/kg PTX was administered to the PTX 8 group; and the PTX 16 group received 16 mg/kg PTX. The cremophore content in PTX groups was the same as in the sham group. All treatments were injected intraperitoneally (i.p.) once/week for 4 weeks. Tissue samples were excised 24 h after the last injection. Tissue sections were prepared and hematoxylin and eosin staining was performed to assess testicular morphology. Expression of Beclin-1, LC3A/B and P62 were assessed using immunohistochemistry. Serum and tissue testosterone levels were determined using ELISA. Light microscopy revealed seminiferous tubule damage, irregularities in germinal epithelium and decreased seminiferous tubule diameter in the PTX treated groups. The immunoreactivity of Beclin-1, LC3A/B, and P62 was increased significantly in the PTX groups compared to the control group. Cremophor EL alone damaged the testis, although not as much as PTX. PTX caused significant damage to testicular tissue and increased autophagy of spermatogenic cells; cremophore EL also may play a role in this effect.

Efficacy of stem cell-based therapies for colistin-induced nephrotoxicity

The increase in infections with multidrug resistant bacteria has forced to return to the use of colistin, antibiotic with known nephrotoxicity. Mesenchymal stem cells (MSCs) are being extensively investigated for their potential in regenerative medicine. This study aimed to investigate the possible protective mechanisms of the MSCs against kidney injury induced by colistin. Forty adult female albino rats were randomly classified into 4 equal groups; the control group, the MSC-treated group (a single dose of 1 ×10⁶ /ml MSCs through the tail vein), the colistin-treated group (36 mg/kg/day colistin was given for 7 days), and the both colistin and MSC group (36 mg/kg/day colistin and 1 ×10⁶ /ml MSCs). Main outcome measures were histopathological alterations, kidney malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and immunohistological autophagy evaluation. MSC repressed the progression of colistin-induced kidney injury as evidenced by the improvement of histopathological alterations and the substantial increase MDA, and decrease SOD and CAT in serum levels. Moreover, MSC resulted in a profound reduction in oxidative stress as manifested by decreased MDA and increased SOD in serum. Notably, MSC suppressed colistin-induced autophagy; it reduced renal levels of Beclin-1, P62 and LC3A/B. Furthermore, MSC decreased renal levels of eNOS. Lastly, MSC efficiently decreased expression of the TUNEL positive cell number. MSC confers protection against colistin-induced kidney injury by alleviating oxidative stress, nitric oxide synthase besides modulating reducing autophagy and apoptosis.

In Situ Identification of Unknown Crystals in Acute Kidney Injury Using Raman Spectroscopy

Raman spectroscopy is a well-established and powerful tool for in situ biomolecular evaluation. Type 2 crystal nephropathies are characterized by the deposition of crystalline materials in the tubular lumen, resulting in rapid onset of acute kidney injury without specific symptoms. Timely crystal identification is essential for its diagnosis, mechanism exploration and therapy, but remains challenging. This study aims to develop a Raman spectroscopy-based method to assist pathological diagnosis of type 2 crystal nephropathies. Unknown crystals in renal tissue slides from a victim suffered extensive burn injury were detected by Raman spectroscopy, and the inclusion of crystals was determined by comparing Raman data with established database. Multiple crystals were scanned to verify the reproducibility of crystal in situ. Raman data of 20 random crystals were obtained, and the distribution and uniformity of substances in crystals were investigated by Raman imaging. A mouse model was established to mimic the crystal nephropathy to verify the availability of Raman spectroscopy in frozen biopsy. All crystals on the human slides were identified to be calcium oxalate dihydrate, and the distribution and content of calcium oxalate dihydrate on a single crystal were uneven. Raman spectroscopy was further validated to be available in identification of calcium oxalate dihydrate crystals in the biopsy specimens. Here, a Raman spectroscopy-based method for in situ identification of unknown crystals in both paraffin-embedded tissues and biopsy specimens was established, providing an effective and promising method to analyze unknown crystals in tissues and assist the precise pathological diagnosis in both clinical and forensic medicine.

Lupeol inhibits pesticides induced hepatotoxicity via reducing oxidative stress and inflammatory markers in the rats

The present study was aimed at investigating the toxicity of various pesticides on rat liver. It also aimed to show whether this toxicity could be avoided using lupeol. Adult male Wistars albino rats were randomly divided into nine groups. Control groups were given saline, corn oil, and lupeol; pesticide groups were given malathion, chlorpyrifos, and tebuconazole; in the other three treatments, same doses of pesticides and lupeol were given to the rats for ten days. Histopathological examination showed severe degenerative changes in the pesticide groups. Serum AChE activities, liver GSH, total antioxidant capacity levels, AChE, CAT, SOD, GPx, GR, Na⁺/K⁺-ATPase, ARE, and PON were decreased, while serum TNF-α, liver LPO, HP, NO, AOPP, total oxidant status, ROS, and oxidative stress index levels as well as AST, ALT, ALP, GST, arginase and xanthine oxidase activities were increased in the pesticides administered groups. It was observed that the PCNA levels determined by the immunohistochemical method increased in the pesticide groups. Also, the results Raman spectroscopy suggest that the technique may be used to understand/have an insight into pesticide toxicity mechanisms. The administration of lupeol demonstrated a hepatoprotective effect against pesticide-induced toxicity.

Effects of 405-, 532-, 650-, and 940-nm wavelengths of low-level laser therapies on orthodontic tooth movement in rats

Background

Investigating the effects of 405-nm, 532-nm, 650-nm, and 950-nm wavelengths of LLLTs (low-level laser therapies) on the orthodontic tooth movement in rats by using histological and immunohistochemical methods. Forty-five Wistar albino rats were randomly divided into 5 groups: control group (positive control: the left maxillary 1st molar side; negative control: the right maxillary 1st molar side), 405 nm LLLT group (Realpoo), 532 nm LLLT group (Realpoo), 650 nm LLLT group (Realpoo), and 940 nm LLLT group (Biolase). The left maxillary 1st molar teeth of all rats were applied mesially 50-g force. Starting from the 1st day, 48 h intervals, LLLT was applied in continuous wave mode and in contact with the tissue. The application area was approximately 1 cm². The lasers were performed for 3 min on each surface (buccal, palatal, mesial), totally 9 min (total dose 54 J/cm²). The amount of the molar mesialization, the bone area between the roots, PDL (periodontal ligament) measurements, TRAP (tartrate-resistant acid phosphatase), and ALP (alkaline phosphatase) immunoreactivity intensity were calculated.

Results

The amount of the molar mesialization was significantly higher in the 650 nm LLLT group (mean 0.878 ± 0.201 mm; 95% CI (confidence interval) 0.724 and 1.032) than in the groups of positive control (mean 0.467 ± 0.357 mm; 95% CI 0.192 and 0.741) and 405 nm LLLT (mean 0.644 ± 0.261 mm; 95% CI 0.443 and 0.845) (p < 0.001). There were significant differences in the PDL-mesial (p = 0.042) and PDL-distal (p = 0.007) regions between the groups. The immunoreactivity intensity for TRAP-mesial was significantly higher in the positive control group (mean 109,420.33 ± 8769.17; 95% CI 100,217.65 and 118,623.02) than in the 405 nm (mean 91,678.83 ± 7313.39; 95% CI 84,003.9 and 99,353.77) and the 650 nm LLLT (mean 87,169.17 ± 4934.65; 95% CI 81,990.56 and 92,347.77) groups (p = 0.002). There was no statistically significant difference between the groups on immunoreactivity intensity with ALP staining.

Conclusions

The results of this study show that LLLT with 650-nm wavelength increases orthodontic tooth movement more than 405-nm, 532-nm, and 940-nm LLLTs. The 940-nm and 650-nm LLLTs also increase the bone area between the roots by more than 405-nm and 532-nm wavelengths.

P-Glycoprotein/ABCB1 Might Contribute to Morphine/Cisplatin-Induced Hepatotoxicity in Rats

To investigate combined effect of the anticancer drug cisplatin (CP) and the opiate analgesic morphine (MOR) on liver, rats were administered MOR (10 mg/kg/day i.p. for 10 days), with or without CP (7.5 mg/kg i.p. once at day 5 of the study). MOR or CP alone caused deterioration of liver function tests and induced damage to histological architecture of liver. In addition, each drug alone caused hepatic oxidative stress, as evident by significant increase of malondialdehyde and nitric oxide, as well as the significant decrease in GSH, catalase and SOD compared to control. Administration of either MOR or CP also caused liver inflammation, evident by the increase in the pro-inflammatory cytokines; TNF-α and IL-6. In addition, either MOR or CP induced liver apoptosis, as shown by significant increase in expression of the pro-apoptotic marker; caspase 3 compared to control. Either MOR or CP also caused up-regulation of the efflux transporter P-glycoprotein (P-gp). Combining MOR with CP caused deterioration in all parameters tested compared to CP alone. Thus, treatment with MOR worsened CP-induced hepatotoxicity through oxidative stress, inflammation and apoptosis mechanisms. In addition, both drugs contributed to the up-regulation of P-gp, which might be a new mechanism for their hepatotoxic effects.