Purification and Biological Activities of Abelmoschus esculentus Seed Lectin

Abstract

The Abelmoschus esculentus (Malvaceae) plant originated in Africa and has spread across a number of tropic countries, including northeastern Brazil. The plant has been used to treat various disorders, such as cancer, microbial infections, hypoglycemia, constipation, urine retention and inflammation. The lectin of A. esculentus (AEL) was isolated by precipitation with ammonium sulfate at a saturation level of 30/60 and purified by ion exchange chromatography (Sephacel-DEAE). The electrophoresis (SDS-PAGE) profile of the AEL showed two protein bands of apparent molecular mass of approximately 15.0 and 21.0 kDa. The homogenity of the protein was confirmed by electrospray mass spectrometry (ESI-MS), which revealed the presence of a 10.29-kDa monomer and a 20.58-kDa dimer. The AEL exhibits agglutinating activity against rabbit (74.41 UH/mP) and human type ABO erythrocytes (21.00 UH/mP). This activity does not require the presence of divalent cations and is specifically inhibited by lactose, fructose and mannose. The intravenous treatment with 0.01, 0.1 and 1 mg/kg of AEL inhibited the paw edema elicited by carrageenan by approximately 15, 22 and 44 %, respectively, but not that induced by dextran. In addition, treatment with 0.1, 1 and 10 mg/kg of AEL also inhibited the abdominal writhing induced by acetic acid by approximately 52, 57 and 69 %, respectively. In conclusion, AEL is a new lectin with a molecular mass of 20.0 kDa, which is -composed of a 10.291-Da monomer and a 20.582-kDa dimer, that exhibits anti-inflammatory, antinociceptive and hemagglutinating activities. In addition, the lectin hemagglutinating property is both metallo-independent and associated with the lectin domain.

Phytochemical information and pharmacological activities of Okra (Abelmoschus esculentus): A literature‐based review

“…However, oxidative stress and pathogenic invasion may cause inflammation in our body (Jin, Liu, Zhang, Nanda, & Li, 2013). Lectin and polysaccharides of A. esculentus have been found to exert anti-inflammatory and immunomodulatory effects in animals and their derived cells (Chen et al, 2016;Ortaç et al, 2018;Sheu & Lai, 2012;Soares et al, 2012), whereas lipid fraction, palmitic, and stearic acids of the plant are evident to act against a number of pathogenic bacteria (de Carvalho et al, 2011;Mollick et al, 2014).…”

“…Lectin from the plant at 0.01, 0.1, and 1 mg/kg (i.v.) was also evident to show an antinociceptive effect in mice (Soares et al, 2012). Moreover, the aqueous and methanolic seed extracts (200 mg/kg [p.o.])…”

“…Lectin of okra at 0.01, 0.1, and 1 mg/kg (i.v.) exerted an inflammatory effect in mice (n = 6-10; Soares et al, 2012). In a recent study, the ethanol extract of okra (500, 250 or 100 mg/kg [p.o.])…”

“…Some in vitro studies suggest that four compounds isolated from the seeds at 2 mg exerted a trypsin inhibitory effect in bovine chymotrypsin (Ogata, Imamura, Hirayama, & Makisumi, 1986), whereas mucilages of the plant showed an anticomplementary effect (Tomoda et al, 1989). Okra lectin in mice showed a hemagglutinating activity (Soares et al, 2012). Aqueous fresh fruit extract (0.2 to 2 mg/mL) in H. pylori (FITC-labled H. pylori J99, 2 clinical isolates, AGS cells, and fluorescence-activated cell sorting) exerted an antiadhesive effect through inhibiting the adhesive binding of membrane proteins BabA, SabA, and HpA to its specific ligands (Messing et al, 2014).…”

Genetic diversity analysis of okra (Abelmoschus esculentus L.) by inter-simple sequence repeat (ISSR) markers

“…Currently, okra are cultivated and distributed throughout the world. China is a large agricultural nation with a long history of okra cultivation (de Sousa Ferreira Soares et al, 2012), with a more than 100-year history of planting in Pingxiang, Jiangxi Province. Okra evolved from potatoes and the spicy pepper a hundred years ago.…”