Current Drug Therapy - Volume 17, Issue 4, 2022

Aims: The aim of this study is validation of antiviral activity of Stephania hernandifolia against HSV-2. Background: Ethnomedicinal plant Stephania hernandifolia, traditionally used for the management of skin, digestive and nerve ailments demonstrated significant anti-HSV-1 activity; similar to Stephania cepharantha having neuroinflammatory and anti-HSV activities. Objectives: Thus, the present study aimed to validate the potential of the most active fraction-2 (F-2) of S. hernandifolia against HSV-2 in vitro, along with the underlying mode or mechanism of action. Methods: The standardized F-2 was characterized by GC-MS, ¹H-NMR, Mass and FTIR spectroscopy. Cytotoxicity (CC50) and antiviral activity (EC50) were evaluated by MTT and Plaque reduction assay. To determine the mode of action, we have used time-of-addition, virus inactivation, and entry (attachment and penetration) assays, followed by semiquantitative PCR. Furthermore, the protein expression levels of immediate early (IE) and early (E) gene products of drug-treated virions were measured by Western blot. Results: The results showed that HSV-2G and ICMR/VU-2012/20, the clinical isolate of HSV-2, were inhibited by F-2 at EC50 of 20.0 and 20.43 μg/ml respectively, with Selectivity Index (SI) of 12. Timeof- addition assay showed that F-2 significantly inhibited HSV-2 infection in Vero cells at 4-8 h posttreatment. The infectivity of the virion was lost within 1h of exposure to F-2 (EC50 and EC99). Furthermore, semi-Q-PCR and Western blot studies demonstrated significant downregulation of IE and E gene products. The characterization revealed that 2-chloroethyl linoleate is the lead compound in the F-2 fraction. Conclusion: Thus, our results showed that the bioactive fraction F-2 inhibits both IE and E transcription of HSV-2.

Background: Recent findings suggest that chitosan has shown antibacterial activity acting through various mechanisms, but when the amine group in chitosan is converted to quaternary ammonium compound, the antibacterial activity of chitosan is elevated due to the increase in its solubility in an acidic environment. Objectives: The purpose of this study was to formulate and standardize metronidazole-loaded Ntrimethyl quaternary ammonium chitosan nanoparticles for the treatment of periodontitis. Method: N-trimethyl quaternary ammonium chitosan derivative was synthesized, and nanoparticles (NPs) were prepared by ionic gelation methodology followed by 3² full factorial designs. Particle size, zeta potential, polydispersity index (PDI), surface morphology, thermal properties, in vitro drug release as well as antimicrobial activity, stability study, ex vivo, and acute toxicity of NPs were evaluated. Results: The optimized batches of NPs were in the size range of 150 to 237 nm with a mean size of 117.01 ± 0.03 nm. Entrapment efficiency (EE) of 81.45 ± 0.03 % was obtained with a zeta potential (mV) of 28.19 ± 0.03 mV. Almost 98.97 ± 7.17% of the drug was released within 24 hours in vitro to obtain a sustained release drug; the optimized batches exhibited a smooth surface with appreciable in vitro, ex vivo antibacterial, and acute toxicity, and it was found that the formulation could be stored for up to 6 months. Conclusion: The present study revealed that metronidazole-loaded N-trimethyl quaternary ammonium chitosan nanoparticles exhibit enhanced antibacterial activity against periodontal infections.

Background: Blonanserin is an atypical antipsychotic potent antagonist of dopamine-D2 and D3 receptors with low aqueous solubility BCS class II drugs. Objective: The present research aims to develop and optimize the Blonanserin-loaded liquid selfmicro emulsifying drug delivery system (SMEDDS) to improve its in vitro drug release by D-optimal mixture design. Methods: Saturation solubility of Blonanserin was checked in various oils, surfactants, and cosurfactants. The pseudo-ternary phase diagram was developed to identify the region of the microemulsion. Trial batches were designed to determine dependent and independent variables in the formulation. DOptimal Mixture design applies for optimization and minimized trials. The amount of oil(X1), surfactant( X2), and co-surfactant(X3) were selected as independent variables, and solubility(Y1) and in vitro percentage cumulative drug release(Y2) and size of globule(Y3) after 250 times dilution were selected as the dependant variable. The level of the independent variables in the design will be selected based on the drug's phase diagram, trial batches, and solubility. The developed SMEDDS was then evaluated for globule size, transparency, self-emulsification time, in vitro dissolution, and relative dissolution of the final formulation with marketed products and a pure drug. Results: BLN shows the highest solubility in (1:1) Captex 200P: Capmul MCM (oil), Tween 20 (surfactant), and Ethanol (cosurfactant). Trial batches were shown at 1:9, 2:8, and 3:7 oil to surfactant and cosurfactant ratios suitable for optimization. Optimization using a D-optimal mixture design gives 11 run batches and the resulting surface and contour plot suggest the best design space. The optimized formula given by the mixture design of the target formulation had maximum drug solubility, maximum drug release, and minimum globule size. Optimized formula containing Blonanserin, Captex 200P: Capmul MCM (1:1) Mixture (23% v/v), Tween 80 (57% v/v), and Ethanol (20% v/v) having 94.72% in vitro diffusion within 30 min with 21 nm globule size. Optimized liquid SMEDDS have a higher in-vitro diffusion rate than marketed products and pure drugs. Conclusion: Blonanserin liquid SMEDDS was successfully developed with high solubility, nanoglobule size, and improvement in in-vitro diffusion rate and vice versa for improvement in bioavailability of the drug.

Objective: Epilepsy is a neurological disorder associated with the elevation of oxidative stress levels and alteration in vitamins and endogenous antioxidant levels. The current study was designed to evaluate the effects of Vit D3, thiamine, melatonin, and their combination on pentylenetetrazol (PTZ)-induced tonic-clonic seizures in mice along with measuring the alteration in oxidative stress markers. Methods: Male mice were randomly divided into seven groups; group I received normal saline (0.5 ml, i.p.) on the 15^th day, group II received PTZ (60 mg/kg, i.p) on the 15^th day, groups III-VI received diazepam (4 mg/kg), Vit D3 (6000 IU/kg, p.o.), thiamine (200 mg/kg, p.o.), and melatonin (20 mg/kg, p.o.), respectively, before PTZ (60 mg/kg, i.p.) injection on the 15th day, and group VII received the combination of Vit D3, thiamine, and melatonin, before PTZ injection on the 15^th day. After PTZ injection, the seizure latency and duration were measured. The malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were evaluated in mice brains. Results: In the treatment group, the seizure latency was greater and the seizure duration was lower than in the PTZ group. These agents decreased the MDA level and increased SOD activity compared to the PTZ group. The combination of these agents was more effective than each alone to increase seizure latency and reduce seizure duration. Conclusion: The combination of Vit D3, thiamine, and melatonin could improve PTZ-induced seizures more effectively than each one alone; this may be mediated by inhibiting oxidative stress and regulating various mechanisms involved in seizures.

Introduction: Pain is one of the most common medical conditions and affects more than diabetes, heart disease, and cancer combined. Current pain treatments mainly rely on NSAID analgesics and remain unsatisfactory. Due to associated adverse effects such as gastrointestinal ulcers and bleeding, low solubility limits its use. Objective: The present research focuses on advances in the field of pain treatment by topical delivery of NSAIDs (aceclofenac) drugs via enhancing its solubility and diminishing related side effects. Materials and Methods: ACE-nanosuspension (ACE-NS) prepared by anti-solvent precipitation technique was characterized for particle size, PDI, zeta-potential, total drug content, DSC, FTIR, P-XRD and FESEM. Furthermore, spreadability, ex-vivo occlusivity, in-vitro release, ex-vivo skin permeation and retention and stability studies were performed. Dermal irritation and histopathological examinations were conducted in accordance with OECD guidelines. Proof of concept studies was accomplished using radiant tail-flick and paw-licking animal models. Results: ACE-NS showed particle size of 148 ± 15 nm with PDI: 0.170, zeta potential: 21.2 mV and total drug content of 86 ± 0.23%, respectively. DSC, FT-IR, P-XRD and FESEM studies revealed the thermal behavior, compatibility, solid-state characterization and morphology of ACE-NS. ACE-NSloaded ointment showed a spreadability ratio of 0.23 and a drug content of 84 ± 1.15%. In-vitro release of ACE from nano-ACE-ointment (88.07%) was higher than the marketed formulation (70.55%) and free drug ointment (70.45%) after 24 hours. Release profile of nano-ACE-ointment fitted best for Higuchi model with r2 = 0.94 and n = 0.45 and its permeation flux was 9.2312 ± 0.8430 mg/cm2/h, which was significantly higher (p ≤0.05) than ACE marketed gel (2.6158 ± 0.4352 mg/cm2/h). Cutaneous irritation and histological studies revealed no inflammatory skin lesions post-treatment with ACE-NS. Furthermore, ACE-NS-ointment showed a better analgesic effect than the marketed formulation in both the radiant tail-flick model (2.87 times) and paw-licking (2.73 times) animal model. Conclusion: Studies highlighted the potential of topical nano-ACE-ointment for pain management.