The effect of aqueous and ethanolic extracts of chamomile on the vital activity of peripheral blood leukocytes of patients with covid-19

Background and Objective: Numerous studies have shown the anti-inflammatory, antimicrobial, anti-allergic, anti-cancer, anti-spasm, analgesic and wound healing effects of chamomile (Matricaria chamomile). In this study, the effect of aqueous and ethanolic extracts of chamomile on the vital activity of cultured leukocytes of patients with covid-19 was investigated. Materials and Methods: After preparation of aqueous and ethanolic extracts of chamomile, peripheral blood mononuclear cells (PBMC) of patients with covid-19 with doses of 200, 300, 400 and 500 micrograms/ml of ethanolic extract of chamomile and doses of 400, 500, 600 and 700 µg/ml chamomile aqueous extract were treated. After 24 hours, the vital activity of PBMCs was measured by MTT method. To analyze the findings, one-way analysis of variance was used in SPSS software version 24. P<0.05 was considered significant. Results: In the current research, chamomile ethanol extract in doses of 500 micrograms/ml and aqueous extract in doses of 600 and 700 micrograms/ml led to a significant decrease in the vital activity of peripheral blood mononuclear cells compared to the control group. Conclusion: Aqueous and ethanol extracts of chamomile significantly decrease the vital activity of peripheral blood mononuclear cells; This decrease in vital activity is dose-dependent, and with increasing dose, a decrease in vital activity is observed

Catalase-gold nanoaggregates manipulate the tumor microenvironment and enhance the effect of low-dose radiation therapy by reducing hypoxia

Radiotherapy as a standard method for cancer treatment faces tumor recurrence and antitumoral unresponsiveness. Suppressive tumor microenvironment (TME) and hypoxia are significant challenges affecting efficacy of radiotherapy. Herein, a versatile method is introduced for the preparation of pH-sensitive catalase-gold cross-linked nanoaggregate (Au@CAT) having acceptable stability and selective activity in tumor microenvironment. Combining Au@CAT with low-dose radiotherapy enhanced radiotherapy effects via polarizing protumoral immune cells to the antitumoral landscape. This therapeutic approach also attenuated hypoxia, confirmed by downregulating hypoxia hallmarks, such as hypoxia-inducible factor α-subunits (HIF-α), vascular endothelial growth factor (VEGF), and EGF. Catalase stability against protease digestion was improved significantly in Au@CAT compared to the free catalase. Moreover, minimal toxicity of Au@CAT on normal cells and increased reactive oxygen species (ROS) were confirmed in vitro compared with radiotherapy. Using the nanoaggregates combined with radiotherapy led to a significant reduction of immunosuppressive infiltrating cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (T-regs) compared to the other groups. While, this combined therapy could significantly increase the frequency of CD8+ cells as well as M1 to M2 macrophages (MQs) ratio. The combination therapy also reduced the tumor size and increased survival rate in mice models of colorectal cancer (CRC). Our results indicate that this innovative nanocomposite could be an excellent system for catalase delivery, manipulating the TME and providing a potential therapeutic strategy for treating CRC