Plants in Anticancer Drug Discovery: From Molecular Mechanism to Chemoprevention

Progress and Impact of Latin American Natural Product Databases

Natural products (NPs) are a rich source of structurally novel molecules, and the chemical space they encompass is far from being fully explored. Over history, NPs have represented a significant source of bioactive molecules and have served as a source of inspiration for developing many drugs on the market. On the other hand, computer-aided drug design (CADD) has contributed to drug discovery research, mitigating costs and time. In this sense, compound databases represent a fundamental element of CADD. This work reviews the progress toward developing compound databases of natural origin, and it surveys computational methods, emphasizing chemoinformatic approaches to profile natural product databases. Furthermore, it reviews the present state of the art in developing Latin American NP databases and their practical applications to the drug discovery area.

Anticancer action of plant products: changing stereotyped attitudes

Compared to humans, plants can synthesize an extremely diverse array of chemical compounds, including phenolic acids, flavonoids, stilbenes, lignans, terpenoids, alkaloids, and many other types of secondary metabolites that have been demonstrated to exert important bioactivities and impacts on the human health. As a result of extensive and sustained efforts, some phytochemicals like vincristine, vinblastine, and paclitaxel have already been approved as anticancer drugs today, while several others are under clinical trials. However, despite this remarkable success, studies on anticancer action of plant-derived products have been and paradoxically are still in some places, mixed up with alternative approaches and thereby considered non-credible, especially in regions where the role of traditional medicine has not been historically so prevalent as in several Asian countries. As a result, only about 10% of higher plants have been explored regarding the potential therapeutic effects of their constituents. Moreover, as one function of secondary metabolites includes the protection of plants against diverse environmental stresses, the content and composition of these phytochemicals might importantly vary between different regional habitats. Therefore, the stereotyped attitudes to plant products as something related to alternative medicine must be changed to identify new lead molecules for novel anticancer drugs. It is possible that plants still harbor an important spectrum of pharmaceutically interesting, but still unidentified, chemical compounds.

Buffalo Milk Whey Activates Necroptosis and Apoptosis in a Xenograft Model of Colorectal Cancer

Recent pharmacological research on milk whey, a byproduct of the dairy industry, has identified several therapeutic properties that could be exploited in modern medicine. In the present study, we investigated the anticancer effects of whey from Mediterranean buffalo (Bubalus bubalis) milk. The antitumour effect of delactosed milk whey (DMW) was evaluated using the HCT116 xenograft mouse model of colorectal cancer (CRC). There were no discernible differences in tumour growth between treated and untreated groups. Nevertheless, haematoxylin and eosin staining of the xenograft tissues showed clearer signs of different cell death in DMW-treated mice compared to vehicle-treated mice. Detailed biochemical and molecular biological analyses revealed that DMW was able to downregulate the protein expression levels of c-myc, phospho-Histone H3 (ser 10) and p-ERK. Moreover, DMW also activated RIPK1, RIPK3, and MLKL axis in tumour tissues from xenograft mice, thus, suggesting a necroptotic effect. The necroptotic pathway was accompanied by activation of the apoptotic pathway as revealed by increased expression of both cleaved caspase-3 and PARP-1. At the molecular level, DMW-induced cell death was also associated with (i) upregulation of SIRT3, SIRT6, and PPAR-γ and (ii) downregulation of LDHA and PPAR-α. Overall, our results unveil the potential of whey as a source of biomolecules of food origin in the clinical setting of novel strategies for the treatment of CRC.

Delving the Role of Caralluma fimbriata: An Edible Wild Plant to Mitigate the Biomarkers of Metabolic Syndrome

Metabolic syndrome (MS), commonly known as syndrome X or insulin resistance syndrome, is a collection of risk factors for cardiovascular diseases and type II diabetes. MS is believed to impact over a billion individuals worldwide. It is a medical condition defined by visceral obesity, insulin resistance, high blood pressure, and abnormal cholesterol levels, according to the World Health Organization. The current dietary trends are more focused on the use of functional foods and nutraceuticals that are well known for their preventive and curative role against such pathological disorders. Caralluma fimbriata is one such medicinal plant that is gaining popularity. It is a wild, edible, succulent roadside shrub with cactus-like leaves. Besides its main nutrient contents, various bioactive constituents have been identified and linked with positive health outcomes of appetite-suppressing, hypolipidemic, antioxidant, hepatoprotective, and anticancer potentials. Hence, such properties make C. fimbriata an invaluable plant against MS. The current review compiles recent available literature on C. fimbriata's nutritional composition, safety parameters, and therapeutic potential for MS. Summarized data in this review reveals that C. fimbriata remains a neglected plant with limited food and therapeutic applications. Yet various studies explored here do prove its positive health-ameliorating outcomes.

A Comparative Study of Diospyros malabarica (Gaub) Extracts in Various Polarity-Dependent Solvents for Evaluation of Phytoconstituents and Biological Activities

Keeping in mind the ascribed repute of Diospyros malabarica (D. malabarica), this investigation was commenced to assess the effect of diverse solvents on extraction yields, phytochemical components and antioxidant capability, and in vitro biological activities of D. malabarica for pharmaceutically active constituents to combat various infections. To screen phytochemicals both qualitatively (flavonoids, terpenoid, saponins, tannins) and quantitatively like total phenolic and flavonoid contents, Diospyros malabarica parts include the following: root, leaves, bark, stem, ripe, and unripe fruit were sequentially extracted with organic solvents such as petroleum ether, dichloromethane, ethyl acetate, ethanol, methanol, and water in increasing order of polarity from less polar to more polar solvents. Furthermore, biological activities such as antibacterial, antifungal, anticancer, antidiabetic, and anti-inflammatory were explored. The results revealed that all the tested solvents displayed a vital role in the extraction yield, the content of phytochemicals, and the studied biological activities. Methanol was found as the best solvent followed by the ethanol for the extraction, representing the highest extraction yield (18.3%), rich diversity of phytochemicals, and the highest total phenolic contents (602 ± 0.001 μg EAG/mg of extract) and total flavonoid contents (455 ± 0.6 μg EQ/mg of extract) in bark extract. Furthermore, methanol bark extract showed high in vitro antibacterial activity (30.25 mm ± 0.9), antifungal activity (18.25 mm ± 0.2), anticancer activity (48%), antidiabetic activity (68%) and anti-inflammatory activity (62%) followed by ethanol amongst other extracts of D. malabarica. Accordingly, methanol might be as an ideal solvent to get maximum content of phytochemicals, promising antioxidants, and in vitro biological activities from bark extract amongst other extracts of D. malabarica compared to pet ether, ethyl acetate, and dichloromethane and may act as free radical rummager because phytochemical constituents exhibit antioxidant capability. Our findings suggest that phytochemical compounds (flavonoids, tannins, phenols, saponins, and terpenoids) found in the bark extract of D. malabarica may be attributed to evaluate potent anti-inflammatory, anticancer, antidiabetic, antibacterial, and antifungal activities.

Unusual dimeric flavonoids (brachydins) induce ultrastructural membrane alterations associated with antitumor activity in cancer cell lines

Notwithstanding the advances in molecular target-based drugs, chemotherapy remains the most common cancer treatment, despite its high toxicity. Consequently, effective anticancer therapies with fewer adverse effects are needed. Therefore, this study aimed to determine the anticancer activity of the dichloromethane fraction (DCMF) isolated from Arrabidae brachypoda roots, whose components are three unusual dimeric flavonoids. The toxicity of DCMF was investigated in breast (MCF-7), prostate (DU145), and cervical (HeLa) tumor cells, as well as non-tumor cells (PNT2), using sulforhodamine B (cell viability), Comet (genotoxicity), clonogenicity (reproductive capacity) and wound healing (cell migration) assays, and atomic force microscopy (AFM) for ultrastructural cell membrane alterations. Molecular docking revealed affinity between albumin and each rare flavonoid, supporting the impact of fetal bovine serum in DCMF antitumor activity. The IC₅₀ values for MCF7, HeLa, and DU145 were 2.77, 2.46, and 2.51 µg/mL, respectively, and 4.08 µg/mL for PNT2. DCFM was not genotoxic to tumor or normal cells when exposed to twice the IC₅₀ for up to 24 h, but it inhibited tumor cell migration and reproduction compared to normal cells. Additionally, AFM revealed alterations in the ultrastructure of tumor nuclear membrane surfaces, with a positive correlation between DCMF concentration and tumor cell roughness. Finally, we found a negative correlation between roughness and the ability of DCMF-treated tumor cells to migrate and form colonies with more than 50 cells. These findings suggest that DCFM acts by causing ultrastructural changes in tumor cell membranes while having fewer toxicological effects on normal cells.