Search

Dengue poses a global health threat, which will persist without therapeutic intervention. Immunity induced by exposure to one serotype does not confer long-term protection against secondary infection with other serotypes and is potentially capable of enhancing this infection. Although vaccination is believed to induce durable and protective responses against all the dengue virus (DENV) serotypes in order to reduce the burden posed by this virus, the development of a safe and efficacious vaccine remains a challenge. Immunoinformatics and computational vaccinology have been utilized in studies of infectious diseases to provide insight into the host–pathogen interactions thus justifying their use in vaccine development. Since vaccination is the best bet to reduce the burden posed by DENV, this study is aimed at developing a multi-epitope based vaccines for dengue control. Combined approaches of reverse vaccinology and immunoinformatics were utilized to design multi-epitope based vaccine from the sequence of DENV. Specifically, BCPreds and IEDB servers were used to predict the B-cell and T-cell epitopes, respectively. Molecular docking was carried out using Schrödinger, PATCHDOCK and FIREDOCK. Codon optimization and in silico cloning were done using JCAT and SnapGene respectively. Finally, the efficiency and stability of the designed vaccines were assessed by an in silico immune simulation and molecular dynamic simulation, respectively. The predicted epitopes were prioritized using in-house criteria. Four candidate vaccines (DV-1–4) were designed using suitable adjuvant and linkers in addition to the shortlisted epitopes. The binding interactions of these vaccines against the receptors TLR-2, TLR-4, MHC-1 and MHC-2 show that these candidate vaccines perfectly fit into the binding domains of the receptors. In addition, DV-1 has a better binding energies of − 60.07, − 63.40, − 69.89 kcal/mol against MHC-1, TLR-2, and TLR-4, with respect to the other vaccines. All the designed vaccines were highly antigenic, soluble, non-allergenic, non-toxic, flexible, and topologically assessable. The immune simulation analysis showed that DV-1 may elicit specific immune response against dengue virus. Moreover, codon optimization and in silico cloning validated the expressions of all the designed vaccines in E. coli. Finally, the molecular dynamic study shows that DV-1 is stable with minimum RMSF against TLR4. Immunoinformatics tools are now applied to screen genomes of interest for possible vaccine target. The designed vaccine candidates may be further experimentally investigated as potential vaccines capable of providing definitive preventive measure against dengue virus infection.

In Africa, medicinal plants have been traditionally used as a source of medicine for centuries. To date, African medicinal plants continue to play a significant role in the treatment of wounds. Chronic wounds are associated with severe healthcare and socio-economic burdens despite the use of conventional therapies. Emergence of novel wound healing strategies using medicinal plants in conjunction with nanotechnology has the potential to develop efficacious wound healing therapeutics with enhanced wound repair mechanisms. This review identified African medicinal plants and biogenic nanoparticles used to promote wound healing through various mechanisms including improved wound contraction and epithelialization as well as antibacterial, antioxidant and anti-inflammatory activities. To achieve this, electronic databases such as PubMed, Scifinder® and Google Scholar were used to search for medicinal plants used by the African populace that were scientifically evaluated for their wound healing activities in both in vitro and in vivo models from 2004 to 2021. Additionally, data on the wound healing mechanisms of biogenic nanoparticles synthesized using African medicinal plants is included herein. The continued scientific evaluation of wound healing African medicinal plants and the development of novel nanomaterials using these plants is imperative in a bid to alleviate the detrimental effects of chronic wounds.

Advancements in nanotechnology have provided insight into the unique opportunities for the application of nanomaterials such as gold nanoparticles (AuNPs) in medicine due to their remarkable properties, which includes low toxicity, large surface area, and the ease of synthesis and conjugation to other molecules. Therefore, AuNPs are often preferred for bio-applications. Citrate-capped AuNPs (cAuNPs) have been reported to be non-cytotoxic and are used in numerous studies as drug delivery vehicles to treat various diseases. However, the limitations of bioassays often used to assess the toxicity of AuNPs have been well documented. Herein, we investigate the cytotoxicity of 14 nm cAuNPs in the human colorectal adenocarcinoma (Caco-2) cell line. Treatment conditions (i.e. dose and exposure time) that were established to be non-toxic to Caco-2 cells were used to investigate the effect of cAuNPs on the expression of a Qiagen panel of 86 genes involved in cytotoxicity. Out of 86 studied, 23 genes were differentially expressed. Genes involved in oxidative stress and antioxidant response, endoplasmic reticulum (ER) stress and unfolded protein response, heat shock response, and lipid metabolism were more affected than others. While low concentrations of 14 nm cAuNPs was not cytotoxic and did not cause cell death, cells treated with these nanoparticles experienced ER and oxidative stress, resulting in the activation of cytoprotective cellular processes. Additionally, several genes involved in lipid metabolism were also affected. Therefore, 14 nm cAuNPs can safely be used as drug delivery vehicles at low doses.

Cardiovascular diseases (CVDs) and kidney diseases in diabetes are linked to increased mortality and morbidity. The aim of this study was to evaluate the effect of vindoline derived from Catharanthus roseus in diabetes-induced CVDs and kidney disease through assessing inflammation, oxidative stress, hyperlipidaemia and kidney function parameters. Type 2 diabetes was induced in male Wistar rats by 10% fructose water intake for two weeks, followed by a single intraperitoneal injection of 40mg/kg body weight of streptozotocin (STZ). Six groups (n = 8) of randomly divided rats received vindoline (20mg/kg) or glibenclamide (5mg/kg) daily for 6 weeks via oral gavage. Lipid profile markers and markers of atherogenic index were decreased in diabetic rats after treatment with vindoline and glibenclamide. The levels of urea were significantly increased in the diabetic control group (13.66 &plusmn, 0.9) compared to the diabetic groups treated with vindoline and glibenclamide (10.62 &plusmn, 0.6 and 10.82 &plusmn, 0.8), respectively. Vindoline did not significantly alter the levels of inflammatory cytokines, however glibenclamide lowered the levels of TNF-&alpha, in kidney and heart tissues. Vindoline improved the ferric reducing antioxidant power in diabetic hearts, while superoxide dismutase (SOD) oxygen radical absorbance capacity was increased in the kidneys. Lipid peroxidation was reduced when compared to the diabetic controls. Vindoline restored the structure of the renal parenchyma and was accompanied by significant decrease in the expression of caspase 9 in diabetic rats when compared to the diabetic controls.

Vindoline, an indole alkaloid present in the leaves of Catharanthus roseus plant, has been recently reported to have insulotropic effects. This present study evaluated the possible hepatoprotective effects of vindoline in a type 2 diabetes mellitus rat model. Diabetes mellitus was induced by exposing rats to 10% fructose water for two weeks followed by a single intraperitoneal injection of 40 mg/kg body weight of streptozotocin (STZ). Rats were randomly divided into six groups (n = 8) and treated daily for 6 weeks with the vehicle via oral gavage, vindoline (20 mg/kg) or glibenclamide (5 mg/kg). Weekly fasting blood glucose (FBG) levels and body weight were measured and recorded. Administration of vindoline significantly (p

Background.Hypoxis hemerocallideais a native plant that grows in the Southern African regions and is well known for its beneficial medicinal effects in the treatment of diabetes, cancer, and high blood pressure.Aim. This study evaluated the effects ofHypoxis hemerocallideaon oxidative stress biomarkers, hepatic injury, and other selected biomarkers in the liver and kidneys of healthy nondiabetic and streptozotocin- (STZ-) induced diabetic male Wistar rats.Materials and Methods. Rats were injected intraperitoneally with 50 mg/kg of STZ to induce diabetes. The plant extract-Hypoxis hemerocallidea(200 mg/kg or 800 mg/kg) aqueous solution was administered (daily) orally for 6 weeks. Antioxidant activities were analysed using a Multiskan Spectrum plate reader while other serum biomarkers were measured using the RANDOX chemistry analyser.Results. Both dosages (200 mg/kg and 800 mg/kg) ofHypoxis hemerocallideasignificantly reduced the blood glucose levels in STZ-induced diabetic groups. Activities of liver enzymes were increased in the diabetic control and in the diabetic group treated with 800 mg/kg, whereas the 200 mg/kg dosage ameliorated hepatic injury. In the hepatic tissue, the oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), catalase, and total glutathione were reduced in the diabetic control group. However treatment with both doses improved the antioxidant status. The FRAP and the catalase activities in the kidney were elevated in the STZ-induced diabetic group treated with 800 mg/kg of the extract possibly due to compensatory responses.Conclusion.Hypoxis hemerocallideademonstrated antihyperglycemic and antioxidant effects especially in the liver tissue.