Background We designed this single-centre clinical trial to assess the potential benefits of N-Acetylcysteine (NAC) in patients with COVID19-associated acute respiratory distress syndrome (ARDS). Methods Ninety-two patients with mild-to-moderate COVID19-associated ARDS were allocated to the placebo (45-cases) or NAC groups (47-cases). Besides standard-of-care treatment, the patients received either intravenous NAC at a dose of 40 mg/kg/day or the placebo for three consecutive days. The efficacy outcomes were overall mortality over 28-day, clinical status on day 28, based on the WHO Master Protocol, the proportion of patients requiring mechanical ventilation, changes in ARDS-severity (based on the PaO 2 /FiO 2 ratio), and Sequential Organ Failure Assessment (SOFA) scores 48 and 96 h after intervention, Results No differences were found in the 28-day mortality rate between the two groups (25.5% vs. 31.1% in the NAC and placebo groups, respectively). Although the distribution of the clinical status at day 28 shifted towards better outcomes in the NAC-treated group, it did not reach a statistical significance level (p value = 0.83). Similar results were achieved in terms of the proportion of patients who required invasive ventilator support (38.3% vs. 44.4%), the number of ventilator-free days (17.4 vs. 16.6), and median time of ICU and hospital stay. Results regarding the change in PaO 2 /FiO 2 ratio and SOFA scores also showed no significant differences between the groups. Conclusions Our pilot study did not support the potential benefits of intravenous NAC in treating patients with COVID-19-associated ARDS. More studies are needed to determine which COVID-19 patients benefit from the NAC administration. Trial registration The trial was registered at Clinicaltrials.gov (identifier code: IRCT20120215009014N355). Registration date: 2020-05-18.

Echium amoenum is an Iranian indigenous medicinal plant. In this research the effect of hydroalchoholic extract of this plant on sodium-selenite induced cataract formation was evaluated. Fifty five white rat pups were selected and divided into six groups. In first group (control 1) no elements injected. Second group (control 2) was received normal saline on 11-18 postpartum. Hydroalchoholic extract of Echium amoenum flower (400 mg/kg/day) intraperitonealy was injected into third group. Rats in group 4 th received sodium selenite (30 nmol/kg) on day 13 postpartum. In group 5 th , the extract was injected 2 days before selenite injection (once a day for two days). And in last group one day before selenite injection, the rats received a single dose of the extract. Cataract development was measured by slit-lamp. Lens opacification was analyzed in each group on day 7 after selenite administration. All lens in control and 3 th groups were clear. However, it was found different type of cataract grades formation in selenite group (2.2 ± 0.83). Cataract grades were 0.4 ± 0.5 and 0.6 ± 0.5 in groups 5 th and 6 th respectively. Echium amoenum extract significantly was shown a protective effect on selenite-induced cataract in rat. This effect is probably associated with antioxidant activity of this medicinal plant.

The present study sought to assess antioxidant effect of Origanum vulgare extract in preventing selenite-induced cataractogenesis. This study was performed on Young white rats received sodium selenite (30 nmol g(-1) birth weight) subcutaneously on day 13 post partum during two months in 2009. Cataract formation and intensity was detected and measured by slit-lamp. Origanum vulgare (Ov) extract (2 g kg(-1)) was given (1-2 times) intraperitoneal at different times with respect to the selenite administration lens opacification was analyzed in selenite, selenite-Ov, Ov and control groups on day 7 after selenite administration. Ov extract have revealed a significant protective effect against selenite induced cataract when injected 1 and 2 day (2 times) before selenite injection. There is a protective effect of Ov against selenite induced cataract formation. It is supposed that the anticataract effect of Ov extract could be based on direct or indirect antioxidant mechanisms.