Nigella sativa oil protects against cadmium-induced intestinal toxicity via promotion of anti-inflammatory mechanisms, mucin expression and microbiota integrity

Assessing Galleria mellonella as a preliminary model for systemic Staphylococcus aureus infection: Evaluating the efficacy and impact of vancomycin and Nigella sativa oil on gut microbiota

Background

Staphylococcus aureus is a Gram-positive bacterium that can cause various infections. The Galleria mellonella has been used as a preliminary test for infection model. The study aimed to evaluate the effectiveness of G. mellonella as a microbiome model and compare the efficacy of vancomycin and antimicrobial activity of Nigella sativa (NS) on the gut flora.

Methods

G. mellonella larvae were subjected to metagenomic analysis. The larvae's guts were collected, homogenized in phosphate-buffered saline (PBS), and the gut contents isolated for bacterial DNA extraction. Larvae were assigned into the following groups: negative control (PBS only); positive control (MRSA only); vancomycin treated group; NS oil treated group and combination (vancomycin and NS oil) treated group. Larvae were cultured, inoculated with S. aureus, and treated with vancomycin and NS oil. Larval activity, cocoon formation, growth, melanization, and survival were monitored. The toxicity of vancomycin and NS oil was tested, and S. aureus burden and natural microbiota were determined. Hemocyte density was measured. Statistical analysis was conducted using R.

Results

Enterococcus related species dominated approximately 90 % of the gastrointestinal tract of the larvae. The survival rate following treatment was 85 % with vancomycin, 64 % with NS oil, and 73 % with a combination of both. The count of Enterococcus Colony Forming Units (CFUs) was significantly lower in the vancomycin treatment group (8.14E+04) compared to those treated with NS oil (1.97E+06) and the combination treatment (8.95E+05). Furthermore, the S. aureus burden was found to be lower in the NS oil (1.04E+06) and combination treatment groups (9.02E+05) compared to the vancomycin treatment group (3.38E+06). Hemocyte densities were significantly higher in the NS oil (8.29E+06) and combination treatment groups (8.18E+06) compared to the vancomycin treatment group (4.89E+06).

Conclusions

The study supported the use of G. mellonella model as a preliminary test to assess the effect of different antimicrobials against S. aureus and gut microbiota. NS oil showed more selectivity against S. aureus and protectiveness for the natural Enterococcus gut flora.

The effect of hydroalcoholic extract of Cichorium intybus leaf on aryl hydrocarbon receptor expression in the testis of Wistar rats exposed to cigarette smoke

Objective

Cigarette smoke (CS) contains compounds such as reactive oxygen species (ROS). Oxidative stress caused by excessive ROS eventually leads to germ cell apoptosis and male infertility. The leaves of Cichorium intybus (chicory) are rich in natural antioxidants, but their protective effects on the adverse effects of CS on testicular tissue have not been studied.

Materials and Methods

24 Wistar rats were classified into four groups: control, extract: treatment with chicory extract (200 mg/kg body weight/day) for 13 weeks, smoke: exposed to CS for 13 weeks, and smoke + extract: exposed to CS and treated with the C. intybus extract. Histological and biochemical analyses and apoptosis assay were done, and Ahr, and Cyp1a1 expression was determined.

Results

Treatment with C. intybus compensated for the reduction of Sertoli cells, spermatogonia, spermatocytes, and spermatids caused by CS. Chicory extract reduced free radicals and improved antioxidant status. The lowest and highest percentage of apoptotic cells was observed in the extract and smoke groups, respectively, while simultaneous treatment with C. intybus extract led to a significant reduction of apoptotic cells. The mean Ahr levels in the control, extract, smoke and smoke + extract groups were 1.00±0.57, 1.93±0.25, 5.98±0.42, and 0.62±0.22, respectively (p˂0.05). The mean levels of Cyp1a1 expression in the control, extract, smoke and smoke + extract groups were 1.00±0.31, 2.28±0.65, 5.55±0.40, and 0.21±0.23 (p˂0.05).

Conclusion

The C. intybus extract probably affected Cyp1a1 expression by downregulation of Ahr. These led to a decrease in free radicals and apoptosis, and an improvement in antioxidant status.