Alpha-terpinyl acetate: A natural monoterpenoid from Elettaria cardamomum as multi-target directed ligand in Alzheimer’s disease

A Novel spice-antioxidant-based nano-vehicle as a putative green alternative of synthetic AChE inhibitor drugs

The present treatment for Alzheimer's disease (AD) involves well known synthetic acetylcholine esterase (AChE) inhibitor drugs which besides having short duration of action also have deleterious impact on human health. Therefore, there is a need for natural plant-based biomolecule(s) with potential AChE inhibition activity (ies). The aim of the work is to design a spice-based nano-vehicle as a novel green alternative of synthetic AD drugs by nanoencapsulating a solvent-less supercritical CO2 extract of small cardamom seeds (SCE) having a synergistic consortium of five antioxidant molecules, using polyethylene glycol and emulsifiers, selected based on Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) analyses. Ellman's assay and enzyme inhibition kinetics of the antioxidant molecules as well as the extract and its nanoliposomal formulation (SCE-NL) were performed, followed by rigorous molecular docking and dynamics studies using MM-PBSA and umbrella sampling. The antioxidants exhibited significant AChE inhibition in vitro, individually with 1, 8-cineole having the least IC50 value of 65.53 ± 0.05 µg/mL. . Although SCE-NL had higher IC50 value (575.67 ± 0.5 µg/mL) vis-à-vis that of rivastigmine (67.52 ± 0.02 µg/mL), it is safer for usage being 'green'.The Lineweaver-Burk plots (Vmax ∼1.04 mM/min) revealed competitive mode(s) of inhibition of AChE with each of these antioxidants. Binding energy analyses suggested very good binding free energies and stable docking/binding complexes (between the antioxidants and AChE). This study has delivered a nanoliposomal vehicle of food antioxidants as a putative 'green' alternative of synthetic AChE inhibitor drugs.Communicated by Ramaswamy H. Sarma.

Plant extracts as emerging modulators of neuroinflammation and immune receptors in Alzheimer's pathogenesis

Memory loss is becoming an increasingly significant health problem, largely due to Alzheimer's disease (AD), which disrupts the brain in several ways, including causing inflammation and weakening the body's defenses. This study explores the potential of medicinal plants as a source of novel therapeutic agents for AD. First, we tested various plant extracts against acetylcholinesterase (AChE) in vitro, following molecular docking simulations with key AD-related protein targets such as MAO-B, P-gp, GSK-3β, and CD14. Rosemary extract was found to be the most inhibitory towards AChE. The compounds found in rosemary (oleanolic acid), sage (pinocembrin), and cinnamon (italicene) showed promise in potentially binding to MAO-B. These chemicals may interact with a key protein in the brain and alter the production and removal of amyloid-β. Luteolin (from rosemary), myricetin (from sage), chamigrene, and italicene (from cinnamon) exhibited potential for inhibiting tau aggregation. Additionally, ursolic acid found in rosemary, sage, and chamigrene from cinnamon could modulate CD14 activity. For the first time, our findings shed light on the intricate interplay between neuroinflammation, neuroprotective mechanisms, and the immune system's role in AD. Further research is needed to validate the in vivo efficacy and safety of these plant-derived compounds, as well as their interactions with key protein targets, which could lead to the development of novel AD therapeutics.

Investigating the Antimicrobial Properties of Essential Oil Constituents and Their Mode of Action

Essential oils (EOs) and plant extracts, rich in beneficial chemical compounds, have diverse applications in medicine, food, cosmetics, and agriculture. This study investigates the antibacterial activity of nine essential oil constituents (EOCs) against Escherichia coli, focusing on the effects of treatment pH and biosynthetic requirements. The impact of EOCs on bacterial inactivation in E. coli strains was examined using both nonselective and selective culture media. Computer-assisted drug design (CADD) methods were employed to identify critical binding sites and predict the main binding modes of ligands to proteins. The EOCs, including citral, α-terpinyl acetate, α-terpineol, and linalool, demonstrated significant bacterial inactivation, particularly under acidic conditions. This study revealed that EOCs have an effect on the presence of sublethal damage to both the cytoplasmic membrane and the outer membrane in Gram-negative bacteria. Adding penicillin G to the repair medium prevents the recovery of sublethal injuries in E. coli treated with α-terpinyl acetate, α-terpineol, linalool, and citral, indicating that peptidoglycan synthesis is essential for recovering from these injuries. However, penicillin G did not hinder the recovery process of most sublethally injured cells treated with the other assessed EOCs. Molecular docking studies revealed the favorable binding interactions of α-terpinyl acetate, α-terpineol, linalool, and citral with the β-lactamase enzyme Toho-1, indicating their potential as effective antibacterial agents. The findings suggest that EOCs could serve as viable alternatives to synthetic preservatives, offering new strategies for combating antibiotic-resistant bacteria.

Glucosidase inhibition and compound identification of stingless bee honey and preserved fruits of Citrus japonica

Food preservation has many benefits, such as increasing shelf life, retaining nutritional values and biological activities. In the current study, total phenolic content (TCP), antioxidant and anti-glucosidase activities, and kinetic of glucose inhibition of stingless bee honey, honey mixed with fruits, and extracts of Citrus japonica were evaluated by measuring color of a reaction using a spectrophotometer. The result showed that high TPC was found in ethanol extract of C. japonica leaves and fruits (26.79 ± 6.94 and 12.79 ± 0.87 mg of gallic acid per g extract), while stingless bee honey revealed the highest antioxidant activity (1/EC50 = 0.2921) and honey mixed with fruits revealed the strongest anti-glucosidase activity (1/EC50 = 1.8181), significantly (P-value <0.05). Kinetic of glucosidase inhibition of honey were found as uncompetitive and mixed competitive inhibition, while the honey mixed with fruits showed mixed competitive inhibition. The FTIR and GC-MS analysis demonstrated the presence of several bioactive compounds. Very strong positive relationship between total phenolic content with GC-MS data was found (r = 0.926, P-value < 0.05). This knowledge confirmed that stingless bee honey and honey mixed with fruits had greater anti-diabatic potential in comparison with the extracts of C. japonica leaves and fruits.

Influence of Sucrose and Activated Charcoal on Phytochemistry and Vegetative Growth in Zephyranthes irwiniana (Ravenna) Nic. García (Amaryllidaceae)

Zephyranthes irwiniana (Ravenna) Nic. García is an endemic, red list threatened species from the Brazilian savanna (Cerrado) with pharmacological potential to treat the symptoms of Alzheimer's Disease (AD). This work analyzed the vegetative growth and phytochemistry of its potential compounds, in response to variations in sucrose concentration and activated carbon (AC). Seeds were germinated in vitro and in the greenhouse. The in vitro bulbs were separated in six treatments with different sucrose concentrations (30, 45 and 60 gL-1) and/or AC (1 gL-1). Biomass increases in individuals grown in the greenhouse were higher than those cultivated in vitro. Sucrose concentration significantly increased biomass and root number. AC had a positive influence on leaf and root size, and a negative influence on root number. GC-MS analyses indicated great variation in the abundance of α-terpenyl-acetate, ethyl linoleate, clionasterol and lycorine between treatments, with maximum concentrations of 53.06%, 38.68, 14.34% and 2.57%, respectively. Histolocalization tests indicated the presence of alkaloids in the leaf chlorenchyma and bulb cataphylls. Finally, the present study provided new evidence that the constitution of the culture medium directly influences the vegetative growth and phytochemistry of this species, providing a good medium condition for propagating the species under threat.

Neuroprotective and anti-amnesic effects of Laurus Nobilis essential oil against scopolamine-induced memory deficits in mice brain

ETHNOPHARMACOLOGICAL RELEVANCE

Laurus nobilis L. (Lauraceae family) has been widely used in traditional Tunisian medicine for the treatment of different health problems such as rheumatism and some neurological disorders.

AIM

In this study, the essential oil obtained from Laurus nobilis L. species from Tunisia (LEO) was studied for its chemical composition and anti-amnesic activities on memory impairment caused by scopolamine injection in mice. The major compounds of LEO oil, 1,8-cineole and, α-terpinyl acetate were docked with AChE (Acetylcholinesterase), using Autodock Vina and Discovery Studio visualizer software.

MATERIALS AND METHODS

The Morris water maze (MWM) tests and the Y maze were used to assess the anti-amnesic effects of LEO in mice with scopolamine-induced memory impairments. In brain tissues, the levels of biomarkers, enzyme activity, and protein expression related to the cholinergic system were measured.

RESULTS

Chronic administration of scopolamine led to a significant decline in cognitive performance in both the Morris Water Maze (MWM) and Y maze tests, accompanied by pronounced oxidative damage and a significant increase in acetylcholinesterase activity compared to the other groups. However, compared to the scopolamine group, treatment with LEO (100 mg/kg) significantly enhanced cognitive function and ameliorated the oxidative damage (p < 0.05 versus scopolamine) CONCLUSION: This study demonstrates the beneficial effect of LEO on scopolamine-induced dementia in mice, potentially achieved through the modulation of cholinergic activity and antioxidant properties. The docking analysis of the major compounds, 1,8-cineole and α-terpinyl acetate, further substantiates their potential as memory enhancers.

Identification and Characterization of Neuroprotective Properties of Thaumatin-like Protein 1a from Annurca Apple Flesh Polyphenol Extract

BACKGROUND

Alzheimer's disease (AD) and Parkinson's disease (PD) are multifactorial neurodegenerative disorders that are mostly treated with drugs inhibiting key enzymes of cholinergic and aminergic neurotransmission, such as acetyl and butyryl cholinesterase (AChE, BuChE) or monoamine oxidases (MAO)-A/B, and of Aβ1-40 aggregation. Diet plant components with multitarget functions are promising compounds in the prevention of AD and PD. Our aim was to identify neuroprotective compounds from Annurca apple polyphenol extract (AFPE).

METHODS

AFPE was fractionated by gel filtration, and the eluted peaks were subjected to chemical analyses (i.e., RP-HPLC and mass spectrometry), determination of inhibitory enzyme activity and cell effects by MTT, and morphology assays.

RESULTS

In AFPE, we identified thaumatin-like protein 1a, belonging to the pathogenesis-related protein (PR) family. This protein showed the best inhibitory activity on AChE, MAO-A (IC50 = 5.53 µM and 1.71 µM, respectively), and Aβ1-40 fibril aggregation (IC50 = 9.16 µM), compared to AFPE and other polyphenol-containing fractions. Among the latter, Peak 4 reverted Aβ fibril formation (IC50 = 104.87 µM). Moreover, thaumatin-like protein 1a protected AGS and MKN-28 cells from serum-deprivation-induced stress conditions.

CONCLUSIONS

We showed that AFPE exerted neuroprotective functions not only through its polyphenols but also through thaumatin-like protein 1a, which acted like a multitarget molecule.

Production of natural flavor compounds using Bacillus subtilis-fermented soybean meal extract and their biological potential: a comprehensive in vitro study

This study aims to investigate the production of natural flavor compounds through the utilization of Bacillus subtilis-fermented soybean meal extract and evaluate their biological potential. The experiment involved a comprehensive in vitro investigation to assess the capabilities and effects of the produced flavor compounds. The resulting flavor compounds were subjected to various in vitro tests to assess their properties, including cytotoxicity, antioxidant activity, anticancer potential, antiviral activity, and antimicrobial activity. To enhance the fermentation process, soybean meal extract was fortified with a combination of L-Lysine and L-Threonine. Gas chromatography-mass spectrometry (GC/MS) analysis was conducted on the fermented soybean meal using two strains of Bacillus subtilis, namely NRCH123 and NRCZ144. This analysis revealed the presence of various volatile compounds in all extracts, including Butylated hydroxytoluene. The fermented soybean extract with bacillus subtilis NRCZ144 (B2) fortified with a combination of 2.5% (w/w) L-Lysine and 2.5% w/w L-threonine (SLT2) exhibited a rich profile of flavor compounds, with Eucalyptol being identified as the predominant compound. The antioxidant activity of the SLT2 extract was found to be 72.04% at a concentration of 100 μg/mL, indicating significant antioxidant potential. Furthermore, when tested against the human liver cancer cell line HepG2, the extract demonstrated anticancer activity with an IC50 value of 2.26 μg/mL. The extract exhibited potent cytotoxicity, with an IC50 value of 1.02 μg/mL. Importantly, the SLT2 extract displayed strong antibacterial and antifungal activity, even at very low concentrations. The extract's antimicrobial properties indicate its potential for inhibiting the growth of bacteria and fungi.

Extraction of Active Compounds from Mixtures of Hemp (Cannabis sativa) with Plants of the Zingiberaceae Family

Hemp is probably one of the most studied plants for its health-promoting properties, with countless documented and patented extraction methods, but literature is scarce on the simultaneous extraction of mixture of raw materials. Hemp, along with other plant materials, could represent a potentially highly valuable source material with resulting reciprocal effects. In this study, hemp (Cannabis sativa) and three members of the Zingiberaceae family, ginger (Zingiber officinale), turmeric (Curcuma longa), and cardamom (Elettaria cardamomum), were extracted simultaneously, and their bioactive component values were investigated. Two extraction methods were used, namely ultrasound-assisted extraction with ethanol and supercritical fluid extraction with carbon dioxide. First, extracts were obtained from separate plant materials. Then, hemp was extracted in combination with ginger, turmeric, and cardamom in a 1:1 ratio. The extracts obtained were evaluated for their antioxidant activity and total phenolic content using UV/VIS spectrophotometry; cannabinoid content, 6-gingerol, and 6-shogaol were measured using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS); volatile components such as 1,8-cineole, alpha-terpinyl acetate, linalool, and aR-turmerone were measured using gas chromatography with mass spectrometry (GC/MS).

Elettaria cardamomum (L.) Maton Essential Oil: An Interesting Source of Bioactive Specialized Metabolites as Inhibitors of Acetylcholinesterase and Butyrylcholinesterase

Elettaria cardamomum (L.) Maton (Zingiberaceae family) is a plant traditionally used in Ayurvedic and Chinese medicine. In this work, the essential oil of E. cardamomum was found to inhibit the enzymes AChE (62.6% of inhibition, IC50 24.9 μg/mL) and BChE (55.8% of inhibition, IC50 25.9 μg/mL) by performing an in vitro colorimetric assay using the Ellman method. A bio-guided fractionation approach was used to isolate fractions/pure compounds that were tested individually to evaluate their activity. The resulting oxygenated fraction was found to be active against both AChE (percentage inhibition 42.8%) and BChE (percentage inhibition 63.7%), while the hydrocarbon fraction was inactive. The activity was attributed to a pool of oxygenated terpenes (α-terpinyl acetate, 1,8-cineole, linalool, linalyl acetate, and α-terpineol) that synergistically contributed to the overall activity of the essential oil.

Chemical composition, cholinesterase, and α-glucosidase inhibitory activity of the essential oils of some Iranian native Salvia species

BACKGROUND

The plants from Salvia genus contain widely distributed species which have been used in folk medicine as well as pharmaceutical and food industries.

METHODS

The chemical composition of 12 native Iranian Salvia species (14 plants) was identified using gas chromatography-mass spectrometry (GC-MS). Also, the inhibitory activity of all essential oils (EOs) was evaluated toward α-glucosidase and two types of cholinesterase (ChE) using spectrophotometric methods. The in vitro α-glucosidase inhibition assay was performed by the determination of p-nitrophenol (pNP) obtained from the enzymatic dissociation of p-nitrophenol-α-D-glucopyranoside (pNPG) as the substrate. In vitro ChE inhibitory assay was conducted based on the modified Ellman's procedure using the measurement of 5-thio-2-nitrobenzoic acid produced from the hydrolysis of thiocholine derivatives as the substrate, in the presence of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE).

RESULTS

Totally, 139 compounds were detected and caryophyllene oxide and trans-β-caryophyllene were the most abundant compounds in all EOs. The yield of EOs extracted from the plants were also calculated in the range of 0.06 to 0.96% w/w. Herein, α-glucosidase inhibitory activity of 8 EOs was reported for the first time and among all, S. spinosa L. was found to be the most potent inhibitor (90.5 inhibition at 500 μg/mL). Also, the ChE inhibitory activity of 8 species was reported for the first time and our results showed that the BChE inhibitory effect of all EOs was more potent than that of AChE. The ChE inhibition assay indicated that S. mirzayanii Rech.f. & Esfand. collected from Shiraz was the most potent inhibitor (72.68% and 40.6% at the concentration of 500 μg/mL, toward AChE and BChE, respectively).

CONCLUSIONS

It seems that native Salvia species of Iran could be considered in the development of anti-diabetic and anti-Alzheimer's disease supplements.

Thymus vulgaris Essential Oil in Beta-Cyclodextrin for Solid-State Pharmaceutical Applications

Antimicrobial resistance related to the misuse of antibiotics is a well-known current topic. Their excessive use in several fields has led to enormous selective pressure on pathogenic and commensal bacteria, driving the evolution of antimicrobial resistance genes with severe impacts on human health. Among all the possible strategies, a viable one could be the development of medical features that employ essential oils (EOs), complex natural mixtures extracted from different plant organs, rich in organic compounds showing, among others, antiseptic properties. In this work, green extracted essential oil of Thymus vulgaris was included in cyclic oligosaccharides cyclodextrins (CD) and prepared in the form of tablets. This essential oil has been shown to have a strong transversal efficacy both as an antifungal and as an antibacterial agent. Its inclusion allows its effective use because an extension of the exposure time to the active compounds is obtained and, therefore, a more marked efficacy, especially against biofilm-producing microorganisms such as P. aeruginosa and S. aureus, was registered. The efficacy of the tablet against candidiasis opens their possible use as a chewable tablet against oral candidiasis and as a vaginal tablet against vaginal candidiasis. Moreover, the registered wide efficacy is even more positive since the proposed approach can be defined as effective, safe, and green. In fact, the natural mixture of the essential oil is produced by the steam current method; therefore, the manufacturer employs substances that are not harmful, with very low production and management costs.

Standardization and Ameliorative effect of Kalyanaka ghrita in β-amyloid induced memory impairment in wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Kalyanaka ghrita (KG) is an Ayurvedic formulation traditionally used in the treatment of Daurbalya (debility) and Smritidaurbalya (impairment of intellectual activities). Clinical studies have reported the effect of KG in the treatment of Manasmandata or Buddhimandyata which is associated with impaired learning, social adjustment and maturation.

AIM OF THE STUDY

The present study aims to standardization of KG and validation of its use in experimental models of neurodegeneration.

MATERIALS AND METHODS

KG was Standardized for biomarkers curcumin, gallic acid, tannic acid, chebulagic acid, and berberine. In male wistar rats, neurodegeneration was induced by administration of intracerebroventricular Amyloid β (Aβ_1-42). The effect of KG (oral and intranasal treatment) was evaluated through behavioral parameters such as Morris water maze, social recognition test, novel object recognition, locomotor activity, and molecular parameters, brain acetylcholinesterase, brain-derived neurotrophic factor (BDNF), inflammatory cytokines, oxidative stress markers, and antioxidants. Brain histopathology was performed for studying the architecture of the brain and plaque formation.

RESULTS AND DISCUSSION

A novel HPLC method has been developed for the standardization of KG. Treatment with KG significantly improved cognition and memory and increased brain BDNF and antioxidant status in Aβ_1-42 induced rats. It also reduced brain acetylcholinesterase, oxidative stress, and inflammatory cytokines and prevented neuronal damage. There were more marked effects with intra-nasal administration compared to oral treatment.

CONCLUSION

The findings suggest that KG has neuroprotective potential and along with its nootropic property could be a promising therapy for neurodegenerative diseases like Alzheimer's disease.

The Discrimination and Characterization of Volatile Organic Compounds in Different Areas of Zanthoxylum bungeanum Pericarps and Leaves by HS-GC-IMS and HS-SPME-GC-MS

The pericarps of Zanthoxylum bungeanum (ZBP) and leaves of Zanthoxylum bungeanum (ZBL) are popular spices in China, and they have pharmacological activities as well. In this experiment, the volatile organic compounds (VOCs) of the pericarps of Zanthoxylum bungeanum in Sichuan (SJ) and its leaves (SJY) and the pericarps of Zanthoxylum bungeanum in Shaanxi (SHJ) and its leaves (SHJY) were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The fingerprint of HS-GC-IMS and the heat maps of HS-SPME-GC-MS were established. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were performed. The results showed that a total of 95 components were identified, 62 components identified by HS-SPME-GC-MS and 40 components identified by HS-GC-IMS, of which 7 were the same. The analysis found that SJ and SHJ were obviously distinguished, while SJY and SHJY were not. There were considerably fewer VOCs in the leaves than in the pericarps. In the characterization of the VOCs of ZBL and ZBP, the flavor of ZBP was more acrid and stronger, while the flavor of ZBL was lighter and slightly acrid. Thirteen and eleven differential markers were identified by HS-GC-IMS and HS-SPME-GC-MS, respectively. This is helpful in distinguishing between SHJ and SJ, which contributes to their quality evaluation.

Eucalyptus cinerea and E. nicholii by-Products as Source of Bioactive Compounds for Agricultural Applications

The cultivation of different species of Eucalyptus has recently expanded in Liguria (Italy) due to the growing demand of the North European floricultural market. Eucalyptus tree branches are cut and selected for their quality, resulting in large amounts of waste biomass to be disposed of. The aim of our study was to evaluate the phytotoxic and antimicrobial activities of essential oils (EOs) from pruning wastes of E. cinerea (EC) and E. nicholii (EN), for potential applications in agriculture. Phytochemical analyses showed eucalyptol (1,8-cineole) as the major component in both EOs, but the EO yield of EN was higher than that of EC, in agreement with a significantly higher oil gland density on EN leaves. EOs from both species showed phytotoxicity on both weeds tested, but no significant inhibition on horticultural crop seed germination, except for Raphanus sativus. The EO from EC showed the strongest antibacterial activity, while the EO from EN showed the strongest antifungal activity. Concluding, EOs from Eucalyptus pruning may be used as possible alternatives to synthetic herbicides and pesticides, acting as antimicrobial and antifungal agents, thus representing a safe strategy for crop management programs.

Therapeutic roles of plants for 15 hypothesised causal bases of Alzheimer's disease

Alzheimer's disease (AD) is progressive and ultimately fatal, with current drugs failing to reverse and cure it. This study aimed to find plant species which may provide therapeutic bioactivities targeted to causal agents proposed to be driving AD. A novel toolkit methodology was employed, whereby clinical symptoms were translated into categories recognized in ethnomedicine. These categories were applied to find plant species with therapeutic effects, mined from ethnomedical surveys. Survey locations were mapped to assess how this data is at risk. Bioactivities were found of therapeutic relevance to 15 hypothesised causal bases for AD. 107 species with an ethnological report of memory improvement demonstrated therapeutic activity for all these 15 causal bases. The majority of the surveys were found to reside within biodiversity hotspots (centres of high biodiversity under threat), with loss of traditional knowledge the most common threat. Our findings suggest that the documented plants provide a large resource of AD therapeutic potential. In demonstrating bioactivities targeted to these causal bases, such plants may have the capacity to reduce or reverse AD, with promise as drug leads to target multiple AD hallmarks. However, there is a need to preserve ethnomedical knowledge, and the habitats on which this knowledge depends.

Anti-Alzheimer's disease potential of traditional chinese medicinal herbs as inhibitors of BACE1 and AChE enzymes

Alzheimer's disease (AD) is a common neurodegenerative disease that often occurs in the elderly population. At present, most drugs for AD on the market are single-target drugs, which have achieved certain success in the treatment of AD. However, the efficacy and safety of single-target drugs have not achieved the expected results because AD is a multifactorial disease. Multi-targeted drugs act on multiple factors of the disease network to improve efficacy and reduce adverse reactions. Therefore, the search for effective dual-target or even multi-target drugs has become a new research trend. Many of results found that the dual-target inhibitors of the beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) and acetylcholinesterase (AChE) found from traditional Chinese medicine have a good inhibitory effect on AD with fewer side effects. This article reviews sixty-six compounds extracted from Chinese medicinal herbs, which have inhibitory activity on BACE1 and AChE. This provides a theoretical basis for the further development of these compounds as dual-target inhibitors for the treatment of AD.

Natural Therapeutics in Aid of Treating Alzheimer's Disease: A Green Gateway Toward Ending Quest for Treating Neurological Disorders

The current scientific community is facing a daunting challenge to unravel reliable natural compounds with realistic potential to treat neurological disorders such as Alzheimer's disease (AD). The reported compounds/drugs mostly synthetic deemed the reliability and therapeutic potential largely due to their complexity and off-target issues. The natural products from nutraceutical compounds emerge as viable preventive therapeutics to fill the huge gap in treating neurological disorders. Considering that Alzheimer's disease is a multifactorial disease, natural compounds offer the advantage of a multitarget approach, tagging different molecular sites in the human brain, as compared with the single-target activity of most of the drugs so far used to treat Alzheimer's disease. A wide range of plant extracts and phytochemicals reported to possess the therapeutic potential to Alzheimer's disease includes curcumin, resveratrol, epigallocatechin-3-gallate, morin, delphinidins, quercetin, luteolin, oleocanthal, and other phytochemicals such as huperzine A, limonoids, and azaphilones. Reported targets of these natural compounds include inhibition of acetylcholinesterase, amyloid senile plaques, oxidation products, inflammatory pathways, specific brain receptors, etc. We tenaciously aimed to review the in-depth potential of natural products and their therapeutic applications against Alzheimer's disease, with a special focus on a diversity of medicinal plants and phytocompounds and their mechanism of action against Alzheimer's disease pathologies. We strongly believe that the medicinal plants and phytoconstituents alone or in combination with other compounds would be effective treatments against Alzheimer's disease with lesser side effects as compared to currently available treatments.

Chemical Stabilization behind Cardamom Pickering Emulsion Using Nanocellulose

Cardamom essential oil (EO) is a rare oil of high scientific and economic interest due to its biofunctionality. This work aims to stabilize the EO by Pickering emulsions with nanocellulose, in the form of nanocrystals (CNC) or nanofibers (CNF), and to investigate the stability and chemical and physical interactions involved in the process. The emulsions were characterized by droplet size, morphology, stability, surface charges, Fourier transform infrared spectroscopy, FT-Raman, nuclear magnetic resonance, and scanning electron microscopy. Stable emulsions were prepared with cellulose morphologies and CNCs resulted in a 34% creaming index, while CNFs do not show instability. Emulsions indicate a possible interaction between nanocellulose, α-terpinyl acetate, and 1,8-cineole active essential oil compounds, where α-terpinyl acetate would be inside the drop and 1,8-cineole is more available to interact with cellulose. The interaction intensity depended on the morphology, which might be due to the nanocellulose’s self-assembly around oil droplets and influence on oil availability and future application. This work provides a systematic picture of cardamomum derived essential oil Pickering emulsion containing nanocellulose stabilizers’ formation and stability, which can further be extended to other value-added oils and can be an alternative for the delivery of cardamom essential oil for biomedical, food, cosmetics, and other industries.

Chemical Profiles of Herbal Compress and Their Persistence Affected by Steaming and Storage Time

The steamed herbal compress is one of the well-known traditional medicines used to relieve pain and stress and to promote emotional and physical well-being. Although it has several therapeutic benefits due to its chemical compounds, there are insufficient reports on the effect of steaming of the herbal compress to promote the release of active compounds and its shelf life. Hence, this study aims at analysing the effect of various steaming processes and storage conditions on the chemical composition of most commonly used herbs such as kaffir lime, lemongrass, plai, soap pod, tamarind, and turmeric. The herbs were extracted with solid-liquid and Soxhlet-mediated extraction using 95% ethanol, hexane, and water as solvents. The analysis of chemical profiles of herbs indicated that Soxhlet extraction is the best extraction procedure based on the extraction yield and abundance of eluted compounds. The herbs were then steam-processed according to the traditional practice of using herbal compress with water alone, and water in combination with 5% ethanol or 5% coconut oil to analyse the effect of steaming. The results indicated that a steaming process can promote the release of bioactive compounds from herbs. The effect of storage was also investigated by storing herbs for 1 day and 7 days at 4°C. The finding suggested that storage has resulted in changes in the bioactive composition of herbs pointing to the necessity of modifying storage conditions to eliminate the loss of beneficial compounds. Thus, this study can be helpful for product development to improve the quality of products by modifying their steaming or storage conditions.

The use of chemometric modelling to determine chemical composition-antimicrobial activity relationships of essential oils used in respiratory tract infections

The antimicrobial effects of essential oils are commonly cited within aromatherapeutic texts for use in respiratory tract infections. These essential oils are inhaled or applied to the skin to treat infections and manage symptoms associated with these conditions. A limited number of these essential oils have been scientifically studied to support these claims, specifically, against respiratory pathogens. This study reports on the minimum inhibitory concentration (MIC) of 49 commercial essential oils recommended for respiratory tract infections, and identifies putative biomarkers responsible for the determined antimicrobial effect following a biochemometric workflow. Essential oils were investigated against nine pathogens. Three essential oils, Amyris balsamifera (amyris), Coriandrum sativum (coriander) and Santalum austrocaledonicum (sandalwood) were identified as having greater activity (MIC value = 0.03-0.13 mg/ml) compared to the other essential oils investigated. The essential oil composition of all 49 oils were determined using Gas Chromatography coupled to Mass Spectroscopy (GC-MS) analysis and the GC-MS data analysed together with the antimicrobial data using chemometric tools. Eugenol was identified as the main biomarker responsible for antimicrobial activity in the majority of the essential oils. The ability of a chemometric model to accurately predict the active and inactive biomarkers of the investigated essential oils against pathogens of the respiratory tract was 80.33%.

Thermolabile essential oils, aromas and flavours: Degradation pathways, effect of thermal processing and alteration of sensory quality

Plant-based aroma chemicals, constituting the essential oils play a great role as the natural flavours and preservatives in the food industries. Many of these metabolites are susceptible to degradation under heat (i.e. thermolabile aroma chemicals) which may influence the organoleptic properties of the end-products e.g. essential oil, oleoresin, dry herb, tea and packaged juice. The current review identified in total 42 thermolabile aroma and/or flavour molecules belonging to monoterpenoids, sesquiterpenoids and phenolics. The probable pathway of their degradation and its promoting conditions were also described. Degradation pathways were categorized into five major classes including oxidation, C-C bond cleavage, elimination, hydrolysis and rearrangement. Numerous evidences were cited in support of the thermosensitivity of these phytochemicals under pyrolytic, thermal heating or gas chromatographic conditions. Various post-harvest processes involved in the manufacturing such as drying and distillation of the crops or thermal treatment of the food-products for storage were highlighted as the root cause of degradation. The influence of thermolabile aroma chemicals to maintain the sensory quality of the end-products such as citrus juices, floral oils and thermally cooked foods was discussed in detail. In the present article, detailed insight into the chemical and sensory aspects of thermosensitive aromas and flavours was provided, covering the period from 1990 up to 2020.

Effects of Essential Oils of Elettaria cardamomum Grown in India and Guatemala on Gram-Negative Bacteria and Gastrointestinal Disorders

The present study examined the chemical composition and antimicrobial and gastrointestinal activity of the essential oils of Elettaria cardamomum (L.) Maton harvested in India (EC-I) and Guatemala (EC-G). Monoterpenes were present in higher concentration in EC-I (83.24%) than in EC-G (73.03%), whereas sesquiterpenes were present in a higher concentration in EC-G (18.35%) than in EC-I (9.27%). Minimum inhibitory concentrations (MICs) of 0.5 and 0.25 mg/mL were demonstrated against Pseudomonas aeruginosa in EC-G and EC-I, respectively, whereas MICs of 1 and 0.5 mg/mL were demonstrated against Escherichia coli in EC-G and EC-I, respectively. The treatment with control had the highest kill-time potential, whereas the treatment with oils had shorter kill-time. EC-I was observed to be more potent in the castor oil-induced diarrhea model than EC-G. At 100 and 200 mg/kg, P.O., EC-I exhibited 40% and 80% protection, respectively, and EC-G exhibited 20% and 60% protection, respectively, in mice, whereas loperamide (10 mg/kg, i.p., positive control) exhibited 100% protection. In the in vitro experiments, EC-I inhibited both carbachol (CCh, 1 µM) and high K⁺ (80 mM)-induced contractions at significantly lower concentrations than EC-G. Thus, EC-I significantly inhibited P. aeruginosa and E. coli and exhibited more potent antidiarrheal and antispasmodic effects than EC-G.

Comparative Study of Chemical Composition and Antioxidant Activity of Essential Oils and Crude Extracts of Four Characteristic Zingiberaceae Herbs

The ginger family (Zingiberaceae) includes plants that are known worldwide to have a distinctive smell and taste, which are often used as spices in the kitchen, but also in various industries (pharmaceutical, medical, and cosmetic) due to their proven biological activity. The aim of this study was to investigate and compare the chemical composition and antioxidant activity (AA) of essential oils (EOs) of four characteristic ginger species: Elettaria cardamomum L. Maton (cardamom), Curcuma Longa L. (turmeric), Zingiber Officinale Roscoe (ginger), and Alpinia Officinarum Hance (galangal). Furthermore, the total phenolic content (TPC) and AA of crude extracts obtained after using ultrasound-assisted extraction (UAE) and different extraction solvents (80% ethanol, 80% methanol and water) were evaluated. A total of 87 different chemical components were determined by GC-MS/MS in the EOs obtained after hydrodistillation, 14 of which were identified in varying amounts in all EOs. The major compounds found in cardamom, turmeric, ginger, and galangal were α-terpinyl acetate (40.70%), β-turmerone (25.77%), α-zingiberene (22.69%) and 1,8-cineol (42.71%), respectively. In general, 80% ethanol was found to be the most effective extracting solvent for the bioactivities of the investigated species from the Zingiberaceae family. Among the crude extracts, ethanolic extract of galangal showed the highest TPC value (63.01 ± 1.06 mg GA g^-1 DW), while the lowest TPC content was found in cardamom water extract (1.04 ± 0.29 mg GA g^-1 DW). The AA evaluated by two different assays (ferric-reducing antioxidant power-FRAP and the scavenging activity of the cationic ABTS radical) proved that galangal rhizome is the plant with the highest antioxidant potential. In addition, no statistical difference was found between the AA of turmeric and ginger extracts, while cardamom rhizome was again inferior. In contrast to the crude extracts, the EOs resulted in significantly lower ABTS and FRAP values, with turmeric EO showing the highest AA.

Downregulation of Candidate Gene Expression and Neuroprotection by Piperine in Streptozotocin-Induced Hyperglycemia and Memory Impairment in Rats

There is accumulating evidence showing that hyperglycemia conditions like diabetes possess a greater risk of impairment to the neuronal system because high glucose levels exacerbate oxidative stress, accumulation of amyloid-beta peptides, and mitochondrial dysfunction, and impair cognitive functions and cause neurodegeneration conditions like Alzheimer’s diseases. Due to the extensive focus on pharmacological intervention to prevent neuronal cells’ impairment induced by hyperglycemia, the underlying molecular mechanism that links between Diabetes and Alzheimer’s is still lacking. Given this, the present study aimed to evaluate the protective effect of piperine on streptozotocin (STZ) induced hyperglycemia and candidate gene expression. In the present study, rats were divided into four groups: control (Vehicle only), diabetic control (STZ only), piperine treated (20 mg/kg day, i.p), and sitagliptin (Positive control) treated. The memory function was assessed by Morris water maze and probe test. After treatment, biochemical parameters such as HOMA index and lipid profile were estimated in the serum, whereas histopathology was evaluated in pancreatic and brain tissue samples. Gene expression studies were done by real-time PCR technique. Present data indicated that piperine caused significant memory improvement as compared to diabetic (STZ) control. The assessment of HOMA indices in serum samples showed that piperine and sitagliptin (positive control, PC) caused significant alterations of insulin resistance, β cell function, and insulin sensitivity. Assessment of brain and pancreas histopathology shows significant improvement in tissue architecture in piperine and sitagliptin treated groups compared to diabetic control. The gene expression profile in brain tissue shows significantly reduced BACE1, PSEN1, APAF1, CASPASE3, and CATALASE genes in the piperine and sitagliptin (PC) treated groups compared to Diabetic (STZ) control. The present study demonstrated that piperine not only improves memory in diabetic rats but also reduces the expression of specific AD-related genes that can help design a novel strategy for therapeutic intervention at the molecular level.

Bioactive Phytocompounds: Anti-amyloidogenic Effects Against Hen Egg-White Lysozyme Aggregation

Amyloidosis is the process of fibril formation responsible for causing several diseases in the human being that involve protein aggregation such as Alzheimer's, Parkinson's, Huntington's disease, and type II diabetes. Natural phytocompounds such as curcumin shown promising anti-amyloidogenic activity. In the present study, selective phytocompounds such as piperine, cinnamaldehyde, eugenol, and cuminaldehyde present in Piper nigrum L, Cinnamomum zeylanicum Blume, Eugenia caryophyllus Thumb, and Cuminum cyminum L, respectively were analyzed for anti-amyloidogenic activity using hen egg white-lysozyme (HEWL) as a model system. Out of the selected phytocompounds, piperine showed the most significant anti-amyloidogenic activity, as evident from in vitro assays that were validated by in silico molecular docking study. Piperine showed 64.7 ± 3.74% inhibition of amyloid formation at 50 μM concentration, as observed by Thioflavin T assay. Subsequently, the anti-amyloidogenic activity of piperine was further validated by congo red, intrinsic fluorescence assay, and transmission electron microscopy analysis. The in silico molecular binding interaction showed piperine with the highest docking score and glide energy. Piperine was found to be interacting with amyloidogenic region residues and Trp62, the most important residue involved in the amyloidogenesis process. In conclusion, piperine can be used as a positive lead for a potential therapeutic role in targeting diseases involved amyloidogenesis.

Inhibition of BACE1, MAO-B, cholinesterase enzymes, and anti-amyloidogenic potential of selected natural phytoconstituents: Multi-target-directed ligand approach

Alzheimer's disease (AD) is a neurodegenerative disorder, and multiple factors are involved in disease progression. This is why there is an urgent need to develop novel molecules with multi-target-directed ligands (MTDLs) potential. The current study explores the active phytoconstituents from traditionally used medicinal spices, namely piperine, cinnamaldehyde, eugenol, cuminaldehyde, and alpha-terpinyl acetate for the inhibition of β-secretase, monoamine oxidase, cholinesterase enzymes, anti-aggregation of amyloid β (Aβ) fibrils, and their protective effect against hydrogen peroxide (H₂ O₂ ) and Aβ-induced toxicity. Eugenol showed inhibitory activity against MAO-B enzyme, free radical scavenging activity, and anti-aggregation activity against Aβ peptides than other phytoconstituents. It also demonstrated a significant cytoprotective effect against H₂ O₂ -induced oxidative stress and Aβ-induced cytotoxicity in pheochromocytoma (PC) 12 cells. A molecular docking study of eugenol showed interactions with active site residue of the target enzymes. The study successfully demonstrated that eugenol could have an MTDLs potential better than synthesized drugs used in the treatment of AD. PRACTICAL APPLICATIONS: The present study demonstrated multi-target-directed ligand potential of eugenol and can be developed to treat complex diseases like Alzheimer's. Eugenol can bind to different Alzheimer's targets such as β-secretase (BACE1), Monoamine oxidase B (MAO-B), Cholinesterase's, and amyloid β_1-42 fibrils and might have a disease-modifying potential. The other natural phytoconstituents such as piperine, cinnamaldehyde, cuminaldehyde, and alpha-terpinyl acetate also demonstrated MTDL potential could also be used for developing novel molecules for disease-modifying effect. It also protects against oxidative stress.