Purification and characterization of a lectin with refolding ability from Genipa americana bark

Phytochemical constitution and pharmacological effects of Genipa americana L. (Rubiaceae): a review

Genipa americana L., popularly known as "jenipapo", is a species easily found, especially in northeastern Brazil. It is remarkable for having iridoids in its composition. Popular for its blue pigment which has been used to manufacture paints and dyes. Furthermore, this plant is utilized for medicinal purposes in addressing a variety of illnesses. This review provide a comprehensive picture of the phytochemical and biological activities characteristics of Genipa americana L. deal with its ethnomedicinal use and botany based on literature reports. These researches pointed out a range of secondary metabolites with iridoids being the most prevalent and abundant. Until now, the biological tests have shown important pharmacological activities, especially the antioxidant, insecticide and antibacterial activities. Besides presenting itself in a very promising way in other areas such as food and cosmetics industry, it is also used in popular medicine to treat several diseases having this potential use disseminated in its various parts. Finally, for a better analysis and validation of its health benefits and properties, extensive research is needed, including clinical trials. The information gathered and approached in this paper might support the planning and discussion of future studies on the topic.

Isolation and characterisation of stress tolerant divalent dependant lectin from insect pest of Corcyra cephalonica (Stainton) (Lepidoptera: Galleriidae) and its functional studies

This study aims to isolate and identify a lectin from an agricultural insect pest of Corcyra cephalonica (CC). The lectin exhibited strong hemagglutination in sheep and goat blood, particularly A+ and B+, influenced by metal ions Ca2+ and Mn2+. Its molecular mass was determined to be 225 kDa, comprising subunits of 95, 68, and 62 kDa. The lectin displayed high thermal stability up to 100 °C and maintained hemagglutination activity at pH 12.0. MALDI-TOF analysis confirmed its identity as a lectin. Notably, it displayed significant antioxidant activity, achieving 93.98% inhibition against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 97.59% against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) at concentrations of 0.5 and 0.05 mg/mL, respectively. This is the first report of Corcyra cephalonica lectin exhibiting such potent antioxidant properties, suggesting its potential as an ingredient in drug development for free radical-mediated inflammatory diseases and cancer since it has high biophysical stability.

Genipa americana L.: A Review on Traditional Uses, Phytochemistry and Biological Activities

Genipa americana L. (Rubiaceae), genip tree, has therapeutic and nutritional potential. This revision aimed to gather information on botanical characteristics, popular uses, phytochemical, and pharmacological aspects of the tree. The methodology adopted integrated literature published between 2000 and 2024, as well as consultations with the World International Intellectual Property Organization (WIPO); resulting in 39 articles and 11 patents to promote this research. The species, which is native and not endemic to Brazil, is most prevalent in the Amazon biome as it is suitable for reconstructing degraded areas, as well as having various traditional applications. Iridoids are the main secondary metabolites present in the species, especially ginipin, geniposide acid, and geniposide, which are the most prevalent in the fruit. The patents registered with the WIPO indicate its use as a colorant, insecticide, anti-inflammatory, and antioxidant potential, in evidence of its antimicrobial and antioxidant activities. Further studies are needed on the mechanisms of the chemical components' action and on ethnopharmacology.

Diversity of transgenes in sustainable management of insect pests

Insecticidal transgenes, when incorporated and expressed in plants, confer resistance against insects by producing several products having insecticidal properties. Protease inhibitors, lectins, amylase inhibitors, and chitinase genes are associated with the natural defenses developed by plants to counter insect attacks. Several toxin genes are also derived from spiders and scorpions for protection against insects. Bacillus thuringiensis Berliner is a microbial source of insecticidal toxins. Several methods have facilitated the large-scale production of transgenic plants. Bt-derived cry, cyt, vip, and sip genes, plant-derived genes such as lectins, protease inhibitors, and alpha-amylase inhibitors, insect cell wall-degrading enzymes like chitinase and some proteins like arcelins, plant defensins, and ribosome-inactivating proteins have been successfully utilized to impart resistance to insects. Besides, transgenic plants expressing double-stranded RNA have been developed with enhanced resistance. However, the long-term effects of transgenes on insect resistance, the environment, and human health must be thoroughly investigated before they are made available for commercial planting. In this chapter, the present status, prospects, and future scope of transgenes for insect pest management have been summarized and discussed.

Purification, Characterization, and Assessment of Antimicrobial Activity and Toxicity of Portulaca elatior Leaf Lectin (PeLL)

Lectins are carbohydrate-binding proteins with several bioactivities, including antimicrobial properties. Portulaca elatior is a species found at Brazilian Caatinga and data on the biochemical composition of this plant are scarce. The present work describes the purification of P. elatior leaf lectin (PeLL) as well as the assessment of its antimicrobial activity and toxicity. PeLL, isolated by chromatography on a chitin column, had native liquid charge and subunit composition evaluated by electrophoresis. Hemagglutinating activity (HA) of PeLL was determined in the presence of carbohydrates or divalent cations, as well as after heating and incubation at different pH values. Changes in the lectin conformation were monitored by evaluating intrinsic tryptophan fluorescence and using the extrinsic probe bis-ANS. Antimicrobial activity was evaluated against Pectobacterium strains and Candida species. The minimal inhibitory (MIC), bactericidal (MBC), and fungicidal (MFC) concentrations were determined. Finally, PeLL was evaluated for in vitro hemolytic activity in human erythrocytes and in vivo acute toxicity in mice (5 and 10 mg/kg b.w. per os). PeLL (pI 5.4; 20 kDa) had its HA was inhibited by mannose, galactose, Ca²⁺, Mg²⁺, and Mn²⁺. PeLL HA was resistant to heating at 100 °C, although conformational changes were detected. PeLL was more active in the acidic pH range, in which no conformational changes were observed. The lectin presented MIC and MBC of 0.185 and 0.74 μg/mL for all Pectobacterium strains, respectively; MIC of 1.48 μg/mL for C. albicans, C. tropicalis, and C. krusei; MIC and MFC of 0.74 and 2.96 μg/mL for C. parapsilosis. No hemolytic activity or signs of acute toxicity were observed in the mice. In conclusion, a new, low-toxic, and thermostable lectin was isolated from P. elatior leaves, being the first plant compound to show antibacterial activity against Pectobacterium.

A new lectin from the floral capitula of Egletes viscosa (EgviL): Biochemical and biophysical characterization and cytotoxicity to human cancer cells

Egletes viscosa is a plant with therapeutic value due to its antibacterial, antinociceptive and gastroprotective properties. This study aimed to purify, characterize, and evaluate the cytotoxicity of a lectin (EgviL) from the floral capitula of E. viscosa. The lectin was isolated from saline extract through precipitation with ammonium sulfate followed by Sephadex G-75 chromatography. The molecular mass and isoelectric point (pI) of EgviL were determined as well as its temperature and pH stability. Physical-chemical parameters of interaction between EgviL and carbohydrates were investigated by fluorescence quenching and ¹H nuclear magnetic resonance (NMR). Cytotoxicity was investigated against human peripheral blood mononuclear cells (PBMCs) and neoplastic cells. EgviL (28.8 kDa, pI 5.4) showed hemagglutinating activity stable towards heating until 60 °C and at the pH range 5.0-7.0. This lectin is able to interact through hydrophobic and electrostatic bonds with galactose and glucose, respectively. EgviL reduced the viability of PBMCs only at the highest concentration tested (100 μg/mL) while was toxic to Jurkat E6-1 cells with IC₅₀ of 24.1 μg/mL,inducing apoptosis. In summary, EgviL is a galactose/glucose-binding protein with acidic character, stable to heating and with cytotoxic effect on leukemic cells.

Ethnopharmacology of Fruit Plants: A Literature Review on the Toxicological, Phytochemical, Cultural Aspects, and a Mechanistic Approach to the Pharmacological Effects of Four Widely Used Species

Fruit plants have been widely used by the population as a source of food, income and in the treatment of various diseases due to their nutritional and pharmacological properties. The aim of this study was to review information from the most current research about the phytochemical composition, biological and toxicological properties of four fruit species widely used by the world population in order to support the safe medicinal use of these species and encourage further studies on their therapeutic properties. The reviewed species are: Talisia esculenta, Brosimum gaudichaudii, Genipa americana, and Bromelia antiacantha. The review presents the botanical description of these species, their geographical distribution, forms of use in popular medicine, phytochemical studies and molecules isolated from different plant organs. The description of the pharmacological mechanism of action of secondary metabolites isolated from these species was detailed and toxicity studies related to them were reviewed. The present study demonstrates the significant concentration of phenolic compounds in these species and their anti-inflammatory, anti-tumor, photosensitizing properties, among others. Such species provide important molecules with pharmacological activity that serve as raw materials for the development of new drugs, making further studies necessary to elucidate mechanisms of action not yet understood and prove the safety for use in humans.

Purification and Characterization of a New Lectin from Loach Skin Mucus

Lectin from loach skin mucus plays an important role in pathogen defense. However, hardly can any paper relevant to the character of lectin from loach skin mucus be found in recent years. In this study, a kind of new lectin (LML), with a high hemagglutination activity of 166.23 × 103 HU/mg, was successfully isolated and purified from loach skin mucus. LML was a kind of glycoprotein with a molecular weight of 245 kDa. Also, the monosaccharide composition suggested that its carbohydrate chain was composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose with a molar ratio of 2.02 : 11.66 : 2.06 : 1.00 : 14.09 : 6.00. Besides, LML depended on Ca2+to induce hemagglutination and was strongly inhibited by D-lactose. The lectin exhibited powerful resistance to alkali and kept about 30% hemagglutination activity at pH 14.0, whereas its capacity of acid resistance was weak. The maximum hemagglutination activity of LML maintained at a temperature range from 20°C to 50°C. Moreover, the structure of LML was preliminarily studied, indicating it contained abundant glutamic acid, histidine, and serine, and its secondary structure containedα-helix (4.97%),β-sheet (27.55%), turns structure (49.78%), and unordered structure (17.70%).