Fernando Petacci

Bio: Fernando Petacci is an academic researcher from Federal University of São Carlos. The author has contributed to research in topics: Dimorphandra mollis & Astilbin. The author has an hindex of 4, co-authored 4 publications receiving 92 citations.

Biological activity of astilbin from Dimorphandra mollis against Anticarsia gemmatalis and Spodoptera frugiperda

Abstract: Astilbin was isolated in high yield from Dimorphandra mollis, and its insecticidal and growth inhibiting activity by stomach ingestion were evaluated against Anticarsia gemmatalis and Spodoptera frugiperda. The insecticidal activity of astilbin, the weight reduction of the larval phase and the prolongation of the larval and pupal phases were verified for both species. Astilbin was identified on the base of its NMR, MS and physical data.

Toxicity of Dimorphandra mollis to Workers of Apis mellifera

Abstract: In this communication we have evaluated the toxic properties of methanol extracts from flowers, peduncles, leaves, petioles and stem bark of Dimorphandra mollis to Apis mellifera workers. Astilbin (5,7,3',4'-tetrahydroxy¾2,3-dihydroflavonol-3-b-O-rhamnoside) has been isolated from peduncles and flowers of this plant in large amounts. Astilbin presented insecticidal activity against confined bees. The results suggest that astilbin reduces the average survival of treated bees.

Oral toxicity of chemical substances found in Dimorphandra mollis (Caesalpiniaceae) against honeybees (Apis mellifera) (Hymenoptera: Apidae)

Abstract: Departamento de Biologia Centro de Estudos de Insetos Sociais UNESP, Av. 24-A, 1515, CEP-13506-900, Rio Claro, SP

Astilbin toxicity to leaf-cutting ant Atta sexdens rubropilosa (Hymenoptera: Formicidae)

Abstract: Centro de Estudos de Insetos Sociais Universidade Estadual Paulista UNESP, Caixa Postal 199, CEP 13506-900, Rio Claro - SP

Consumptive emasculation: the ecological and evolutionary consequences of pollen theft.

Abstract: Many of the diverse animals that consume floral rewards act as efficient pollinators; however, others 'steal' rewards without 'paying' for them by pollinating. In contrast to the extensive studies of the ecological and evolutionary consequences of nectar theft, pollen theft and its implications remain largely neglected, even though it affects plant reproduction more directly. Here we review existing studies of pollen theft and find that: (1) most pollen thieves pollinate other plant species, suggesting that theft generally arises from a mismatch between the flower and thief that precludes pollen deposition, (2) bees are the most commonly documented pollen thieves, and (3) the floral traits that typically facilitate pollen theft involve either spatial or temporal separation of sex function within flowers (herkogamy and dichogamy, respectively). Given that herkogamy and dichogamy occur commonly and that bees are globally the most important floral visitors, pollen theft is likely a greatly under-appreciated component of floral ecology and influence on floral evolution. We identify the mechanisms by which pollen theft can affect plant fitness, and review the evidence for theft-induced ecological effects, including pollen limitation. We then explore the consequences of pollen theft for the evolution of floral traits and sexual systems, and conclude by identifying key directions for future research.

Effect of different host plants on nutritional indices of the pod borer, helicoverpa armigera

Abstract: Nutritional indices of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) on different host plants including chickpea (cultivars Arman, Hashem, Azad, and Binivich), common bean (cultivar Khomein), white kidney bean (cultivar Dehghan), red kidney bean (cultivar Goli), cowpea (cultivar Mashhad), tomato (cultivar Meshkin) and potato (cultivars Agria and Satina) were studied under laboratory conditions (25 ± 1 °C, 65 ± 5% RH, 16:8 L:D). Third instar larvae reared on potato Agria showed the highest efficiency of conversion of digested food (ECD) and efficiency of conversion of ingested food (ECI) (50.800 e 0.104% and 13.630 ± 0.016%, respectively). Approximate digestibility (AD) values of the fourth instar larvae were highest (92.651 ± 0.004%) and lowest (57.140 — 0.049%) on chickpea Azad and potato Agria, respectively. The fifth instar larvae fed on tomato Meshkin and white kidney bean Dehghan had the highest consumption index (CI) (3.717 ± 0.091) and relative consumption rate (RCR) (1.620 ± 0.074), respectively. Whole larval instars showed the highest ECI and ECD values on potatoes Satina (14.640 ± 0.014%) and Agria (21.380 ± 0.015%), respectively, and the lowest of both values on tomato Meshkin (ECI: 5.748 ± 0.002% and ECD: 7.341 ± 0.002%). The results of nutritional indices and the cluster analysis indicated that tomato Meshkin was an unsuitable host for feeding of H. armigera.

Astilbin suppresses collagen-induced arthritis via the dysfunction of lymphocytes.

Abstract: Objective and Design: To examine the therapeutic effects of astilbin, a flavanoid isolated from Rhizoma Smilacis Glabrae, on arthritis and to compare it with cyclosporine A (CsA). Materials and Methods: Type II collagen-induced arthritis in mice and its in vitro assays for proliferation, matrix metalloproteinase (MMP) and NO production were performed. Results: Astilbin dose-dependently inhibited the footpad swelling, arthritic incidence, and clinical scores without influencing the body weights, while CsA showed strong inhibition with a significant weight loss. Histological examination revealed marked inflammatory damage in arthritic mice including joint swelling, synovial hyperplasia, and cartilage destruction. Against these, an intact joint structure was maintained in astilbin-treated or CsA-treated mice. In isolated spleen cells from arthritic mice, increased potentials in proliferation, NO production, and MMP-2 and 9 activities were suppressed dose-dependently by the oral administration of astilbin. Additionally, astilbin showed neither any cytotoxicity to nor influence on Con A-induced proliferation of spleen cells from naive mice, while CsA showed a dose-dependent cytotoxicity and inhibition of the proliferation. Conclusions: Astilbin may act as an efficient therapeutic agent for arthritis like CsA but with less toxicity. Its mechanism includes a selective suppression on lymphocyte functions via reducing MMP and NO production.

Astilbin inhibits contact hypersensitivity through negative cytokine regulation distinct from cyclosporin A.

Abstract: Background IL-10 is known as a negative regulator for inflammatory diseases, including contact dermatitis. However, only a few drug candidates are reported to induce endogenous IL-10. Objective We sought to elucidate a new mechanism underlying the immunosuppressive properties of astilbin through negative cytokine regulation in comparison with the effective pattern with cyclosporin A. Methods Contact hypersensitivity was induced in mice with picryl chloride. Lymph node cells were isolated for adoptive transfer and cytokine assays. Results Astilbin significantly inhibited contact hypersensitivity when given in the elicitation phase but not in the sensitization phase, whereas cyclosporin A inhibited both phases. Lymph node cells from donor mice administered astilbin failed to adoptively transfer the hypersensitivity. Astilbin in vivo remarkably induced IL-10 expression in lymph node cells at an earlier time and decreased TNF-α and IFN-γ expression at a later time. Furthermore, the in vivo neutralization of IL-10 significantly impaired the effect of astilbin on contact hypersensitivity. In the isolated lymphocytes sensitized with picryl chloride in vivo and challenged with trinitrobenzene–sulfonic acid in vitro , astilbin did not affect the cell proliferation but modulated the above cytokine profiles as its in vivo effect in a concentration-dependent manner and furthermore significantly enhanced the expressions of suppressor of cytokine signaling 1 and 3. On the other hand, cyclosporin A strongly inhibited proinflammatory cytokine production but influenced neither IL-10 nor downstream suppressor of cytokine signaling 1 and 3 expression. Conclusion Astilbin alleviates contact hypersensitivity through a unique mechanism involving a negative cytokine regulation through stimulating IL-10, which is distinct from the immunosuppressant cyclosporin A.