Topical anti-inflammatory potential of Physalin E from Physalis angulata on experimental dermatitis in mice

The anti-inflammatory effect of physalin E, a seco-steroid isolated from Physalis angulata L. was evaluated on acute and chronic models of dermatitis induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and oxazolone, respectively, in mouse ear. The changes in ear edema/thickness, production of pro-inflammatory cytokines (TNF-alpha and IFN-gamma), myeloperoxidase (MPO) activity, and histological and immunohistochemical findings were analysed, as indicators of dermal inflammation. Similar to dexamethasone, topically applied Physalin E (0.125; 0.25 and 0.5 mg/ear) potently inhibited the TPA and oxazolone-induced dermatitis, leading to substantial reductions in ear edema/thickness, pro-inflammatory cytokines, and MPO activity. These effects were reversed by mifepristone, a steroid antagonist and confirmed by immunohistochemical and histopathological analysis. The data suggest that physalin E may be a potent and topically effective anti-inflammatory agent useful to treat the acute and chronic skin inflammatory conditions.

In-vitro and in-vivo antitumour activity of physalins B and D from Physalis angulata

We have evaluated the in-vitro and in-vivo antitumour activity of physalin B and physalin D isolated from the aerial parts of Physalis angulata. In-vitro, both compounds displayed considerable cytotoxicity against several cancer cell lines, showing IC50 values in the range of 0.58 to 15.18 μg mL−1 for physalin B, and 0.28 to 2.43 μg mL−1 for physalin D. The antitumour activity of both compounds was confirmed in-vivo using mice bearing sarcoma 180 tumour cells. The in-vivo antitumour activity was related to the inhibition of tumour proliferation, as observed by the reduction of Ki67 staining in tumours of treated animals. Histopathological examination of the kidney and liver showed that both organs were affected by physalin treatment, but in a reversible manner. These compounds were probably responsible for the previously described antitumour activity of ethanol extracts of P. angulata, and their identification and characterization presented here could explain the ethnopharmacological use of this species in the treatment of cancer.

Selective cytotoxicity of withaphysalins in myeloid leukemia cell lines versus peripheral blood mononuclear cells

Withaphysalins are C(28)-steroidal lactones structurally based on the ergostane skeleton that possess antiproliferative activity against tumor cell lines. In the present study, the antileukemic actvity of withaphysalin O (1), M (2), and N (3) isolated from Acnistus arborescens, against two leukemic cell lines, HL-60 and K562, was evaluated, and the cytotoxicity compared with the effects on peripheral blood mononuclear cells (PBMC). All tested compounds reduced the number of viable cells of the tumor cell lines after 24 h of exposure, except for compound 2 against the K562 cell line. The reduction was time-and concentration-dependent, and the IC(50) values ranged from 0.7 to 3.5 microM after 72 h of incubation. In addition to the growth inhibitory properties, the drugs decreased DNA synthesis after 24 h of drug exposure evaluated by the 5-bromo-2 -deoxyuridine incorporation method. None of the tested compounds reduced the number of PBMC (IC(50)>20 microM) after 72 h of incubation, in contrast to doxorubicin that decreased viable cells and increased non-viable cells even after 24 h of incubation. Morphological analysis of treated cells using hematoxylin/eosin staining indicated the presence of necrotic cells for all tested compounds in HL-60, confirmed by the use of acridine orange/ethidium bromide staining. In addition to necrotic cells, K562 cells showed morphological alterations consistent with apoptosis.

Cytotoxic epimeric withaphysalins from leaves of Acnistus arborescens

Phytochemical analysis of the leaves of Acnistus arborescens (Solanaceae) resulted in the isolation of two new epimeric withaphysalins (17S,20R,22R)-5beta,6beta: 18,20-diepoxy-4beta,18-dihydroxy-1-oxowitha-24-enolide (2, 18R and 18S), together with the known withaphysalin F (1, 18R and 18S). Their structures were established by spectroscopic methods, including 2D NMR data and comparison with literature data. Compounds 1 and 2 dis-played potent cytotoxic activities against several cancer cell lines with IC50 values in the range of 0.20 to 1.46 microg/mL for 1 and 0.89 to 8.08 microg/mL for 2. The strong cytotoxicity presented by 1 suggests that in this series of compounds, the 2,3-unsaturated ketone moiety is an important pharmacophoric unit. The cytotoxic activity seemed to be related to DNA synthesis inhibition, as revealed by the reduction of 5-bromo-2'-deoxyuridine incorporation after 24 hours of incubation on leukemic cells.

Cytotoxic withaphysalins from the leaves of Acnistus arborescens

Three withaphysalins, rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-1,18-dioxowitha-2,24-dienolide(withaphysalin M) (1), rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-18-ethoxy-1-oxowitha-2,24-dienolide (withaphysalin F ethyl ether, withaphysalin O) (2), and rel-(17S,20R,22R)-5 beta,6 beta:18,20-diepoxy-4 beta-hydroxy-1,18-dioxowitha-24-enolide (withaphysalin N) (3), were isolated from the leaves of Acnistus arborescens. The structures were deduced from 1D ((1)H NMR, (13)C NMR, DEPT-(13)C NMR) and 2D (COSY, HMQC, HMBC) NMR analysis and the relative stereochemical assignments based on 1D NOESY correlations and analysis of coupling constants. Compounds 1 and 2 displayed potent cytotoxic activity against a panel of human cancer cell lines.