Effect of the lectin of Bauhinia variegata and its recombinant isoform on surgically induced skin wounds in a murine model

Phytochemistry and pharmacological activities of five species of Bauhinia genus: A review

Genus Bauhinia has been widely used in the treatment of diabetes, malaria, cough, headache, fever, piles, dysentery, flatulence, diarrhoea, ulcer and cardiovascular problems. Among 600 species of this genus, Bauhinia variegata, B. purpurea, B. championii, B. racemosa, and B. forficata are commonly used in the traditional medicine and found to be throughly investigated for their medicinal properties. They possess diverse pharmacological activities such as anti-diabetic, anti-microbial, antioxidant, anti-arthritic, cardioprotective, hepatoprotective, nephroprotective, fibrinolytic, and wound healing properties and most of the biological activities are corelating with traditional knowledge. Phytochemical analysis indicated that steroids, terpenoids, and flavonoids are prominent in the selected species, whereas bauhiniastatins, bauhinoxepins, racemosols, roseosides, and bauhichamines are found unique to the genus. This review aims to decipher active molecules from the aforementioned species of Bauhinia covering comprehensive analysis of phytochemistry, pharmacological activities and traditional uses. The data has been carefully analyzed to find compounds or fractions with a translational value. In most of the cases, the pharmacological activities have been established, however, further studies are needed such as safety evaluations, target identification, bioavailability, metabolite identification, and pharmacokinetic properties. In conclusion, the pharmacological potential of Bauhinia plants show promise with various leads such as insulin-like protein, roseoside, bauhiniastatin, and melibiose binding lectin. However, further investigations are required to address existing gaps and advance them towards product development. This review will lay the groundwork for future research initiatives aimed at fully realizing the therapeutic potential of Bauhinia plants.

The Role of Plant Lectins in the Cellular and Molecular Processes of Skin Wound Repair: An Overview

There is increasing pressure for innovative methods to treat compromised and difficult-to-heal wounds. Consequently, new strategies are needed for faster healing, reducing infection, hydrating the wound, stimulating healing mechanisms, accelerating wound closure, and reducing scar formation. In this scenario, lectins present as good candidates for healing agents. Lectins are a structurally heterogeneous group of glycosylated or non-glycosylated proteins of non-immune origin, which can recognize at least one specific monosaccharide or oligosaccharide specific for the reversible binding site. Cell surfaces are rich in glycoproteins (glycosidic receptors) that potentially interact with lectins through the number of carbohydrates reached. This lectin-cell interaction is the molecular basis for triggering various changes in biological organisms, including healing mechanisms. In this context, this review aimed to (i) provide a comprehensive overview of relevant research on the potential of vegetable lectins for wound healing and tissue regeneration processes and (ii) discuss future perspectives.

Schinus terebinthifolius Leaf Lectin (SteLL) Reduces the Bacterial and Inflammatory Burden of Wounds Infected by Staphylococcus aureus Promoting Skin Repair

Staphylococcus aureus is commonly found in wound infections where this pathogen impairs skin repair. The lectin isolated from leaves of Schinus terebinthifolius (named SteLL) has antimicrobial and antivirulence action against S. aureus. This study evaluated the effects of topical administration of SteLL on mice wounds infected by S. aureus. Seventy-two C57/BL6 mice (6−8 weeks old) were allocated into four groups: (i) uninfected wounds; (ii) infected wounds, (iii) infected wounds treated with 32 µg/mL SteLL solution; (iv) infected wounds treated with 64 µg/mL SteLL solution. The excisional wounds (64 mm2) were induced on the dorsum and infected by S. aureus 432170 (4.0 × 106 CFU/wound). The daily treatment started 1-day post-infection (dpi). The topical application of both SteLL concentrations significantly accelerated the healing of S. aureus-infected wounds until the 7th dpi, when compared to untreated infected lesions (reductions of 1.95−4.55-fold and 1.79−2.90-fold for SteLL at 32 µg/mL and 64 µg/mL, respectively). The SteLL-based treatment also amended the severity of wound infection and reduced the bacterial load (12-fold to 72-fold for 32 µg/mL, and 14-fold to 282-fold for 64 µg/mL). SteLL-treated wounds show higher collagen deposition and restoration of skin structure than other groups. The bacterial load and the levels of inflammatory markers (IL-6, MCP-1, TNF-α, and VEGF) were also reduced by both SteLL concentrations. These results corroborate the reported anti-infective properties of SteLL, making this lectin a lead candidate for developing alternative agents for the treatment of S. aureus-infected skin lesions.

Wound healing activity of lectin isolated from seeds of Centrolobium microchaete Mart. ex Benth. on cutaneous wounds in mice

This study aims to evaluate the wound healing potential of lectin isolated from the seeds of Centrolobium microchaete (Mart. ex Benth) (CML) on cutaneous wounds in mice. CML did not show cytotoxicity on murine dermal fibroblasts (L929 cell line). The wounds treated with CML (200 μg/mL) showed a decrease in area within 12 days post-operative (P.O.) when compared to control. On 3^rd and 7^th day P.O., the CML-treated group exhibited fibroblast proliferation and neovascularization. On 12^th day P.O., complete restructuring of the epithelial layer and connective tissue was observed in the CML-treated group, whereas control groups exhibited incomplete reepithelialization. CML treatment enhanced the wound closure via the wound contraction process, resulting in the restructuring of the skin layers on 12^th day P.O. In conclusion, CML induced a fast and efficient wound healing, suggesting that it can be used as a promising therapeutic tool to heal acute wounds.

Lectins from red algae and their biomedical potential

Lectins are unique proteins or glycoproteins of non-immune origin that bind specifically to carbohydrates. They recognise and interact reversibly to either free carbohydrates or glycoconjugates, without modifying their structure. Lectins are highly diverse and widely distributed in nature and have been extensively reported from various red algae species. Numerous red algae species have been reported to possess lectins having carbohydrate specificity towards complex glycoproteins or high-mannose N-glycans. These lectin-glycan interactions further trigger many biochemical responses which lead to their extensive use as valuable tools in biomedical research. Thus, owing to their exceptional glycan recognition property, red algae lectins are potential candidate for inhibition of various viral diseases. Hence, the present report integrates existing information on the red algae lectins, their carbohydrate specificity, and characteristics of purified lectins. Further, the review also reports the current state of research into their anti-viral activity against various enveloped viruses such as HIV, hepatitis, influenza, encephalitis, coronavirus and herpes simplex virus and other biomedical activities such as anti-cancer, anti-microbial, anti-inflammatory, anti-nociceptive and acaricidal activities.

Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications

Lectins are proteins extensively used in biomedical applications with property to recognize carbohydrates through carbohydrate-binding sites, which identify glycans attached to cell surfaces, glycoconjugates, or free sugars, detecting abnormal cells and biomarkers related to diseases. These lectin abilities promoted interesting results in experimental treatments of immunological diseases, wounds, and cancer. Lectins obtained from virus, microorganisms, algae, animals, and plants were reported as modulators and tool markers in vivo and in vitro; these molecules also play a role in the induction of mitosis and immune responses, contributing for resolution of infections and inflammations. Lectins revealed healing effect through induction of reepithelialization and cicatrization of wounds. Some lectins have been efficient agents against virus, fungi, bacteria, and helminths at low concentrations. Lectin-mediated bioadhesion has been an interesting characteristic for development of drug delivery systems. Lectin histochemistry and lectin-based biosensors are useful to detect transformed tissues and biomarkers related to disease occurrence; antitumor lectins reported are promising for cancer therapy. Here, we address lectins from distinct sources with some biological effect and biotechnological potential in the diagnosis and therapeutic of diseases, highlighting many advances in this growing field.

Ethnomedicinal plants used to treat skin diseases by Tharu community of district Udham Singh Nagar, Uttarakhand, India

ETHNOPHARMACOLOGICAL RELEVANCE

Tharu community is the largest primitive indigenous community of the Uttarakhand, India. In this article we have scientifically enumerated medicinal plants and herbal preparations used by the Tharu community to treat various skin diseases, and discussed dermatological properties of these plants in the light of previous ethnomedicinal, microbiological, pharmacological, toxicological, phytochemical and clinical studies.

MATERIALS AND METHODS

Ethnomedicinal survey was conducted in different villages of Tharu community located in district Udham Singh Nagar, Uttarakhand, India. Ethnomedicinal information on plants used to treat various skin diseases was collected from 122 individuals (93 males and 29 females), including 35 experienced herbal practitioners and 87 local villagers. For each of the recorded plant species the use value (UV) and fidelity level (FL) was calculated. The informant consensus factor (Fic) was also calculated to find out the homogeneity in the information given by the informants.

RESULTS

A total of 90 plant species belonging to 86 genera and 48 families were used by the Tharu community to treat various skin diseases viz., wounds (38 spp.), boils (32 spp.), cuts (18 spp.), leprosy (11 spp.), eczema (10 spp.), itching (7 spp.), ringworm (5 spp.), burns (4 spp.), leucoderma (4 spp.), cracked heels (2 spp.), dandruff (3 spp.), body infection (2 spp.), chilblains (2 spp.), hair fall (2 spp.) and toes infection (2 spp.). Information on botanical name, family, vernacular name, ailments treated, mode and dose of herbal preparations, UV and FL values are provided for each of the recorded species. According to UV value most preferred plant species used to treat skin diseases by Tharu community was Ricinus communis L. followed by Tridax procumbens (L.) L., Azadirachta indica A. Juss., Ageratum conyzoides and Allium cepa L.

CONCLUSIONS

The present study has revealed significant information on various medicinal plants used to treat skin diseases by Tharu community. Literature review has confirmed most of the claims made by the Tharu community regarding treatment of various skin diseases by the reported plants. The literature review has also revealed that products from very few of the reported plants are available in market, while most of the reported plants are still under preclinical or clinical trials. There are various known phytochemicals, and antibiotic, antibacterial, antiviral and antifungal agents present in these plants which may be synthesized or transformed to make pharmaceuticals. Some of the reported plants have shown promising results in preclinical trails and there is a need of clinical trials to see their safety and efficacy in treating various skin diseases. These plants may be targeted for development of new medicines, ointments or drugs for the treatment of skin diseases. However further toxicological, preclinical and clinical studies are needed to validate claims about little worked out plant species reported in the present study viz., Sida cordata (Burm. F.) Borss. Waalk., Millettia extensa (Benth.) Baker, Caesulia axillaris Roxb., Ehretia laevis Roxb., Vanda tessellate (Roxb.) Hook. Ex G.Don. and Eualaliopsis binata (Retz.) C.E. Hubb. Further studies on these plants are recommended to assess their potential in development of new skin care products.

A lectin from Dioclea violacea Interacts with midgut surface of Lutzomyia migonei, unlike its homologues, Cratylia floribunda lectin and Canavalia gladiata lectin

Leishmaniasis is a vector-borne disease transmitted by phlebotomine sand fly. Susceptibility and refractoriness to Leishmania depend on the outcome of multiple interactions that take place within the sand fly gut. Promastigote attachment to sand fly midgut epithelium is essential to avoid being excreted together with the digested blood meal. Promastigote and gut sand fly surface glycans are important ligands in this attachment. The purpose of the present study was to evaluate the interaction of three lectins isolated from leguminous seeds (Diocleinae subtribe), D-glucose and D-mannose-binding, with glycans on Lutzomyia migonei midgut. To study this interaction the lectins were labeled with FITC and a fluorescence assay was performed. The results showed that only Dioclea violacea lectin (DVL) was able to interact with midgut glycans, unlike Cratylia floribunda lectin (CFL) and Canavalia gladiata lectin (CGL). Furthermore, when DVL was blocked with D-mannose the interaction was inhibited. Differences of spatial arrangement of residues and volume of carbohydrate recognition domain (CRD) may be the cause of the fine specificity of DVL for glycans in the surface on Lu. migonei midgut. The findings in this study showed the presence of glycans in the midgut with glucose/mannose residues in its composition and these residues may be important in interaction between Lu. migonei midgut and Leishmania.

Parkia pendula seed lectin: potential use to treat cutaneous wounds in healthy and immunocompromised mice

Parkia pendula seed lectin was used to treat cutaneous wounds of normal and immunocompromised mice, inducing cicatrization. Methotrexate (0.8 mg/kg/week) was used as immunosuppressive drug. Wounds were produced in the dorsal region (1 cm(2)) of female albino Swiss mice (Mus musculus), health and immunocompromised. Wounds were daily topically treated with 100 μL of the following solutions: (1) control (NaCl 0.15 M), (2) control Im (0.15 M NaCl), (3) P. pendula seed lectin (100 μg/mL), and (4) P. pendula seed lectin Im (100 μg/mL). Clinical evaluation was performed during 12 days. Biopsies for histopathology analysis and microbiological examinations were carried out in the second, seventh, and 12th days. The presence of edema and hyperemia was observed in all groups during inflammatory period. The first crust was detected from the second day, only in the groups treated with P. pendula seed lectin. Microbiological analysis of wounds from day 0 to day 2 did not show bacterium at P. pendula seed lectin group; however, Staphylococcus sp. was detected every day in the other groups. The lectin markedly induced a total wound closing at P. pendula seed lectin and P. pendula seed lectin Im groups on 11th day of evolution. The present study suggests that P. pendula seed lectin is a biomaterial potential to show pharmacological effect in the repair process of cutaneous wounds.

Structure predictions of two Bauhinia variegata lectins reveal patterns of C-terminal properties in single chain legume lectins

Bauhinia variegata lectins (BVL-I and BVL-II) are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures. The present study used prediction and validation algorithms to elucidate the likely structures of BVL-I and -II. The program Bhageerath-H was chosen from among three different structure prediction programs due to its better overall reliability. In order to predict the C-terminal region cleavage sites, other lectins known to have this modification were analysed and three rules were created: (1) the first amino acid of the excised peptide is small or hydrophobic; (2) the cleavage occurs after an acid, polar, or hydrophobic residue, but not after a basic one; and (3) the cleavage spot is located 5-8 residues after a conserved Leu amino acid. These rules predicted that BVL-I and -II would have fifteen C-terminal residues cleaved, and this was confirmed experimentally by Edman degradation sequencing of BVL-I. Furthermore, the C-terminal analyses predicted that only BVL-II underwent α-helical folding in this region, similar to that seen in SBA and DBL. Conversely, BVL-I and -II contained four conserved regions of a GS-I association, providing evidence of a previously undescribed X4+unusual oligomerisation between the truncated BVL-I and the intact BVL-II. This is the first report on the structural analysis of lectins from Bauhinia spp. and therefore is important for the characterisation C-terminal cleavage and patterns of quaternary association of single chain lectins.

Characterization of isoforms of the lectin isolated from the red algae Bryothamnion seaforthii and its pro-healing effect

Lectins are a structurally heterogeneous group of proteins that have specific binding sites for carbohydrates and glycoconjugates. Because of their biotechnological potential, lectins are widely used in biomedical research. The present study aimed to evaluate the healing potential of the lectin isolated from the marine red alga Bryothamnion seaforthii (BSL). The lectin was purified using ion exchange chromatography with DEAE cellulose and characterized using tandem mass spectrometry. For healing tests, skin wounds were induced in the dorsal thoracic region of mice. These animals were randomly divided into three groups and subjected to topical treatment for 12 days with BSL, bovine serum albumin and 150 mM NaCl. To evaluate the potential of each treatment, the animals were anesthetized and sacrificed on days 2, 7 and 12, respectively. The parameters evaluated included the wound area, the proportion of wound closure and the histological diagnosis. The wound closure was more effective with BSL (Postoperative Day 7 and 12) than controls. The luminal epithelium was completely restructured; the presence of collagen in the dermis and the strongly active presence of young skin annexes demonstrate the potential of treatment with BSL compared with controls. Our findings suggest that BSL has pro-healing properties and can be a potential medical process in the treatment of acute wounds.