Neutrophilic Lung Inflammation Suppressed by Picroside II Is Associated with TGF-β Signaling

Pharmacologic Activities of Plant-Derived Natural Products on Respiratory Diseases and Inflammations

Respiratory inflammation is caused by an air-mediated disease induced by polluted air, smoke, bacteria, and viruses. The COVID-19 pandemic is also a kind of respiratory disease, induced by a virus causing a serious effect on the lungs, bronchioles, and pharynges that results in oxygen deficiency. Extensive research has been conducted to find out the potent natural products that help to prevent, treat, and manage respiratory diseases. Traditionally, wider floras were reported to be used, such as Morus alba, Artemisia indica, Azadirachta indica, Calotropis gigantea, but only some of the potent compounds from some of the plants have been scientifically validated. Plant-derived natural products such as colchicine, zingerone, forsythiaside A, mangiferin, glycyrrhizin, curcumin, and many other compounds are found to have a promising effect on treating and managing respiratory inflammation. In this review, current clinically approved drugs along with the efficacy and side effects have been studied. The study also focuses on the traditional uses of medicinal plants on reducing respiratory complications and their bioactive phytoconstituents. The pharmacological evidence of lowering respiratory complications by plant-derived natural products has been critically studied with detailed mechanism and action. However, the scientific validation of such compounds requires clinical study and evidence on animal and human models to replace modern commercial medicine.

Hopes and Limits of Adipose-Derived Stem Cells (ADSCs) and Mesenchymal Stem Cells (MSCs) in Wound Healing

Adipose tissue derived stem cells (ADSCs) are mesenchymal stem cells identified within subcutaneous tissue at the base of the hair follicle (dermal papilla cells), in the dermal sheets (dermal sheet cells), in interfollicular dermis, and in the hypodermis tissue. These cells are expected to play a major role in regulating skin regeneration and aging-associated morphologic disgraces and structural deficits. ADSCs are known to proliferate and differentiate into skin cells to repair damaged or dead cells, but also act by an autocrine and paracrine pathway to activate cell regeneration and the healing process. During wound healing, ADSCs have a great ability in migration to be recruited rapidly into wounded sites added to their differentiation towards dermal fibroblasts (DF), endothelial cells, and keratinocytes. Additionally, ADSCs and DFs are the major sources of the extracellular matrix (ECM) proteins involved in maintaining skin structure and function. Their interactions with skin cells are involved in regulating skin homeostasis and during healing. The evidence suggests that their secretomes ensure: (i) The change in macrophages inflammatory phenotype implicated in the inflammatory phase, (ii) the formation of new blood vessels, thus promoting angiogenesis by increasing endothelial cell differentiation and cell migration, and (iii) the formation of granulation tissues, skin cells, and ECM production, whereby proliferation and remodeling phases occur. These characteristics would be beneficial to therapeutic strategies in wound healing and skin aging and have driven more insights in many clinical investigations. Additionally, it was recently presented as the tool key in the new free-cell therapy in regenerative medicine. Nevertheless, ADSCs fulfill the general accepted criteria for cell-based therapies, but still need further investigations into their efficiency, taking into consideration the host-environment and patient-associated factors.

Kaurenoic acid activates TGF-β signaling

BACKGROUND

Kaurenoic acid (ent-kaur-16-en-19-oic acid: KA) is a key constituent found in the roots of Aralia continentalis Kitagawa (Araliaceae) that has been used for treating rheumatism in traditional Asian medicine.

HYPOTHESIS

Although KA was reported to suppress inflammation by activating Nrf2, the anti-inflammatory function of KA is less characterized. Given the complex nature of the inflammatory response and the critical role of TGF-β in resolving inflammation, we hypothesized that KA suppresses inflammatory response by activating TGF-β signaling.

METHODS

Murine macrophage RAW 264.7, human lung epithelial cell MRC-5, and a TGFβRII defective cell HCT116 were treated with various amounts of KA. KA was also administered to mouse lung via intratracheal (i.t.) route. Phosphorylated Smad2 and Smad3 were analyzed by western blot. TGFβ-dependent gene expression was determined by immunoblotting of α-SMA and luciferase assay.

RESULTS

KA induced the phosphorylation of Smad2 and Smad3, key activator molecules in TGF-β signaling. EW7197, an inhibitor for activin receptor-like kinase 5/TGF-β receptor I (TGFβR1) suppressed KA-mediated phosphorylation of Smad2. Similarly, KA failed to phosphorylate Smad2 in HCT116, suggesting that KA acts through the prototypic TGFβR. KA treatment increased the transcriptional activity driven by a Smad-binding element in a luciferase reporter assay and induced the α-smooth muscle actin (α-SMA). Similarly, i.t. KA induced the phosphorylation of Smad2 and increased the expression ofα-SMA in mouse lungs.

CONCLUSION

KA activated TGF-β signaling, suggesting that TGFβ signaling is associated with KA suppressing inflammation.

Therapeutic Potential of Medicinal Plants and Their Constituents on Lung Inflammatory Disorders

Acute bronchitis and chronic obstructive pulmonary diseases (COPD) are essentially lung inflammatory disorders. Various plant extracts and their constituents showed therapeutic effects on several animal models of lung inflammation. These include coumarins, flavonoids, phenolics, iridoids, monoterpenes, diterpenes and triterpenoids. Some of them exerted inhibitory action mainly by inhibiting the mitogen-activated protein kinase pathway and nuclear transcription factor-κB activation. Especially, many flavonoid derivatives distinctly showed effectiveness on lung inflammation. In this review, the experimental data for plant extracts and their constituents showing therapeutic effectiveness on animal models of lung inflammation are summarized.

Neuroprotective effect of picroside II in brain injury in mice

Various types of brain injury which led to the damage of brain tissue structure and neurological dysfunction continues to be the major causes of disability and mortality. Picroside II (PII) possesses a wide range of pharmacological effects and has been proved to ameliorate ischemia and reperfusion injury of kidney and brain. However, critical questions remain about other brain injuries. We investigated the protective effect of PII in four well-characterized murine models of brain injury. Models showed a subsequent regional inflammatory response and oxidative stress in common, which might be improved by the administration of PII (20 mg/kg). Meanwhile, a series of morphological and histological analyses for reinforcement was performed. In traumatic, ischemic and infectious induced injuries, it was observed that the survival rate, apoptosis related proteins, Caspase-3, and the expression of acute inflammatory cytokines (IL-1β, IL-6 and TNF-α) were significantly alleviated after PII injection, but PII treatment alone showed no effect on them as well. The western blot results indicated that TLR4 and NF-κB were clearly downregulated with PII administration. In conclusion, our results suggested that PII with a recommended concentration of 20 mg/kg could provide neuroprotective effects against multi-cerebral injuries in mice by suppressing the over-reactive inflammatory responses and oxidative stress and attenuating the damage of brain tissue for further neurological recovery.

Picroside II protects against sepsis via suppressing inflammation in mice

Picroside II, an iridoid compound extracted from Picrorhiza, exhibits anti-inflammatory and anti-apoptotic activities. We explored the protective effects and mechanisms of picroside II in a mouse model of sepsis induced by cecal ligation and puncture (CLP), using three groups of mice: Group A (sham), Group B (CLP+NS) and Group C (CLP+20 mg/kg picroside II). The mortality in mice with sepsis was decreased by the administration of picroside II, and lung injury was alleviated simultaneously. Picroside II treatment enhanced bacterial clearance in septic mice. Further, picroside II treatment alleviated the inflammatory response in sepsis and enhanced immune function by inhibiting the activation of NLRP3 inflammasome and NF-κB pathways. Picroside II may represent an anti-inflammatory drug candidate, providing novel insight into the treatment of sepsis.

Evidences of Herbal Medicine-Derived Natural Products Effects in Inflammatory Lung Diseases

Pulmonary inflammation is a hallmark of many respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and acute respiratory syndrome distress (ARDS). Most of these diseases are treated with anti-inflammatory therapy in order to prevent or to reduce the pulmonary inflammation. Herbal medicine-derived natural products have been used in folk medicine and scientific studies to evaluate the value of these compounds have grown in recent years. Many substances derived from plants have the biological effects in vitro and in vivo, such as flavonoids, alkaloids, and terpenoids. Among the biological activities of natural products derived from plants can be pointed out the anti-inflammatory, antiviral, antiplatelet, antitumor anti-allergic activities, and antioxidant. Although many reports have evaluated the effects of these compounds in experimental models, studies evaluating clinical trials are scarce in the literature. This review aims to emphasize the effects of these different natural products in pulmonary diseases in experimental models and in humans and pointing out some possible mechanisms of action.