Punicalagin, a pomegranate compound, induces apoptosis and autophagy in acute leukemia

Progress in the study of autophagy-related proteins affecting resistance to chemotherapeutic drugs in leukemia

Leukemia is a life-threatening malignant tumor of the hematopoietic system. Currently, the main treatment modalities are chemotherapy and hematopoietic stem cell transplantation. However, increased drug resistance due to decreased sensitivity of leukemia cells to chemotherapeutic drugs presents a major challenge in current treatments. Autophagy-associated proteins involved in autophagy initiation have now been shown to be involved in the development of various types of leukemia cells and are associated with drug resistance. Therefore, this review will explore the roles of autophagy-related proteins involved in four key autophagic processes: induction of autophagy and phagophore formation, phagophore extension, and autophagosome formation, on the development of various types of leukemias as well as drug resistance. Autophagy may become a promising therapeutic target for treating leukemia.

Pomegranate (Punica granatum L.) phytochemicals target the components of metabolic syndrome

Pomegranate (Punica granatum L.) is a multipurpose dietary and medicinal plant known for its ability to promote various health benefits. Metabolic syndrome (MetS) is a complex metabolic disorder driving health and socioeconomic challenges worldwide. It may be characterized by insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study aims to conduct a review of pomegranate's effects on MetS parameters using a mechanistic approach relying on pre-clinical studies. The peel, juice, roots, bark, seeds, flowers, and leaves of the fruit present several bioactive compounds that are related mainly to anti-inflammatory and antioxidant activities as well as cardioprotective, antidiabetic, and antiobesity effects. The use of the juice extract can work as a potent inhibitor of angiotensin-converting enzyme activities, consequently regulating blood pressure. The major bioactive compounds found within the fruit are phenolic compounds (hydrolysable tannins and flavonoids) and fatty acids. Alkaloids, punicalagin, ellagitannins, ellagic acid, anthocyanins, tannins, flavonoids, luteolin, and punicic acid are also present. The antihyperglycemia, antihyperlipidemia, and weight loss promoting effects are likely related to the anti-inflammatory and antioxidant effects. When considering clinical application, pomegranate extracts are found to be frequently well-tolerated, further supporting its efficacy as a treatment modality. We suggest that pomegranate fruit, extract, or processed products can be used to counteract MetS-related risk factors. This review represents an important step towards exploring potential avenues for further research in this area.

Unveiling autophagy complexity in leukemia: The molecular landscape and possible interactions with apoptosis and ferroptosis

Autophagy is a self-digestion multistep process in which causes the homeostasis through degradation of macromolecules and damaged organelles. The autophagy-mediated tumor progression regulation has been a critical point in recent years, revealing the function of this process in reduction or acceleration of carcinogenesis. Leukemia is a haematological malignancy in which abnormal expansion of hematopoietic cells occurs. The current and conventional therapies from chemotherapy to cell transplantation have failed to appropriately treat the leukemia patients. Among the mechanisms dysregulated in leukemia, autophagy is a prominent one in which can regulate the hallmarks of this tumor. The protective autophagy inhibits apoptosis and ferroptosis in leukemia, while toxic autophagy accelerates cell death. The proliferation and invasion of tumor cells are tightly regulated by the autophagy. The direction of regulation depends on the function of autophagy that is protective or lethal. The protective autophagy accelerates chemoresistance and radio-resistsance. The non-coding RNAs, histone transferases and other pathways such as PI3K/Akt/mTOR are among the regulators of autophagy in leukemia progression. The pharmacological intervention for the inhibition or induction of autophagy by the compounds including sesamine, tanshinone IIA and other synthetic compounds can chance progression of leukemia.

In vitro studies for antiparasitic activities of Punica granatum extract

Because of the drug resistance, medicinal plants are used more frequently than coccidiostats to treat and control coccidiosis. Punica granatum is a powerful antioxidant with a variety of medicinal uses. This study used an in vitro experiment to investigate how different P. granatum from Yemen (Y) and Egypt (E) sources affected oocyst sporulation and served as an anthelminthic effector. In contrast to PGE and mebendazole, PGY (200 mg/mL) has the shortest time to paralyze and death the earthworm Eisenia fetida in this investigation. In addition, the treated worm groups' cuticle thickness and shrinkage in comparison to the control group were assessed and contrasted. Eimeria papillata is used as a model protozoan parasite in anticoccidial assays. This study shows that P. granatum affects oocysts sporulation in a dose-dependent manner, with maximal percentages of 100% (PGY) and 48.60% (PGE) at 96 h for P. granatum concentrations of 200 mg/mL. Inhibition (%) was compared to various detergents, as well as positive and negative controls. According to our research, the P. granatum extract had powerful anthelmintic and anticoccidial properties, with the potency changing according to the environmental conditions of each fruit source. RESEARCH HIGHLIGHTS: Habitat of the plant is useful for production and accumulation of some secondary metabolites in plants which be effective for the therapeutic uses. Different parameters in the environmental ecosystem affecting variation in chemical compositions and biological activity of P. granatum.

Punicalagin is cytotoxic to human colon cancer cells by modulating cell proliferation, apoptosis, and invasion

Purpose: The purpose of this study was to explore the anticancer effect of punicalagin, an abundant bioactive tannin compound isolated from Punica granatum L., on three colon cancer cell lines, namely, HCT 116, HT-29, and LoVo.Research Design: Normal and colon cancer cells were treated with different concentrations of punicalagin for different periods. Data Collection and Analysis: Cell viability was measured with a CCK-8 assay. Programmed cell death and invasion were analyzed using an annexin V and cell death kit and a cell invasion analysis kit. The expression of active caspase-3, MMP-2, MMP-9, Snail, and Slug were measured by Western blot.Results: The results of the cell viability analysis showed that punicalagin was cytotoxic to colon cancer cells, but it was not to normal cells in a dose- and time-dependent manner. Additionally, punicalagin induced apoptosis in colon cancer cells (shown by the cumulative percentage of colorectal cancer cells in early and late apoptosis). It was found that caspase-3 activity increased following punicalagin treatment. Western blot results also showed that punicalagin increased the expression of activated caspase-3. In contrast, punicalagin inhibited the invasion of colon cancer cells. Further, treatment of colon cancer cells with punicalagin suppressed the expression of MMP-2, MMP-9, Snail, and Slug. Conclusions: These results showed that the activation of caspase-3 and the inhibition of MMP-2, MMP-9, Snail and Slug were involved in the effects of punicalagin on colon cancer cells.

Anti-leukemic effect of menthol, a peppermint compound, on induction of apoptosis and autophagy

Background

Menthol, a natural compound in peppermint leaves, has several biological activities, including antioxidant, anti-inflammatory, antiviral, antibacterial and anticancer properties. This study revealed the anti-leukemic effects and its underlying mechanisms of the menthol related apoptosis signaling pathway and autophagy in both NB4 and Molt-4 leukemic cell lines.

Methods

Both leukemic cells were treated with menthol in various concentration. Cell viability was assessed using MTT assay, whereas apoptosis and autophagy were analyzed by flow cytometry using Annexin V-FITC/PI and anti-LC3/FITC antibodies staining, respectively. Apoptotic and autophagic related gene and protein expression were detected using RT-qPCR and western blot analysis, respectively. Moreover, STITCH database was used to predicts the interaction between menthol and proposed proteins.

Results

Menthol significantly decreased cell viability in NB4 and Molt-4 cell lines in dose dependent manner. In combination of menthol and daunorubicin, synergistic cytotoxic effects were observed in leukemic cells. However, there was a minimal effect found on normal, peripheral blood mononuclear cells (PBMCs). Moreover, menthol significantly induced apoptosis induction via upregulation of caspase-3, BAX, p53 and downregulation of MDM2 mRNA expression. Autophagy was also induced by menthol through upregulating ATG3 and downregulating mTOR mRNA expression. For protein expression, menthol significantly increased caspase-3 whereas decreased mTOR in both leukemic cells. Conclusions. These results suggest that menthol exhibits cytotoxic activities by inhibition of cell proliferation, induction of apoptosis and autophagy through activating the caspase cascade, altering BAX and p53/MDM2, and regulating autophagy via the ATG3/mTOR signaling pathway.

Punica granatum as Anticandidal and Anti-HIV Agent: An HIV Oral Cavity Potential Drug

The oral cavity is crucial from diagnosis to adherence to HAART therapy in the HIV/AIDS population; consequently, drugs that can maintain healthy conditions in the oral cavity are necessary for patients with HIV/AIDS. Punica granatum (pomegranate) is a tree that has been employed extensively for centuries in the traditional medicine of ancient cultures for the treatment of a wide range of diseases, including oral and dental diseases. In recent decades, its potent anticandidal properties have been shown, especially on Candida albicans, the cause of the most common clinical manifestation in HIV patients. The present work contributes to the review of the anti-HIV and anticandidal properties of the plant species P. granatum as involved with the oral cavity. The literature reviewed revealed that crude extracts of pomegranate and its main isolated compounds possess inhibitory activity on different HIV targets, including binding viral proteins and the three replicative HIV enzymes. In addition, in the literature reviewed, pomegranate exhibited anticandidal effects on 10 different species. Thus, pomegranate appears to be an excellent candidate to explore and incorporate into the treatment of the oral cavity of HIV/AIDS patients, in that, in addition to its pharmacological effects such as antiviral and anticandidal, pomegranate represents an easily available, inexpensive, and safe natural source.

Unravelling the In Vitro and In Vivo Anti-Helicobacter pylori Effect of Delphinidin-3-O-Glucoside Rich Extract from Pomegranate Exocarp: Enhancing Autophagy and Downregulating TNF-α and COX2

Fruits containing antioxidants, e.g., anthocyanins, exhibit antimicrobial activities. The emergence of drug resistance represents a major challenge in eradicating H. pylori. The current study aims to explore the effect of pomegranate exocarp anthocyanin methanol extract (PEAME) against H. pylori isolates recovered from antral gastric biopsies. The UPLC-PDA-MS/MS and 1H NMR analyses indicated delphinidin-3-O-glucoside as the major anthocyanin in the extract. The PEAME showed activity against all tested resistant isolates in vitro recording minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 128 and 256 µg/mL, respectively. In vivo investigation included evaluation of the rat gastric mucosa for malondialdehyde (MDA), catalase activity, COX2, TNF-α, and key autophagy gene expression. The combination of pomegranate with metronidazole markedly reduced the viable count of H. pylori and the level of COX2, with alleviation of H. pylori-induced inflammation and oxidative stress (reduction of MDA, p-value < 0.001; and increase in catalase activity, p-value < 0.001). Autophagy gene expression was significantly upregulated upon treatment, whereas TNF-α was downregulated. In conclusion, we comprehensively assessed the effect of PEAME against H. pylori isolates, suggesting its potential in combination with metronidazole for eradication of this pathogen. The beneficial effect of PEAME may be attributed to its ability to enhance autophagy.

Punicalagin protects against the development of pancreatic injury and insulitis in rats with induced T1DM by reducing inflammation and oxidative stress

Pancreatic inflammation and oxidative damage remain major concerns in type 1 diabetes mellitus (T1DM). Punicalagin, a major polyphenol in pomegranates, exhibited antioxidant and protective effects on several organs in case of T1DM; however, no study has yet explored the protective effects of punicalagin on the pancreas and islets of Langerhans. T1DM was induced by injecting 40 mg/kg streptozotocin (STZ) intraperitoneally. Punicalagin (1 mg/kg ip) was injected daily for 15 days after T1DM induction. In diabetic rats, punicalagin treatment lowered the levels of inflammatory biomarkers (monocyte chemoattractant protein-1 and C-reactive protein) and adhesion molecules (E-selectin, intercellular adhesion molecule, and vascular cell adhesion molecule) while activating myeloperoxidase activity. Treatment of diabetic rats with punicalagin improved glutathione content and superoxide dismutase, catalase, and glutathione peroxidase activities; upregulated serum paraoxonase-1 activity; and prevented the elevation lipid peroxidation and protein oxidation products in the pancreas. Furthermore, punicalagin protected the pancreas against STZ-induced histopathological alterations and increased immune-reactive β-cells while reducing leucocyte infiltration into the islets of Langerhans, leading to normalized blood glucose and insulin levels. These findings indicated that punicalagin might protect against the development of insulitis in T1DM. In conclusion, punicalagin exerts a strong protective effect on the pancreas against oxidative injury and inflammation in STZ-induced experimental T1DM. The present results recommend punicalagin as a potential adjuvant for reducing diabetes-associated insulitis.

Immunomodulatory Properties of Pomegranate Peel Extract in a Model of Human Peripheral Blood Mononuclear Cell Culture

Pomegranate peel extract (PoPEx) has been shown to have antioxidant and anti-inflammatory properties, but its effect on the adaptive immune system has not been sufficiently investigated. In this study, the treatment of human peripheral blood mononuclear cells (PBMC) with PoPEx (range 6.25–400 µg/mL) resulted in cytotoxicity at concentrations of 100 µg/mL and higher, due to the induction of apoptosis and oxidative stress, whereas autophagy was reduced. At non-cytotoxic concentrations, the opposite effect on these processes was observed simultaneously with the inhibition of PHA-induced PBMC proliferation and a significant decrease in the expression of CD4. PoPEx differently modulated the expression of activation markers (CD69, CD25, ICOS) and PD1 (inhibitory marker), depending on the dose and T-cell subsets. PoPEx (starting from 12.5 µg/mL) suppressed the production of Th1 (IFN-γ), Th17 (IL-17A, IL-17F, and IL-22), Th9 (IL-9), and proinflammatory cytokines (TNF-α and IL-6) in culture supernatants. Lower concentrations upregulated Th2 (IL-5 and IL-13) and Treg (IL-10) responses as well as CD4+CD25hiFoxp3+ cell frequency. Higher concentrations of PoPEx increased the frequency of IL-10- and TGF-β-producing T-cells (much higher in the CD4+ subset). In conclusion, our study suggested for the first time complex immunoregulatory effects of PoPEx on T cells, which could assist in the suppression of chronic inflammatory and autoimmune diseases.

Punicalagin suppresses inflammation in ventilator-induced lung injury through protease-activated receptor-2 inhibition-induced inhibition of NLR family pyrin domain containing-3 inflammasome activation

Punicalagin is recorded to be a potent anti-inflammatory drug, while its effect on inflammation existing in ventilator-induced lung injury (VILI) requires further verification. Rats were pretreated with punicalagin, followed by VILI modeling. Lung histopathological examination was performed with hematoxylin-eosin staining accompanied by the lung injury score. The lung wet/dry (W/D) weight ratio and total bronchoalveolar lavage fluid (BALF) protein level were measured. After transfection with protease-activated receptor-2 (PAR2) overexpression plasmids, mouse alveolar epithelial MLE-12 cells were treated with punicalagin and then subjected to cyclic stretching. Punicalagin's cytotoxicity to MLE-12 cells were measured by MTT assay. The levels of inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6), PAR2, NLR family pyrin domain containing-3 (NLRP3), and apoptosis-associated speck-like protein containing a CARD (ASC) in the BALF, lung tissues or cells were analyzed by enzyme-linked immune-sorbent assay (ELISA), qRT-PCR or/and western blot. Punicalagin treatment attenuated VILI-induced lung histopathological changes and counteracted VILI-induced increases in the lung injury score, W/D weight ratio and total protein level in BALF. Also, punicalagin treatment counteracted in vivo VILI/cyclic stretching-induced increases in the levels of PAR2, inflammatory cytokines, NLRP3, and ASC. PAR2 overexpression potentiated the cyclic stretching-induced effects, while punicalagin treatment revoked this PAR2 overexpression-induced potentiation effect. In turn, PAR2 overexpression partly resisted the punicalagin treatment-induced counteractive effects on the cyclic stretching-induced effects. Punicalagin suppresses inflammation in VILI through PAR2 inhibition-induced inhibition of NLRP3 inflammasome activation.