Therapeutic Applications of Physalins: Powerful Natural Weapons

Protective Effects of Physalis angulata on Podocythopathies Through B-Cell-Activating Factor Inhibition in Doxorubicin-Induced Nephrotic Syndrome Rat Model

Background/Objectives: Nephrotic syndrome, a glomerular disease caused by podocyte dysfunction, is characterized by proteinuria, hypoalbuminemia, edema, and hyperlipidemia. Current treatment relies on corticosteroids, which carry the risk of long-term side effects. Physalis angulata has potential as an adjunct therapy for immune-mediated kidney injury. This study aims to evaluate the effects of Physalis angulata extracts on anti-nephrin IgG, IL-4, and podocytopathy through BAFF inhibition in a doxorubicin-induced nephrotic syndrome rat model. Methods: This experimental study involved 36 Sprague-Dawley rats divided into control and treatment groups. The treatment groups received Physalis angulata extract at doses of 500 mg/kgBW, 1500 mg/kgBW, and 2500 mg/kgBW, or in combination with prednisone, alongside a group receiving prednisone monotherapy. Podocytopathy was assessed using proteinuria, nephrin, podocalyxin, and GLEPP-1. Proteinuria was measured using spectrophotometry. Serum BAFF levels, renal IL-4, urinary nephrin, and urinary podocalyxin were analyzed using ELISA. Renal nephrin, renal podocalyxin, GLEPP-1, and BAFF expression were evaluated by immunofluorescence microscopy. The data were analyzed using SPSS 25. Results: The results showed significant reductions in proteinuria, serum BAFF levels, renal BAFF expression, anti-nephrin IgG, IL-4, urinary nephrin, and urinary podocalyxin, along with significant increases in GLEPP-1, renal nephrin, and renal podocalyxin expression, in all treatment groups compared to the nephrotic syndrome control group. The combination of Physalis angulata at 2500 mg/kgBW with prednisone demonstrated the best effects. Conclusions: Physalis angulata shows promise as an adjuvant therapy for nephrotic syndrome by improving podocytopathy through BAFF inhibition. Further research is needed to evaluate its long-term safety, optimize dosing, and explore clinical applications in humans.

Untargeted Chemical Profile, Antioxidant, and Enzyme Inhibition Activity of Physalis angulata L. from the Peruvian Amazon: A Contribution to the Validation of Its Pharmacological Potential

Physalis angulata is a plant of great value in traditional medicine known for its content of bioactive compounds, such as physalins and withanolides, which possess diverse biological activities. In this study, the chemical profile, antioxidant activity, and enzyme inhibition capacity of aqueous and ethanolic extracts obtained from the root, stem, leaves, calyx, and fruits of P. angulata collected in Peru were evaluated. A total of forty-two compounds were detected in the extracts using UHPLC-ESI-QTOF-MS analysis. In vitro analyses revealed that leaf extracts contained the highest concentration of phenolic compounds, while leaf and fruit extracts showed the best results in FRAP, DPPH, and ABTS antioxidant tests; on the other hand, inhibition of AChE, BChE, α-glucosidase, and α-amylase enzymes was variable, but calyx and fruit extracts showed higher effectiveness. In silico analyses indicated that the compounds physagulin A, physagulin F, physagulide P, physalin B, and withaminimin showed stable interactions and favorable binding affinities with the catalytic sites of the enzymes studied. These results confirm the pharmacological potential of extracts and compounds derived from different organs of P. angulata, suggesting their promising use in treating diseases related to the central nervous system and metabolic syndrome.

Physalin F, a Potent Inhibitor of Lymphocyte Function, Is a Calcineurin Inhibitor and Has Synergistic Effect with Dexamethasone

The dysregulation of immune responses are responsible for the development of several diseases, such as allergic and autoimmune diseases. The medications used to treat these conditions have numerous side effects, creating the need for new drugs. Physalins are natural compounds with various pharmacological activities already described. Here, we aimed to investigate the immunomodulatory effects of physalin F in mouse splenocytes and in a delayed-type hypersensitivity (DTH) model. In a cytotoxicity assay, physalin F had low cytotoxicity to mouse splenocytes in concentrations equal to or below 2 µM. It significantly inhibited lymphocyte proliferation in a concentration-dependent manner and reduced the production of cytokines, including IL-2, IL-4, IL-10, and IFN-γ, in activated splenocytes. The combined therapy of physalin F with dexamethasone was investigated in vitro, showing a synergistic action of the two compounds. Mechanistically, physalin F reduced calcineurin activity in concanavalin A-stimulated splenocyte cultures. Finally, in vivo, the intraperitoneal administration of physalin F in a DTH model reduced paw edema induced by bovine serum albumin immunization. Our results demonstrate the potential of physalin F as an immunosuppressive agent, to be used alone or in combination with glucocorticoids.

Unveiling the Potential of Natural Resources-Derived Therapeutics for Improved Malaria Management: Computational to Experimental Studies

Malaria kills millions of people annually, and it is one of the major causes of preventable mortality in the world. Of the different plasmodium species that induce malaria, Plasmodium falciparum and Plasmodium vivax account for the most severe form of malarial disease in humans. This review focuses on understanding preventive measures, mutation-based disease evolution, malaria-related biomarkers, and potential plant bioactive components for the treatment and management of malaria. The burden of malaria drug resistance has made it necessary for scientists to focus on alternative therapeutics, with particular interests in those involving plant-based bioactive components that could mediate biochemical pathways, consisting of metabolic interactions essential for parasitic inhibition. To avoid artefacts or false positives, these bioactive components from plant sources are further filtered using the "pan-assay-interfering compounds" (PAINS) tool. This review discussed the history of malaria treatment, current treatment options, malaria preventive measures, and challenges associated with current treatment strategies. Additionally, this work discusses the barriers while developing drugs from phytochemicals and the steps needed to accelerate the development of new antimalarial from the lead compounds.

Physalins and neophysalins from the calyx of Physalis alkekengi: Structures and anti-inflammatory efficacy

To explore potential anti-inflammatory lead compounds, ten new physalin steroids, including three neophysalins (1, 4, and 9) and seven physalins (2, 3, 5-8, and 10), along with eleven known analogs, were isolated from an ethanol extract of the calyx of Physalis alkekengi. The new structures were rigorously determined through comprehensive HRESIMS, 1D/2D-NMR, and X-ray diffraction analysis. Among these compounds, 1 was identified as a new 1,10-seco-neophysalin, and 2 was identified as a new 11,15-cyclo-9,10-seco-physalin characterized by an aromatic A-ring. Evaluation of the anti-inflammatory activities of the isolated compounds revealed that compound 15 displayed remarkable potency, inhibiting NO production in RAW 264.7 macrophages with an IC50 value of 2.26 ± 0.12 μM, while exhibiting low cytotoxicity (IC50 = 90.45 ± 6.10 μM). It suppressed the expression levels of IL-6, IL-1β, iNOS and COX-2, while upregulating the expression levels of HO-1 and Nrf2, indicating the involvement of multiple mechanisms. Further studies indicated that compound 15 significantly attenuated the LPS-induced increase in the phosphorylation of p38, ERK, and JNK in a dose-dependent manner, indicating its potential to exert anti-inflammatory effects through modulation of the MAPK signaling pathway. In vivo studies further demonstrated the efficacy of compound 15, as it showed inhibitory activity against mouse ear edema, achieving an inhibition rate of 37.30 % at a dosage of 25 mg/kg. Importantly, compound 15 (25 mg/kg) significantly ameliorated colitis-related symptoms in a dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) model, highlighting its potential as a therapeutic candidate for inflammatory disorders.

Inhibition of B-cell activating factor activity using active compounds from Physalis angulata in the mechanism of nephrotic syndrome improvement: A computational approach

Nephrotic syndrome, a multifaceted medical condition characterized by significant proteinuria, has recently prompted a reorientation of research efforts toward B-cell-mediated mechanisms. This shift underscores the pivotal role played by B-cells in its pathogenesis. The aim of this study was to explore potential therapeutic pathways, with specific attention given to compounds found in Physalis angulata, including withanolides, such as physalins, which constitute one of the five distinct withanolide subgroups identified in Physalis angulata. Furthermore, the study assessed the monoclonal antibody belimumab, designed to target B-cell activating factor (BAFF) and its associated receptors (TACI, BCMA, and BAFF-R). Various research techniques were employed, encompassing data mining, bioactivity analysis, Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) profiling, molecular modeling, and docking studies. Withanolide was demonstrated as a potential inhibitor for the protein BAFF, showing a binding energy of -7.1 kcal/mol. Physalin F emerged as the leading candidate inhibitor for the protein TACI, with a binding energy of -8.3 kcal/mol. Similarly, withanolide was identified as the top inhibitor candidate for the protein BCMA, exhibiting a binding energy of -7.0 kcal/mol. The most favorable interaction with BAFF-R was physalin F, which displayed a binding energy of -8.0 kcal/mol. Moreover, molecular dynamic simulation suggested that physalin F was able to maintain protein stability, hence being a good inhibitor candidate for BAFF-R and TACI proteins. The results of this investigation demonstrated substantial promise, indicating that these withanolides and withaphysalin A compounds derived from Physalis angulata offer alternative avenues for B-cell targeting. Consequently, this study presents opportunities for pioneering treatments in the management of nephrotic syndrome.

Therapeutic role of physalin A in the pathogenesis of Graves' orbitopathy

BACKGROUND

Graves' orbitopathy (GO) is an autoimmune condition that causes serious ocular symptoms; its treatment strategies are limited. Physalin A is a phytosterol that has shown various therapeutic properties, including anti-inflammatory and anti-fibrotic effects. In this study, we investigated whether physalin A could inhibit inflammation, fibrosis, hyaluronan (hyaluronic acid) production, and adipogenesis, which are crucial to the pathogenesis of GO.

METHODS

Orbital tissue explants were obtained from patients with GO during orbital decompression surgery and healthy controls. Orbital fibroblasts (OFs) were isolated and treated with different concentrations of physalin A. Using western blot and ELISA analyses, we determined the effects of physalin A on OFs.

RESULTS

Physalin A treatment suppressed the production of interleukin (IL)-1β-induced prostaglandin E2 (PGE2) and pro-inflammatory molecules, including cyclooxygenase (COX)-2, IL-6, IL-8, and intercellular adhesion molecule (ICAM)-1. We discovered that physalin A attenuated hyaluronan production induced by IL-1β or insulin-like growth factor (IGF)-1. Moreover, physalin A reduced lipid droplet formation and production of peroxisome proliferator activator (PPAR) γ, CCAAT-enhancer-binding protein (C/EBP) α, C/EBP β, sterol regulatory element binding protein (SREBP)-1, leptin, and adiponectin proteins. Physalin A suppressed the phosphorylation of extracellular signal-related kinase (ERK), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and suppressor of mothers against decapentaplegic (SMAD) 2 signaling protein.

CONCLUSIONS

Our study suggests that the major mechanisms by which physalin A suppresses GO include reducing inflammation, fibrosis, hyaluronan production, and adipogenesis in OFs. The findings of this study provide evidence of the therapeutic effect of physalin A in GO.

Covalent binding of withanolides to cysteines of protein targets

Withanolides represent an important category of natural products with a steroidal lactone core. Many of them contain an α,β-unsaturated carbonyl moiety with a high reactivity toward sulfhydryl groups, including protein cysteine thiols. Different withanolides endowed with marked antitumor and anti-inflammatory have been shown to form stable covalent complexes with exposed cysteines present in the active site of oncogenic kinases (BTK, IKKβ, Zap70), metabolism enzymes (Prdx-1/6, Pin1, PHGDH), transcription factors (Nrf2, NFκB, C/EBPβ) and other structural and signaling molecules (GFAP, β-tubulin, p97, Hsp90, vimentin, Mpro, IPO5, NEMO, …). The present review analyzed the covalent complexes formed through Michael addition alkylation reactions between six major withanolides (withaferin A, physalin A, withangulatin A, 4β-hydroxywithanolide E, withanone and tubocapsanolide A) and key cysteine residues of about 20 proteins and the resulting biological effects. The covalent conjugation of the α,β-unsaturated carbonyl system of withanolides with reactive protein thiols can occur with a large set of soluble and membrane proteins. It points to a general mechanism, well described with the leading natural product withaferin A, but likely valid for most withanolides harboring a reactive (electrophilic) enone moiety susceptible to react covalently with cysteinyl residues of proteins. The multiplicity of reactive proteins should be taken into account when studying the mechanism of action of new withanolides. Proteomic and network analyses shall be implemented to capture and compare the cysteine covalent-binding map for the major withanolides, so as to identify the protein targets at the origin of their activity and/or unwanted effects. Screening of the cysteinome will help understanding the mechanism of action and designing cysteine-reactive electrophilic drug candidates.

Physalin H, physalin B, and isophysalin B suppress the quorum-sensing function of Staphylococcus aureus by binding to AgrA

The virulence of Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), depends on the expression of toxins and virulence factors controlled by the quorum-sensing (QS) system, encoded on the virulence accessory gene regulator (agr) locus. The aim of this study was to identify a phytochemical that inhibits Agr-QS function and to elucidate its mechanism. We screened 577 compounds and identified physalin H, physalin B, and isophysalin B--phytochemicals belonging to physalins found in plants of the Solanaceae family--as novel Agr-QS modulators. Biological analyses and in vitro protein-DNA binding assays suggested that these physalins suppress gene expression related to the Agr-QS system by inhibiting binding of the key response regulator AgrA to the agr promoters, reducing the function of hemolytic toxins downstream of these genes in MRSA. Furthermore, although physalin F suppressed gene expression in the Agr-QS system, its anti-hemolytic activity was lower than that of physalins H, B, and isophysalin B. Conversely, five physalins isolated from the same plant with the ability to suppress Agr-QS did not reduce bacterial Agr-QS activity but inhibited AgrA binding to DNA in vitro. A docking simulation revealed that physalin interacts with the DNA-binding site of AgrA in three docking states. The carbonyl oxygens at C-1 and C-18 of physalins, which can suppress Agr-QS, were directed to residues N201 and R198 of AgrA, respectively, whereas these carbonyl oxygens of physalins, without Agr-QS suppression activity, were oriented in different directions. Next, 100-ns molecular dynamics simulations revealed that the hydrogen bond formed between the carbonyl oxygen at C-15 of physalins and L186 of AgrA functions as an anchor, sustaining the interaction between the carbonyl oxygen at C-1 of physalins and N201 of AgrA. Thus, these results suggest that physalin H, physalin B, and isophysalin B inhibit the interaction of AgrA with the agr promoters by binding to the DNA-binding site of AgrA, suppressing the Agr-QS function of S. aureus. Physalins that suppress the Agr-QS function are proposed as potential lead compounds in the anti-virulence strategy for MRSA infections.

Targeting Cell Signaling Pathways in Lung Cancer by Bioactive Phytocompounds

Lung cancer is a heterogeneous group of malignancies with high incidence worldwide. It is the most frequently occurring cancer in men and the second most common in women. Due to its frequent diagnosis and variable response to treatment, lung cancer was reported as the top cause of cancer-related deaths worldwide in 2020. Many aberrant signaling cascades are implicated in the pathogenesis of lung cancer, including those involved in apoptosis (B cell lymphoma protein, Bcl-2-associated X protein, first apoptosis signal ligand), growth inhibition (tumor suppressor protein or gene and serine/threonine kinase 11), and growth promotion (epidermal growth factor receptor/proto-oncogenes/phosphatidylinositol-3 kinase). Accordingly, these pathways and their signaling molecules have become promising targets for chemopreventive and chemotherapeutic agents. Recent research provides compelling evidence for the use of plant-based compounds, known collectively as phytochemicals, as anticancer agents. This review discusses major contributing signaling pathways involved in the pathophysiology of lung cancer, as well as currently available treatments and prospective drug candidates. The anticancer potential of naturally occurring bioactive compounds in the context of lung cancer is also discussed, with critical analysis of their mechanistic actions presented by preclinical and clinical studies.

Physalis pubescens L. branch and leaf extracts inhibit lymphoma proliferation by inducing apoptosis and cell cycle arrest

Physalis pubescens L. is an annual or perennial plant in the family Solanaceae It is used in traditional medicine for treating sore throats, coughs, urinary discomfort, and astringent pain, and externally for pemphigus and eczema in northern China. The proliferation inhibitory activity and mechanisms of the ethyl acetate extract (PHY-EA) from the leaves of Physalis pubescens were investigated. High performance liquid chromatography was used to identify the chemical composition of PHY-EA; sulforhodamine B was used to detect the proliferation inhibitory effect of PHY-EA on MCF-7, CA-46, Hela, HepG2, B16, and other tumor cells; flow cytometry was used to detect the effect of PHY-EA on the lymphoma cell cycle and apoptosis; Western blot was used to detect the expression of the cycle- and apoptosis-related proteins. The expression of Ki-67 and cleaved caspase 3 was detected by immunohistochemistry. The results showed that PHY-EA contained physalin B, physalin O, and physalin L. PHY-EA blocked the cell cycle of G2/M→G0/G1 in lymphoma cells and induced apoptosis in tumor cells. Mouse transplantation tumor experiments showed that PHY-EA had a significant inhibitory effect on mouse transplantation tumors, and the tumor volume and weight were significantly reduced. In conclusion, PHY-EA has a good antiproliferative effect on Burkkit lymphoma, indicating its potential medicinal value.