Development and biological evaluation of Gymnema sylvestre extract-loaded nonionic surfactant-based niosomes

Pharmacokinetics and bioequivalence of Withania somnifera (Ashwagandha) extracts - A double blind, crossover study in healthy adults

Introduction

Withania somnifera (WS) or ashwagandha is an adaptogenic plant used extensively in traditional medicines and as a food supplement. Despite a long history of use and numerous clinical trials, the human pharmacokinetics of withanolides, the active phytochemicals in WS extracts, have not been fully evaluated. This study evaluated the oral pharmacokinetics and bioequivalence of active withanolides in human plasma after administration of a single dose of two commercial ashwagandha extracts containing equal amounts of total withanolides.

Methods

This randomized, double-blind, single-dose crossover study of 16 healthy human volunteers evaluated the acute oral bioavailability of withanolides and the bioequivalence of two WS extracts, WS-35 and WS-2.5. WS-35 was standardized to total withanolides not less than 40% comprising not less than 35% withanolide glycosides and WS-2.5 was standardized to 2.5% withanolides. The clinical dosages were normalized to 185 mg of total withanolide in each extract at the bioequivalent dosages. The pharmacokinetic parameters of withanolide A, withanoside IV, withaferin A, and total withanolides were quantified in the blood plasma using a validated LC-MS/MS method.

Results

The half-life, C-max, and mean residence time of the total withanolides were 5.18, 5.62 and 4.13 times significantly higher and had lower systemic clearance with WS-35 than with WS-2.5 extract. Considering the plasma AUC 0-inf of total withanolides per mg of each WS extract administered orally, WS-35 was 280.74 times more bioavailable than WS-2.5.

Conclusion

The results of this study highlight the importance of withanolide glycosides in improving the pharmacokinetics of WS extracts. Owing to its superior pharmacokinetic profile, WS-35, with 35% withanolide glycosides, is a promising candidate for further studies on Withania somnifera.

Clinical trial registration

CTRI/2020/10/028397 [registered on:13/10/2020] (Trial prospectively registered) http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=42149&EncHid=&userName=CTRI/2020/10/028397.

Current advances in niosomes applications for drug delivery and cancer treatment

The advent of nanotechnology has led to an increased interest in nanocarriers as a drug delivery system that is efficient and safe. There have been many studies addressing nano-scale vesicular systems such as liposomes and niosome is a newer generation of vesicular nanocarriers. The niosomes provide a multilamellar carrier for lipophilic and hydrophilic bioactive substances in the self-assembled vesicle, which are composed of non-ionic surfactants in conjunction with cholesterol or other amphiphilic molecules. These non-ionic surfactant vesicles, simply known as niosomes, can be utilized in a wide variety of technological applications. As an alternative to liposomes, niosomes are considered more chemically and physically stable. The methods for preparing niosomes are more economic. Many reports have discussed niosomes in terms of their physicochemical properties and applications as drug delivery systems. As drug carriers, nano-sized niosomes expand the horizons of pharmacokinetics, decreasing toxicity, enhancing drug solvability and bioavailability. In this review, we review the components and fabrication methods of niosomes, as well as their functionalization, characterization, administration routes, and applications in cancer gene delivery, and natural product delivery. We also discuss the limitations and challenges in the development of niosomes, and provide the future perspective of niosomes.

Harnessing role of sesamol and its nanoformulations against neurodegenerative diseases

Sesamol is a lignan of sesame seeds and a natural phenolic molecule that has emerged as a useful medical agent. Sesamol is a non-toxic phytoconstituent, which exerts certain valuable effects in the management of cancer, diabetes, cardiovascular diseases, neurodegenerative diseases (NDs), etc. Sesamol is known to depict its neuroprotective role by various mechanisms, such as metabolic regulators, action on oxidative stress, neuroinflammation, etc. However, its poor oral bioavailability, rapid excretion (as conjugates), and susceptibility to gastric irritation/toxicity (particularly in rats' forestomach) may restrict its effectiveness. To overcome the associated limitations, novel drug delivery system-based formulations of sesamol are emerging and being researched extensively. These can conjugate with sesamol and enhance the bioavailability and solubility of free sesamol, along with delivery at the target site. In this review, we have summarized various research works highlighting the role of sesamol on various NDs, including Alzheimer's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Parkinson's disease. Moreover, the formulation strategies and neuroprotective role of sesamol-based nano-formulations have also been discussed.

Assessment of the antidiabetic potential of extract and novel phytoniosomes formulation of Tradescantia pallida leaves in the alloxan-induced diabetic mouse model

Diabetes inflicts health and economic burdens on communities and the present antidiabetic therapies have several drawbacks. Tradescantia pallida leaves have been used as a food colorant and food preservative; however, to our knowledge antidiabetic potential of the leaves of T. pallida has not been explored yet. The current study aimed to investigate the antidiabetic potential of T. pallida leaves extract and its comparison with the novel nisosome formulation of the extract. The leaves extract and phytoniosomes of T. pallida in doses of 15, 25 and 50 mg/kg were used to assess the oral glucose loaded, and alloxan-induced diabetic mice models. The biological parameters evaluated were; change in body weight, blood biochemistry, relative organ to body weight ratio and histopathology of the liver, pancreas and kidney. Results revealed that the extract 50 mg/kg and phytoniosomes 25 and 50 mg/kg remarkably reduced the blood glucose level in all hyperglycemic mice by possibly inhibiting α-amylase and α-glucosidase production. Body weight and blood biochemical parameters were considerably improved in phytoniosomes 50 mg/kg treated group. The relative body weight was similar to those of healthy mice in extract 50 mg/kg, phytoniosomes 25 mg/kg, and phytoniosomes 50 mg/kg treated groups. Histopathology showed the regeneration of cells in the CHN50 treated group. Hyphenated chromatographic analysis revealed potent metabolites, which confirmed the antidiabetic potential of the extract by inhibiting α-amylase and α-glucosidase using in silico analysis. The present data suggested that phytoniosomes have shown better antidiabetic potential than crude extract of these leaves.

An Overview of Herbal-Based Antidiabetic Drug Delivery Systems: Focus on Lipid- and Inorganic-Based Nanoformulations

Diabetes is a metabolic pathology with chronic high blood glucose levels that occurs when the pancreas does not produce enough insulin or the body does not properly use the insulin it produces. Diabetes management is a puzzle and focuses on a healthy lifestyle, physical exercise, and medication. Thus far, the condition remains incurable; management just helps to control it. Its medical treatment is expensive and is to be followed for the long term, which is why people, especially from low-income countries, resort to herbal medicines. However, many active compounds isolated from plants (phytocompounds) are poorly bioavailable due to their low solubility, low permeability, or rapid elimination. To overcome these impediments and to alleviate the cost burden on disadvantaged populations, plant nanomedicines are being studied. Nanoparticulate formulations containing antidiabetic plant extracts or phytocompounds have shown promising results. We herein aimed to provide an overview of the use of lipid- and inorganic-based nanoparticulate delivery systems with plant extracts or phytocompounds for the treatment of diabetes while highlighting their advantages and limitations for clinical application. The findings from the reviewed works showed that these nanoparticulate formulations resulted in high antidiabetic activity at low doses compared to the corresponding plant extracts or phytocompounds alone. Moreover, it was shown that nanoparticulate systems address the poor bioavailability of herbal medicines, but the lack of enough preclinical and clinical pharmacokinetic and/or pharmacodynamic trials still delays their use in diabetic patients.

A Review on the Delivery of Plant-Based Antidiabetic Agents Using Nanocarriers: Current Status and Their Role in Combatting Hyperglycaemia

Diabetes mellitus is a prevalent metabolic syndrome that is associated with high blood glucose levels. The number of diabetic patients is increasing every year and the total number of cases is expected to reach more than 600 million worldwide by 2045. Modern antidiabetic drugs alleviate hyperglycaemia and complications that are caused by high blood glucose levels. However, due to the side effects of these drugs, plant extracts and bioactive compounds with antidiabetic properties have been gaining attention as alternative treatments for diabetes. Natural products are biocompatible, cheaper and expected to cause fewer side effects than the current antidiabetic drugs. In this review, various nanocarrier systems are discussed, such as liposomes, niosomes, polymeric nanoparticles, nanoemulsions, solid lipid nanoparticles and metallic nanoparticles. These systems have been applied to overcome the limitations of the current drugs and simultaneously improve the efficacy of plant-based antidiabetic drugs. The main challenges in the formulation of plant-based nanocarriers are the loading capacity of the plant extracts and the stability of the carriers. A brief review of lipid nanocarriers and the amphipathic properties of phospholipids and liposomes that encapsulate hydrophilic, hydrophobic and amphiphilic drugs is also described. A special emphasis is placed on metallic nanoparticles, with their advantages and associated complications being reported to highlight their effectiveness for treating hyperglycaemia. The present review could be an interesting paper for researchers who are working in the field of using plant extract-loaded nanoparticles as antidiabetic therapies.

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.

Ameliorative effect of rubiadin-loaded nanocarriers in STZ-NA-induced diabetic nephropathy in rats: formulation optimization, molecular docking, and in vivo biological evaluation

Diabetic nephropathy (DN) is a significant source of end-stage renal illness all over the world in both developed and developing countries. The aim of the study was to optimize rubiadin-loaded niosomes (RLN) using Box-Behnken design for the management of streptozotocin-nicotinamide (STZ-NA)-induced DN in Wistar rats. The RLN were formulated by a "thin-layer hydration technique." The optimization of RLN was done by Box-Behnken design; the independent variables were cholesterol (CHOL), Span 80, and methanol, while the dependent factors were the vesicle size, zeta potential, and entrapment efficiency. The optimized formulation was characterized for various biochemical parameters including anti-diabetic activity in Wistar rats. The optimized RLN presented vesicle size of 238 nm, zeta potential -68 mV, and entrapment efficiency 85%. A noteworthy decreased in blood glucose level was detected in STZ-NA-induced DN rats when orally treated with RLN (100 mg/kg/week and 200 mg/kg/week). Oral administration of RLN formulation considerably decreased the levels of urea, uric acid, and creatinine in DN rats. In addition, treatment of DN rats with RLN formulation considerably improves the level of TBARS, GSH, SOD, and CAT. The lipid profile of DN rats was also improved on treatment with RLN formulation. This study revealed that the prepared RLN formulation was successfully optimized by Box-Behnken design and found to be useful for the management of STZ-NA-induced DN in Wistar rats.

Diabetic eye: associated diseases, drugs in clinic, and role of self-assembled carriers in topical treatment

Introduction: Diabetes is a pandemic disease that causes relevant ocular pathologies. Diabetic retinopathy, macular edema, cataracts, glaucoma, or keratopathy strongly impact the quality of life of the patients. In addition to glycemic control, intense research is devoted to finding more efficient ocular drugs and improved delivery systems that can overcome eye barriers. Areas covered: The aim of this review is to revisit first the role of diabetes in the development of chronic eye diseases. Then, commercially available drugs and new candidates in clinical trials are tackled together with the pros and cons of their administration routes. Subsequent sections deal with self-assembled drug carriers suitable for eye instillation combining patient-friendly administration with high ocular bioavailability. Performance of topically administered polymeric micelles, liposomes, and niosomes for the management of diabetic eye diseases is analyzed in the light of ex vivo and in vivo results and outcomes of clinical trials. Expert opinion: Self-assembled carriers are being shown useful for efficient delivery of not only a variety of small drugs but also macromolecules (e.g. antibodies) and genes. Successful design of drug carriers may offer alternatives to intraocular injections and improve the treatment of both anterior and posterior segments diabetic eye diseases.

Advances of Non-Ionic Surfactant Vesicles (Niosomes) and Their Application in Drug Delivery

Non-Ionic surfactant based vesicles, also known as niosomes, have attracted much attention in pharmaceutical fields due to their excellent behavior in encapsulating both hydrophilic and hydrophobic agents. In recent years, it has been discovered that these vesicles can improve the bioavailability of drugs, and may function as a new strategy for delivering several typical of therapeutic agents, such as chemical drugs, protein drugs and gene materials with low toxicity and desired targeting efficiency. Compared with liposomes, niosomes are much more stable during the formulation process and storage. The required pharmacokinetic properties can be achieved by optimizing components or by surface modification. This novel delivery system is also easy to prepare and scale up with low production costs. In this paper, we summarize the structure, components, formulation methods, quality control of niosome and its applications in chemical drugs, protein drugs and gene delivery.

Development, physicochemical characterization, and antimicrobial evaluation of niosomal myrtle essential oil

Myrtus communis (myrtle) is well known for its therapeutic effects pertaining to the major secondary metabolites including essential oils (EOs). EOs are composed of volatile compounds and simply evaporate or decompose leading to their instability. Preparation of EOs niosomal formulation may be a promising approach to deal with these obstacles. Niosomal formulations of myrtle essential oil (nMEO) were provided using non-ionic surfactants and cholesterol (Chol). In the next steps, vesicle size, zeta potential, percentage of entrapment efficiency (EE%) and physical stability of nMEO were investigated. Finally, the effect of myrtle essential oil (MEO) and nMEO on microbial growth inhibition were assessed. Values for nMEO size and zeta potential ranged from 6.17 ± 0.32 to 7.24 ± 0.61 (μm) and -20.41 ± 0.17 to -31.75 ± 0.45 (mV), respectively. Higher degrees of EE% were obtained by F6 formulation (Span/Tween 60:Chol (50:50 molar ratio)). Moreover, niosomes have been reported to be stable at 4 °C during a three-month time period. It was revealed that nMEO F6 formulation inhibited growth of Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens, and Bacillus subtilis at concentrations lower than that of MEO. Overall, it was found that stable multilamellar vesicles were formed in the presence of 0.5% MEO and F6 formulation. This formulation also exhibited better antibacterial activity than MEO.

Niosomes from 80s to present: the state of the art

Efficient and safe drug delivery has always been a challenge in medicine. The use of nanotechnology, such as the development of nanocarriers for drug delivery, has received great attention owing to the potential that nanocarriers can theoretically act as "magic bullets" and selectively target affected organs and cells while sparing normal tissues. During the last decades the formulation of surfactant vesicles, as a tool to improve drug delivery, brought an ever increasing interest among the scientists working in the area of drug delivery systems. Niosomes are self assembled vesicular nanocarriers obtained by hydration of synthetic surfactants and appropriate amounts of cholesterol or other amphiphilic molecules. Just like liposomes, niosomes can be unilamellar or multilamellar, are suitable as carriers of both hydrophilic and lipophilic drugs and are able to deliver drugs to the target site. Furthermore, niosomal vesicles, that are usually non-toxic, require less production costs and are stable over a longer period of time in different conditions, so overcoming some drawbacks of liposomes. The niosome properties are specifically dictated by size, shape, and surface chemistry which are able to modify the drug's intrinsic pharmacokinetics and eventual drug targeting to the areas of pathology. This up-to-date review deals with composition, preparation, characterization/evaluation, advantages, disadvantages and application of niosomes.