Inhibition of enzymes important for Alzheimer’s disease by antioxidant extracts prepared from 15 New Zealand medicinal trees and bushes

Novel Anti-Acetylcholinesterase Effect of Euonymus laxiflorus Champ. Extracts via Experimental and In Silico Studies

Alzheimer's disease (AD) is the most common form of dementia, which is recorded as a global health issue. Natural acetylcholinesterase inhibitors (AChEIs) are considered a helpful therapy for the management of symptoms of patients with mild-to-moderate AD. This work aimed to investigate and characterize Euonymus laxiflorus Champ. (ELC) as a natural source of AChEIs compounds via in vitro and virtual studies. The screening parts used, including the leaves, heartwood, and trunk bark of ELC, revealed that the trunk bark extract possessed the highest activity, phenolics and flavonoid content. The in vitro anti-Alzheimer activity of ELC trunk bark was notably reclaimed for the first time with comparable effect (IC₅₀ = 0.332 mg/mL) as that of a commercial AChEI, berberine chloride (IC₅₀ = 0.314 mg/mL). Among various solvents, methanol was the most suitable to extract ELC trunk bark with the highest activity. Twenty-one secondary metabolites (1-21) were identified from ELC trunk bark extract, based on GCMS and UHPLC analyses. Of these, 10 volatile compounds were identified from this herbal extract for the first time. One phenolic (11) and seven flavonoid compounds (15-21) were also newly found in this herbal extract. Of the identified compounds, chlorogenic acid (11), epigallocatechin gallate (12), epicatechin (13), apigetrin (18), and quercetin (20) were major compounds with a significant content of 395.8-2481.5 μg/g of dried extract. According to docking-based simulation, compounds (11-19, and 21) demonstrated more effective inhibitory activity than berberine chloride, with good binding energy (DS values: -12.3 to -14.4 kcal/mol) and acceptable RMSD values (0.77-1.75 Å). In general, these identified compounds processed drug properties and were non-toxic for human use, based on Lipinski's rule of five and ADMET analyses.

Antimicrobial Properties Against Human Pathogens of Medicinal Plants from New Zealand

The emergence of resistant microorganisms towards standard antibiotics has stimulated an on-going exploration for new sources of antimicrobials. The microbial susceptibility of extracts produced from leaf, bark, or rhizome parts of nine different New Zealand bushes was investigated using liquid broth dilution and agar plating techniques. Minimum inhibitory (MIC) and lethal concentrations (MLC) were expressed in micrograms of dry extract per milliliters of solution. The lowest MIC of 62.5 μg/mL was determined for methanol extract of Kunzea ericoides against Bacillus cereus and Candida albicans, and ethyl acetate extract of Pseudowintera colorata against Staphylococcus aureus. Additionally, K. ericoides also presented the lowest MLC of 250 μg/mL against S. aureus and B. cereus (methanol extract), and against S. aureus (ethyl acetate extract). The methanol extract of Weinmannia racemosa was lethal to B. cereus (MLC = 250 µg/mL). Some of the extracts of Phormium tenax, Schefflera digitata, and Pomaderris kumeraho were antimicrobial against S. aureus and B. cereus (MIC = 500 µg/mL). The extracts of Geniostoma ligustrifolium and Melicytus ramiflorus plants did not exhibit antimicrobial activity.

Phytochemical and pharmacological uses of medicinal plants to treat cancer: A case study from Khyber Pakhtunkhwa, North Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

Cancer is the top death causing disease in the world, due to its occurrence through various mechanism and form. Medicinal plants have been extensively used for the purifications and isolations of phytochemicals for the treatment and prevention of cancer.

OBJECTIVES

Consequently, this research was designed to document the traditional practices of anti-cancer plants and its phytochemical essay across the districts of KP, Pakistan.

MATERIALS AND METHODS

Semi-structured interviews were conducted in 24 districts from the informants mostly the traditional herbalists (key informants). The information were compared with the publish data using various authentic search engines including, google, researchgate, google scholar and NCBI.

RESULTS

One hundred and fifty-four (154) anti-cancer plants were recognized belonging to 69 families among all, Lamiaceae (13 sp.), Asteraceae (12 sp.) and Solanaceae (9 sp.) were the preferred families. The local inhabitants in the area typically prepare ethnomedicinal recipes from leaves (33.70%) and whole plants (23.37%) in the form of decoction and powder (24.67%), respectively. Herbs stayed the most preferred life form (61.68%) followed by shrub (21.4%). Similarly, breast (29.22%) and lung cancer (14.83%) was the common disease type. Literature study also authorize that, the medicinal plants of the research area were rich in phytochemical like quercetin, coumarine, kaempferol, apigenin, colchicine, alliin, rutin, lupeol, allicin, berbarine, lutolin, vanilic acid, urocilic acid and solamargine have revealed significant activates concerning the cancer diseases, that replicating the efficacy of these plants as medicines.

CONCLUSION

The Khyber Pakhtunkhwa is rural area and the local inhabitants have very strong traditional knowledge about the medicinal plants for different diseases like cancer. The medicinal plants for significant ranked disorder might be pharmacologically and phtyochemicaly explored to demonstrate their efficacy. Moreover, the local flora especially medicinal plants facing overgrazing, overexploitation and inappropriate way of collection, however, proper management strategies like reforestation, controlled grazing, proper permission from concerned department and rangeland strategies among others may be assumed to enhance the proper usage of medicinal plants.

Polyphenol-Peptide Interactions in Mitigation of Alzheimer's Disease: Role of Biosurface-Induced Aggregation

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder, responsible for nearly two-thirds of all dementia cases. In this review, we report the potential AD treatment strategies focusing on natural polyphenol molecules (green chemistry) and more specifically on the inhibition of polyphenol-induced amyloid aggregation/disaggregation pathways: in bulk and on biosurfaces. We discuss how these pathways can potentially alter the structure at the early stages of AD, hence delaying the aggregation of amyloid-β (Aβ) and tau. We also discuss multidisciplinary approaches, combining experimental and modelling methods, that can better characterize the biochemical and biophysical interactions between proteins and phenolic ligands. In addition to the surface-induced aggregation, which can occur on surfaces where protein can interact with other proteins and polyphenols, we suggest a new concept referred as "confinement stability". Here, on the contrary, the adsorption of Aβ and tau on biosurfaces other than Aβ- and tau-fibrils, e.g., red blood cells, can lead to confinement stability that minimizes the aggregation of Aβ and tau. Overall, these mechanisms may participate directly or indirectly in mitigating neurodegenerative diseases, by preventing protein self-association, slowing down the aggregation processes, and delaying the progression of AD.