Protective effect of flavonoids on oxidative stress injury in Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disease, which is mainly caused by the damage of the structure and function of the central nervous system. At present, there are many adverse reactions in market-available drugs, which can't significantly inhibit the occurrence of AD. Therefore, the current focus of research is to find safe and effective therapeutic drugs to improve the clinical treatment of AD. Oxidative stress bridges different mechanism hypotheses of AD and plays a key role in AD. Numerous studies have shown that natural flavonoids have good antioxidant effects. They can directly or indirectly resist -oxidative stress, inhibit Aβ aggregation and Tau protein hyperphosphorylation by activating Nrf2 and other oxidation-antioxidation-related signals, regulating synaptic function-related pathways, promoting mitochondrial autophagy, etc., and play a neuroprotective role in AD. In this review, we summarised the mechanism of flavonoids inhibiting oxidative stress injury in AD in recent years. Moreover, because of the shortcomings of poor biofilm permeability and low bioavailability of flavonoids, the advantages and recent research progress of nano-drug delivery systems such as liposomes and solid lipid nanoparticles were highlighted. We hope this review provides a useful way to explore safe and effective AD treatments.

Natural compounds as lactate dehydrogenase inhibitors: potential therapeutics for lactate dehydrogenase inhibitors-related diseases

Lactate dehydrogenase (LDH) is a crucial enzyme involved in energy metabolism and present in various cells throughout the body. Its diverse physiological functions encompass glycolysis, and its abnormal activity is associated with numerous diseases. Targeting LDH has emerged as a vital approach in drug discovery, leading to the identification of LDH inhibitors among natural compounds, such as polyphenols, alkaloids, and terpenoids. These compounds demonstrate therapeutic potential against LDH-related diseases, including anti-cancer effects. However, challenges concerning limited bioavailability, poor solubility, and potential toxicity must be addressed. Combining natural compounds with LDH inhibitors has led to promising outcomes in preclinical studies. This review highlights the promise of natural compounds as LDH inhibitors for treating cancer, cardiovascular, and neurodegenerative diseases.

Update on new trends and progress of natural active ingredients in the intervention of Alzheimer's disease, based on understanding of traditional Chinese and Western relevant theories: A review

Alzheimer's disease (AD) is one of the major neurological disorders causing death in the elderly worldwide. As a neurodegenerative disease that is difficult to prevent and cure, the pathogenesis of AD is complex and there is no effective cure. A variety of natural products derived from plants have been reported to have promising anti-AD activities, including flavonoids, terpenes, phenolic acids and alkaloids, which can effectively relieve the symptoms of AD in a variety of ways. This paper mainly reviews the pharmacological activity and mechanisms of natural products against AD. Although the clinical efficacy of these plants still needs to be determined by further high-quality studies, it may also provide a basis for future researchers to study anti-AD in depth.

Efficacy of a mixture of Ginkgo biloba, sesame, and turmeric on cognitive function in healthy adults: Study protocol for a randomized, double-blind, placebo-controlled trial

BACKGROUND AND PURPOSE

Ginkgo biloba extract (GBE) reportedly ameliorates cognitive function in patients with chronic cerebrovascular insufficiency. However, its efficacy in healthy adults is ambiguous. It was reported that concentrations of terpene lactones, active components of GBE that are present in very low concentrations in the brain, were significantly increased following administration of a mixture of GBE, sesame seed, and turmeric (GBE/MST) in mice. This study aims to investigate the effectiveness of GBE/MST on the cognitive function of healthy adults by comparing it with that of GBE alone.

METHODS

Altogether, 159 participants providing informed consent will be recruited from a population of healthy adults aged 20-64 years. Normal cognitive function at baseline will be confirmed using the Japanese version of the Montreal Cognitive Assessment battery. Participants will be randomly assigned in a double-blind manner to the GBE/MST, GBE, and placebo groups in a 1:1:1 ratio. The Wechsler Memory Scale, Trail Making Test, and Stroop Color and Word Test will be used to assess the memory and executive functions at baseline and at the endpoint (24 weeks). For biological assessment, resting state functional magnetic resonance imaging (rs-fMRI) will be performed simultaneously with the neuropsychological tests.

DISCUSSION

This study aims to obtain data that can help compare the profile changes in memory and executive functions among participants consuming GBE/MST, GBE alone, and placebo for 24 weeks. Alterations in the default mode network will be evaluated by comparing the rs-fMRI findings between baseline and 24 weeks in the aforementioned groups. Our results may clarify the impact of GBE on cognitive function and the functional mechanism behind altered cognitive function induced by GBE components.

TRIAL REGISTRATION

This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR; registration number: UMIN000043494). This information can be searched on the website of the International Clinical Trials Registry Platform Search Portal of the World Health Organization under the Japan Primary Registries Network.

Pharmacological Profile, Bioactivities, and Safety of Turmeric Oil

The pharmacological attributes of turmeric have been extensively described and frequently related to the action of curcuminoids. However, there is also scientific evidence of the contribution of turmeric oil. Since the oil does not contain curcuminoids in its composition, it is crucial to better understand the therapeutic role of other constituents in turmeric. The present review discusses the pharmacokinetics of turmeric oil, pointing to the potential application of its active molecules as therapeutic compounds. In addition, the bioactivities of turmeric oil and its safety in preclinical and clinical studies were revised. This literature-based research intends to provide an updated overview to promote further research on turmeric oil and its constituents.

Microwave-assisted Natural Deep Eutectic Solvents Pretreatment Followed by Hydrodistillation Coupled with GC-MS for Analysis of Essential Oil from Turmeric (Curcuma longa L.)

In the past decade, natural deep eutectic solvents (NADESs) as green and sustainable extraction solvents with great potential for the efficient extraction of bioactive compounds from the plants are emerging. In this study, a microwave-assisted technology is used to prepare natural deep eutectic solvents. And natural deep eutectic solvents as pretreatment solvents coupled with microwave-assisted hydrodistillation (MAHD) for isolating essential oil (EO) derived from turmeric (Curcuma longa L.) is investigated. To improve the essential oil yield of turmeric (Curcuma longa L.) as a target, various factors affecting extraction efficiency including the type and amount of natural deep eutectic solvents, pretreatment time, pretreatment temperature and hydrodistillation (HD) time are discussed and optimized through central composite design (CCD) of the response surface methodology (RSM). The optimal conditions are as follows: natural deep eutectic solvent composed of choline chloride and oxalic acid (molar ratio with 1:1) as a pretreatment solvent, an amount of 60 g, a pretreatment time of 5 min, a pretreatment temperature of 84 ºC, a hydrodistillation time of 76 min. Under the optimum conditions, the highest essential oil yield of 0.85% is achieved. Additionally, the essential oil is analyzed by using gas chromatography-mass spectrometry (GC-MS), with a total of 49 compounds being identified. Through combining natural deep eutectic solvents with a microwave-assisted hydrodistillation technique, this work provides an eco-friendly extraction way of isolating essential oil, which boosts development in the monitoring other spice quality field.

Experimental evidence and mechanism of action of some popular neuro-nutraceutical herbs

Brain and neuronal circuits constitute the most complex organ networks in human body. They not only control and coordinate functions of all other organs, but also represent one of the most-affected systems with stress, lifestyle and age. With global increase in aging populations, these neuropathologies have emerged as major concern for maintaining quality of life. Recent era has witnessed a surge in nutritional remediation of brain dysfunctions primarily by "nutraceuticals" that refer to functional foods and supplements with pharmacological potential. Specific dietary patterns with a balanced intake of carbohydrates, fatty acids, vitamins and micronutrients have also been ascertained to promote brain health. Dietary herbs and their phytochemicals with wide range of biological and pharmacological activities and minimal adverse effects have gained remarkable attention as neuro-nutraceuticals. Neuro-nutraceutical potentials of herbs are often expressed as effects on cognitive response, circadian rhythm, neuromodulatory, antioxidant and anti-inflammatory activities that are mediated by effects on gene expression, epigenetics, protein synthesis along with their turnover and metabolic pathways. Epidemiological and experimental evidence have implicated enormous applications of herbal supplementation in neurodegenerative and psychiatric disorders. The present review highlights the identification, experimental evidence and applications of some herbs including Bacopa monniera, Withania somnifera, Curcuma longa, Helicteres angustifolia, Undaria pinnatifida, Haematococcus pluvialis, and Vitis vinifera, as neuro-nutraceuticals.

Pharmacokinetics, Bioavailability, Excretion and Metabolism Studies of Akebia Saponin D in Rats: Causes of the Ultra-Low Oral Bioavailability and Metabolic Pathway

Background: Akebia saponin D (ASD) has a variety of biological activities and great medicinal potential, but its oral bioavailability is so low as to limit its development. Its pharmacokinetic profiles and excretion and metabolism in vivo have not been fully elucidated. This study was an attempt in this area.

Methods: A simple LC-MS/MS method to simultaneously quantify ASD and its metabolites M1∼M5 in rat plasma, feces, urine and bile was established with a negative ESI model using dexketoprofen as the internal standard. Meanwhile, the UPLC-HR/MS system was used to screen all possible metabolites in the urine, feces and bile of rats, as compared with blank samples collected before administration. Absolute quantitative analysis was for M0, M3, M4, and M5, while semi-quantitative analysis was for M1, M2, and Orbitrap data.

Results: The AUC_0-t values after intravenous administration of 10 mg/kg and intragastrical administration of 100 mg/kg ASD were 19.05 ± 8.64 and 0.047 ± 0.030 h*μg/ml respectively. The oral bioavailability was determined to be extremely low (0.025%) in rats. The exposure of M4 and M5 in the oral group was higher than that of M0 in the terminal phase of the plasma concentration time profile, and ASD was stable in the liver microsome incubation system of rats, but metabolism was relatively rapid during anaerobic incubation of intestinal contents of rats, suggesting that the low bioavailability of ASD might have been attributed to the poor gastrointestinal permeability and extensive pre-absorption degradation rather than to the potent first pass metabolism. This assertion was further verified by a series of intervention studies, where improvement of lipid solubility and intestinal permeability as well as inhibition of intestinal flora increased the relative bioavailability to different extents without being changed by P-gp inhibition. After intravenous administration, the cumulative excretion rates of ASD in the urine and bile were 14.79 ± 1.87%, and 21.76 ± 17.61% respectively, but only 0.011% in feces, suggesting that the urine and bile were the main excretion pathways and that there was a large amount of biotransformation in the gastrointestinal tract. Fifteen possible metabolites were observed in the urine, feces and bile. The main metabolites were ASD deglycosylation, demethylation, dehydroxylation, decarbonylation, decarboxylation, hydroxylation, hydroxymethylation, hydroxyethylation and hydrolysis.

Conclusion: The pharmacokinetics, bioavailability, metabolism and excretion of ASD in rats were systematically evaluated for the first time in this study. It has been confirmed that the ultra-low oral bioavailability is due to poor gastrointestinal permeability, extensive pre-absorption degradation and biotransformation. ASD after iv administration is not only excreted by the urine and bile, but possibly undergoes complex metabolic elimination.

Intercropping With Turmeric or Ginger Reduce the Continuous Cropping Obstacles That Affect Pogostemon cablin (Patchouli)

Continuous cropping (CC) restricts the development of the medicinal plant cultivation industry because it alters soil properties and the soil microbial micro-ecological environment. It can also lead to reductions in the chemical contents of medicinal plants. In this study, we intercropped continuously cropped Pogostemon cablin (patchouli) with turmeric or ginger. High-throughput sequencing was used to study the soil bacteria and fungi. Community composition, diversity, colony structure, and colony differences were also analyzed. A redundancy analysis (RDA) was used to study the interactions between soil physical and chemical factors, and the bacteria and fungi. The correlations between the soil community and the soil physical and chemical properties were also investigated. The results showed that intercropping turmeric and ginger with patchouli can improve soil microbial abundance, diversity, and community structure by boosting the number of dominant bacteria, and by improving soil bacterial metabolism and the activities of soil enzymes. They also modify the soil physical and chemical properties through changes in enzyme activity, soil pH, and soil exchangeable Ca (Ca). In summary, turmeric and ginger affect the distribution of dominant bacteria, and increase the contents of the active ingredient in patchouli. The results from this study suggested that the problems associated with continuously cropping patchouli can be ameliorated by intercropping it with turmeric and ginger.