Potential role of free-radical processes in biomolecules damage during COVID-19 and ways of their regulation

Phytochemical composition and antioxidant activities of some wild edible plants locally consumed by rural communities in northern Uganda

Background

Acalypha rhomboidea, Asystacia gangetica, Crassocephalum sacrobasis, Crotalaria ochroleuca, Heterosis rotundifolia, Hibiscus cannabinus, Hibiscus sp., Hibiscus surratensis, Ipomoea eriocarpa, Maerua angolensis, Senna obtusifolia and Vigna membranacea are among the common wild edible plants in the Acholi sub-region, northern Uganda. This study evaluated the phytochemical constituents and antioxidant potential of the plants.

Methods

Fresh leaves collected from each plant species were air-dried under shade. The phytochemical contents of the ethanol and petroleum ether extracts were determined using standard protocols. The antioxidant content of the methanolic extracts was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.

Results

Preliminary phytochemical analyses indicated the presence of tannins, reducing compounds, alkaloids, flavonoids, flavons aglycones, flavanosides, anthracenosides, anthocyanosides, volatile oils, coumarins, steroid glycosides, sterols and triterpenes. However, the extracts did not contain any emodols and saponins. The results of the quantitative phytochemical analysis showed that the contents of different phytochemicals detected varied significantly (p < 0.05) among the selected plants. The amount of tannins in mg/g (gallic acid equivalent) of dry weight varied from 3.90 ± 0.16 in C. ochroleuca to 10.41 ± 0.78 in I. eriocarpa, total flavonoids in RE, mg/g dry matter from 4.07 ± 0.11 in I. eriocarpa to 14.94 ± 0.08 in S. obtusifolia. Total alkaloids in mg/100 g ranged from 1.59 ± 0.30 in I. eriocarpa to 6.37 ± 0.24 in Hibiscus sp. Total phenolic content in GAE, mg/g dry matter ranged from 13.39 ± 0.26 in A. rhomboidea to 64.25 ± 0.54 in I. eriocarpa. The in vitro antioxidant assays revealed substantial free radical scavenging activity in all the plants. Antioxidant activity expressed as IC50 (ppm) ranged from 13.39 for A. rhomboidea to 64.84 for I. eriocarpa, compared to 12.82 for ascorbic acid standard. The total phenolic compounds and total tannins had significant and positive correlations with DPPH free radical scavenging activity.

Conclusion

The findings of this study provide evidence that the species are good natural sources of phytochemicals and antioxidants, whose regular consumption could provide human health benefits by protecting against oxidative stress related diseases. Further research is needed on the structural characterization of the phytochemicals, profiling the plant extracts with high antioxidant activity and determining the antimicrobial activities.

Evaluating the effect of Edaravone on clinical outcome of patients with severe COVID-19 admitted to ICU: a randomized clinical trial

Cytokine storm is the most prominent hallmark in patients with coronavirus disease 2019 (COVID-19) that stimulates the free radical storm, both of which induce an overactive immune response during viral infection. We hypothesized that owning to its radical-scavenging and anti-inflammatory properties, Edaravone could reduce multi-organ injury, clinical complications, and mortality in severe COVID-19 cases. This single-center randomized clinical trial was accompanied in the intensive care units (ICUs) of the teaching hospital of Tabriz University of Medical Sciences to evaluate the effect of Edaravone on the outcome of patients with severe COVID-19. Thirty-eight patients admitted to ICU were included and randomized into two control and intervention arms. Patients in the intervention group received 30 mg Edaravone by slow intravenous infusion for three days in addition to receiving national therapy. The primary outcome was the need for intubation, the intubation length, and mortality rate. Secondary endpoints were clinical improvement. Edaravone administration improved the primary outcomes; it decreased the need for endotracheal intubation and mechanical ventilation [10.52% (n = 2) versus 42.1% (n = 8); p = 0.03] and intubation length [3 (1–7) versus 28 (4–28), p = 0.04] compared to control group. Baseline characteristics and laboratory tests were similar between the studied groups. No marked differences were observed in secondary endpoints (p > 0.05). Administration of Edaravone could decrease the need for mechanical ventilation and length of intubation in severe COVID-19 patients admitted to ICU.