Radical-scavenging and Pro-/anti-inflammatory Activity of Tetracycline and Related Phenolic Compounds With or Without Visible Light Irradiation

Cardioprotective effects of minocycline against doxorubicin-induced cardiotoxicity

BACKGROUND

Doxorubicin (Dox)-induced cardiotoxicity has limited its use. Inflammation, oxidative stress, and apoptosis have important roles in Dox-induced cardiotoxicity. Minocycline (Min) is an antibiotic with anti-inflammatory, anti-oxidant and anti-apoptotic properties. Here, the cardioprotective effects of Min against Dox-induced cardiotoxicity in adult male rats were evaluated.

METHODS

Forty-two adult male rats were divided into six groups including control group (normal saline), Dox group, Min groups (Min 45 mg/kg and Min 90 mg/kg), and treatment groups (Dox + Min 45 mg/kg and Dox + Min 90 mg/kg). Dox (2.5 mg/kg) was administered three times a week for two weeks, and Min once a day for three weeks via intraperitoneal route. Cardiac tissue sections were stained with hematoxylin and eosin for histological examination. The activities of lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB) in serum as well as the activity of catalase and superoxide dismutase (SOD) in cardiac tissue were measured. Cardiac tissue levels of malondialdehyde (MDA), TNF-α, and IL-1β were also measured using ELISA.

RESULTS

Compared with the Dox group, treatment with Min significantly decreased the activity of LDH and CK-MB. Min also increased the activity of catalase and SOD in the tissue samples. The results showed that the levels of MDA, TNF-α, and IL-1β in cardiac tissue samples were significantly lower in the Min groups compared with the Dox group. In addition, histopathological results showed that Min reduced the tissue damage caused by Dox.

CONCLUSION

Min reduced Dox-induced cardiotoxicity. The anti-oxidant and anti-inflammatory properties of Min may contribute to its protective effects.

Minocycline-Derived Silver Nanoparticles for Assessment of Their Antidiabetic Potential against Alloxan-Induced Diabetic Mice

Diabetes is a life-threatening disease, and chronic diabetes affects parts of the body including the liver, kidney, and pancreas. The root cause of diabetes is mainly associated with oxidative stress produced by reactive oxygen species. Minocycline is a drug with a multi-substituted phenol ring and has shown excellent antioxidant activities. The objective of the present study was to investigate the antidiabetic potential of minocycline-modified silver nanoparticles (mino/AgNPs) against alloxan-induced diabetic mice. The mino/AgNPs were synthesized using minocycline as reducing and stabilizing agents. UV-visible, FT-IR, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were applied for the characterization of mino/AgNPs. A 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay was conducted to determine the antioxidant potential of newly synthesized mino/AgNPs. The results revealed that the mino/AgNPs showed higher radical scavenging activity (IC₅₀ = 19.7 µg/mL) compared to the minocycline (IC₅₀ = 26.0 µg/mL) and ascorbic acid (IC₅₀ = 25.2 µg/mL). Further, mino/AgNPs were successfully employed to examine their antidiabetic potential against alloxan-induced diabetic mice. Hematological results showed that the mice treated with mino/AgNPs demonstrated a significant decrease in fasting blood glucose level and lipid profile compared to the untreated diabetic group. A histopathological examination confirmed that the diabetic mice treated with mino/AgNPs showed significant recovery and revival of the histo-morphology of the kidney, central vein of the liver, and islet cells of the pancreas compared to the untreated diabetic mice. Hence, mino/AgNPs have good antidiabetic potential and could be an appropriate nanomedicine to prevent the development of diabetes.

Dietary therapeutic dose of oxytetracycline negatively influences the antioxidant capacity and immune-related genes expression in Nile tilapia Oreochromis niloticus (L.)

Effects of the dietary therapeutic dose of oxytetracycline (OTC) at 80 mg/kg biomass/day for consecutive 10 days on the behaviour, feed intake, mortality, residue accumulation and depletion, antioxidant capacity and immune-related genes expression in juvenile Nile tilapia Oreochromis niloticus were evaluated. OTC-dosing caused mortalities, reduced feed intake, and biomass reduction at 24.5-28.5 °C. OTC residues recorded on day 10 (161.40 ± 11.10 ng/g) were within the maximum residue limits of the Codex Alimentarius. The withdrawal period was 7 days as per the European Commission's regulation. Traces of residues were present even on day 42 post-OTC-dosing. Dietary OTC reduced the antioxidant capacity of the liver and muscle tissues and down-regulated the expression of tumour necrosis factor-α, interleukin-1β, and heat shock protein-70 genes in the liver significantly during the dosing period. The data generated on the biosafety of OTC-dosing may offer inputs for the development of management strategies in maintaining fish health and food safety.

Antileishmanial and lung adenocarcinoma cell toxicity of Withania somnifera (Linn.) dunal root and fruit extracts

This study aims to evaluate the anti-Leishmania major and the lung adenocarcinoma (A549) cytotoxicity of Withania somnifera root and fruit. The total extracts were obtained by homogenisation in aqueous MeOH, and the sub-extracts [n-hexane, ethyl acetate (EtOAc), n-butanol (n-BuOH), and methanol (MeOH)] were obtained by flash chromatography. The activity evaluation showed that n-BuOH sub-extracts from root and fruit exhibited noticeable antileishmanial promastigote properties. The n-hexane and EtOAc sub-extracts from both organs, and the MeOH sub-extract from the fruit exerted mild to moderate effects on the promastigotes. In-vitro growth-inhibitory test results on axenic amastigote and cytotoxicity testing on macrophages (RAW264.7), the parasite-host at the amastigote stage, revealed that the activity was mainly concentrated in the root EtOAc and n-BuOH sub-extracts and to a lesser extent the fruit MeOH and EtOAc, and the root n-hexane sub-extracts. Only the roots' EtOAc and n-BuOH sub-extracts demonstrated low cytotoxicity on the A549 cell line.

IL-8 as a Potential Therapeutic Target for Periodontitis and Its Inhibition by Caffeic Acid Phenethyl Ester In Vitro

Salivary levels of interleukin-8 (IL-8) are elevated in patients with periodontitis. Caffeic acid phenethyl ester (CAPE) improves the periodontal status in subjects. However, whether CAPE can reduce IL-8 expression is unclear. We collected saliva to determine proinflammatory cytokine levels and used subgingival calculus and surrounding tissues from patients with periodontitis for oral microbiota analysis via 16s ribosomal RNA gene sequencing. THP-1 cells were stimulated with sterile-filtered saliva from patients, and target gene/protein expression was assessed. IL-8 mRNA expression was analyzed in saliva-stimulated THP-1 cells treated with CAPE and the heme oxygenase-1 (HO-1) inhibitor tin-protoporphyrin (SnPP). In 72 symptomatic individuals, IL-8 was correlated with periodontal inflammation (bleeding on probing, r = 0.45; p < 0.001) and disease severity (bleeding on probing, r = 0.45; p < 0.001) but not with the four oral microbiota species tested. Reduced salivary IL-8 secretion was correlated with effective periodontitis treatment (r = 0.37, p = 0.0013). In THP-1 cells, saliva treatment induced high IL-8 expression and IKK2 and nuclear factor-κB (NF-κB) phosphorylation. However, the IKK inhibitor BMS-345541, NF-κB inhibitor BAY 11-7082, and CAPE attenuated saliva-induced IL-8 expression. CAPE induced HO-1 expression and inhibited IKK2, IκBα, and NF-κB phosphorylation. Blocking HO-1 decreased the anti-inflammatory activity of CAPE. The targeted suppression of IL-8 production using CAPE reduces inflammation and periodontitis.