A newly developed silymarin nanoformulation as a potential antidiabetic agent in experimental diabetes

Formulation of silymarin surface modified vesicles: In vitro characterization to cell viability assessment

Silymarin (SLR) is a poorly water-soluble bioactive compound with a wide range of therapeutic activities. Nanosized silymarin vesicles (F1-F6) were prepared by the solvent evaporation rehydration method. The silymarin vesicles were evaluated for vesicle size, surface charge, entrapment efficiency, and drug release studies. The optimized SLR lipid vesicle (F3) was further modified with the addition of the cationic polymer chitosan. After that, the modified vesicle (F3C1) was assessed for permeation flux, antimicrobial activity, cell viability, and molecular docking studies. The silymarin vesicles showed nanometric size (<250 nm), low polydispersibility index (<0.05), negative surface charge, and high SLR entrapment (85-95 %). The drug release study result demonstrated a maximum drug release of 91.2 ± 2.8 %. After adding chitosan to the surface, there was a significant change in the size, polydispersibility index, surface charge (positive), and encapsulation efficiency. The drug release was found to be prolonged, and the permeation flux was also increased in comparison to free SLR. A comparative antimicrobial result was observed in comparison to the free SLR and standard drug. The cell viability assay also demonstrated a low IC50 value for F3C1 against the cell line.

Phthalocyanine-based glucose-responsive nanocochleates for dynamic prevention of β-cell damage in diabetes

Phthalocyanine is a blue-colored macrocyclic compound with excellent anti-oxidant and lipid-peroxidation abilities due to its intermolecular π-π stacking structure. Antioxidants inhibit intracellular reactive oxygen species formation and decrease oxidation defense ability of the enzymes in diabetes management. The present study aimed to fabricate concanavalin A conjugated phthalocyanine-loaded cochleates (Formulation PhConA) as a glucose-sensitive lipidic system and estimate its efficacy in streptozotocin-induced male Sprague Dawley diabetic rats for 28 days. Thin-film hydration and trapping methods were used in the preparation of liposomes and cochleates, respectively, whereas the surface was modified for concanavalin A conjugation using EDAC: NHS (1:1). Formulation PhConA with rod-shaped structures showed particle size of 415.7 ± 0.46 nm, PdI value of 0.435 ± 0.09, encapsulation efficiency of 85.64 ± 0.34%, and 84.55 ± 0.29% release of phthalocyanine for 56 h. The circular dichroism study displayed a slight deviation after the conjugation effect of concanavalin A to cochleates. The in-vivo studies of the formulation PhConA improved the blood glucose levels along with defensive effect on the liver to overcome the hyperlipidemic effect. The rigid structure of cochleates prolongs the drug elimination from systemic circulation and extends its effect for a longer duration by decreasing the blood glucose level. Thus, the glucose-sensitive formulation PhConA showed significant improvement in diabetic rats within the period of 28 days by improving the oxidative defense and protecting the pancreatic β-cells.

Novel nano-drug delivery system for natural products and their application

The development of natural products for potential new drugs faces obstacles such as unknown mechanisms, poor solubility, and limited bioavailability, which limit the broadened applicability of natural products. Therefore, there is a need for advanced pharmaceutical formulations of active compounds or natural products. In recent years, novel nano-drug delivery systems (NDDS) for natural products, including nanosuspensions, nanoliposomes, micelle, microemulsions/self-microemulsions, nanocapsules, and solid lipid nanoparticles, have been developed to improve solubility, bioavailability, and tissue distribution as well as for prolonged retention and enhanced permeation. Here, we updated the NDDS delivery systems used for natural products with the potential enhancement in therapeutic efficiency observed with nano-delivery systems.

An Insight of Naturally Occurring Phytoconstituents and Novel Approaches Towards the Treatment of Diabetes

BACKGROUND

The rising in diabetes incidents has clearly become one main worldwide health problem. Individuals suffering from diabetes are still more susceptible to many long-term and short-term side effects, which most often cause fatalities. Even though chemically synthesized anti-diabetic entities are capable of helping manage and treat, there has been significant risks related with their prolong and repetitive use. Hence, there is a requirement for safer and novel approaches that might be formed and utilized.

OBJECTIVE

Aim of the present review is to explain the naturally occurring phytochemicals and novel approach as anti-diabetic agents in the treatment of diabetes and its related issues.

METHOD

A survey of Google scholar, Research Gate, Pubmed, Science Direct, NCBI database was carried out conducted to determine a most hopeful phytochemicals and novel drug delivery systems in the management of diabetes.

RESULT

The study stressed the significance of phytomolecules and some novel approaches researched or reported in the literature for the management and cure of diabetes. It is suggested that changes in lifestyle can help patients and like nutritional support, assessment and lifestyle guidance must be individualized based on physical and functional capacity. Further evaluations and improved preventative medicine were the result of improving patient outcomes.

CONCLUSION

Conventional or synthetic drugs provide relief for short time but nanoformulations of phytomolecules offer an improved therapeutic with fewer negative side effects. Herbal medicines are rich in phytoconstituents and possess variety of health benefits. This review is compilation of phytoconstituents and novel drug delivery system of phytomolecules i.e. nanoparticles, niosomes, microsphere, microparticle and others.

Therapeutic application of natural compounds for skeletal muscle-associated metabolic disorders: A review on diabetes perspective

Skeletal muscle (SM) plays a vital role in energy and glucose metabolism by regulating insulin sensitivity, glucose uptake, and blood glucose homeostasis. Impaired SM metabolism is strongly linked to several diseases, particularly type 2 diabetes (T2D). Insulin resistance in SM may result from the impaired activities of insulin receptor tyrosine kinase, insulin receptor substrate 1, phosphoinositide 3-kinase, and AKT pathways. This review briefly discusses SM myogenesis and the critical roles that SM plays in insulin resistance and T2D. The pharmacological targets of T2D which are associated with SM metabolism, such as DPP4, PTB1B, SGLT, PPARγ, and GLP-1R, and their potential modulators/inhibitors, especially natural compounds, are discussed in detail. This review highlights the significance of SM in metabolic disorders and the therapeutic potential of natural compounds in targeting SM-associated T2D targets. It may provide novel insights for the future development of anti-diabetic drug therapies. We believe that scientists working on T2D therapies will benefit from this review by enhancing their knowledge and updating their understanding of the subject.

Effects of silibinin on apoptosis and insulin secretion in rat RINm5F pancreatic β-cells

We investigated whether silibinin, a flavonoid, might be useful for treating diabetes mellitus by treating five groups of rat RINm5F β-insulinemia cells as follows: control streptozotocin (STZ) group administered citrate buffer and dimethyl sulfoxide; STZ group administered 20 mM STZ; silibinin group administered 50 µM silibinin; pre-silibinin group administered 50 µM silibinin 5 h before administering 20 mM STZ; simultaneous group administered 50 µM silibinin at the same time as 20 mM STZ. For all groups, MTT assay and flow cytometry were used to evaluate cell viability and necrosis, respectively. Glucose-stimulated insulin secretion (GSIS) and insulin cell content were determined using enzyme-linked immunosorbent assay. Also, expression of genes, pancreatic and duodenal homeobox 1 (pdx1), neuronal differentiation 1 (neurod1), v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog A (mafa), glucose transporter 2 (glut2)) was determined using the real-time polymerase chain reaction. We found that silibinin improved the viability of RINm5F cells and increased GSIS and cellular insulin under glucotoxic conditions. Silibinin increased the expression of neurod1, mafa and glut2, but reduced pdx1 expression. Our findings suggest that silibinin might increase glucose sensitivity and insulin synthesis under glucotoxic conditions, which could be useful for diabetes treatment.

Diabetes mellitus and diabetic foot ulcer: Etiology, biochemical and molecular based treatment strategies via gene and nanotherapy

Diabetes mellitus (DM) is a collection of metabolic and pathophysiological disorders manifested with high glucose levels in the blood due to the inability of β-pancreatic cells to secrete an adequate amount of insulin or insensitivity of insulin towards receptor to oxidize blood glucose. Nevertheless, the preceding definition is only applicable to people who do not have inherited or metabolic disorders. Suppose a person who has been diagnosed with Type 1 or Type 2DM sustains an injury and the treatment of the damage is complicated and prolonged. In that case, the injury is referred to as a diabetic foot ulcer (DFU). In the presence of many proliferating macrophages in the injury site for an extended period causes the damage to worsen and become a diabetic wound. In this review, the scientific information and therapeutic management of DM/DFU with nanomedicine, and other related data were collected (Web of Science and PubMed) from January 2000 to January 2022. Most of the articles revealed that standard drugs are usually prescribed along with hypoglycaemic medications. Conversely, such drugs stabilize the glucose transporters and homeostasis for a limited period, resulting in side effects such as kidney damage/failure, absorption/gastrointestinal problems, and hypoglycemic issues. In this paper, we review the current basic and clinical evidence about the potential of medicinal plants, gene therapy, chemical/green synthesized nanoparticles to improving the metabolic profile, and facilitating the DM and DFU associated complications. Preclinical studies also reported lower plasma glucose with molecular targets in DM and DFU. Research is underway to explore chemical/green synthesized nanoparticle-based medications to avoid such side effects. Hence, the present review is intended to address the current challenges, recently recognized factors responsible for DM and DFU, their pathophysiology, insulin receptors associated with DM, medications in trend, and related complications.

Novel doxorubicin / folate-targeted trans-ferulic acid-loaded PLGA nanoparticles combination: In-vivo superiority over standard chemotherapeutic regimen for breast cancer treatment

AIM

Doxorubicin/Cyclophosphamide (AC) is one of the standard adjuvant anthracycline-containing regimens that is still in use for breast cancer treatment. Cancer cell resistance and AC-induced side effects make treatment suboptimal and worsen patients' quality of life. This study aimed to improve trans-ferulic acid's (TFA) efficiency via loading into folate-receptor-targeted-poly lactic-co-glycolic acid nanoparticles (FA-PLGA-TFA NPs). Also, investigating both the antitumor efficacy of Doxorubicin (Dox)/FA-PLGA-TFA NPs combination against dimethylbenz[a]anthracene (DMBA)-induced breast cancer and its safety profile.

METHODS

FA-PLGA-TFA NPs were optimally fabricated and characterized. Levels of Notch1, Hes1, Wnt-3a, β-catenin, MMP-9, cyclin D1, Permeability-Glycoprotein (P-gp), ERα, PR, and HER2 were assessed as a measure of the antitumor efficacy of different treatment protocols. Histopathological examination of heart and bone, levels of ALT, AST, ALP, CK-MB, and WBCs count were evaluated to ensure the combination's safety profile.

KEY FINDINGS

Dox/FA-PLGA-TFA NPs not only inhibited Notch signaling but also suppressed Notch synergy with Wnt, estrogen, progesterone, and HER2 pathways. Interestingly, Dox/FA-PLGA-TFA NPs decreased P-gp level and preserved heart, bone, and liver health as well as WBCs count.

SIGNIFICANCE

Dox/FA-PLGA-TFA NPs reduced the side-effects of each single drug, and at the same time exerted excellent antitumor activity that surpass the AC regimen in evading cancer cell resistance and having a superior safety profile.

Nano-based drug delivery systems used as vehicles to enhance polyphenols therapeutic effect for diabetes mellitus treatment

Diabetes mellitus is one of the biggest health emergencies of the 21^st century worldwide, characterized by deficiency in insulin secretion and/or action, leading to hyperglycemia. Despite the currently available antidiabetic therapeutic options, 4.2 million people died in 2019 due to diabetes. Thus, new effective interventions are required. Polyphenols are plant secondary metabolites and have been recognized for their vast number of biological activities, including potential antidiabetic effects. However, the poor bioavailability and high metabolization of polyphenols restrict their biological effects in vivo. Nanotechnology is a promising area of research to improve the therapeutic effect of several compounds. Therefore, this review provides an overview of the literature about the utility of nano-based drug delivery systems as vehicles of polyphenols in diabetes treatment. It was possible to conclude that, in general, nano-based drug delivery systems can potentiate the beneficial antidiabetic properties of polyphenols, when compared with the free compounds, opening a new field of research in diabetology.

Silymarin ameliorates the disordered glucose metabolism of mice with diet-induced obesity by activating the hepatic SIRT1 pathway

Obesity-induced insulin resistance is the principal cause of type 2 diabetes worldwide. The use of natural products for the treatment of diabetes is increasingly attracting attention. Silymarin (SLM) is a flavonolignan compound that has been shown to have promise for the treatment of diabetes. In the present study, we aimed to investigate the mechanisms underlying its therapeutic effects. C57BL/6 mice were fed a high-fat diet (HFD) for 12 weeks and then orally administered SLM (30 mg/kg) daily for 1 month. The effects of SLM were also investigated in HepG2 cells that had been rendered insulin resistant by palmitic acid (PA) treatment. SLM ameliorated the dyslipidemia, hepatic steatosis, and insulin resistance of the HFD-fed mice. HFD-feeding and PA treatment reduced the expression of sirtuin-1 (SIRT1) in the livers of the mice and in HepG2 cells, respectively. SLM increased the phosphorylation of AKT and FOXO1, and reduced the level of FOXO1 acetylation in PA-treated cells. However, SIRT1 knockdown by RNA interference reduced these effects of SLM. Moreover, the results of molecular dynamic simulation and in vitro activity assays indicated that SLM may directly bind to SIRT1 and increase its enzymatic activity. These findings suggest that hepatic SIRT1 may be an important pharmacological target of SLM and mediate effects on insulin resistance and gluconeogenesis, which may underlie its anti-diabetic activity.

Protective effect of acorn (Quercus liaotungensis Koidz) on streptozotocin-damaged MIN6 cells and type 2 diabetic rats via p38 MAPK/Nrf2/HO-1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Acorn obtained from the Quercus liaotungensis Koidz tree is consumed as a Chinese folk medicine for the treatment of diarrhea, abdominal pain, and inflammation, also having strong antioxidant activity and have been utilized for the treatment of diabetes in China. However, its mechanism of action on complications of diabetes and oxidative stress is unclear.

AIM OF THE STUDY

The purpose of this research was to assess the effects of acorn (Quercus liaotungensis Koidz) ethanol extract (AE) on pancreatic β-cell dysfunction through a streptozotocin (STZ)-damaged mouse normal pancreatic β-cell (MIN6 cell) model in vitro, and by using a high-fat and high-sugar diet with STZ-induced diabetic rat model in vivo to explore the possible mechanism of action against diabetes.

MATERIALS AND METHODS

MIN6 cells were pretreated with AE (20, 40, 80 μM) for 2 h and then treated with 3 mM STZ for 24 h. Cell viability was measured by MTT assay. The amount of intracellular reactive oxygen species was measured by 2,7-dichlorodi-hydrofluorescein diacetate. The activities of insulin secretion, superoxide dismutase, catalase and glutathione were determined by kits. Sprague Dawley rats were either given normal feed or a high sugar and fat diet for four weeks, followed STZ (25 mg/kg, via i. p.) was given. Rats with fasting blood glucose ≥11.1 mmol/l after one week were deemed to be diabetic. Animals were divided into 5 groups, which received saline (10 mL/kg), metformin (200 mg/kg), or AE at doses of 200 and 400 mg/kg during 4 weeks by oral gavage. Blood samples were used to evaluate hematological and biochemical indicators, and pancreas was removed for post-analysis. Body weight and fasting blood glucose were recorded weekly. The expression levels of Bax, Bcl-2, p38, p-p38, Nrf2 and HO-1 were determined by Western blot.

RESULTS

Data showed that AE inhibited apoptosis and increased antioxidant level in STZ-induced MIN6 cells. In addition, the AE-administered group lowered blood glucose, increased insulin secretion, and alleviated weight loss in the diabetic rats. Histopathologically, the AE-administered group reduced pancreatic injury by significantly restoring the insulin content in β-islets. It was observed that the anti-diabetic effects of AE were associated with the suppressed the p38 MAPK pathway and actived the Nrf2 pathway.

CONCLUSIONS

The ameliorative impact of AE on diabetes may be attributed to protection of the function of pancreatic β islets and by improving serum insulin levels, hence reducing the blood glucose, which involved in the p38 MAPK and Nrf2 pathways.

Preparation and characterisation of a new form of silymarin as a potential antidiabetic agent in the adult male rat

Silymarin is used for a wide variety of biological applications including, antidiabetic activities. However, the effectiveness of Silymarin is affected by its poor aqueous solubility and low systemic bioavailability after oral administration. The present study aimed to formulate a new, simple, and inexpensive form of silymarin solution. A new form of silymarin solution (NFSM) characterised by small particle size (227.5 nm), high entrapment efficiency (>82%), and appropriate zeta potential(-24.7mv). Moreover, the antidiabetic effects of NESM were evaluated relative to native Silymarin (SM). Oral administration of NFSM for 14 days in diabetic rats significantly decreased fasting blood glucose, oxidative stress levels, and improved lipid profile compared with SM. Also, NFSM significantly increased serum insulin levels, the gene expression of insulin and Pdx1, restored and improved the structure of the liver, and pancreas histologically. Our results concluded that NFSM may be an efficient carrier for oral delivery of silymarin for the management of diabetes and aggravated antioxidant status.

Oral Nano Drug Delivery Systems for the Treatment of Type 2 Diabetes Mellitus: An Available Administration Strategy for Antidiabetic Phytocompounds

In view of the worldwide serious health threat of type 2 diabetes mellitus (T2DM), natural sources of chemotherapies have been corroborated as the promising alternatives, with the excellent antidiabetic activities, bio-safety, and more cost-effective properties. However, their clinical application is somewhat limited, because of the poor solubility, instability in the gastrointestinal tract (GIT), low bioavailability, and so on. Nowadays, to develop nanoscaled systems has become a prominent strategy to improve the drug delivery of phytochemicals. In this review, we primarily summarized the intervention mechanisms of phytocompounds against T2DM and presented the recent advances in various nanosystems of antidiabetic phytocompounds. Selected nanosystems were grouped depending on their classification and structures, including polymeric NPs, lipid-based nanosystems, vesicular systems, inorganic nanocarriers, and so on. Based on this review, the state-of-the-art nanosystems for phytocompounds in T2DM treatment have been presented, suggesting the preponderance and potential of nanotechnologies.

Innovative coenzyme Q10-loaded nanoformulation as an adjunct approach for the management of moderate periodontitis: preparation, evaluation, and clinical study

Periodontal diseases are worldwide chronic inflammatory conditions that are associated with heavy production of reactive oxygen species followed by damage of the tooth-supporting tissues. Although the mechanical approach of scaling and root planing (SRP) for removing of plaque is considered as the key element for controlling periodontitis, the anatomical complexity of the teeth hinders accessibility to deeper points. The aim of this study was to design a micellar nanocarrier of coenzyme Q10 (Q₁₀) to support the management of moderate periodontitis. Q₁₀ was formulated in nanomicelles (NM_Q10) and evaluated regarding encapsulation efficiency, loading efficiency, percent yield, hydrodynamic size (D_h), polydispersity index (PDI), and zeta potential (ζ potential). NM_Q10 was incorporated to in situ gelling systems and the in vitro release of Q₁₀ was studied. A clinical study including evaluation of periodontal parameters and biochemical assay of total antioxidant capacity (T-AOC) and lipid peroxide was achieved. Results revealed that Q₁₀ was efficiently entrapped in spherical-shaped stable NM_Q10 with D_h, PDI, and ζ potential of 154.0 nm, 0.108, and - 31.67 mV, respectively. The clinical study revealed that SRP only exhibited improvement of the periodontal parameters. Also, assay of T-AOC and lipid peroxide revealed that their values diminished by 21.5 and 23.8%, respectively. On the other hand, SRP combined with local application of NM_Q10 resulted in a significant management of the periodontal parameters, and likewise, the assayed biomarkers proved enhanced antioxidant activity over SRP alone. In conclusion, NM_Q10 can be suggested as a promising nanosystem as an approach to support the management of chronic periodontitis. Such results could be used to conduct larger clinical studies. Graphical abstrac.

Niclosamide-loaded polymeric micelles ameliorate hepatocellular carcinoma in vivo through targeting Wnt and Notch pathways

AIM

Niclosamide (NIC) is an anthelmintic agent repurposed as a potent anticancer agent. However, its use is hindered by its poor solubility. We investigated the underlying mechanisms of NIC anticancer activity employing a novel oral NIC pluronic-based nanoformulation and tested its effect in thioacetamide-induced hepatocellular carcinoma (HCC) in rats. We evaluated its antitumor effect through regulating Wnt/β-catenin and Notch signaling pathways and apoptosis.

MAIN METHODS

Niclosamide-loaded pluronic nanoparticles (NIC-NPs) were optimally developed and characterized with sustained release properties up to 7 days. Sixteen weeks after HCC induction, NIC (70 mg/kg) and an equivalent dose of NIC-NPs were administered orally for 3 consecutive weeks. Hepatocyte integrity was assessed by measuring serum levels of aminotransferases, ALP, GGT, bilirubin, albumin and total protein. HCC development was detected by measuring AFP expression. Necroinflammation and fibrosis were scored by histopathological examination. Wnt/β-catenin and Notch signaling were evaluated by measuring hepatic mRNA levels of Wnt3A, Lrp5 and Lrp6 Co-receptors, Dvl-2, Notch1 and Hes1 and β-catenin protein levels. Apoptosis was assessed by measuring mRNA and protein levels of cyclin D1 and caspase-3.

KEY FINDING

The novel NIC-NPs restored liver integrity, reduced AFP levels and showed improved anticancer and proapoptotic activities compared to drug alone. The inhibitory effect of NIC on Wnt/β-catenin and Notch signaling pathways was potentiated by the NIC-NPs formulation.

SIGNIFICANCE

We conclude that NIC acts by inhibiting Wnt/β-catenin and Notch signaling and inducing apoptosis in HCC. Developing pluronic-based nanoformulations may be a promising approach to improve NIC solubility and offer the possibility of controlled release.

Nanophytomedicines for the Prevention of Metabolic Syndrome: A Pharmacological and Biopharmaceutical Review

Metabolic syndrome includes a series of metabolic abnormalities that leads to diabetes mellitus and cardiovascular diseases. Plant extracts, due to their unique advantages like anti-inflammatory, antioxidant, and insulin sensitizing properties, are interesting therapeutic options to manage MetS; however, the poor solubility and low bioavailability of lipophilic bioactive components in the herbal extracts are two critical challenges. Nano-scale delivery systems are suitable to improve delivery of herbal extracts. This review, for the first time, focuses on nanoformulations of herbal extracts in MetS and related complications. Included studies showed that several forms of nano drug delivery systems such as nanoemulsions, solid lipid nanoparticles, nanobiocomposites, and green-synthesized silver, gold, and zinc oxide nanoparticles have been developed using herbal extracts. It was shown that the method of preparation and related parameters such as temperature and type of polymer are important factors affecting physicochemical stability and therapeutic activity of the final product. Many of these formulations could successfully decrease the lipid profile, inflammation, oxidative damage, and insulin resistance in in vitro and in vivo models of MetS-related complications. Further studies are still needed to confirm the safety and efficacy of these novel herbal formulations for clinical application.

Plant-Based Antidiabetic Nanoformulations: The Emerging Paradigm for Effective Therapy

Diabetes mellitus is a life-threatening metabolic syndrome. Over the past few decades, the incidence of diabetes has climbed exponentially. Several therapeutic approaches have been undertaken, but the occurrence and risk still remain unabated. Several plant-derived small molecules have been proposed to be effective against diabetes and associated vascular complications via acting on several therapeutic targets. In addition, the biocompatibility of these phytochemicals increasingly enhances the interest of exploiting them as therapeutic negotiators. However, poor pharmacokinetic and biopharmaceutical attributes of these phytochemicals largely restrict their clinical usefulness as therapeutic agents. Several pharmaceutical attempts have been undertaken to enhance their compliance and therapeutic efficacy. In this regard, the application of nanotechnology has been proven to be the best approach to improve the compliance and clinical efficacy by overturning the pharmacokinetic and biopharmaceutical obstacles associated with the plant-derived antidiabetic agents. This review gives a comprehensive and up-to-date overview of the nanoformulations of phytochemicals in the management of diabetes and associated complications. The effects of nanosizing on pharmacokinetic, biopharmaceutical and therapeutic profiles of plant-derived small molecules, such as curcumin, resveratrol, naringenin, quercetin, apigenin, baicalin, luteolin, rosmarinic acid, berberine, gymnemic acid, emodin, scutellarin, catechins, thymoquinone, ferulic acid, stevioside, and others have been discussed comprehensively in this review.

Silymarin: not just another antioxidant

Silymarin (Silybum marianum; SM), popularly known as milk thistle, is an extract that has been used for many centuries to treat liver diseases. In recent years, several studies have shown that SM is not only just another antioxidant but also a multifunctional compound that exhibits several beneficial properties for use in the treatment and prevention of different types of pathologies and disorders. This review aims at demonstrating the main protective activities of SM in diseases, such as cancer, diabetes, hepatitis, non-alcoholic fatty liver disease, alcoholic liver disease, hepatitis C virus, hepatitis B virus, metabolic syndrome, depression, cardiovascular diseases and thalassemia, in addition to its photoprotective activity in in vitro tests and preclinical studies. Its main functions include antioxidant and anti-inflammatory effects, and it acts as modulator of signaling pathways. It has been suggested that SM presents great multifunctional potential and is capable of achieving promising results in different types of research. However, caution is still needed regarding its indiscriminate use in humans as there are only a few clinical studies relating to the adequate dose and the actual efficacy of this extract in different types of diseases.

Protective efficacy of Tinospora sinensis against streptozotocin induced pancreatic islet cell injuries of diabetic rats and its correlation to its phytochemical profiles

ETHNOPHARMACOLOGICAL RELEVANCE

Tinospora sinensis Lour. (Merr.) belongs to the family Menispermaceae and its stem extract have been used traditionally in broad aspects of therapeutic remedies including debility, dyspepsia, fever, jaundice, ulcer, bronchitis, urinary disease, skin disease, liver disease and diabetes.

AIM OF THE STUDY

The aim of the study was to evaluate the protective effects of methanol extract of stem of Tinospora sinensis (METS) on streptozotocin induced pancreatic islet cell injuries of diabetic rats and its correlation to its phytochemical profiles.

MATERIALS AND METHODS

A high-performance liquid chromatography technique (HPLC) was used to identify and quantify the major phytochemicals present in the METS. Diabetic rats were administered with METS at a dose of (100, 200 and 400 mg/kg respectively orally) and standard drug Metformin (300 mg/kg) was given orally to group serving positive control. Effect of the METS on glucose homeostasis, oxidative stress, antioxidant status, histopathology of pancreas and also on intracellular reactive oxygen species (ROS), mitochondrial membrane potential, apoptosis, cell cycle of pancreatic islet cells were studied in diabetic rats.

RESULTS

The major phytochemicals identified and quantified by HPLC in the extract were berberine, caffeic acid, myricetin and ferulic acid. This result showed that methanol extract exhibited good antioxidant effect. The methanol extract of the plant prevented the diabetogenic effect of STZ and significantly lowered the fasting blood glucose level, glycated haemoglobin and increased insulin and C-peptide level in treated rats. METS reduced apoptosis of STZ treated islet cells by significantly decreasing pro-inflammatory cytokines (TNFα, IL6), intracellular ROS generation, lipid peroxidation, nitric oxide (NO) production and increasing mitochondrial membrane potential and sub-G₀ peak area, enzymatic and nonenzymatic antioxidants.

CONCLUSION

The results revealed that the methanol extract of the stem of the plant possesses protective effects against diabetes and associated complications.

Formulation of Nanomicelles to Improve the Solubility and the Oral Absorption of Silymarin

Two novel nanomicellar formulations were developed to improve the poor aqueous solubility and the oral absorption of silymarin. Polymeric nanomicelles made of Soluplus and mixed nanomicelles combining Soluplus with d-α-tocopherol polyethylene glycol 1000 succinate (vitamin E TPGS) were prepared using the thin film method. Physicochemical parameters were investigated, in particular the average diameter, the homogeneity (expressed as polydispersity index), the zeta potential, the morphology, the encapsulation efficiency, the drug loading, the critical micellar concentration and the cloud point. The sizes of ~60 nm, the narrow size distribution (polydispersity index ≤0.1) and the encapsulation efficiency >92% indicated the high affinity between silymarin and the core of the nanomicelles. Solubility studies demonstrated that the solubility of silymarin increased by ~6-fold when loaded into nanomicelles. Furthermore, the physical and chemical parameters of SLM-loaded formulations stored at room temperature and in refrigerated conditions (4 °C) were monitored over three months. In vitro stability and release studies in media miming the physiological conditions were also performed. In addition, both formulations did not alter the antioxidant properties of silymarin as evidenced by the 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH) assay. The potential of the nanomicelles to increase the intestinal absorption of silymarin was firstly investigated by the parallel artificial membrane permeability assay. Subsequently, transport studies employing Caco-2 cell line demonstrated that mixed nanomicelles statistically enhanced the permeability of silymarin compared to polymeric nanomicelles and unformulated extract. Finally, the uptake studies indicated that both nanomicellar formulations entered into Caco-2 cells via energy-dependent mechanisms.

Modulation of Skin Inflammatory Response by Active Components of Silymarin

In this study, we compared selected silymarin components, such as quercetin (QE), 2,3-dehydrosilybin (DHS) and silybin (SB), with the anti-inflammatory drug indomethacin (IND) in terms of their wound healing potential. In view of the fact that pathological cutaneous wound healing is associated with persistent inflammation, we studied their anti-inflammatory activity against inflammation induced by bacterial lipopolysaccharide (LPS). We investigated the regulation of crucial pro-inflammatory transcription factors—nuclear factor kappa-B (NF-κB) and activator protein 1 (AP-1)—as well as the expression of downstream inflammatory targets by Western blotting, real-time PCR (RT-PCR), electrophoretic mobility shift assay (EMSA), and/or enzyme-linked immunosorbent assay (ELISA) in vitro using primary normal human dermal fibroblasts (NHDF). We demonstrated the greater ability of DHS to modulate the pro-inflammatory cytokines production via the NF-κB and AP-1 signaling pathways when compared to other tested substances. The prolonged exposure of LPS-challenged human dermal fibroblasts to DHS had both beneficial and detrimental consequences. DHS diminished interleukin-6 (IL-6) and interleukin-8 (IL-8) secretion but induced the significant upregulation of IL-8 mRNA associated with NF-κB and AP-1 activation. The observed conflicting results may compromise the main expected benefit, which is the acceleration of the healing of the wound via a diminished inflammation.

The effects of silymarin supplementation on metabolic status and oxidative stress in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of clinical trials

OBJECTIVE

The effect of silymarin supplementation on metabolic status and oxidative stress of subjects with type 2 diabetes mellitus (T2DM) has not been conclusively studied. Therefore, the efficacy of silymarin supplementation in these patients was assessed through a meta-analysis.

METHODS

The following databases were searched up to May 15, 2018: PubMed, Scopus, Ovid (Cochrane library), Google scholar and ISI web of science. All randomized clinical trials using silymarin supplements to improve T2DM included in this meta-analysis. Mean Difference (MD) was pooled using a random-effects model.

RESULTS

Eight eligible publications from seven trials were identified for the present meta-analysis. Our results revealed that supplementation with silymarin can decrease fasting blood sugar, hemoglobin A1C, insulin, low-density lipoprotein cholesterol and malondialdehyde and increase high-density lipoprotein cholesterol levels. However, silymarin did not have any significant effects on total cholesterol or triglyceride concentrations.

CONCLUSION

Our data suggest that silymarin supplements have beneficial effects on metabolic status and oxidative stress among patients with T2DM. However, there is currently insufficient evidence to make firm conclusions about the full efficacy of supplementation.

Silymarin nanoformulation as potential anticancer agent in experimental Ehrlich ascites carcinoma-bearing animals

Aim: This study aimed to evaluate, for the first time the potential use of a safe biocompatible nanoformulation of silymarin (SM) as antitumor agent and to provide its mechanism of action compared with native SM. Materials & methods: SM was loaded into pluronic nanomicelles and Ehrlich ascites carcinoma-tumor-bearing mice were used as experimental model. Biochemical parameters including SOD, CAT and GSH, lipid peroxidation biomarkers (MDA), histopathological, ultrastructural and immunohistochemical studies were applied on the Ehrlich ascites carcinoma cells. Furthermore, the cell cycle as well as caspase-3 were examined. Results & conclusion: Nanoformulated SM (SMnp) destroyed tumors via increasing SOD, CAT and GSH concomitant with decreasing MDA. Moreover, SMnp-induced apoptosis through decreasing Ki-67 and Bcl2 expression, along with the activation of caspase-3, leads to inhibition of proliferation and the arrest of ceel cycle progression at the G1/S phase. Electron microscopy studies presented the superiority of SMnp over native SM in causing mitochondrial and nuclear degeneration in cancer cells.

Improvement of antihyperglycemic activity of nano-thymoquinone in rat model of type-2 diabetes

Thymoquinone is a bioactive constituent of Nigella sativa seeds. It has been reported to possess antihyperglycemic effect in rats. However, the effect of nanoformulation (NF) of thymoquinone has not been reported in literature. So, the present study was designed with the aim to investigate the effect of nanoformulation of thymoquinone in streptozotocin-nicotinamide induced type-2 diabetic rats and compare its effect with pure bioactive compound as well as metformin, a standard antidiabetic drug. It is the first study reporting the use of thymoquinone NF against diabetes. Polymeric nanocapsules (NCs) of thymoquinone and metformin were prepared by nanoprecipitation method using gum rosin, a biocompatible polymer. Box-Behnken statistical analysis tool was used for the optimization of polymer and other excipients. The NCs were then characterized with respect to particle size, stability, morphology, and in vitro drug dissolution profiles. Furthermore, thymoquinone (20, 40 & 80 mg/kg), metformin (150 mg/kg) and their nanoformulations (20, 40 & 80 mg/kg for thymoquinone and 80 mg/kg for metformin) per se were administered for 21 successive days to type-2 diabetic rats. Body weight and blood glucose levels were measured every week for 3 weeks. Serum lipid profile and glycosylated hemoglobin were estimated on 22^nd day. The nanocapsules were stable, spherical in shape and size was less than 100 nm. Thymoquinone-and metformin-loaded NCs showed sustained release profile as compared to their pure forms. Oral administration of thymoquinone, metformin and their nanoformulations significantly decreased blood glucose level and glycated haemoglobin; and improved the lipid profile of diabetic rats as compared to diabetic control rats. Thymoquinone-loaded NCs (containing 10, 20 and 40 mg of thymoquinone) produced dose-dependent antihyperglycemic effect and this effect was comparable to thymoquinone and metformin. In conclusion, thymoquinone nanocapsules (actually containing half of the doses of thymoquinone) produced better antihyperglycemic effect in type-2 diabetic rats as compared to thymoquinone alone.

Nanoformulated natural therapeutics for management of streptozotocin-induced diabetes: potential use of curcumin nanoformulation

Aim: The goal of this study was to improve curcumin (CUR) aqueous solubility and bioavailability via nanoformulation, and then study its activity and mechanism of action as an antidiabetic agent. Methods: CUR-loaded pluronic nanomicelles (CURnp) were prepared and characterized. Biochemical assessments were performed as well as histological, confocal and RTPCR studies on pancreatic target tissues. Results: CURnp with a diameter of 333 ± 6 nm and ζ potential of -26.1 mv were obtained. Antidiabetic action of CURnp was attributed to significant upregulation of Pdx-1 and NKx6.1 gene expression and achievement of optimum redox balance, which led to alleviation of streptozotocin-induced β-cell damage via a significant upregulation in insulin gene expression proved by RTPCR studies and by the presence of 40% insulin positive cells through confocal microscope studies on pancreatic tissue.

Fabrication, characterization and in vitro evaluation of silibinin nanoparticles: an attempt to enhance its oral bioavailability

Background

Silibinin has gained in importance in the past few decades as a hepatoprotector and is used widely as oral therapy for toxic liver damage, liver cirrhosis, and chronic inflammatory liver diseases, as well as for the treatment of different types of cancers. Unfortunately, it has low aqueous solubility and inadequate dissolution, which results in low oral bioavailability.

Materials and methods

In this study, nanoparticles (NPs) of silibinin, which is a hydrophobic drug, were manufactured using two cost-effective methods. Antisolvent precipitation with a syringe pump (APSP) and evaporative precipitation of nanosuspension (EPN) were used. The prepared NPs were characterized using different analytical techniques such as scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray powder diffractometry (XRD) and were sifted for their bioavailability through in vitro dissolution and solubility studies. Moreover, the prepared NPs were evaluated for antimicrobial activity against a battery of bacteria and yeast.

Results

DSC and XRD studies indicated that the prepared NPs were amorphous in nature, with more solubility and dissolution compared to the crystalline form of this drug. NPs prepared through the EPN method had better results than those prepared using the APSP method. Antimicrobial activities of the NPs were improved compared to the unprocessed drugs, while having comparable activities to standard antimicrobial drugs.

Conclusion

Results indicate that the NPs have significantly increased solubility, dissolution rate, and antimicrobial activities due to the conversion of crystalline structure into amorphous form.