Antimicrobial, Immunomodulatory and Anti-Inflammatory Potential of Liposomal Thymoquinone: Implications in the Treatment of Bacterial Pneumonia in Immunocompromised Mice

Abstract

Acinetobacter baumannii has recently been increasing as an aggressive pathogen in immunocompromised persons. In the present study, we determined the in vitro antibacterial and anti-biofilm activity of thymoquinone (TQ) against A. baumannii. A liposomal formulation of TQ (Lip-TQ) was prepared and its therapeutic potential was investigated in the treatment of A. baumannii infection in immunocompromised mice. Leukopenia was induced in mice by injecting cyclophosphamide (CYP) at a dose of 200 mg/kg and the leukopenic mice were infected with 1 × 106 CFUs of A. baumannii. The effectiveness of free TQ or Lip-TQ against A. baumannii infection was assessed by analyzing the survival rate and bacterial burden. Moreover, the efficacy of Lip-TQ was also studied by examining the systemic inflammatory markers and the histological changes in the lung tissues. The results showed that the mice in the group treated with Lip-TQ at a dose of 10 mg/kg exhibited a 60% survival rate on day 40 post-infection, whereas all the mice treated with free TQ at the same dose died within this duration. Likewise, the lowest bacterial burden was found in the lung tissue of mice treated with Lip-TQ (10 mg/kg). Besides, Lip-TQ treatment remarkably alleviated the infection-associated inflammation, oxidative stress, and histological changes in the lung tissues. Based on the findings of the present study, we recommend considering Lip-TQ as a valuable therapeutic formulation in the treatment of A. baumannii-associated pneumonia in immunocompromised subjects.

Enhanced activity of Ellagic acid in lipid nanoparticles (EA-liposomes) against Acinetobacter baumannii in immunosuppressed mice

“…A multi-drug resistant strain of A. baumannii (ATCC 19606) was used in the current study ( Su et al, 2006 , Allemailem et al, 2021a , Allemailem et al, 2021b ).…”

The significance of thymoquinone administration on liver toxicity of diazinon and cholinesterase activity; a recommendation for prophylaxis among individuals at risk

“…Thymoquinone (TQ; 2-isopropyl-5-methylbenzo-1, 4-quinone) is the most bioactive component of the volatile oil of N. sativa seeds that has potent pharmacological properties including antioxidant, anti-inflammatory and immunomodulatory, antimicrobial, neuroprotective, nephroprotective as well as hepatoprotective effects along with other beneficial effects [24][25][26][27]. Administration of N. sativa oil can possess hepatoprotective activity against carbon tetrachloride (CCl 4 ) induced hepatotoxicity in male Wistar rats which provides a rationale to the medicinal use of this herbal supplement [28].…”

Natural Bioactive Compounds Targeting NADPH Oxidase Pathway in Cardiovascular Diseases

“…Thymoquinone (TQ) is a monoterpene compound identified chemically as 2-methyl-5-isopropyl-1, 4-benzoquinone and is the most prominent constituent of Nigella sativa seeds essential oil [ 117 , 118 ]. TQ has been studied for a wide range of pharmacological activities, which include antioxidant [ 119 ] anti-inflammatory [ 120 ], immunomodulatory [ 121 ], antihistamine [ 122 ], antimicrobial [ 123 ], and antitumour properties [ 124 ].…”