Assessment of inhibitory potential of Pothos scandens L. on ovalbumin-induced airway hyperresponsiveness in balb/c mice

Isolation and antimicrobial activity of secondary metabolites of pothos tener wall

The Pothos genus is extensively utilised in traditional medicine in China and India. An underexplored species of Pothos tener Wall was identified in Sulawesi, Indonesia. Antimicrobial activity was assessed using microdilutions and streak plates against Staphylococcus aureus, Eschericia coli, Aeromonas hydrophila, Aspergillus niger, and Candida albicans. Significant effectiveness was observed in the methanol extract, as indicated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values for three different extracts (methanol, ethyl acetate, and n-hexane) of P. tener. The isolates obtained were structurally analysed using Ultraviolet (UV)-spectroscopy, Fourier-transform Infra Red-Spectroscopy (FT-IR), Mass Spectroscopy (MS), Nuclear Magnetic Resonance (NMR), and antimicrobial testing after undergoing fractionation and subfractionation. The isolate obtained was stigmasterol with moderate antimicrobial activity against A. niger and A. hydrophila, with MIC equivalent to MBC of 500 µg/ml. The first report of stigmasterol from P. tener has potent antimicrobial properties, bolstering empirical data in this field.

Sex-Steroid Signaling in Lung Diseases and Inflammation

Sex/gender difference exists in the physiology of multiple organs. Recent epidemiological reports suggest the influence of sex-steroids in modulating a wide variety of disease conditions. Sex-based discrepancies have been reported in pulmonary physiology and various chronic inflammatory responses associated with lung diseases like asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, and rare lung diseases. Notably, emerging clinical evidence suggests that several respiratory diseases affect women to a greater degree, with increased severity and prevalence than men. Although sex-specific differences in various lung diseases are evident, such differences are inherent to sex-steroids, which are major biological variables in men and women who play a central role to control these differences. The focus of this chapter is to comprehend the sex-steroid biology in inflammatory lung diseases and to understand the mechanistic role of sex-steroids signaling in regulating these diseases. Exploring the roles of sex-steroid signaling in the regulation of lung diseases and inflammation is crucial for the development of novel and effective therapy. Overall, we will illustrate the importance of differential sex-steroid signaling in lung diseases and their possible clinical implications for the development of complementary and alternative medicine to treat lung diseases.

Androgen receptor activation alleviates airway hyperresponsiveness, inflammation, and remodeling in a murine model of asthma

Epidemiological studies demonstrate an apparent sex-based difference in the prevalence of asthma, with a higher risk in boys than girls, which is reversed postpuberty, where women become more prone to asthma than men, suggesting a plausible beneficial role for male hormones, especially androgens as a regulator of pathophysiology in asthmatic lungs. Using a murine model of asthma developed with mixed allergen (MA) challenge, we report a significant change in airway hyperresponsiveness (AHR), as demonstrated by increased thickness of epithelial and airway smooth muscle layers and collagen deposition, as well as Th2/Th17-biased inflammation in the airways of non-gonadectomized (non-GDX) and gonadectomized (GDX) male mice. Here, compared with non-GDX mice, MA-induced AHR and inflammatory changes were more prominent in GDX mice. Activation of androgen receptor (AR) using 5α-dihydrotestosterone (5α-DHT, AR agonist) resulted in decreased Th2/Th17 inflammation and remodeling-associated changes, resulting in improved lung function compared with MA alone challenged mice, especially in GDX mice. These changes were not observed with Flutamide (Flut, AR antagonist). Overall, we show that AR exerts a significant and beneficial role in asthma by regulating AHR and inflammation.

Cellular and Biochemical Analysis of Bronchoalveolar Lavage Fluid from Murine Lungs

Bronchoalveolar lavage (BAL) is a technique used to collect the contents of the airways. The fluid recovered, called BAL fluid (BALF), serves as a dynamic tool to identify various disease pathologies ranging from asthma to infectious diseases to cancer in the lungs. A wide array of tests can be performed with BALF, including total and differential leukocyte counts (DLC), enzyme-linked immunosorbent assays (ELISA) or flow-cytometric quantitation of inflammatory mediators, such as cytokines, chemokines and adhesion molecules, and assessment of nitrate and nitrite content for estimation of nitric oxide synthase (NOS) activity. Here, we describe a detailed procedure for the collection of BALF for a variety of downstream usages, including DLC by cytological and flow-cytometry-based methods, multiplex cytokine analysis by flow cytometry, and NOS activity analysis by determining nitrate and nitrite levels.

Role of Estrogen Receptors α and β in a Murine Model of Asthma: Exacerbated Airway Hyperresponsiveness and Remodeling in ERβ Knockout Mice

Epidemiological data suggests increased prevalence of asthma in females than males, suggesting a plausible role for sex-steroids, especially estrogen in the lungs. Estrogen primarily acts through estrogen-receptors (ERα and ERβ), which play a differential role in asthma. Our previous studies demonstrated increased expression of ERβ in asthmatic human airway smooth muscle (ASM) cells and its activation diminished ASM proliferation in vitro and airway hyperresponsiveness (AHR) in vivo in a mouse (wild-type, WT) model of asthma. In this study, we evaluated the receptor specific effect of circulating endogenous estrogen in regulating AHR and remodeling using ERα and ERβ knockout (KO) mice. C57BL/6J WT, ERα KO, and ERβ KO mice were challenged intranasally with a mixed-allergen (MA) or PBS. Lung function was measured using flexiVent followed by collection of broncho-alveolar lavage fluid for differential leukocyte count (DLC), histology using hematoxylin and eosin (H&E) and Sirius red-fast green (SRFG) and detecting αsmooth muscle actin (α-SMA), fibronectin and vimentin expression using immunofluorescence (IF). Resistance (Rrs), elastance (Ers), tissue-damping (G) and tissue-elasticity (H) were significantly increased, whereas compliance (Crs) was significantly decreased in WT, ERα KO, and ERβ KO mice (males and females) challenged with MA compared to PBS. Interestingly, ERβ KO mice showed declined lung function compared to ERα KO and WT mice at baseline. MA induced AHR, remodeling and immune-cell infiltration was more prominent in females compared to males across all populations, while ERβ KO females showed maximum AHR and DLC, except for neutrophil count. Histology using H&E suggests increased smooth muscle mass in airways with recruitment of inflammatory cells, while SRFG staining showed increased collagen deposition in MA challenged ERβ KO mice compared to ERα KO and WT mice (males and females), with pronounced effects in ERβ KO females. Furthermore, IF studies showed increased expression of α-SMA, fibronectin and vimentin in MA challenged populations compared to PBS, with prominent changes in ERβ KO females. This novel study indicates ERβ plays a pivotal role in airway remodeling and AHR and understanding the mechanisms involved might help to surface it out as a potential target to treat asthma.

The effects of chrysophanol on ovalbumin (OVA)-induced chronic lung toxicology by inhibiting Th17 response

Chrysophanol (CH), extracted from plants of Rheum genus, possesses various pharmacological effects including anti-inflammatory activity. The purpose of the present study was to evaluate the protective effects and the underlying mechanisms of CH on ovalbumin (OVA)-induced asthma in mice. Fifty mice were randomly assigned to five experimental groups: control group, model group, dexamethasone (2 mg/kg) group and CH (5 and 10 mg/kg) groups. The number of eosinophil cells and the production of interleukin-6 (IL-6), IL-1β, IL-17 A and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF) were measured. In addition, pulmonary histopathology, airway resistance (Raw), T-helper17 (Th17) cells frequency and RORγt expression were evaluated. Our study demonstrated that CH effectively decreased eosinophil count and inflammatory cytokines production in BALF. In addition, treatment with CH significantly inhibited the Raw, Th17 percentage and RORγt expression in OVA-induced animals compared with those in model group. Histological studies also demonstrated that CH significantly suppressed OVA-induced eosinophilia in lung tissue compared with model group. Our findings supported that CH can prevent allergic asthma in the mouse model.

In vitro anti-inflammatory activity of Pothos scandens extract in RAW 264.7 cells

Pothos scandens, an edible plant, has been traditionally used for reducing swelling and treating wounds, muscle catches, sprains, bone fractures, blisters, and diarrhea. P. scandens ethanol extract (PSE) was evaluated for its anti-inflammatory potential in lipopolysaccharide-stimulated murine RAW 264.7 cells. Present studies showed that PSE reduced the mRNA expression of inducible nitric oxide synthase and cyclooxygenase-2, followed by a decrease in production of nitric oxide and prostaglandin E₂. In addition, the secretion of pro-inflammatory cytokines such as interleukin (IL)-6 and IL-1β was suppressed by PSE treatment. Immunoblotting analyses demonstrated that PSE inhibited the phosphorylation of extracellular signal-regulated kinase and signal transducer and activator of transcription 3 protein, without altering the phosphorylation of inhibitor of κBα, c-Jun N-terminal kinase, and p38 protein kinase. In conclusion, this study demonstrated that P. scandens exhibited anti-inflammatory activity, which might be useful for the development of anti-inflammatory agents.

Phenolic constituents of the Bangladeshi medicinal plant Pothos scandens and their anti-estrogenic, hyaluronidase inhibition, and histamine release inhibitory activities

Extracts from the stem and roots of the Bangladeshi medicinal plant Pothos scandens L. (Araceae) were isolated, and three hemiterpene glucoside aromatic esters, pothobanosides A (1), B (2), and C (3), and a phenylisobutanoid, pothobanol (4), along with 14 known compounds, were characterized. The isolates were tested for their estrogenic/anti-estrogenic activity using the estrogen-responsive human breast cancer cell lines MCF-7 and T47D, and syringoyl derivatives (2, 3, and canthoside B) showed strong inhibitory activity against both cell lines. Their less oxygenated analogs (1, and markhamioside F) were almost inactive. The isolates were also evaluated for hyaluronidase and histamine release inhibitory activities, and pothobanoside A (1) showed significant hyaluronidase inhibitory activity among the isolated compounds, which was similar to that of the positive control rosmarinic acid. Because hyaluronidase produces an angiogenic response that has been implicated in tumor invasiveness and metastasis, 1 could be valuable as an anti-tumor compound with a different mechanism of action from related compounds (2, 3). Pothobanoside C (3) and pothobanol (4) were also found to inhibit histamine release to a similar degree to the positive control epigallocatechin 3-O-(3"-O-methyl)-gallate. The histamine release inhibitory potency of these isolates may support the traditional uses of this plant in folk medicine.

Salicylic acid derivatives as potential anti asthmatic agents using disease responsive drug delivery system for prophylactic therapy of allergic asthma

Asthma is a multi-factorial and complicated lung disorder of the immune system which has expanded to a wider ambit unveiling its etiology to be omnipresent at both ends of the spectrum involving basic pharmacology and in-depth immunology. As asthma occurs through triggered activation of various immune cells due to different stimuli, it poses a great challenge to uncover specific targets for therapeutic interventions. Recent pharmacotherapeutic approaches for asthma have been focused on molecular targeting of transcription factors and their signaling pathways; mainly nucleus factor kappa B (NFκB) and its associated pathways which orchestrate the synthesis of pro-inflammatory cytokines (IL-1β, TNF-α, GM-CSF), chemokines (RANTES, MIP-1a, eotaxin), adhesion molecules (ICAM-1, VCAM-1) and inflammatory enzymes (cyclooxygenase-2 and iNOS). 5-aminosalicylic acid (5-ASA) and sodium salicylate are known to suppress NFκB activation by inhibiting inhibitor of kappa B kinase (IKκB). In order to target the transcription factor, a suitable carrier system for delivering the drug to the intracellular space is essential. 5-ASA and sodium salicylate loaded liposomes incorporated into PEG-4-acrylate and CCRGGC microgels (a polymer formed by crosslinking of trypsin sensitive peptide and PEG-4-acrylate) could probably suit the needs for developing a disease responsive drug delivery system which will serve as a prophylactic therapy for asthmatic patients.