Health benefits of fraxetin: From chemistry to medicine

Fraxetin is a bioactive molecule present in various natural plants, especially Cortex Fraxini. Evidenced outcomes in phytochemical and biological analyses for this agent are now available in the literature, but an insightful review is yet unknown. The goal of the current research is to offer a panoramic illustration of natural observation, biosynthesis, synthesis, pharmacology, and pharmacokinetics for fraxetin. Esculetin and ferulic acid acted as precursors in the enzymatic biosynthetic route, whereas fraxetin could be easily synthesized from simple phenols. A great deal of interest was obtained in using this molecule for pharmacological targets. Herein, its pharmacological value included anticancer, antioxidative, anti-inflammatory, antidiabetic, antiobesity, and antimicrobial activities, as well as the protection of the liver, neurons, heart, bone, lung, kidney, and others. Anticancer activity may involve the inhibition of proliferation, invasion, and migration, together with apoptotic induction. Health benefits from this molecule were deduced from its ability to suppress cytokines and protect the immune syndrome. Various signaling pathways, such as Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3), phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt), nuclear factor kappa B (NF-κB)/NLRP3, Akt/AMPK, have been proposed for in vitro and in vivo mechanisms of action. Fraxetin is highly distributed to rat plasma and several organs. However, more pharmacokinetic studies to improve its bioavailability are needed since its solubility in water is still limited.

Synthesis of the MnO2-Fe3O4 catalyst support on amorphous silica: a new Fenton's reagent in the degradation of the reactive blue-19 in aqueous solution

In this study, a new Fenton's reagent was synthesized via two steps: (1) the dispersed Fe₃O₄ nanoparticles were immobilized on the surface of the SiO₂ carrier via the precipitation process, and (2) the MnO₂ nano-sheets were coated on the surface of Fe₃O₄/SiO₂ via hydrothermal method. The SiO₂ carrier has been synthetically utilized from Vietnamese rice husk. The successful formation of the MnO₂-Fe₃O₄/SiO₂ composite has been analytically characterized by the XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy dispersive spectrometry)-mapping, FTIR (Fourier transform infrared), S_BET (Brunauer-Emmett-Teller specific surface area), and adsorption/desorption isotherms. This Fenton system was employed to catalyze degradation process of the reactive-blue 19 (RB19) with approximately 100% of removal efficiency after 25 min at the optimal condition of 0.15 g/100 mL of catalyst dosage, pH = 3, and the H₂O₂ concentration of 3 mL/100 mL. Moreover, the catalyst could be reused at least six times with high catalytic activity that was more than 90%. In conclusion, this study showed that the mesoporous MnO₂-Fe₃O₄/SiO₂ composite has a great potential for the removal application of dyes from wastewater, and the application of Vietnam rice husk in environmental treatment was developed.

The Genus Cryptocarya: A Review on Phytochemistry and Pharmacological Activities

Cryptocarya (the laurel family) is a large genus of great economic plants found in tropics and subtropics. Plants of this genus are a rich resource of essential oils, and pharmacological compounds. An overview of phytochemistry and pharmacological aspect is not yet available. This review aims to establish insightful information on phytochemistry, and pharmacological values. The literature collection is based on keywords 'Cryptocarya', 'phytochemistry', and 'pharmacology' using a broad panel of scientific sources, such as Google Scholar, Sciencedirect, and Wiley. Since the 1950s, Cryptocarya plants have been the main object in various phytochemical studies, by which about 390 metabolite compounds were isolated. Alkaloids, α-pyrones, and flavonoids could be seen as the main classes of Cryptocarya isolates. Cryptocarya constituents displayed potential pharmacological values such as anti-inflammatory, antimicrobial, antioxidative, antiviral, vasorelaxant activities, especially cytotoxicity.

Wedelolactone: A molecule of interests

BACKGROUND

The search for bioactive molecules from medicinal plants of the family Asteraceae has been one of the targets in various phytochemical and pharmacological investigations for many years. According to these studies, wedelolactone, a coumestan of the secondary metabolite type, is a key compound found in several Eclipta and Wedelia herbal plants. To date, numerous experimental studies with intention of highlighting its role in drug development programs were carried out, but an extensive review is not sufficient.

OBJECTIVE

The current review aims to fill the gaps in extensive knowledge about phytochemistry, synthesis, pharmacology, and pharmacokinetics of coumestan wedelolactone.

MATERIALS AND METHODS

The databases Google Scholar, Scopus, PubMed, Web of Science, Science Direct, Medline, and CNKI were used to compile the list of references. In order to find references, "wedelolactone" was considered separately or in combination with "phytochemistry", "synthesis", "pharmacology", and "pharmacokinetics." Since the 1950s, >100 publications have been collected and reviewed.

RESULTS

Wedelolactone is likely to be a characteristic metabolite of two genera Eclipta and Wedelia, the family Asteraceae, while it could be synthetically derived from mono-phenol derivatives, through Sonogashira and cross-coupling reactions. Numerous biomedical investigations on wedelolactone revealed that its pharmacological values included anticancer, antiinflammatory, antidiabetic, antiobesity, antimyotoxicity, antibacterial, antioxidant, antivirus, anti-aging, cardiovascular, serine protease inhibition, especially its protective health benefits to living organs such as liver, kidney, lung, neuron, eye, bone, and tooth. The combination of wedelolactone and potential agents is a preferential approach to improve its biomedical values. Pharmacokinetic study exhibited that wedelolactone was metabolized in rat plasma due to hydrolysis, open-ring lactone, methylation, demethylation, and glucuronidation.

CONCLUSIONS

Wedelolactone is a promising agent with the great pharmacological values. Molecular mechanisms of the actions of this compound at both in vitro and in vivo levels are now available. However, reports highlighting biosynthesis and structure-activity relationship are still not adequate. Moreover, chemo-preventive records utilizing nano-technological approaches to improve its bioavailability are needed since the solubility in the living body environment is still limited.

Assessment of the distribution and ecological risks of heavy metals in coastal sediments in Vietnam's Mong Cai area

Coastal sediments in the Mong Cai area were collected and analyzed for grain size, heavy metals, total organic carbon, and isotopes (²¹⁰Pb, ²²⁶Ra, δ¹⁵N, δ¹³C) to assess sediment quality. The most common sediments were fine sand in surface sediment, very fine sand in core C1, and very coarse and coarse silt in core C2. The total organic carbon was highest in C2 next to the surface and lowest in C1, with content levels of 1.81%, 0.40%, and 0.31%, respectively. The chronology in C1 was 1877-2019 (142 years, 0-5 0 cm), with an average sedimentation rate of 0.71 cm/year. In C2, the chronology was 1944-2019 (75 years, 0-14 cm), with an average sedimentation rate of 0.27 cm/year. These δ¹³C and δ¹⁵N in the sediment reflect the source of the organic matter mix from the marine and terrigenous sediments. All studied heavy metals were lower than the ISQGs, with the exception of As in C1 and C2, which were higher. C1 showed a decline in As over time, while C2 As levels increased between 1996 and 2019. In terms of heavy metal pollution indexes, the geoaccumulation index (Igeo) showed that C1 and C2 were unpolluted to moderately polluted with As, with Li and Pb in C2; the enrichment factor (EF) was moderately enriched with As; the contamination factor (CF) was moderately contaminated (Pb, Cd, Fe, Mo, and Li) in C2 and C1 (Cd, As, Li) and considerably contaminated (As) in C2. The risk factor (ER) of As showed a moderate potential ecological risk in C2. The degree of contamination (CD) ranged from moderate to considerable (C1, C2), and the ecological risk (RI) was low. Although CD ranged from moderate (C1) to considerable (C2), most contamination was concentrated at the bottom of the cores. RI was low. The Mong Cai sediment quality does not currently affect the coastal area's ecosystem and fauna.

Siamese, Indian, and Brazilian Rosewoods: A Review on Phytochemistry, Applications, and Pharmacology

For the first time, the current review fully provides information on the phytochemicals, applications, and pharmacological aspects relating to 3 Dalbergia species, Siamese Rosewood ( Dalbergia cochinchinensis Pierre ex Laness.), Indian Rosewood ( D sissoo Roxb.), and Brazilian Rosewood ( D nigra (Vell.) Benth.). Based on chromatographic separation, phytochemical studies on these plants have, to date, resulted in the isolation and structural elucidation of 136 secondary metabolites. Among them, flavonoids and simple phenols are major components, whereas terpenoids, quinones, benzofurans, benzophenols, phytosterols, stilbenes, phthalates, xanthones, and lignans have been also detected. Dalbergia rosewoods are heavy and strong, taking an outstanding polish, and are very suitable for furniture. They are also used as natural dyes, raw materials for removing contaminants from water, and might be a rich resource of essential oils, polysaccharides, and active glycosidase enzymes. Dalbergia crude extracts and their secondary metabolites have a wide range of pharmacological actions, such as anti-inflammatory, anti-oxidative, anti-aging, anti-bacterial, anti-nociceptive, anti-diarrheal, anti-pyretic, gastrointestinal, biocontrol activities, but sexual and anti-osteoporosis activities are the most valuable.

Genus Tupistra: A Comprehensive Review of Phytochemistry and Pharmacological Activity

In the current paper, secondary metabolites separated from Tupistra plants have been reviewed. Approximately 200 phytochemicals, classified in various chemical classes of bioactive compounds, have been compiled, along with their sources and references. The most striking feature is that the most frequently isolated compounds have been spirostanol sapogenins, and spirostanol and furostanol saponins, most of which are new in nature. The application of both Tupistra plant extracts and isolated compounds in biological assays is also one of the crucial aims in pharmacological discoveries. Tupistra constituents have demonstrated valuable properties in the field of pharmacology, such as antioxidative, antimicrobial, antidiabetic, and antihepatic activities, but their cytotoxic and anti-inflammatory actions can be considered as the more remarkable. In vivo cancer-related activities of the tested Tupistra samples were mostly based on apoptosis. Further phytochemical investigations, together with extensive assessments of the biological profiles and mechanism of action studies of the components of Tupistra species are to be expected.

The Effectiveness of Sperm Preparation Using Density Mini-Gradient and Single-Layer Centrifugation for Oligospermia Samples

Background:

Sperm preparation is an important step during assisted reproduction, and different assisted reproductive techniques have different sperm quality requirements. For intrauterine insemination (IUI), the total motile sperm count is a predictor of a patient’s fertility.

Objective:

The aim of this study was to compare the sperm recovery rate and DNA fragmentation index (DFI) outcomes following density mini-gradient and single-layer centrifugation in preparation for intrauterine insemination (IUI).

Methods:

A total of 30 semen samples with concentrations under 15 million cells/ml were obtained, and each sample was divided into 3 aliquots, with each aliquot subjected to 1 of 3 separation methods: mini-gradient, single-layer using a 90% density layer (single 90-layer), and single-layer using a 45% density layer (single 45-layer). Total sperm motility and sperm recovery rates were compared before and after preparation using each method.

Results:

The sperm concentration obtained using single 45-layer was higher than the other groups (p<0.05), but sperm motility was higher using the mini-gradient and single 90-layer methods higher than the single 45-layer method (p<0.05). The recovered sperm motility rates for the mini-gradient, single 90-layer, and single 45-layer methods were 57.6% ± 20.6%, 62.8% ± 18.5%, and 78.7% ± 12.4%, respectively, indicating a better outcome for the single 45-layer method than for the other methods.

Conclusion:

All of these methods can be applied to sperm preparation for IUI, and the optimal method can be selected based on initial sperm quality to collect sperm with good motility and DNA integrity to achieve a satisfactory pregnancy rate.

Proliferation and Differentiation of Dopaminergic Neurons from Human Neuroepithelial Stem Cells Obtained from Embryo Reduction Following In Vitro Fertilization

Background:

Recent advances in stem cell technologies have rekindled an interest in the use of cell therapies to treat patients with Parkinson’s disease. Although the transplantation of dopaminergic mesencephalic human fetal brain tissue has previously been reported in the treatment of patients with Parkinson’s disease, this method is limited by the availability of tissue obtained from each human embryo.

Objective:

Our study aimed to isolate, culture, proliferate, and differentiate dopaminergic neurons from human neuroepithelial stem cells obtained from embryo reduction procedures performed in multifetal pregnancies following in vitro fertilization.

Materials and Methods:

A total of 201 human embryos were dissected for isolation and culture of neuroepithelial stem cells for proliferation and differentiation into dopaminergic neurons. All embryos were obtained from embryo reduction procedures performed in multifetal pregnancies after in vitro fertilization treatments.

Results:

Human neuroepithelial stem cells were isolated and cultured from embryos from 6.0 to 8.0 weeks. Neuroepithelial stem cells were successfully isolated, proliferated, and differentiated into dopaminergic neurons. The cells adhered to the surfaces of cell culture plates after 2 days and could be proliferated and differentiated into neurons within 4 days. Cultured cells expressed the dopaminergic marker tyrosine hydroxylase after 6 days, suggesting that these cells were successfully differentiated into dopaminergic neurons.

Conclusion:

The successful isolation, culture, proliferation, and differentiation of human dopaminergic neurons from embryo reductions performed for multifetal pregnancies after in vitro fertilization suggests that this pathway may serve as a potential source of cell therapy materials for use in the treatment of Parkinson’s disease.

A New Technique in Alveolar Cleft Bone Grafting for Dental Implant Placement in Patients With Cleft Lip and Palate

OBJECTIVE

To evaluate 2 iliac corticocancellous-block grafting techniques for dental implant placement in residual alveolar clefts.

DESIGN

Nonrandomized prospective clinical trial between March 2010 and December 2014.

SETTING

National Hospital of Odonto-Stomatology, Hanoi, Vietnam.

PARTICIPANTS

Thirty-two patients (23 female, 9 male; mean age, 21.28 years; range, 16-31 years) with unilateral complete alveolar cleft after reconstructive surgery for cleft lip and palate (CLP).

INTERVENTIONS

Harvested iliac crest bone was cut into 2 corticocancellous blocks. The smaller block was adapted against the sutured nasal mucoperiosteum and overlaid with cancellous bone; the larger one overlapped the labial cleft margin and was fixed with screws. Endosteal dental implants were placed after 4 to 6 months, and final restorations were delivered 6 months later.

MAIN OUTCOME MEASURES

Flap statuses were assessed clinically. Bone formation was assessed using the Enemark scale. Cone-beam computed tomography was used for graft height and width measurements. Implant health was assessed by the Misch criteria.

RESULTS

The mean postgrafting follow-up period was 36.7 ± 10.4 (range, 18-53) months. Three patients (9.4%) showed flap dehiscence but no infection 7 days after bone grafting. Twenty-nine patients (90.6%) had 75% to 100% bone fill (Enemark score of 1). The mean graft height and width were 11.4 ± 2.4 and 6.1 ± 1.0 mm, respectively. Sufficient bone for implant placement was noted in 29 patients (90.6%); the others required partially fixed prostheses. All implants functioned for at least 18 months.

CONCLUSION

The proposed technique is reliable to reconstruct the alveolar cleft for implant placement in CLP patients.

Polybrominated diphenyl ethers in plastic products, indoor dust, sediment and fish from informal e-waste recycling sites in Vietnam: a comprehensive assessment of contamination, accumulation pattern, emissions, and human exposure

Residue concentrations of polybrominated diphenyl ethers (PBDEs) in different kinds of samples including consumer products, indoor dust, sediment and fish collected from two e-waste recycling sites, and some industrial, urban and suburban areas in Vietnam were determined to provide a comprehensive assessment of the contamination levels, accumulation pattern, emission potential and human exposure through dust ingestion and fish consumption. There was a large variation of PBDE levels in plastic parts of obsolete electronic equipment (from 1730 to 97,300 ng/g), which is a common result observed in consumer plastic products reported elsewhere. PBDE levels in indoor dust samples collected from e-waste recycling sites ranged from 250 to 8740 ng/g, which were markedly higher than those in industrial areas and household offices. Emission rate of PBDEs from plastic parts of disposed electronic equipment to dust was estimated to be in a range from 3.4 × 10^-7 to 1.2 × 10^-5 (year^-1) for total PBDEs and from 2.9 × 10^-7 to 7.2 × 10^-6 (year^-1) for BDE-209. Some fish species collected from ponds in e-waste recycling villages contained elevated levels of PBDEs, especially BDE-209, which were markedly higher than those in fish previously reported. Overall, levels and patterns of PBDE accumulation in different kinds of samples suggest significant emission from e-waste sites and that these areas are potential sources of PBDE contamination. Intakes of PBDEs via fish consumption were generally higher than those estimated through dust ingestion. Intake of BDE-99 and BDE-209 through dust ingestion contributes a large proportion due to higher concentrations in dust and fish. Body weight normalized daily intake through dust ingestion estimated for the e-waste recycling sites (0.10-3.46 ng/day/kg body wt.) were in a high range as compared to those reported in other countries. Our results highlight the potential releases of PBDEs from informal recycling activities and the high degree of human exposure and suggest the need for continuous investigations on environmental pollution and toxic impacts of e-waste-related hazardous chemicals.