Potent antiviral activity of carbohydrate-specific algal and leguminous lectins from the Brazilian biodiversity

Abstract

Brazil has one of the largest biodiversities in the world. The search for new natural products extracted from the Brazilian flora may lead to the discovery of novel drugs with potential to treat infectious and other diseases. Here, we have investigated 9 lectins extracted and purified from the Northeastern Brazilian flora, from both leguminous species: Canavalia brasiliensis (ConBr), C. maritima (ConM), Dioclea lasiocarpa (DLasiL) and D. sclerocarpa (DSclerL), and algae Amansia multifida (AML), Bryothamniom seaforthii (BSL), Hypnea musciformis (HML), Meristiella echinocarpa (MEL) and Solieria filiformis (SfL). They were exposed to a panel of 18 different viruses, including HIV and influenza viruses. Several lectins showed highly potent antiviral activity, often within the low nanomolar range. DSclerL and DLasiL exhibited EC 50 values (effective concentration of lectin required to inhibit virus-induced cytopathicity by 50%) of 9 nM to 46 nM for HIV-1 and respiratory syncytial virus (RSV), respectively, DLasiL also inhibited feline corona virus at an EC 50 of 5 nM, and DSclerL, ConBr and ConM showed remarkably low EC 50 values ranging from 0.4 to 6 nM against influenza A virus strain H3N2 and influenza B virus. For HIV, evidence pointed to the blockage of entry of the virus into its target cells as the underlying mechanism of antiviral action of these lectins. Overall, the most promising lectins based on their EC 50 values were DLasiL, DSclerL, ConBr, ConM, SfL and HML. These novel findings indicate that lectins from the Brazilian flora may provide novel antiviral compounds with therapeutic potential. 390 | Med. Chem. Commun., 2019, 10, 390-398 This journal is

Plant-Based Natural Products and Extracts: Potential Source to Develop New Antiviral Drug Candidates

“…DSclerL and DLasiL exhibited EC 50 values of 9 nM for HIV-1 and 46 nM for the respiratory syncytial virus (RSV). DLasiL also showed inhibitory property against feline coronavirus at an EC 50 of 5 nM, and DSclerL, ConBr, and ConM revealed significantly low EC 50 against influenza A virus strain H3N2 (0.4 nM) and influenza B virus (6 nM) [ 29 ].…”

Lectin Protein as a Promising Component to Functionalize Micelles, Liposomes and Lipid NPs against Coronavirus

“…Red, brown, and particularly green alga (nearly 500 types of lectin) are the main sources of algal lectins. Self-assembly of viruses may be disrupted by the effects of MBL [60]. More antiviral activities of MBL (extracted from red algae Grateloupia chiangii) toward the herpes simplex virus was observed compared to the influenza virus.…”

Development of Protein- and Peptide-Based HIV Entry Inhibitors Targeting gp120 or gp41

“…However, CV-N and GRFT can be amply expressed in E. coli with low cytotoxicity; therefore, both are expected to be further developed as microbicides. Recently, several legume lectins, including (ConBr) Canavalia brasiliensis lectin, (ConM) Canavalia maritima lectin, (DLasiL) Dioclea lasiocarpa lectin, (DScler L) Dioclea sclerocarpa lectin and (HHA) Hyppeastrum hybrid agglutinin all showed a low nM level of HIV-1 inhibitory activity and thus deserve further study [108].…”