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Antivenoms, produced using animal hyperimmune plasma, remains the standard therapy for snakebites. Although effective against systemic damages, conventional antivenoms have limited efficacy against local tissue damage. Additionally, the hypersensitivity reactions, often elicited by antivenoms, the high costs for animal maintenance, the difficulty of producing homogeneous lots, and the instability of biological products instigate the search for innovative products for antivenom therapy. In this study, camelid antibody fragments (VHH) with specificity to Bothropstoxin I and II (BthTX-I and BthTX-II), two myotoxic phospholipases from Bothrops jararacussu venom, were selected from an immune VHH phage display library. After biopanning, 28 and 6 clones recognized BthTX-I and BthTX-II by ELISA, respectively. Complementarity determining regions (CDRs) and immunoglobulin frameworks (FRs) of 13 VHH-deduced amino acid sequences were identified, as well as the camelid hallmark amino acid substitutions in FR2. Three VHH clones (KF498607, KF498608, and KC329718) were capable of recognizing BthTX-I by Western blot and showed affinity constants in the nanomolar range against both toxins. VHHs inhibited the BthTX-II phospholipase A2 activity, and when tested for cross-reactivity, presented specificity to the Bothrops genus in ELISA. Furthermore, two clones (KC329718 and KF498607) neutralized the myotoxic effects induced by B. jararacussu venom, BthTX-I, BthTX-II, and by a myotoxin from Bothrops brazili venom (MTX-I) in mice. Molecular docking revealed that VHH CDRs are expected to bind the C-terminal of both toxins, essential for myotoxic activity, and to epitopes in the BthTX-II enzymatic cleft. Identified VHHs could be a biotechnological tool to improve the treatment for snake envenomation, an important and neglected world public health problem.

Toxic effects triggered by crotalic envenoming are mainly related to crotoxin (CTX), composed of a phospholipase A2 (CB) and a subunit with no toxic activity (CA). Camelids produce immunoglobulins G devoid of light chains, in which the antigen recognition domain is called VHH. Given their unique characteristics, VHHs were selected using Phage Display against CTX from Crotalus durissus terrificus. After three rounds of biopanning, four sequence profiles for CB (KF498602, KF498603, KF498604, and KF498605) and one for CA (KF498606) were revealed. All clones presented the VHH hallmark in FR2 and a long CDR3, with the exception of KF498606. After expressing pET22b-VHHs in E. coli, approximately 2 to 6 mg of protein per liter of culture were obtained. When tested for cross-reactivity, VHHs presented specificity for the Crotalus genus and were capable of recognizing CB through Western blot. KF498602 and KF498604 showed thermostability, and displayed affinity constants for CTX in the micro or nanomolar range. They inhibited in vitro CTX PLA2 activity, and CB cytotoxicity. Furthermore, KF498604 inhibited the CTX-induced myotoxicity in mice by 78.8%. Molecular docking revealed that KF498604 interacts with the CA–CB interface of CTX, seeming to block substrate access. Selected VHHs may be alternatives for the crotalic envenoming treatment.

Antivenoms, produced using animal hyperimmune plasma, remains the standard therapy for snakebites. Although effective against systemic damages, conventional antivenoms have limited efficacy against local tissue damage. Additionally, the hypersensitivity reactions, often elicited by antivenoms, the high costs for animal maintenance, the difficulty of producing homogeneous lots, and the instability of biological products instigate the search for innovative products for antivenom therapy. In this study, camelid antibody fragments (VHH) with specificity to Bothropstoxin I and II (BthTX-I and BthTX-II), two myotoxic phospholipases from Bothrops jararacussu venom, were selected from an immune VHH phage display library. After biopanning, 28 and 6 clones recognized BthTX-I and BthTX-II by ELISA, respectively. Complementarity determining regions (CDRs) and immunoglobulin frameworks (FRs) of 13 VHH-deduced amino acid sequences were identified, as well as the camelid hallmark amino acid substitutions in FR2. Three VHH clones (KF498607, KF498608, and KC329718) were capable of recognizing BthTX-I by Western blot and showed affinity constants in the nanomolar range against both toxins. VHHs inhibited the BthTX-II phospholipase A.sub.2 activity, and when tested for cross-reactivity, presented specificity to the Bothrops genus in ELISA. Furthermore, two clones (KC329718 and KF498607) neutralized the myotoxic effects induced by B. jararacussu venom, BthTX-I, BthTX-II, and by a myotoxin from Bothrops brazili venom (MTX-I) in mice. Molecular docking revealed that VHH CDRs are expected to bind the C-terminal of both toxins, essential for myotoxic activity, and to epitopes in the BthTX-II enzymatic cleft. Identified VHHs could be a biotechnological tool to improve the treatment for snake envenomation, an important and neglected world public health problem.

Amazonian Robustas are ten new clones of high yield potential with characteristics typical of the botanical varieties conilon and robusta. With individual registration, the new cultivars were developed to be grown together with other clones, with flexibility of composition of the crops according to the preference of the producer.

Meloidogyne incognita (kofoid & white) chitwood. is one of the species of phytoparasitic nematodes that causes the most losses to world agriculture. The aim of the study was to evaluate the effect of the aqueous extracts of Tithonia diversifolia and Gymnanthemum amygdalinum on the hatching of juveniles of M. incognita and their effect on tomato plants. The extracts were obtained by dynamic infusion. For the in vitro test, microtubes containing extract and the suspension of nematode eggs were prepared. After 15 days of incubation, the number of eggs and mobile and immobile juveniles were evaluated to calculate hatch inhibition. The results demonstrated that all the tested extracts had an inhibitory effect on the hatching of M. incognita when compared to the conventional nematicide. In the in vivo test, tomato plants of the cultivar Santa Cruz Kada, aged three weeks, were inoculated with a suspension with 2000 eggs of M. incognita and subjected to application of the extracts. After 60 days, the reproduction factor (FR) and the number of galls/grams of root (NGGR) were evaluated, as well as the weight of the fresh root material (PMFR) and the aerial part of the plants (PFPA). The best results were observed in plants treated with the extract of the leaves and dry stem of T. diversifolia.

A cultura do café está sujeita ao ataque de pragas que podem afetar o desenvolvimento e a produção das plantas, sendo relevantes alternativas de controle de insetos que diminuam os efeitos adversos de inseticidas como o emprego de plantas e uso de seus componentes químicos com ação inseticida. Este trabalho visou avaliar o uso de extratos botânicos de Piper carniconnectivum, Piper permucronatum, Piper tubercullatum, Piper umbellatum, Cecropia sp., Cymbopogon citratus, Eucalyptus citriodora, Vismia guianensis no controle da broca-do-café. O trabalho foi conduzido nos Laboratórios de Entomologia e de Fitopatologia da Embrapa Rondônia. Para os experimentos, extratos obtidos a partir de folhas secas e frescas foram utilizados e testados seu potencial inseticida, assim como a efetividade das vias de aplicação (uso tópico, superfície contaminada e pulverização dirigida. O extrato hidroalcoólico (seco) da folha de Piper tuberculatum apresentou 90% de mortalidade e o de Piper umbellatum 65% de mortalidade. Das espécies, cujos extratos botânicos frescos foram avaliados, Vismia guianensis e Piper tuberculatum apresentaram efeito de mortalidade de 80% e 50%, respectivamente. A caracterização qualitativa dos extratos de Vismia guianensis, Piper umbellatum e Piper tuberculatum demonstraram a presença de componentes químicos como saponinas, compostos fenólicos, flavonoides e taninos. Os extratos mostraram-se como uma possibilidade em potencial de estratégia de manejo da broca por apresentar menos riscos ao meio ambiente e à saúde humana. Assim se torna relevante a continuidade dos estudos para a inserção segura dos produtos botânicos no mercado.

Fusarium oxysporum Schlecht and Thanatephorus cucumeris (A.B. Frank) Donk are fungi which cause some diseases in important plant cultures in Brazil - like bananas and beans. Hedychium coronarium J. König is a native plant from Asia that currently occurs in Brazil, where it is used in folk medicine to treat infections in general. The objective of this work was to evaluate the effect of the H. coronarium essential oil from leaves on the in vitro growth of F. oxysporum and T. cucumeris colonies. Discs of 5 mm diameter from isolated cultures of each fungi were placed in the center of 90 mm diameter Petri dishes with potato dextrose agar. In the peripheral area of the dishes four discs of filter paper were placed with 10 µL of essential oil, extracted through distillation system. For a control treatment, discs without essential oil were used. A completely randomized design was used with four replications (of four dishes). Every 24 hours for 8 days the fungi growth was evaluated by measuring the diameter of the colonies. After 192 hours F. oxysporum colonies had 37.4 mm diameter in the treatment with essential oil, while in the control the diameter was 66.4 mm. T. cucumeris colonies reached 11.9 mm diameter with essential oil and covered the dishes in the control. The results showed that the essential oil from leaves of H. coronarium has an inhibitory effect on the in vitro growth of F. oxysporum and T. cucumeris , thus suggesting its potential use in agriculture, mainly with respect to banana and bean cultures. Keywords: phytopathology, medicinal plants, biological control.