Types Of Secondary Metabolites Research Articles

Review of the Structural Characteristics and Biological Activities of Tricholoma Secondary Metabolites (2018-2023).

Tricholoma are significant medicinal and edible mushrooms within Basidiomycota. Known for their various medicinal properties such as anti-tumor, immune regulation, and antioxidant effects, they are regarded worldwide as health foods of the 21st century. Tricholoma species produce various types of secondary metabolites, which have been extensively studied by the scientific community. In 2018, Clericuzio et al. summarized the structures, biosynthesis, and biological activities of over one hundred different secondary metabolites isolated from the fruiting bodies of 25 Tricholoma species. Building on this, the present article reviews the research progress on Tricholoma secondary metabolites from 2018 to 2023, identifying a total of 101 compounds, 46 of which were newly discovered. These secondary metabolites include a wide range of chemical categories such as terpenoids, steroids, and alkaloids, demonstrating broad biological activities. This article aims to provide in-depth scientific insights and guidance for researchers in this field by summarizing the chemical and biological properties of these secondary metabolites, promoting further applications and development of Tricholoma fungi in the pharmaceutical and food industries.

Phenolic Constituents, Photoprotective Effect, and Antioxidant Capacities of Achillea ligustica All.

The present investigation was performed to figure out the chemical constituents and biological potential of polar extracts (AcOEt and BuOH) from Achillea ligustica, a medicinal species of the Asteraceae family. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) was utilized to conduct a preliminary analysis of the phytochemical profiles of the AcOEt and BuOH extracts. The analysis revealed the existence of twenty compounds in the AcOEt extract and twenty-two in the BuOH extract, classified into various types of secondary metabolites. Subsequently, the exudate from the plant yielded five flavonoids, including two 6-methoxyflavonols identified for the first time in this genus. The isolation of compounds from AcOEt and BuOH extracts was achieved through the combined use of column chromatography (silica gel and Sephadex LH-20) and preparative TLC chromatography. The structures have been elucidated using 1D and 2D NMR spectroscopy, alongside comparisons with research data. Our study measured the total phenolic and flavonoid contents and carried out a comprehensive range of antioxidant tests using DPPH, GOR, CUPRAC, reducing power, and O-phenanthroline assays. Both extracts exhibited considerable antioxidant potential and contained high levels of phenolic and flavonoid compounds. The photoprotective effect of the AcOEt and BuOH extracts was evaluated in vitro by measuring the sun protection factor. Both extracts exhibited a high capacity for UV radiation absorption. Consequently, this plant presents an intriguing prospect for future research focused on incorporating it into photoprotective cosmetic products and pharmaceutical formulations.

1H-NMR-based metabolomics profiling of Beauveria bassiana on different growth media for the determination of its secondary metabolites

The entomopathogenic fungus (EPF) Beauveria bassiana is commercially used as a microbial insecticide against agricultural pests. Some strains of B. bassiana protect crops from pathogens. B. bassiana produces bioactive secondary metabolites (SMs) with potential applications. The present study aims to monitor the growth and behaviour of B. bassiana in different growth media and the effect of different growth media on the production of SMs. The fungal culture was recultivated and then inoculated in broth and agar growth media to perform this study. After 12 days of incubation of B. bassiana in potato dextrose broth (PDB) and a specific medium at temperatures between 28 - 30℃, SMs were extracted from broth cultures using liquid-liquid extraction. To harvest the SMs, the broth media of each culture was extracted using ethyl acetate. After the evaporation of the ethyl acetate using a rotary evaporator, the crude extracts were obtained. The crude extracts were then subjected to 1H-NMR and 2D HSQC analysis using a 600 MHz NMR spectrometer to monitor the presence of different SMs in the crude extracts. The analysis revealed that different types of SMs were produced by B. bassiana under different media and conditions. However, some SMs were detected in the 1H- NMR spectrum of the PDB extract that was completely absent in specific Fingal medium, further confirmed by the 2D HSQC experiment. In conclusion, this study revealed that modifying the media constituents and conditions, such as variable temperatures, could produce different SMs, as predicted by the NMR analysis.

Strategies, Achievements, and Potential Challenges of Plant and Microbial Chassis in the Biosynthesis of Plant Secondary Metabolites.

Diverse secondary metabolites in plants, with their rich biological activities, have long been important sources for human medicine, food additives, pesticides, etc. However, the large-scale cultivation of host plants consumes land resources and is susceptible to pest and disease problems. Additionally, the multi-step and demanding nature of chemical synthesis adds to production costs, limiting their widespread application. In vitro cultivation and the metabolic engineering of plants have significantly enhanced the synthesis of secondary metabolites with successful industrial production cases. As synthetic biology advances, more research is focusing on heterologous synthesis using microorganisms. This review provides a comprehensive comparison between these two chassis, evaluating their performance in the synthesis of various types of secondary metabolites from the perspectives of yield and strategies. It also discusses the challenges they face and offers insights into future efforts and directions.

Search for Snail Repellents: Antimollusc Activities from Stemona parviflora and Six Other Chinese Stemona Species.

Snails are important agricultural pests difficult to control, but data regarding molluscicidal assays are scant. Stemona alkaloids are typical secondary metabolites for the taxa and have been broadly investigated for their pharmacological and toxicological effects. This makes it possible for us to further develop the toxicities of these compounds to snails. In this work, we tested the antifeedant properties of leaves from seven Chinese Stemona species against the land snail species Bradybaena ravida in choice and non-choice feeding assays. The tested leaves Stemona parviflora exhibited the most deterrent effects, and a further phytochemical investigation of aerial parts led to the identification of 16 alkaloids. Among them, three novel alkaloids could be identified. The alkaloidal fraction and single alkaloids were further assayed against this snail species, and the results suggest a cocktail effect because the impact of the alkaloidal fraction was higher than the effects caused by single alkaloids. The study can promote the search process of natural antimollusc products from plants to control snails.

Biochanin A – A G6PD inhibitor: In silico and in vitro studies in non-small cell lung cancer cells (A549)

Secondary metabolites from medicinal plants have a well-established therapeutic potential, with many of these chemicals having specialized medical uses. Isoflavonoids, a type of secondary metabolite, have little cytotoxicity against healthy human cells, making them interesting candidates for cancer treatment. Extensive research has been conducted to investigate the chemo-preventive benefits of flavonoids in treating various cancers. Biochanin A (BA), an isoflavonoid abundant in plants such as red clover, soy, peanuts, and chickpeas, was the subject of our present study. This study aimed to determine how BA affected glucose-6-phosphate dehydrogenase (G6PD) in human lung cancer cells. The study provides meaningful insight and a significant impact of BA on the association between metastasis, inflammation, and G6PD inhibition in A549 cells. Comprehensive in vitro tests revealed that BA has anti-inflammatory effects. Molecular docking experiments shed light on BA's high binding affinity for the G6PD receptor. BA substantially decreased the expression of G6PD and other inflammatory and metastasis-related markers. In conclusion, our findings highlight the potential of BA as a therapeutic agent in cancer treatment, specifically by targeting G6PD and related pathways. BA's varied effects, which range from anti-inflammatory capabilities to metastasis reduction, make it an appealing option for future investigation in the development of new cancer therapeutics.

OSMAC-Based Discovery and Biosynthetic Gene Clusters Analysis of Secondary Metabolites from Marine-Derived Streptomyces globisporus SCSIO LCY30.

The one strain many compounds (OSMAC) strategy is an effective method for activating silent gene clusters by cultivating microorganisms under various conditions. The whole genome sequence of the marine-derived strain Streptomyces globisporus SCSIO LCY30 revealed that it contains 30 biosynthetic gene clusters (BGCs). By using the OSMAC strategy, three types of secondary metabolites were activated and identified, including three angucyclines, mayamycin A (1), mayamycin B (2), and rabolemycin (3); two streptophenazines (streptophenazin O (4) and M (5)); and a macrolide dimeric dinactin (6), respectively. The biosynthetic pathways of the secondary metabolites in these three families were proposed based on the gene function prediction and structural information. The bioactivity assays showed that angucycline compounds 1-3 exhibited potent antitumor activities against 11 human cancer cell lines and antibacterial activities against a series of Gram-positive bacteria. Mayamycin (1) selectively exhibited potent cytotoxicity activity against triple-negative breast cancer (TNBC) cell lines such as MDA-MB-231, MDA-MB-468, and Bt-549, with IC50 values of 0.60-2.22 μM.

Isolation and Structural Elucidation of Coumarin and Flavonoids from Citrus grandis Linn. (Tubtim Siam Pomelo) and Their Biological Activities

Natural products from plants have the potential to exert antioxidant, anti-tyrosinase, antibacterial, and cytotoxic activities and have been widely used as ingredients in cosmetics, medicines, or supplementary food. Several types of secondary metabolites from the Citrus genus have been reported to exhibit interesting biological activity. Due to this lack of studies and biological activity of compounds from related species, it was considered important to investigate Citrus grandis Linn. (Tubtim Siam Pomelo) to be studied. The objective of this research was to isolate and elucidate the structures of chemical constituents and to evaluate their biological activity from the peels of C. grandis Linn. A coumarin (1) and 3 flavonoids (2 - 4) were isolated from the peels of C. grandis Linn. The structures of these compounds were elucidated by analyses of spectroscopic data as well as comparison of their spectroscopic data with the previously published data. Compounds 1 - 4 have been evaluated for antioxidant, anti-tyrosinase, antibacterial and cytotoxic activities. Compound 2 showed the highest inhibition in DPPH and tyrosinase with IC50 values of 0.219 ± 0.011 and 0.033 ± 0.002 mg/mL, respectively. Interestingly, compound 1 - 4 were the first time being isolated from Tubtim Siam Pomelo. HIGHLIGHTS Chemical constituents from grandis Linn. (Tubtim Siam Pomelo) have not been reported Coumarin and flavonoids have been isolated from acetone extract (-) meranzin hydrate, 5-demethoxynobiletin, tangeretin and naringin were isolated for the first time from Tubtim Siam Pomelo Four compounds exhibited good antioxidant and anti-tyrosinase activities GRAPHICAL ABSTRACT

Antioxidant Activity of Mahogany Parasite Leaves (Dendrophthu pentandra (L.) Miq.) Assessed Using the DPPH (2,2-Diphenyl-1-Picrylhydrazyl) Method

Synthetic antioxidants, such as butyl hydroxyanisole (BHA), have carcinogenic (cancer-causing) adverse effects because they can cause type I alveolar damage and damage to lung endothelial genes. The objective of this study was to use the DPPH (2,2 diphenyl-1-picrylhydrazyl) method to investigate the antioxidant activity of natural substances found in the leaves of the mahogany parasite (Dendrophthu pentandra (L.) Miq.). Extraction, chromatography, and spectrophotometry are the techniques used. Maceration in stages utilizing n-hexane, ethyl acetate, and ethanol as solvents yielded mahogany parasite leaf extract. Phytochemical screening, thin layer chromatography testing, antioxidant activity testing utilizing a Visible Spectrophotometer, and estimating the IC50 were all performed on mahogany parasite leaf extract. The phytochemical screening results revealed that the samples included four types of secondary metabolites: flavonoids, tannins, saponins, and steroids. A thin layer chromatographic test revealed four well-separated stains using n-hexane and ethyl acetate eluent in a volume ratio of 5:5, showing the Rf as the value of the four secondary metabolites mentioned above. Based on the results of the experiments, it is possible to conclude that mahogany parasite leaves have strong antioxidant activity, with an IC50 of 8.47 ppm.

Allelopathic effects of three lichen secondary metabolites on cultures of aposymbiotically grown lichen photobionts and free-living alga Scenedesmus quadricauda

In the present work, we studied the influence of lichen secondary metabolites (evernic acid, orcinol, usnic acid) on selected species of algae: Trebouxia erici, photobiont of lichen Cladonia cristatella producing typical lichen secondary metabolites, Coccomyxa solorinae-saccatae, photobiont of lichen Solorina saccata which does not produce typical secondary metabolites of lichens, and free-living alga Scenedesmus quadricauda.For the determination of the cytotoxic effects of these compounds, algae were cultivated on the surface of disks composed of glass microfibers, in quantities of 0.1 mg/disk for each metabolite. After 14-days prolonged cultivation, we analysed selected physiological parameters: growth of algae, chlorophyll a fluorescence, the content of ascorbic acid, content of reduced and oxidized glutathione and contents of selected organic acids. The presence of secondary compounds typically inhibited the growth of tested algae and chlorophyll a fluorescence. In the presence of evernic acid and usnic acid, we observed a decrease of ascorbic acid, glutathione, and significant changes in the composition of organic acids.Lichen metabolites, except for their other biological and ecological roles, may act as phytotoxic substances, causing oxidative stress in photobiont cells. These metabolites may play an important role in the “controlled parasitism” of fungal partner on algal/cyanobacterial partner of symbiosis. Differences in the sensitivity of algal cells from different habitats to lichen compounds are, however, not understood sufficiently.

Antibacterial Activity of Extra Ethanol Kopasanda Leaves (Chromolaena Odorate L.) Against Pathogenic Bacteria of Urinary Tract Infection by TLC-Bioautography and Agar Diffusion

Kopasanda (Chromolaena odorata L.) leaves are one of the plants (herbs) containing various types of secondary metabolites, including saponins, tannins, alkaloids, and flavonoids, which function as antibacterial agents used as wound medicine for the community. This study aims to determine the antibacterial activity of the ethanol extract of Kopasanda (Chromolaena odorate L.) leaves using the TLC-bioautography and diffusion methods. The results of the antibacterial activity screening test obtained the active extract at a concentration of 0.1% against Escherichia coli and Staphylococcus aureus. The results of the antibacterial activity test using the TLC-Bioautography method with the eluent N-Hexane:Ethyl Acetate (4:1) showed results from Staphylococcus aureus bacteria with Rf values = 0.90, 0.78, 0.67, 0.52, 0.38, 0.27, 0.14, 0.05, and Escherichia coli bacteria with Rf values = 0.90, 0.52, 0.38, 0.27, 0.14, 0.05. Based on the results of testing the antibacterial activity with the agar diffusion method, the largest diameter of the inhibition zone at a concentration of 10% was obtained for Escherichia coli bacteria with an inhibition zone diameter of 13.59 mm, and Staphylococcus aureus with an inhibition zone diameter of 15.52 mm.

In vitro inhibitory effects on free radicals, pigmentation, and skin cancer cell proliferation from Dendrobium hybrid extract: A new plant source of active compounds

Orchidaceae are diverse plants whose bioactive compounds have various biological activities. New hybrids of Dendrobium have been generated to gain characteristics shared with their ancestors. Dendrobium Pearl Vera (designated as DH) is derived from parents used for dermatological treatments and cosmetics. However, the phytoconstituents and biological properties of DH have not been reported. The current study investigated extracts from DH plants using four solvents (water, methanol, ethanol, or 2-propanol). The propanolic extract (DH-P) contained the highest phenolic and flavonoid contents, along with a high scavenging performance for free radicals. In total, 25 tentative constituents in the DH-P matrix were identified, consisting of amino acids, nucleotides, and three types of secondary metabolites: furan, phenolics, and alkaloids. The DH-P inhibited human tyrosinase in vitro in a concentration-dependent manner of the phenolic content. Furthermore, there was no significant difference between DH-P with 10 μg/ml phenolic content and 0.75 mM kojic acid (a commercial whitening agent) on the inhibition of human tyrosinase. Incubation with DH-P containing at least 15 μg/ml phenolic content greatly inhibited the proliferation of human melanoma; however, the cell viability was not affected by the phenolic content at 5 μg/ml or less. The half-maximal inhibitory concentration (IC50) of the phenolic content in DH-P on melanoma viability was 12.90 ± 1.04 μg/ml. Melanin production in vivo by human melanoma incubated with 5 μg/ml phenolic content in DH-P was reduced significantly, compared to 2.5 μg/ml phenolic content in DH-P, 100 μg/ml arbutin, and in control. The identified components, including 5-hydroxymethyl-2-furaldehyde, salicylic acid, nicotinamide, acetophenone, cytidine, adenosine, proline, or valine, have been reported to be associated with depigmentation, antioxidant, and anticancer. This research revealed, for the first time, the tentative phytoconstituents of Dendrobium Pearl Vera and their biological activities, thus demonstrating the potential use of DH-P in dermal applications.

A Review on Valeriana wallichii: Chemical Composition and Pharmacological Research

Background: In the past decade, a rising trend has seen in the use of plant-based medicines because of fewer/no side effects. Plants are always the major source of traditional medicines in every culture. The main objective of this review is to shed a light on phytochemical composition and pharmacological research of Valeriana wallichii. Methods: Electronic databases like Google Scholar, PubMed, Scopus, etc., were searched for traditional uses, extraction of phytoconstituents, therapeutical uses and pharmacology of V. wallichii. Results: V. wallichii has been used as a sleep remedy since ancient times in the Indian traditional system of medicines. It is also used as diuretic, spasmolytic and pain relieving agent. It is used for the treatment of epilepsy, dyspeptic symptoms, failing reflexes, habitual constipation, insanity, nervous debility, obesity, spastic disorders, and in snake poisoning, and also reported to have cytotoxic potential. The pharmacological activity of the plant is due to presence of different types of secondary metabolites, including valerianic acid, valerosidatum glycoside, valepotriates, dihydrovaltrate, 6-methylapigenin, hesperidin, sesquiterpenoids, bornylisovalerianate, isovalerenic acid, 1-camphene, 1-pinene, terpineol, valerianine, bornylisovalerianate, valerianine and so on. This review focuses on detailed phytochemistry of the plant and its therapeutic indication. The main emphasis is given on anticancer potential of V. wallichii, with in vitro cytotoxic as well as in vivo antitumor description. Conclusion: The review reveals that further research, as well as clinical trials, are needed to know this plant as an effective drug for the treatment of cancer in future with exact molecular mechanisms.

Phytochemical Screening and Antioxidant Activity of Tampoi Leaves (Baccaurea macrocarpa (Miq.)Mull.Arg ) by Leaf Age and Solvent Type

Tampoi (Baccaurea macrocarpa (Miq.) Mull.Arg) is a member of the genus Baccaurea which is distributed mainly in the regions of Borneo and Sumatra. The use of tampoi can be done by exploring the potential of tampoi plants as medicinal plants. The research was conducted to determine the content of secondary metabolites and the results of the analysis of the antioxidant activity of tampoi leaves. The leaf extraction process uses polar solvents in the form of water, 70% ethanol, 70% methanol and non-polar in the form of chloroform, toluene, and n-hexane. Analysis of antioxidant activity using the DPPH method (2,2-diphenyl-1-picrylhydrazil). The results showed that polar solvents are better used in extracting secondary metabolites of tampoi leaves in non-plar solvents. The conclusion of this study is the types of secondary metabolites contained in tampoi leaves, namely alkaloids, flavonoids, saponins, tannins, steroids, and triterpenoids. Young tampoi leaves have a stronger antioxidant activity value than old leaves. The most effective solvent for extracting secondary metabolite compounds of tampoi leaves is 70% methanol.

Effects of Electrical Conductivity and Pruning on Secondary Metabolite Contents in Fruits of Jaltomata procumbens (Cav.) J. L. Gentry

Jaltomata procumbens is a semidomesticated plant species used as food, and the presence of several types of secondary metabolites are detected in one of its forms. Growth conditions, the electrical conductivity (EC) of the nutrient solution, and the pruning management may influence the secondary metabolite content. The objective was to evaluate the effects of EC and pruning on the metabolite content of 2 J. procumbens forms, in greenhouse and hydroponics. Treatments included 2 forms (erect and decumbent), 3 EC levels (1, 2, and 3 dS m−1), and 2 pruning levels (with and without pruning). The contents of phenolic acids, flavonoids, and terpenoids were evaluated. EC and pruning management differentially influenced the contents of each group of metabolites in both forms in a combined and individual manner, with EC exerting a stronger effect than pruning. A total of 7 phenolic acids, 4 flavonoids, and 5 terpenoids were detected: the erect form contained significant amounts of syringic acid, rutin, and carnosol at 33.44, 36.43, and 0.26 mg 100 g−1 of dry weight, respectively, whereas the decumbent form had high contents of gallic and rosmarinic acids and morin at 59.03, 28.31, and 61.54 mg 100 g−1 of dry weight, respectively. Considering the variability observed depending on the metabolite group of interest, the specific management of EC and pruning is required for each form.

Natural flavonoids derived from herbal medicines are potential anti-atherogenic agents by inhibiting oxidative stress in endothelial cells.

As the common pathological basis of various cardiovascular diseases, the morbidity and mortality of atherosclerosis (AS) have increased in recent years. Unfortunately, there are still many problems in the treatment of AS, and the prevention and treatment of the disease is not ideal. Up to now, the occurrence and development of AS can roughly include endothelial cell dysfunction, vascular smooth muscle cell proliferation, inflammation, foam cell production, and neoangiogenesis. Among them, endothelial dysfunction, as an early event of AS, plays a particularly important role in promoting the development of AS. In addition, oxidative stress occurs throughout the causes of endothelial dysfunction. Some previous studies have shown that flavonoids derived from herbal medicines are typical secondary metabolites. Due to its structural presence of multiple active hydroxyl groups, it is able to exert antioxidant activity in diseases. Therefore, in this review, we will search PubMed, Web of Science, Elesvier, Wliey, Springer for relevant literature, focusing on flavonoids extracted from herbal medicines, and summarizing how they can prevent endothelial dysfunction by inhibiting oxidative stress. Meanwhile, in our study, we found that flavonoid represented by quercetin and naringenin showed superior protective effects both in vivo and in vitro, suggesting the potential of flavonoid compounds in the treatment of AS.

Diversity, Lifestyle, Genomics, and Their Functional Role of Cochliobolus, Bipolaris, and Curvularia Species in Environmental Remediation and Plant Growth Promotion under Biotic and Abiotic Stressors.

Cochliobolus, Bipolaris, and Curvularia genera contain various devastating plant pathogens that cause severe crop losses worldwide. The species belonging to these genera also perform a variety of diverse functions, including the remediation of environmental contaminations, beneficial phytohormone production, and maintaining their lifestyle as epiphytes, endophytes, and saprophytes. Recent research has revealed that despite their pathogenic nature, these fungi also play an intriguing role in agriculture. They act as phosphate solubilizers and produce phytohormones, such as indole acetic acid (IAA) and gibberellic acid (GAs), to accelerate the growth of various plants. Some species have also been reported to play a significant role in plant growth promotion during abiotic stresses, such as salinity stress, drought stress, heat stress, and heavy metal stress, as well as act as a biocontrol agent and a potential mycoherbicide. Similarly, these species have been reported in numerous industrial applications to produce different types of secondary metabolites and biotechnological products and possess a variety of biological properties, such as antibacterial, antileishmanial, cytotoxic, phytotoxic, and antioxidant activities. Additionally, some of the species have been utilized in the production of numerous valuable industrial enzymes and biotransformation, which has an impact on the growth of crops all over the world. However, the current literature is dispersed, and some of the key areas, such as taxonomy, phylogeny, genome sequencing, phytohormonal analysis, and diversity, are still being neglected in terms of the elucidation of its mechanisms, plant growth promotion, stress tolerance, and bioremediation. In this review, we highlighted the potential role, function, and diversity of Cochliobolus, Curvularia, and Bipolaris for improved utilization during environmental biotechnology.

Structure-function analysis of CYP719As involved in methylenedioxy bridge-formation in the biosynthesis of benzylisoquinoline alkaloids and its de novo production

Benzylisoquinoline alkaloids (BIAs) are a type of secondary metabolite with clinical application value. (S)-stylopine is a special BIA which contains methylenedioxy bridge structures. CYP719As could catalyze the methylenedioxy bridge-formation on the A or D rings of protoberberine alkaloids, while displaying significant substrate regiospecificity. To explore the substrate preference of CYP719As, we cloned and identified five CyCYP719A candidates from Corydalis yanhusuo. Two CyCYP719As (CyCYP719A39 and CyCYP719A42) with high catalytic efficiency for the methylenedioxy bridge-formation on the D or A rings were characterized, respectively. The residues (Leu 294 for CyCYP719A42 and Asp 289 for CyCYP719A39) were identified as the key to controlling the regioselectivity of CYP719As affecting the methylenedioxy bridge-formation on the A or D rings by homology modeling and mutation analysis. Furthermore, for de novo production of BIAs, CyCYP719A39, CyCYP719A42, and their mutants were introduced into the (S)-scoulerine-producing yeast to produce 32 mg/L (S)-stylopine. These results lay a foundation for understanding the structure-function relationship of CYP719A-mediated methylenedioxy bridge-formation and provide yeast strains for the BIAs production by synthetic biology.

The Role of Propolis as a Natural Product with Potential Gastric Cancer Treatment Properties: A Systematic Review.

Gastric cancer is one of the most common, aggressive, and invasive types of malignant neoplasia. It ranks fifth for incidence and fourth for prevalence worldwide. Products of natural origin, such as propolis, have been assessed for use as new complementary therapies to combat cancer. Propolis is a bee product with antiproliferative and anticancer properties. The concentrations and types of secondary metabolites contained in propolis mainly vary according to the geographical region, the season of the year, and the species of bees that make it. The present study is a systematic review of the main articles related to the effects of propolis against gastric cancer published between 2011 and 2021 in the PubMed and Science Direct databases. Of 1305 articles published, only eight studies were selected; among their principal characteristics was the use of in vitro analysis with cell lines from gastric adenocarcinoma and in vivo murine models of the application of propolis treatments. These studies suggest that propolis arrests the cell cycle and inhibits proliferation, prevents the release of oxidizing agents, and promotes apoptosis. In vivo assays showed that propolis decreased the number of tumors by regulating the cell cycle and the expression of proteins related to apoptosis.

Role of Plant Metabolites in Curing Neurodegenerative Disorders

Plant metabolites are the products produced during metabolism which occurs naturally in cells. Different types of secondary metabolites have their different therapeutic effects. Herbal medicines have been used for a long time to cure neurodegenerative disorders. Two of major types of neurodegenerative diseases which are of huge concern nowadays are- Parkinson's disease and Alzheimer's disease. During the past few decades, plant secondary metabolites have shown a large variety of beneficial effects against lots of neurodegenerative disorders including Parkinson's disease and Alzheimer's disease. More research is required to discover new bioactive compounds from plants which can be used to treat these neurodegenerative diseases.