Antineoplastic Activity of Rhus trilobata Nutt. (Anacardiaceae) against Ovarian Cancer and Identification of Active Metabolites in This Pathology.

Rhus trilobata (RHTR) is a medicinal plant with cytotoxic activity in different cancer cell lines. However, the active compounds in this plant against ovarian cancer are unknown. In this study, we aimed to evaluate the antineoplastic activity of RHTR and identify its active metabolites against ovarian cancer. The aqueous extract (AE) and an active fraction (AF02) purified on C18-cartridges/ethyl acetate decreased the viability of SKOV-3 cells at 50 and 38 µg/mL, respectively, compared with CHO-K1 (>50 µg/mL) in MTT assays and generated changes in the cell morphology with apoptosis induction in Hemacolor® and TUNEL assays (p ≤ 0.05, ANOVA). The metabolite profile of AF02 showed a higher abundance of flavonoid and lipid compounds compared with AE by UPLC-MSE. Gallic acid and myricetin were the most active compounds in RHTR against SKOV-3 cells at 50 and 166 µg/mL, respectively (p ≤ 0.05, ANOVA). Antineoplastic studies in Nu/Nu female mice with subcutaneous SKOV-3 cells xenotransplant revealed that 200 mg/kg/i.p. of AE and AF02 inhibited ovarian tumor lesions from 37.6% to 49% after 28 days (p ≤ 0.05, ANOVA). In conclusion, RHTR has antineoplastic activity against ovarian cancer through a cytostatic effect related to gallic acid and myricetin. Therefore, RHTR could be a complementary treatment for this pathology.

Functional Characterization of the Lin28/let-7 Circuit During Forelimb Regeneration in Ambystoma mexicanum and Its Influence on Metabolic Reprogramming.

The axolotl (Ambystoma mexicanum) is a caudate amphibian, which has an extraordinary ability to restore a wide variety of damaged structures by a process denominated epimorphosis. While the origin and potentiality of progenitor cells that take part during epimorphic regeneration are known to some extent, the metabolic changes experienced and their associated implications, remain unexplored. However, a circuit with a potential role as a modulator of cellular metabolism along regeneration is that formed by Lin28/let-7. In this study, we report two Lin28 paralogs and eight mature let-7 microRNAs encoded in the axolotl genome. Particularly, in the proliferative blastema stage amxLin28B is more abundant in the nuclei of blastemal cells, while the microRNAs amx-let-7c and amx-let-7a are most downregulated. Functional inhibition of Lin28 factors increase the levels of most mature let-7 microRNAs, consistent with an increment of intermediary metabolites of the Krebs cycle, and phenotypic alterations in the outgrowth of the blastema. In summary, we describe the primary components of the Lin28/let-7 circuit and their function during axolotl regeneration, acting upstream of metabolic reprogramming events.

Linearolactone and Kaempferol Disrupt the Actin Cytoskeleton in Entamoeba histolytica: Inhibition of Amoebic Liver Abscess Development.

Linearolactone (1) and kaempferol (2) have amebicidal activity in in vitro studies. The type of cell death induced by 1 and 2 and their effects on the virulence of E. histolytica were analyzed by transmission and confocal electron microscopy, reactive oxygen species (ROS) production, and apoptosis, detected by flow cytometry with dichlorofluorescein 2',7'-diacetate and annexin-V binding, respectively, and confirmed by TUNEL. The interaction of 1 and 2 with actin was analyzed by docking, and the in vivo amoebicidal activity was established with the Mesocricetus auratus model; amebic liver abscess (ALA) development was evaluated by magnetic resonance (MR) and validated post mortem. In vitro, compounds 1 and 2 caused chromatin condensation, intracellular ROS, and loss of actin structures. Coupling analysis showed that they bind to the allosteric and catalytic sites of actin with binding energies of -11.30 and -8.45 kcal/mol, respectively. Treatments with 1 and 2 induced a decrease in ALA formation without toxic effects on the liver and kidney. Thus, compound 1, but not 2, was able to induce apoptosis-like effects in E. histolytica trophozoites by intracellular production of ROS that affected the actin cytoskeleton structuration. In vivo, compound 1 was more active than compound 2 to reduce the development of ALA.

Effect of Gallic acid and Myricetin on ovarian cancer models: a possible alternative antitumoral treatment.

BACKGROUND: Ovarian cancer is the leading cause of mortality among malignant gynecological tumors. Surgical resection and chemotherapy with intravenous platinum/taxanes drugs are the treatments of choice, with little effectiveness in later stages and severe toxicological effects. Therefore, this study aimed to evaluate the antineoplastic activity of gallic acid (GA) and myricetin (Myr) administrated peritumorally in Nu/Nu mice xenotransplanted with SKOV-3 cells. METHODS: Biological activity of GA and MYR was evaluated in SKOV-3 and OVCAR-3 cells (ovarian adenocarcinomas) by confocal/transmission electron microscopy, PI-flow cytometry, H2-DCF-DA stain, MTT, and Annexin V/PI assays. Molecular targets of compounds were determined with ACD/I-Labs and SEA. Antineoplastic activity was performed in SKOV-3 cells subcutaneously xenotransplanted into female Nu/Nu mice treated peritumorally with 50 mg/kg of each compound (2 alternate days/week) for 28 days. Controls used were paclitaxel (5 mg/kg) and 20 µL of vehicle (0.5% DMSO in 1X PBS). Tumor lesions, organs and sera were evaluated with NMR, USG, histopathological, and paraclinical studies. RESULTS: In vitro studies showed a decrease of cell viability with GA and Myr in SKOV-3 (50 and 166 µg/mL) and OVCAR-3 (43 and 94 µg/mL) cells respectively, as well as morphological changes, cell cycle arrest, and apoptosis induction due to ROS generation (p ≤ 0.05, ANOVA). In silico studies suggest that GA and MYR could interact with carbonic anhydrase IX and PI3K, respectively. In vivo studies revealed inhibitory effects on tumor lesions development with GA and MYR up to 50% (p ≤ 0.05, ANOVA), with decreased vascularity, necrotic/fibrotic areas, neoplastic stroma retraction and apoptosis. However, toxicological effects were observed with GA treatment, such as leukocyte infiltrate and hepatic parenchyma loss, hypertransaminasemia (ALT: 150.7 ± 25.60 U/L), and hypoazotemia (urea: 33.4 ± 7.4 mg/dL), due to the development of chronic hepatitis (p ≤ 0.05, ANOVA). CONCLUSION: GA and Myr (50 mg/kg) administered by peritumoral route, inhibit ovarian tumor lesions development in rodents with some toxicological effects. Additional studies will be necessary to find the appropriate therapeutic dose for GA. Therefore, GA and Myr could be considered as a starting point for the development of novel anticancer agents.

Biological and toxicological evaluation of Rhus trilobata Nutt. (Anacardiaceae) used traditionally in mexico against cancer.

BACKGROUND: Rhus trilobata Nutt. (Anacardiaceae) (RHTR) is a plant of Mexico that is traditionally used as an alternative treatment for several types of cancer. However, the phytochemical composition and potential toxicity of this plant have not been evaluated to support its therapeutic use. Therefore, this study aimed to evaluate the biological activity of RHTR against colorectal adenocarcinoma cells, determine its possible acute toxicity, and analyze its phytochemical composition. METHODS: The traditional preparation was performed by decoction of stems in distilled water (aqueous extract, AE), and flavonoids were concentrated with C18-cartridges and ethyl acetate (flavonoid fraction, FF). The biological activity was evaluated by MTT viability curves and the TUNEL assay in colorectal adenocarcinoma (CACO-2), ovarian epithelium (CHO-K1) and lung/bronchus epithelium (BEAS-2B) cells. The toxicological effect was determined in female BALB/c mice after 24 h and 14 days of intraperitoneal administration of 200 mg/kg AE and FF, respectively. Later, the animals were sacrificed for histopathological observation of organs and sera obtained by retro-orbital bleeding for biochemical marker analysis. Finally, the phytochemical characterization of AE and FF was conducted by UPLC-MSE. RESULTS: In the MTT assays, AE and FF at 5 and 18 µg/mL decreased the viability of CACO-2 cells compared with cells treated with vehicle or normal cells (p ≤ 0.05, ANOVA), with changes in cell morphology and the induction of apoptosis. Anatomical and histological analysis of organs did not reveal important pathological lesions at the time of assessment. Additionally, biochemical markers remained normal and showed no differences from those of the control group after 24 h and 14 days of treatment (p ≤ 0.05, ANOVA). Finally, UPLC-MSE analysis revealed 173 compounds in AE-RHTR, primarily flavonoids, fatty acids and phenolic acids. The most abundant compounds in AE and FF were quercetin and myricetin derivates (glycosides), methyl gallate, epigallocatechin-3-cinnamate, ß-PGG, fisetin and margaric acid, which might be related to the anticancer properties of RHTR. CONCLUSION: RHTR exhibits biological activity against cancer cells and does not present adverse toxicological effects during its in vivo administration, supporting its traditional use.