Asian Pacific Journal of Tropical Biomedicine

231-243

Authors: Arnica F Lal, Shaminder Singh, Francisco C Franco, Sonam Bhatia

Polyphenols are the secondary metabolic products of plants and are considered as active constituents to possess therapeutic effects. To date, a vast number of scientific literature addressed the potential of polyphenols as bio-efficient compounds owing to their structural diversity. Due to the presence of several hydroxyl groups, they are metabolized quickly due to conjugation reaction and thus, readily produce toxic metabolites as a defense material against many pathogens, reflecting their safety strategy. This review focuses on the anti-quorum sensing and biofilm inhibition activity of polyphenols, which display their potential to treat bacterial infections by combating the virulence caused by pathogenic agents. Thus, for mitigating quorum sensing-controlled pathogenesis, the use of polyphenol-based phytochemicals holds immense potential to cure infections. The application of polyphenol as sensitizing agent/ adjuvant therapeutics which act in synergism with antibiotics is highly remarkable.

254-262

Authors: Raghda A El-Sayed, Fatma M El-Demerdash, Mohammed A El-Magd

Objective: To investigate the protective and therapeutic role of ginseng against silicon dioxide nanoparticles (SiO2NPs)-induced toxicity in the lungs. Methods: Sixty male rats were divided into five groups (n = 12/ group); group 1 was used as a control, group 2 received ginseng, group 3 was treated with SiO2NPs, and group 4 was pretreated with ginseng one week before SiO2NPs, while group 5 was given SiO2NPs one week before supplementation with ginseng. Animals were treated with both ginseng and SiO2NPs orally for five weeks. Real-time PCR was used to measure gene expression. Besides, DNA damage and cell cycle changes were determined by comet assay and flow cytometry, respectively. Histological study was also done to assess the effect of ginseng on SiO2NPs-induced toxicity. Results: SiO2NPs increased lipid peroxidation and decreased the activities of antioxidant enzymes. SiO2NPs induced apoptosis in lung tissues as revealed by upregulation of Bax and caspase 3 and downregulation of Bcl-2 as well as the induction of DNA damage. SiO2NPs also caused inflammation as indicated by upregulation of the inflammation-related genes [interleukin 1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), nuclear factor kappa B (NF-κB), cyclooxygenase 2 (COX2), and transforming growth factor-beta 1 (TGFβ1)] as well as cell cycle arrest in the G0/G1 phase of lung cells. Moreover, histopathological examination proved the biochemical and molecular perturbations that occurred due to SiO2NPs toxicity. However, ginseng alleviated SiO2NPs-induced toxicity in rat lung. Conclusions: Ginseng has a potent preventive and therapeutic effect and could be used in the treatment of SiO2NPs-induced pulmonary toxicity.

273-284

Authors: Li-Shan Yan, Li Wang, Brian Chi-Yan Cheng, Yu Ding, Jing Kong, Qing Gao Wang, Xiu-Qiong Fu, Shuo-Feng Zhang, Gan Luo, Yi Zhang

Objective: To investigate the anti-inflammatory effects of the total flavonoids from Saussurea involucrata on lipopolysaccharides (LPS)-stimulated murine RAW264.7 macrophages and explore its underlying mechanism of action. Methods: Total flavonoids from Saussurea involucrata were extracted using chromatographic column method. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The production of nitric oxide was detected by Griess assay and the release of cytokines (IL-10 and TNF-α) and chemokines (MCP-1, MIP-1a, and CCL5/RANTES) was determined by ELISA to evaluate the anti-inflammatory activity of total flavonoids from Saussurea involucrata. Moreover, nuclear translocation of p65, c-Jun, and IRF3 was detected by immunofluorescence microscopy and Western blotting analysis was performed to determine the expression of related proteins. Results: Total flavonoids extracted from Saussurea involucrata were 751.5 mg/g and the content of rutin was 506.5 mg/g. The production of inflammatory mediators including nitric oxide, cytokines, and chemokines was effectively inhibited by total flavonoids from Saussurea involucrata. Meanwhile, total flavonoids also suppressed the nuclear translocation of p65, c-Jun, and IRF3 in LPS-stimulated RAW264.7 cells. The LPS-induced expression of iNOS and COX-2 was remarkably reduced by treatment with total flavonoids from Saussurea involucrata. Moreover, total flavonoids decreased the expression levels of p-IKKa/β, p-TBK1, p-p38, p-ERK, p-JNK, p-p65, p-c-Jun, and p-IRF3 in LPS-exposed RAW264.7 macrophages. Conclusions: Total flavonoids from Saussurea involucrata potentially inhibit the secretion of pro-inflammatory mediators, which may be related to inhibition of p65, c-Jun, and IRF3 signaling pathways in LPS-stimulated RAW264.7 cells.