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The fruits, leaves, and bark of the guava (Psidium guajava) tree have traditionally been used to treat a myriad of ailments, especially in the tropical and subtropical regions. The various parts of the plant have been shown to exhibit medicinal properties, such as antimicrobial, antioxidant, anti-inflammatory, and antidiabetic activities. Recent studies have shown that the bioactive phytochemicals of several parts of the P. guajava plant exhibit anticancer activity. This review aims to present a concise summary of the in vitro and in vivo studies investigating the anticancer activity of the plant against various human cancer cell lines and animal models, including the identified phytochemicals that contributes to their activity via the different mechanisms. In vitro growth and cell viability studies, such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the sulforhodamine B (SRB) assay, and the trypan blue exclusion test, were conducted using P. guajava extracts and their biomolecules to assess their effects on human cancer cell lines. Numerous studies have showcased that the P. guajava plant and its bioactive molecules, especially those extracted from its leaves, selectively suppress the growth of human cancer cells without cytotoxicity against the normal cells. This review presents the potential of the extracts of P. guajava and the bioactive molecules derived from it, to be utilized as a feasible alternative or adjuvant treatment for human cancers. The availability of the plant also contributes towards its viability as a cancer treatment in developing countries. [ABSTRACT FROM AUTHOR]

The fungal toxin aflatoxin B1 (AB1) and its reactive intermediate, aflatoxin B1-8, 9 epoxide, could cause liver cancer by inducing DNA adducts. AB1 exposure can induce changes in the expression of several cancer-related genes. In this study, the effect of AB1 exposure on breast cancer MCF7 and normal breast MCF10A cell lines at the phenotypic and epigenetic levels was investigated to evaluate its potential in increasing the risk of breast cancer development. We hypothesized that, even at low concentrations, AB1 can cause changes in the expression of important genes involved in four pathways, i.e., p53, cancer, cell cycle, and apoptosis. The transcriptomic levels of BRCA1, BRCA2, p53, HER1, HER2, cMyc, BCL2, MCL1, CCND1, WNT3A, MAPK1, MAPK3, DAPK1, Casp8, and Casp9 were determined in MCF7 and MCF10A cells. Our results illustrate that treating both cells with AB1 induced cytotoxicity and apoptosis with reduction in cell viability in a concentration-dependent manner. Additionally, AB1 reduced reactive oxygen species levels. Phenotypically, AB1 caused cell-cycle arrest at G1, hypertrophy, and increased cell migration rates. There were changes in the expression levels of several tumor-related genes, which are known to contribute to activating cancer pathways. The effects of AB1 on the phenotype and epigenetics of both MCF7 and MCF10A cells associated with cancer development observed in this study suggest that AB1 is a potential risk factor for developing breast cancer. [ABSTRACT FROM AUTHOR]

Enzymes have evolved to catalyze their precise reactions at the necessary rates, locations, and time to facilitate our development, to respond to a variety of insults and challenges, and to maintain a healthy, balanced state. Enzymes achieve this extraordinary feat through their unique kinetic parameters, myriad regulatory strategies, and their sensitivity to their surroundings, including substrate concentration and pH. The Cancer Genome Atlas (TCGA) highlights the extraordinary number of ways in which the finely tuned activities of enzymes can be disrupted, contributing to cancer development and progression often due to somatic and/or inherited genetic alterations. Rather than being limited to the domain of enzymologists, kinetic constants such as kcat, Km, and kcat/Km are highly informative parameters that can impact a cancer patient in tangible ways--these parameters can be used to sort tumor driver mutations from passenger mutations, to establish the pathways that cancer cells rely on to drive patients' tumors, to evaluate the selectivity and efficacy of anti-cancer drugs, to identify mechanisms of resistance to treatment, and more. In this review, we will discuss how changes in enzyme activity, primarily through somatic mutation, can lead to altered kinetic parameters, new activities, or changes in conformation and oligomerization. We will also address how changes in the tumor microenvironment can affect enzymatic activity, and briefly describe how enzymology, when combined with additional powerful tools, and can provide us with tremendous insight into the chemical and molecular mechanisms of cancer. [ABSTRACT FROM AUTHOR]

Candida albicans has been reported globally as the most widespread pathogenic species contributing candidiasis from superficial to systemic infections in immunocompromised individuals. Their metabolic adaptation depends on glyoxylate cycle to survive in nutrient-limited host. The long term usage of fungistatic drugs and the lack of cidal drugs frequently result in strains that could resist commonly used antifungals and display multidrug resistance (MDR). In search of potential therapeutic intervention and novel fungicidals, we have explored a plant alkaloids, namely arborinine and graveoline for its antifungal potential. Alkaloids belongs to Rutaceae family have been reported with numerous antimicrobial activities. In this study, we aimed to isolate and identify the antifungal active alkaloids of R. angustifolia and assess antifungal effect targeting C. albicans isocitrate lyase (ICL) gene which regulates isocitrate lyase, key enzyme in glyoxylate cycle contributing to the virulence potential of C. albicans. Alkaloids were extracted by bioassay guided isolation technique which further identified by TLC profile and compared with the standard through HPLC and NMR analysis. The antifungal activities of the extracted alkaloids were quantified by means of MIC (Minimum Inhibitory Concentration). The gene expression of the targeted gene upon treatment was analysed using RT-qPCR and western blot. Additionally, this study looked at the drug-likeness and potential toxicity effect of the active alkaloid compounds in silico analysis. Spectroscopic analysis showed that the isolated active alkaloids were characterized as acridone, furoquinoline, 4-quinolone known as arborinine and graveoline. Results showed that each compound significantly inhibited the growth of C. albicans at the dose of 250 to 500 µg/mL which confirm its antifungal activity. Each alkaloid was found to successfully downregulate the expression of both ICL1 gene CaIcl1 protein. Finally, ADMET analysis suggests a good prediction of chemical properties, namely absorption, distribution, metabolism, excretion and toxicity (ADMET) that will contribute in drug discovery and development later on. [ABSTRACT FROM AUTHOR]

Despite the availability of anticancer drugs, breast cancer remains the most death-causing tumor-related disease in women. Hence, there is a need for discovery and development of efficient alternative drugs, and sources such as plants need to be explored. In this study, antioxidant capacities and inhibitory effects against MCF7 cells of the extracts of stem bark of three Nigerian medicinal plants (Detarium microcarpum, Guiera senegalensis, and Cassia siamea) were investigated. The D. microcarpum extracts had the highest antioxidant and antiproliferative effects, followed by that of G. senegalensis, and the C. siamea extracts had minimal effects. The IC50 values of the methanol and aqueous extracts from the three plants that inhibited the proliferation of MCF7 cells ranged from 78–> 500 μg/ml. Moreover, all the plant extracts but the aqueous extract of Cassia siamea exhibited antimetastatic action and induced apoptosis and cell cycle arrest in MCF7 cells. Liquid chromatography/time-of-flight/mass spectrometry profiling revealed that the five potent extracts contain many phenols and omega-6 fatty acids, and some of the identified compounds (isorhamnetin, eupatorin, alpinumisoflavone, procyanidin B3, syringin, and gallic acid) have been reported to have antiproliferative effects on cancer cells. Hence, the stem bark of these plants could be potential sources of antibreast cancer agents. [ABSTRACT FROM AUTHOR]