ABSTRACT
Pseudobombax ellipticum is native to South America and is cultivated worldwide mostly for its medicinal benefits. The plant is used traditionally in respiratory disorders such as dry cough, in the treatment of fever and stomach pain, and as an antimicrobial and analgesic. The antisickling and antioxidant effects of the flowers of P. ellipticum (Kunth) Dugand (red) and P. ellipticum cultivar alba (white) were compared using an in vitro assay in 2% sodium metabisulfite sickling induction model, DPPH, and metal chelation assays. Both red and white flowers exhibited antioxidant and antisickling activities. In DPPH assay, lower IC50 (34.89 ± 0.98 and 53.28 ± 1.14 µg mL-1) in red and white flowers respectively were detected relative to Trolox as a positive control (56.82 ± 0.87 µg mL-1). Comparable metal chelation activity (81.4 and 77.8 µM EDTA equivalent/mg) was detected in red and white flowers of both cultivars respectively. The average readings of the "reversal of sickling test "revealed a decrease in sickling percent from 49% to 15% in red flowers and to 18% in white flowers. Also, polymerization inhibition rate was increased from 0.34 to 1 and to 0.92 in red and white flowers respectively. Total phenolics, flavonoids and anthocyanins were quantified in red and white flowers as (163.9, 43.13 mg gallic acid equivalent/g extract), (71.92, 34.5 mg rutin equivalent/g extract) and (127.0, 85.9 mg pelargonidine-3-mono glucoside equivalent/kg extract), respectively. Liquid chromatography mass spectrometry (LC-MS) analysis was further employed for detection and identification of anthocyanins in flower extracts. Eight new anthocyanins were identified for the first time in genus Pseudobombax. These results reveal the potential role for both red and white flower extracts as possible antisickling agents in sickle cell anemia management.
ABSTRACT
Severe respiratory involvement that follows a process of immune dysregulation and intense cytokine production remains to be the most dreaded complication of Coronavirus Disease-2019 (COVID-19) infection. The aim of this study was to analyze T lymphocyte subsets and natural killer (NK) lymphocytes in moderate and severe cases of COVID-19 infection and assess their significance in disease severity and prognosis. Twenty moderate cases and 20 severe cases of COVID-19 were studied and compared regarding blood picture, biochemical markers, T lymphocyte population subsets, and NK lymphocytes, which were determined by flow cytometric analysis. On analyzing the flow cytometric data of T lymphocyte cells and their subsets and NK cells in two groups of COVID-19 infection (one group moderate and the other severe cases), some immature NK lymphocyte relative and absolute counts were higher in the severe patients with worse outcome and death, while some mature NK lymphocyte relative and absolute counts were depressed in both groups. Also, interleukin (IL)-6 was significantly higher in severe cases when compared to moderate cases, and there was a positive significant correlation between immature NK lymphocyte relative and absolute counts and IL-6. There was no statistically significant difference between T lymphocyte subsets (T helper and T cytotoxic) with disease severity or outcome. Some immature NK lymphocyte subsets contribute to the widespread inflammatory response that complicates severe cases of COVID-19; therapeutic approaches directed to enhancing NK maturation or drugs that block NK cell inhibitory receptors have a potential role in controlling COVID-19 induced cytokine storm.
