Fabrication and characterization of a Bi2O3-modified chitosan@ZIF-8 nanocomposite for enhanced drug loading-releasing efficacy

In this study, a simple novel hybrid mesoporous nanomaterial derived from a metal-organic framework (ZIF-8) and chitosan, which were coated on green bismuth oxide, has been successfully synthesized, characterized, and applied to investigate its dapsone loading-releasing capability in the aqueous media. This suggested nanocomposite showed promise for drug loading from water b using hydrogen bonds, pi-pi, and electrostatic interactions. Structural and morphological analyses were performed on the proposed green synthesized nanocomposite through scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis, and thermogravimetric analysis. Various influencing parameters, including pH, nanocomposite dose, and contact time, were investigated to optimize the dapsone loading process. Utilizing the non-linear optimization methodology, the results show that dapsone-loading efficiency was >85 % for 50 mg.L-1 of dapsone drug. The optimum parameters for achieving maximal loading of dapsone drug were pH = 6.8, hybrid mesosphere dose = 2.6 mg.mL-1, and time = 53 min. Based on the release investigations, the dapsone-loaded nanocomposite was put into phosphate buffer saline, at pH = 7.4 and T = 37 °C, with a maximum efficiency of 93.9 after 24 h.

A Comprehensive Review on Potentially Therapeutic Agents against COVID-19 from Natural Sources

Abstract:

Acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the recent pandemic and worldwide outbreak of respiratory disease. Since there are no known specific drugs for fighting this virus and the process for new drug development is lengthy, scientists have been trying to develop drugs against this viral infection. The potent antiviral activity of natural products has been confirmed in several previous studies. Viral and host proteins contributing to COVID-19 infections can be targeted by natural compounds derived from plants, marine organisms, and microorganisms. The most important of these compounds are polyphenols (e.g., anthraquinone polyphenol, hinokinin, curcumin, and epigallocatechin gallate), alkaloids (e.g., isoquinoline, 10-hydroxyusambarensine, anisotine, and adhatodine), and terpenoids (salvinorin A, thymoquinone, bilobalide, ginkgolide A, and celastrol) from plants, sulphated polysaccharides (carrageenans, chondroitin sulfate C, and fucoidan) from marine organisms, and glycocin F and lactococcin G phycocyanin, and lipopeptide from microorganisms. This study reviews these compounds and their mechanism of action for treating COVID-19 infection and guides researchers in developing effective and safe therapeutic agents against this disease from naturally derived compounds.

Effects of a combination of Nigella sativa and Vitex agnus-castus with citalopram on healthy menopausal women with hot flashes: results from a subpopulation analysis

The goal of the current study was to evaluate the efficiency of a phytotherapeutic intervention consisting of a combination of Nigella sativa and Vitex agnus-castus with citalopram in the control of hot flashes in healthy menopausal women. An 8 week, double-blind, randomized, placebo-controlled study was performed among 46 women aged between 40 and 60 years experiencing an average of more than four hot flashes per day recruited during July 2016 to June 2017. Data on severity of vasomotor symptoms were collected at the end of the eighth week. Herbal medication or placebo capsules were administered once daily in morning. At the end of the 8-week treatment period, analyses of covariance demonstrated the superiority of herbal combination with citalopram over placebo and citalopram for three MENQOL domain scores including vasomotor (p < .001), physical (p = .036), psychosocial (p = .001) but no significant differences were observed in terms of sexual function (p = .231). Based on the results, the addition of a combination of N. sativa and V. agnus-castus to the citalopram may be a potential clinical application for improving therapeutic outcomes. Larger randomized, controlled trials are also warranted for further investigations of these symptoms.

Development and In-vitro Evaluation of a Contraceptive Vagino-Adhesive Propranolol Hydrochloride Gel

The objective of the present investigation was to develop and evaluate a contraceptive vagino-adhesive propranolol hydrochloride gel. To achieve this, various mucoadhesive polymers including guar gum (1-4% w/w), sodium alginate (4-7% w/w), xanthan gum (2-5% w/w ), HPMC 4000 (3-5% w/w), Na CMC (4-7% w/w), carbomer 934 and carbomer 940 both in the range of 0.5-2.0% w/w, were dispersed in an aqueous-based solution containing the drug (1.6% w/w). The mucoadhesive properties of the gels were assessed on sheep vaginal mucosa (as model mucosa) in pH 4.5 citrate-phosphate buffer at 37°C. Formulations containing charged functional groups in their polymeric structure, showed higher mucoadhesive strengths in comparison to those composed of neutral polymers. In-vitro drug release profiles of the gels were determined in pH 4.5 citrate-phosphate buffer. Results indicated that, only formulation F13 (containing sodium alginate 6.5% w/w), could release its drug over 12 h, with a burst release at the initial phase followed by a sustained release pattern. This formulation, which showed a good mucoadhesive strength (386.97 ± 9.31 mN), was considered as the final formulation and underwent complementary tests including determination of drug content and duration of mucoadhesion. Its drug content was found to be 101.05 ± 0.106% (n = 3) and it attached to the model mucosa for more than 10 h. In conclusion, formulation F13 was considered as the most desirable formulation as it exhibited appropriate mucoadhesive properties while having the potential of providing an immediate contraceptive effect, followed by a prolonged drug release which is assumed to render longer contraceptive efficacy.