Euphorbiaceae, also known as the spurge family, is a large group of flowering plants. Despite being tropical natives, they are now widespread. Due to its medicinal and commercial importance, this family of plants attracted a lot of attention in the scientific community. The distinctive characteristic of the family is production of milky latex, which is a rich source of several lectins, the proteins that bind carbohydrates. Although their function is unclear, they are believed to defend plants against damaging phytopathogenic microorganisms, insects, and predatory animals. Additionally, they serve as crucial metabolic regulators under a variety of stressors. Detection, separation, purification, and characterization of lectins from the Euphorbiaceae family - mostly from the latex of plants - began over 40 years ago. This effort produced over 35 original research papers that were published. However, no systematic review that compiles these published data has been presented yet. This review summarizes and describes several procedures and protocols employed for extraction and purification of lectins belonging to this family. Physicochemical properties and biological activities of the lectins, along with their medicinal and pharmacological properties, have also been analyzed. Additionally, using examples of ricin and ricin agglutinin, we have structurally analyzed characteristics of the lectin known as Ribosome Inactivating Protein Type II (RIP-Type II) that belongs to this family. We anticipate that this review article will offer a useful compendium of information on this important family of lectins, show the scientists involved in lectin research the gaps in our knowledge, and offer insights for future research.

Ricin toxin (RT) belongs to the ribosome-inactivating protein (RIP) family of toxins and is considered to be a moderate threat by the US Center of Disease Control and Prevention (CDC). RT poses a great potential threat to the public, but there has been a lack of effective treatment options so far. Over the past few decades, researches on the prevention and treatment of RT poisoning have been investigated, among which neutralizing antibodies targeting RT specifically have always been a research hotspot. In this review, we have summarized the mechanism of action of RT, the research results and the design strategies of RT neutralizing antibodies, and discussed the key issues in the development of RT neutralizing antibody researches.

Type Ⅱ ribosome-inactivating proteins (RIPs) are an important class of protein toxins that consist of A and B chains linked by an interchain disulfide bond. The B-chain with lectin-like activity is responsible for binding to the galactose-containing receptors on eukaryotic cell surfaces, which is essential for A-chain internalization by endocytosis. The A-chain has N-glycosidase activity that irreversibly depurinates a specific adenine from 28S ribosomal RNA (28S rRNA) and terminates protein synthesis. The synergistic effect of the A-B chain inactivates the ribosome, inhibits protein synthesis, and exhibits high cytotoxicity. Ricin and abrin that are expressed by the plants Ricinus communis and Abrus precatorius, respectively, are typical type Ⅱ RIPs. The toxicity of ricin and abrin are 385 times and 2885 times, respectively, more that of the nerve agent VX. Owing to their ease of preparation, wide availability, and potential use as a bioterrorism agent, type Ⅱ RIPs have garnered increasing attention in recent years. Ricin is listed as a prohibited substance under schedule 1A of the Chemical Weapons Convention (CWC). The occurrence of ricin-related bioterrorism incidents in recent years has promoted the development of accurate, sensitive, and rapid detection and identification technology for type Ⅱ RIPs. Significant progress has been made in the study of toxicity mechanisms and detection methods of type Ⅱ RIPs, which primarily involve qualitative and quantitative analysis methods including immunological assays, mass spectrometry analysis methods, and toxin activity detection methods based on depurination and cytotoxicity. Immunoassays generally involve the specific recognition of antigens and antibodies, which is based on oligonucleotide molecular recognition elements called aptamers. These methods are fast and highly sensitive, but for highly homologous proteins in complex samples, they provide false positive results. With the rapid development of biological mass spectrometry detection technology, techniques such as electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) are widely used in the identification of proteins. These methods not only provide accurate information on molecular weight and structure of proteins, but also demonstrate accurate quantification. Enzyme digestion combined with mass spectrometry is the predominantly used detection method. Accurate identification of protein toxins can be achieved by fingerprint analysis of enzymatically digested peptides. For analysis of protein toxins in complex samples, abundant peptide markers are obtained using a multi-enzyme digestion strategy. Targeted mass spectrometry analysis of peptide markers is used to obtain accurate qualitative and quantitative information, which effectively improves the accuracy and sensitivity of the identification of type Ⅱ RIP toxins. Although immunoassay and mass spectrometry detection methods can provide accurate identification of type Ⅱ RIPs, they cannot determine whether the toxins will retain potency. The widely used detection methods for activity analysis of type Ⅱ RIPs include depurination assay based on N-glycosidase activity and cytotoxicity assay. Both the methods provide simple, rapid, and sensitive analysis of type Ⅱ RIP toxicity, and complement other detection methods. Owing to the importance of type Ⅱ RIP toxins, the Organization for the Prohibition of Chemical Weapons (OPCW) has proposed clear technical requirements for the identification and analysis of relevant samples. We herein reviewed the structural characteristics, mechanism of action, and the development and application of type Ⅱ RIP detection methods; nearly 70 studies on type Ⅱ RIP toxins and their detection methods have been cited. In addition to the technical requirements of OPCW for the unambiguous identification of biotoxins, the trend of future development of type Ⅱ RIP-based detection technology has been explored.

BACKGROUND: Ricin, a toxic glycoprotein derived from the castor bean plant, is one of the most potent poisons known in the world. Ricin intoxication is a fatal and uncommon medical condition and recently its use as a potential bioterrorism agent has also been reported. This study aims to identify the main characteristics of diagnosed ricin poisoning cases worldwide in order to raise awareness of this toxin among the population and clinicians.
METHODS: A collection of human case studies of ricin intoxication in the world was produced. The databases Pubmed, Sciencedirect and Google Scholar were used to extract articles from January 1980 to June 2020.
RESULTS: Fifty ricin-intoxicated patients worldwide described in the literature have been identified. Most cases were found in Asia (19 cases), Europe (12 cases) and America (15 cases). Intoxication was mostly accidental (37 cases). Intoxication by castor bean is characterized by acute gastroenteritis-like disease as primary manifestations leading to severe fluid and electrolyte imbalance. The mechanism of death was peripheral vascular collapse and progressing multiple organ failure occurring 10h-72h after intoxication. The questioning of patients and family made it possible to retrieve an history of castor seeds or castor oil ingestion Patients received symptomatic treatment consisting mostly to rehydration with intravenous fluids and digestive decontamination performed with activated charcoal and/or gastric lavage within one day after the ingestion, to reduce gastrointestinal absorption of ricin. This decontamination treatment administered early has been very effective. Only six deaths were observed.
CONCLUSIONS: Currently, no antidote, vaccine, or other specific effective treatment is available for ricin poisoning or prevention. Prompt treatment with supportive care was necessary to limit morbidity and mortality. To date, patient education is essential to prevent this accidental poisoning.
CONCLUSIONS: Clinicians and health care professionals should have a high level of suspicion when faced with an outbreak of serious respiratory or gastrointestinal illness.

UNASSIGNED: >1000 ricin poisoning cases secondary to intentional castor bean consumption have been reported in the literature since the late 1800s. The lethality of ricin poisoning after oral ingestion is determined by a few factors.
UNASSIGNED: We present a case that highlights the erratic absorption of ricin after accidental oral ingestion. On admission, the physical examination found a somnolent patient, with miosis, and a generalized abdominal tenderness. Her blood tests showed metabolic acidosis. Thanks to her early management, the discharge was possible three days later.
UNASSIGNED: The toxicity of ricin is dependent on the dose delivered and the route of the exposure. Supportive care is the mainstay of treatment. As shown in our case, early management is crucial for a good outcome.

Ricinus cmmunis L. (Castor oil plant) is an important medicinal plant belonging to family Euphorbiaceae. Its phytochemistry, biological and pharmacological activities, and ethnomedicinal uses have been reviewed in the present study. The reported chemical constituents showed the presence of flavonoids, phenolic compounds, fatty acids, amino acids, terpenoids, phytosterol etc. The compounds have been reported to exhibit anticonceptive, antidiabetic, antifertility, anti-inflammatory, antimicrobial, antioxidant, hepatoprotective, insecticidal and wound-healing activities. They also showed free radical scavenging and Hg scavenging activities, and repellent properties. Various parts of R. communis have been widely used in traditional medicine such as abdominal disorders, arthritis, backache, muscle aches, bilharziasis, chronic backache and sciatica, chronic headache, constipation, expulsion of placenta, gallbladder pain, period pain, menstrual cramps, rheumatism, sleeplessness, and insomnia. Castor oil plant has also revealed toxic effects due to the presence of ricin (protein) and ricinine (alkaloid). Comparatively, ricin is more toxic. But still there is need of more research to be conducted with reference to its medicinal importance (particularly exploring of medicinal recipes) and active compounds responsible for various activities.

BACKGROUND: Ricin is a protein toxin derived from the castor bean plant Ricinus communis. Several cases secondary to its consumption have been published and, more recently, its use as a potential bioterrorism agent has also been reported. Oral absorption of ricin is highly erratic, leading to a wide spectrum of symptoms. In addition, conventional urine drug screening tests will not be able to detect this compound, posing a diagnostic challenge.
METHODS: A male teenager intended to die by ingesting 200 castor beans after mixing and blending them with juice. Eight hours later, he presented with weakness, light-headedness, nausea, and vomiting and sought medical treatment. The patient was admitted and treated conservatively. An immune-based standard urine toxicology drug screen panel was reported as negative. A comprehensive untargeted urine drug screen test showed the presence of ricinine, a surrogate marker of ricin intoxication. He was transferred to the psychiatric service 3 days after admission. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the importance of knowing the peculiar pharmacokinetic properties of ricin after oral ingestion of castor beans and toxin release through mastication. Emergency physicians should be aware that oral absorption of ricin is dependent on several factors, such type and size of seeds and the geographic harvesting region, making it extremely difficult to estimate its lethality based solely on the number of ingested beans. Finally, comprehensive untargeted urine drug screening testing is highly valuable as a diagnostic tool in this context.

Immunotoxins are a novel class of cancer therapeutics that contains a cytotoxic agent fused to a targeting moiety. Various toxic agents from different sources are used in immunotoxin development, including bacterial, plant and human origin cytotoxic elements. Although bacterial and plant-derived toxins are highly toxic and commonly used in immunotoxins, their immunogenicity for human restricted their application in cancer therapy. Here, we discuss the advantages and limitations of bacterial toxins such as Pseudomonas and Diphtheria toxins, plant toxins such as ricin and gelonin, and some endogenous protein of human origin such as RNases and Granzymes. This article will also review different generations of immunotoxins with special focus on immunotoxins which are under clinical trials or approved for clinical use. Finally, current deimmunization strategies for development of new less-immunogenic recombinant immunotoxins will be discussed.
mAbs: Monoclonal antibodies; EF2: elongation factor 2; ITs: Immunotoxins; DT: Diphtheria toxin; PE: Pseudomonas exotoxin; dgA: de-glycosylated A-chain of ricin; rGel: recombinant de-glycosylated form of gelonin; NKC: natural killer cells; HTR: human transferrin receptor; EGF: epidermal growth factor; GM-CSF: granulocyte-macrophage colony-stimulating factor; DAB389: truncated Diphtheria toxin; B-CCL: B-cell chronic lymphocytic leukemia; RCC: renal cell carcinoma; GVHD: Graft-versus-host disease; EGFR: epidermal growth factor receptor; AML: acute myeloid leukemia; Fab: fragment antigen-binding; dsFv: disulfide-stabilized fragment variable; scFv: single-chain fragment variable; B-ALL: B-lineage Acute Lymphoblastic Leukemia; Fv: fragment variable; HCL: hairy cell leukemia; IL-2R: Interleukin-2 receptor; CR: complete response; CLL: chronic lymphocytic leukemia; ATL: adult T-cell leukemia; DARPins: designed Ankyrin repeat proteins; pmol: picomolar; HAMA: human-anti mouse antibody.

Toxins are hazardous biochemical compounds derived from bacteria, fungi, or plants. Some have mechanisms of action and physical properties that make them amenable for use as potential warfare agents. Currently, some toxins are classified as potential biological weapons, although they have several differences from classic living bio-terror pathogens and some similarities to manmade chemical warfare agents. This review focuses on category A and B bio-terror toxins recognized by the Centers for Disease Control and Prevention: Botulinum neurotoxin, staphylococcal enterotoxin B, Clostridium perfringens epsilon toxin, and ricin. Their derivation, pathogenesis, mechanism of action, associated clinical signs and symptoms, diagnosis, and treatment are discussed in detail. Given their expected covert use, the primary diagnostic challenge in toxin exposure is the early detection of morbidity clusters, apart from background morbidity, after a relatively short incubation period. For this reason, it is important that clinicians be familiar with the clinical manifestations of toxins and the appropriate methods of management and countermeasures.

Exposure of the lungs to airborne toxicants from different sources in the environment may lead to acute and chronic pulmonary or even systemic inflammation. Cigarette smoke is the leading cause of chronic obstructive pulmonary disease, although wood smoke in urban areas of underdeveloped countries is now recognized as a leading cause of respiratory disease. Mycotoxins from fungal spores pose an occupational risk for respiratory illness and also present a health hazard to those living in damp buildings. Microscopic airborne particulates of asbestos and silica (from building materials) and those of heavy metals (from paint) are additional sources of indoor air pollution that contributes to respiratory illness and is known to cause respiratory illness in experimental animals. Ricin in aerosolized form is a potential bioweapon that is extremely toxic yet relatively easy to produce. Although the aforementioned agents belong to different classes of toxic chemicals, their pathogenicity is similar. They induce the recruitment and activation of macrophages, activation of mitogen-activated protein kinases, inhibition of protein synthesis, and production of interleukin-1 beta. Targeting either macrophages (using nanoparticles) or the production of interleukin-1 beta (using inhibitors against protein kinases, NOD-like receptor protein-3, or P2X7) may potentially be employed to treat these types of lung inflammation without affecting the natural immune response to bacterial infections.