A Study of the Therapeutic Effects of Resveratrol on Blunt Chest Trauma-Induced Acute Lung Injury in Rats and the Potential Role of Endocan as a Biomarker of Inflammation

Phytochemicals: Potential Therapeutic Interventions Against Coronavirus-Associated Lung Injury

Since the outbreak of coronavirus disease 2019 (COVID-19) in December 2019, millions of people have been infected and died worldwide. However, no drug has been approved for the treatment of this disease and its complications, which urges the need for finding novel therapeutic agents to combat. Among the complications due to COVID-19, lung injury has attained special attention. Besides, phytochemicals have shown prominent anti-inflammatory effects and thus possess significant effects in reducing lung injury caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also, the prevailing evidence reveales the antiviral effects of those phytochemicals, including anti-SARS-CoV activity, which could pave the road in providing suitable lead compounds in the treatment of COVID-19. In the present study, candidate phytochemicals and related mechanisms of action have been shown in the treatment/protection of lung injuries induced by various methods. In terms of pharmacological mechanism, phytochemicals have shown potential inhibitory effects on inflammatory and oxidative pathways/mediators, involved in the pathogenesis of lung injury during COVID-19 infection. Also, a brief overview of phytochemicals with anti-SARS-CoV-2 compounds has been presented.

Dexmedetomidine alleviates blunt chest trauma and hemorrhagic shock‑resuscitation‑induced acute lung injury through inhibiting the NLRP3 inflammasome

Blunt chest trauma with hemorrhagic shock frequently induces pulmonary inflammation that leads to acute lung injury (ALI). The present study aimed to explore the protective effects of dexmedetomidine (Dex) in blunt chest trauma and hemorrhagic shock-resuscitation (THSR)-induced ALI by mediating nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome formation in rats. An ALI model in rats induced by THSR was constructed and Dex was administered intraperitoneally (5 µg/kg/h) immediately after blunt chest trauma. Blood samples were collected for the determination of proinflammatory factor levels, and lung tissue specimens were harvested for wet/dry (W/D) weight ratio, hematoxylin and eosin staining, and transmission electron microscopy analyses. Additionally, malondialdehyde (MDA), superoxide dismutase (SOD), lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity were evaluated, and the expression of protein in lung tissues was examined via western blot analysis. Compared with the sham group, pathological alterations in the ALI group and the W/D ratios were significantly increased. MDA, LDH and MPO activity, and the levels of interleukin (IL)-1β, IL-18, IL-6 and tumor necrosis factor-α were significantly elevated. NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain and caspase-1 expression was significantly increased. Conversely, Dex treatment significantly reversed these changes. The present study demonstrated that by reducing inflammatory responses, Dex exerted protective effects against THSR-ALI in rats, potentially via the inhibition of NLRP3 signaling pathways.

Activation of multiple Toll-like receptors serves different roles in sepsis-induced acute lung injury

The activation of Toll-like receptors (TLRs) is involved in the innate immune response and the acute inflammatory response following sepsis-induced acute lung injury (ALI). Increasing evidence has demonstrated that sepsis-induced ALI may be closely associated with several abnormal TLRs, activated by components of microorganisms. However, the number of TLRs involved in this process and the extent of their involvement has not been fully elucidated. The current study examined the simultaneous activation of four TLRs closely associated with sepsis-induced ALI. The results demonstrated that in contrast to the sham-operated group, the mRNA and protein expression levels of TLR2/4/9 were significantly increased in the cecal ligation and puncture (CLP)-operated group. In addition, TLR2^-/-, TLR3^-/-, TLR4^-/- and TLR9^-/- C57BL/6 mice were used to establish a CLP-induced ALI animal model and measure the expression levels of TNF-α and IL-6 in plasma and lung tissue samples. The expression of both TNF-α and IL-6 were significantly decreased in TLR2^-/-, TLR4^-/- and TLR9^-/- mice compared with WT mice. In addition, the results revealed that knockdown of TLR2, 4 or 9 decreased immune cell infiltration and therefore may attenuate lung injury. Furthermore, the overall survival was significantly increased in TLR2^-/-, 4^-/- and 9^-/- CLP-induced ALI mice compared with the WT CLP-induced ALI mice. However, there was no statistical significance between TLR3^-/- CLP-induced ALI and WT CLP-induced ALI in the current study. Taken together, these results suggest that in the sepsis-induced ALI model, several TLRs are upregulated and participate in the inflammatory response. Therefore, inhibition of multiple TLRs including TLR2, 9, and especially TLR4 simultaneously, but not TLR3, may be a potential therapeutic target for the treatment of sepsis-induced ALI.

Resveratrol and Its Effects on the Vascular System

Resveratrol, the phenolic substance isolated initially from Veratrum grandiflorum and richly present in grapes, wine, peanuts, soy, and berries, has been attracting attention of scientists and medical doctors for many decades. Herein, we review its effects on the vascular system. Studies utilizing cell cultures and pre-clinical models showed that resveratrol alleviates oxidative stress and inflammation. Furthermore, resveratrol suppresses vascular smooth muscle cell proliferation, promotes autophagy, and has been investigated in the context of vascular senescence. Pre-clinical models unambiguously demonstrated numerous vasculoprotective effects of resveratrol. In clinical trials, resveratrol moderately diminished systolic blood pressure in hypertensive patients, as well as blood glucose in patients with diabetes mellitus. Yet, open questions remain, as exemplified by a recent report which states that the intake of resveratrol might blunt certain positive effects of exercise in older persons, and further research addressing the framework for long-term use of resveratrol as a food supplement, will stay in demand.