Physalin F, a seco-steroid from Physalis angulata L., has immunosuppressive activity in peripheral blood mononuclear cells from patients with HTLV1-associated myelopathy.

Human T-lymphotropic virus type 1 (HTLV-1) induces a strong activation of the immune system, especially in individuals with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Physalin F is a secosteroid with potent anti-inflammatory and immunomodulatory activities. The present study aimed to investigate the effects of physalin F on peripheral blood mononuclear cells (PBMC) of HAM/TSP subjects. A concentration-dependent inhibition of spontaneous proliferation of PBMC from HAM/TSP subjects was observed in the presence of physalin F, as evaluated by (3)H-thymidine uptake. The IC50 for physalin F was 0.97 ± 0.11 µM. Flow cytometry analysis using Cytometric Bead Array (CBA) showed that physalin F (10 µM) significantly reduced the levels of IL-2, IL-6, IL-10, TNF-α and IFN-γ, but not IL-17A, in supernatants of PBMC cultures. Next, apoptosis induction was addressed by using flow cytometry to evaluate annexin V expression. Treatment with physalin F (10 µM) increased the apoptotic population of PBMC in HAM/TSP subjects. Transmission electron microscopy analysis of PBMC showed that physalin F induced ultrastructural changes, such as pyknotic nuclei, damaged mitochondria, enhanced autophagic vacuole formation, and the presence of myelin-like figures. In conclusion, physalin F induces apoptosis of PBMC, decreasing the spontaneous proliferation and cytokine production caused by HTLV-1 infection.

Physalins B and F, seco-steroids isolated from Physalis angulata L., strongly inhibit proliferation, ultrastructure and infectivity of Trypanosoma cruzi.

We previously observed that physalins have immunomodulatory properties, as well as antileishmanial and antiplasmodial activities. Here, we investigated the anti-Trypanosoma cruzi activity of physalins B, D, F and G. We found that physalins B and F were the most potent compounds against trypomastigote and epimastigote forms of T. cruzi. Electron microscopy of trypomastigotes incubated with physalin B showed disruption of kinetoplast, alterations in Golgi apparatus and endoplasmic reticulum, followed by the formation of myelin-like figures, which were stained with MDC to confirm their autophagic vacuole identity. Physalin B-mediated alteration in Golgi apparatus was likely due to T. cruzi protease perturbation; however physalins did not inhibit activity of the trypanosomal protease cruzain. Flow cytometry examination showed that cell death is mainly caused by necrosis. Treatment with physalins reduced the invasion process, as well as intracellular parasite development in macrophage cell culture, with a potency similar to benznidazole. We observed that a combination of physalins and benznidazole has a greater anti-T. cruzi activity than when compounds were used alone. These results indicate that physalins, specifically B and F, are potent and selective trypanocidal agents. They cause structural alterations and induce autophagy, which ultimately lead to parasite cell death by a necrotic process.

Physalin B inhibits Trypanosoma cruzi infection in the gut of Rhodnius prolixus by affecting the immune system and microbiota.

Physalin B is a natural secosteroidal, extracted from the Solanaceae plant, Physalis angulata, and it presents immune-modulator effects on the bloodsucking bug, Rhodnius prolixus. In this work, R. prolixus was treated with physalin B at a concentration of 1 mg/ml of blood meal (oral application), or 20 ng/insect (applied topically) or 57 ng/cm(2) of filter paper (contact treatment), and infected with Trypanosoma cruzi Dm28c clone (2×10(6) epimastigotes/insect). The three types of applications significantly decreased the number of T. cruzi Dm28c in the gut comparing with the non-treated infected insects (controls). All groups of infected insects treated with physalin B had higher numbers of bacterial microbiota in the gut than the non-treated controls infected with T. cruzi. We observed that the infected physalin B insects with topical and contact treatments had a lower antibacterial activity in the gut when compared with control infected insects. Furthermore, infected insects with the physalin B oral treatment produced higher levels of nitrite and nitrate in the gut than control infected insects. These results demonstrate that physalin B decreases the T. cruzi transmission by inhibiting the parasite development in the insect vector R. prolixus. Herein the importance of physalin B modulation on the immune system and microbiota population in terms of parasite development and transmission are discussed.

Antimalarial activity of physalins B, D, F, and G.

The antimalarial activities of physalins B, D, F, and G (1-4), isolated from Physalis angulata, were investigated. In silico analysis using the similarity ensemble approach (SEA) database predicted the antimalarial activity of each of these compounds, which were shown using an in vitro assay against Plasmodium falciparum. However, treatment of P. berghei-infected mice with 3 increased parasitemia levels and mortality, whereas treatment with 2 was protective, causing a parasitemia reduction and a delay in mortality in P. berghei-infected mice. The exacerbation of in vivo infection by treatment with 3 is probably due to its potent immunosuppressive activity, which is not evident for 2.

Activity of physalin F in a collagen-induced arthritis model.

The effects of physalin F (1), a steroid derivative purified from Physalis angulata, were investigated in models of collagen-induced arthritis in DBA/1 mice and allergic airway inflammation in BALB/c mice. Oral treatment with 1 or dexamethasone caused a marked decrease in paw edema and joint inflammation when compared to vehicle-treated arthritic mice. In contrast, treatment with 1 had no effect in mice with allergic airway inflammation caused by ovalbumin immunization, whereas dexamethasone significantly reduced the number of inflammatory cells and eosinophils in the broncoalveolar lavage fluid and in lung sections of challenged mice. To further demonstrate that 1 acts through a mechanism different from that of glucocorticoids, a nuclear translocation assay was performed of the glucocorticoid receptor (GR) using COS-7 cells transfected with a plasmid encoding for a yellow fluorescent protein (YFP)-GR fusion protein. Untreated or treated cells with 1 had YFP staining mainly in the cytoplasm, whereas in dexamethasone-treated cells the YFP staining was concentrated in the nuclei. It is concluded that the mechanism of the immunosuppressive activity of physalin F is distinct from that of the glucocorticoids.

Atividades antimicrobiana e fototóxica de extratos de frutos e raízes de Physalis angulata L. / Antimicrobial and phototoxic activities of Physalis angulata L (Solanaceae) extracts, fruits and roots

Extratos e frações de frutos e raízes de Physalis angulata L. (Solanaceae) foram ensaiados para encontrar atividade antimicrobiana. Aplicando o método de difusão em agar, todas as amostras foram testadas contra Staphylococcus aureus ATCC 6538. O extrato etanólico dos frutos apresentou atividade antibacteriana, a qual teve a atividade fototóxica estimada em cobaias quando expostas a luz ultravioleta, e não foram observados eritemas. Esses dados impulsionaram a pesquisar diferentes formas de obtenção de extratos da planta, com o objetivo de preparar formulações com atividade anti-séptica, que possam se apresentar mais eficazes e seguras, quando aplicadas no tratamento de doenças infecciosas.

Extracts and fractions of Physalis angulata L. prepared from fruits and roots were assayed to find out antimicrobial activity. Using the agar diffusion method all samples were tested against Staphylococcus aureus ATCC 6538. The ethanolic extract of the fruits displayed bacterial activity. Phototoxic property was estimated with guinea pigs when they were exposed to ultraviolet light, no erythemas were observed. These data encouraged us to look for different forms of extracts wich could be applied as a safe and effective antiseptic product.

Trypanosoma rangeli: effects of physalin B on the immune reactions of the infected larvae of Rhodnius prolixus.

Physalins are seco-steroids obtained from plants of the family Solanaceae. Herein, we tested Physalis angulata L purified physalin B as an immunomodulatory compound in 5th-instar larvae of Rhodnius prolixus, which were systemically infected with the H14 Trypanosoma rangeli strain protozoan. In uninfected insects, the effective concentration of physalin B, which inhibited 50% of the blood ingested (ED(50)) volume, was 15.2+/-1.6 microg/ml of the meal. Ecdysis processes and mortality in uninfected larvae, treated orally with physalin B in concentrations ranging from 1 to 10 microg/ml, was similar to that observed in insects not treated with physalin B. However, R. prolixus larvae previously fed on blood containing 1.0, 0.1, and 0.01 microg of physalin B/ml exhibited mortality rates of 78.1, 54.3, and 12.7%, respectively, 6 days after inoculation of T. rangeli (1 x 10(3) parasites/insect), whereas only 7.2% mortality was observed in the control group, injected with sterile culture medium. The insects treated with physalin B (0.1 microg/ml) and inoculated with T. rangeli did not modify the phenoloxidase (PO) activity and total hemocyte count in the hemolymph. However, physalin B treatment caused a reduction in hemocyte micro-aggregation and nitric oxide production and enhanced the parasitemia in the hemolymph. These results demonstrate that physalin B from P. angulata is a potent immunomodulatory substance for the bloodsucking insect, R. prolixus.

Studies on antimicrobial activity, in vitro, of Physalis angulata L. (Solanaceae) fraction and physalin B bringing out the importance of assay determination

Complex physalin metabolites present in the capsules of the fruit of Physalis angulata L. have been isolated and submitted to a series of assays of antimicrobial activity against Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538P, Neisseria gonorrhoeae ATCC 49226, Escherichia coli ATCC 8739; E. coli ATCC 25922, Candida albicans ATCC 10231 applying different methodologies such as: bioautography, dilution broth, dilution agar, and agar diffusion techniques. A mixture of physalins (pool) containing physalins B, D, F, G inhibit S. aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538P, and N. gonorrhoeae ATCC 49226 at a concentration of 200 mg/æl, using agar dilution assays. The mixture was inactive against P. aeruginosa ATCC27853, E. coli ATCC 8739; E. coli ATCC 25922, C. albicans ATCC 10231 when applying bioautography assays. Physalin B (200 æg/ml) by the agar diffusion assay inhibited S. aureus ATCC 6538P by n 85 percent; and may be considered responsible for the antimicrobial activity.

Studies on antimicrobial activity, in vitro, of Physalis angulata L. (Solanaceae) fraction and physalin B bringing out the importance of assay determination.

Complex physalin metabolites present in the capsules of the fruit of Physalis angulata L. have been isolated and submitted to a series of assays of antimicrobial activity against Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538P, Neisseria gonorrhoeae ATCC 49226, Escherichia coli ATCC 8739; E. coli ATCC 25922, Candida albicans ATCC 10231 applying different methodologies such as: bioautography, dilution broth, dilution agar, and agar diffusion techniques. A mixture of physalins (pool) containing physalins B, D, F, G inhibit S. aureus ATCC 29213, S. aureus ATCC 25923, S. aureus ATCC 6538P, and N. gonorrhoeae ATCC 49226 at a concentration of 200 mg/microl, using agar dilution assays. The mixture was inactive against P. aeruginosa ATCC27853, E. coli ATCC 8739; E. coli ATCC 25922, C. albicans ATCC 10231 when applying bioautography assays. Physalin B (200 microg/ml) by the agar diffusion assay inhibited S. aureus ATCC 6538P by +/- 85%; and may be considered responsible for the antimicrobial activity.

Inhibition of macrophage activation and lipopolysaccaride-induced death by seco-steroids purified from Physalis angulata L.

Physalis angulata L. is an annual herb widely used in popular medicine for the treatment of a variety of pathologies. Here, we tested immunomodulatory activities of physalins, seco-steroids purified from P. angulata extracts. Addition of physalins B, F or G, but not D, caused a reduction in nitric oxide production by macrophages stimulated with lipopolysaccaride and interferon-gamma. In the presence of physalin B, macrophages stimulated with lipopolysaccaride, alone or in combination with interferon-gamma, produced lower levels of tumour necrosis factor (TNF)-alpha, interleukin-6 and interleukin-12. The inhibitory activity of physalin B, unlike that of dexamethasone, was not reversed by RU486 [(4-dimethylamino) phenyl-17beta-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one], an antiglucocorticoid. Physalin B-treated mice had lower levels of serum TNF-alpha than control mice after lipopolysaccaride challenge. More importantly, mice injected with physalins B, F or G survived after a lethal lipopolysaccaride challenge. These results demonstrate that seco-steroids from P. angulata are potent immunomodulatory substances and act through a mechanism distinct from that of dexamethasone.