Abstract: A punicalagin is a metabolic product of pomegranate fruits and peeled. We have compiled the recent literature review from different sources. The extract of pomegranate fruits and peel has been reported for health-beneficial properties in inflammation-associated chronic disease and the regulatory role in NF-KB, MAPK, IL-6/JAK/STAT3, and PI3K/AKT/mTOR signaling pathway. Punicalagin is an ellagitannin found in the peel of pomegranate (Punica granatum). It is a polyphenol with proven biological/pharmacological activities like antioxidant, hepatoprotective, an-ti-atherosclerotic, anti-cancer, anti-neurological, anti-diabetic, and anti-digestive. The extracts have a rich source of hydrolyzable tannin and anthocyanin exhibiting strong anti-neoplastic properties. Anti-cancer activities of pomegranate with reference to modulated signaling pathways in various cancer diseases have been recently reported. The punicalagin-induced redirection of the signal-transduction pathway from survival and proliferation into the cell cycle by arrested the living cells. Apoptosis senescence and autophagy and thus compromising neoplastic progression are delineated. This review is based mainly on data obtained from various sources including the in-vitro cell line model and its activities that are concerned with the effect of punicalagin activities on various cell types.

Skin aging is one of the most common problems facing humanity. It occurs because of altering the balance between free radicals and antioxidants and increasing the amount of the reactive oxygen species (ROS) in skin cells, which leads to oxidative stress especially when exposed to UV radiation. Antioxidants can neutralize the harmful effects of ROS, and secondary plant metabolites can help protect against UV radiation. In this study, punicalagin was extracted from pomegranate and concentrations of total polyphenolics and flavonoids were determined and antioxidant activities measured. Punicalagin was loaded onto niosomes and its morphology and release were studied. An in vitro study was performed on human fibroblast cell line HFB4 cells with aging induced by H2O2 and UV radiation. Cell cycle arrest was studied and different genes (MMP3, Col1A1, Timp3, and TERT) involved in the skin aging process were selected to measure punicalagin's effect. Punicalagin succeeded in reducing the growth arrest of HFB4 cells, activated production of the Col1A1 and Timp3 genes, maintained collagen level, and lowered of MMP3. Punicalagin increased human TERT concentration in skin cells. Punicalagin is promising as a natural antioxidant to protect human skin from aging.

Oxidative stress and chronic inflammation, both at the systemic and central level, are critical early events in atherosclerosis and Alzheimer’s disease (AD). Purpose. To investigate the oxidative stress, inflammatory, and Tau-phosphorylation lowering effects of pomegranate polyphenols (PP) (punicalagin, ellagic acid, peels, and arils extracts). Methods. We used flow cytometry to quantify protein expression of proinflammatory cytokines (IL-1β) and anti-inflammatory mediators (IL-10) in THP-1 macrophages, as well as M1/M2 cell-specific markers (CD86 and CD163) expression in human microglia HMC3 cells. IL-10 protein expression was also quantified in U373-MG human astrocytes. The effect of PP on human amyloid beta 1-42 (Aβ1-42)-induced oxidative stress was assessed in microglia by measuring ROS generation and lipid peroxidation, using respectively two ′,7′-dichlorofluorescein diacetate (DCFH-DA) and thiobarbituric acid reactive substances (TBARS) tests. Neuronal viability and cell apoptotic response to Aβ1-42 toxicity were assayed using the MTT (3-(4, 5-dimethyl thiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay and the annexinV-FITC apoptosis detection kit; respectively. Finally, flow cytometry analysis was also performed to evaluate the ability of PP to modulate Aβ1-42-induced Tau-181 phosphorylation (pTau-181). Results. Our data indicate that PP was significantly (p<0.05) effective in countering Aβ1-42-induced inflammation through increasing the anti-inflammatory cytokines (IL-10) (in U373-MG astrocytes and THP1 macrophages) and decreasing proinflammatory markers (IL-1β) expression in THP1 macrophages. PP was also significantly (p<0.05) effective in inducing the phenotypic transition of THP-1 macrophages and microglial cells from M1 to M2 by decreasing CD86 and increasing CD163 surface receptor expression. Moreover, our treatments have a significant (p<0.05) beneficial impact on oxidative stress, illustrated in the reduction of TBARS and ROS generation. Our treatments have significant (p<0.05) cell viability improvement capacities and anti-apoptotic effects on human H4 neurons. Furthermore, our results suggest that Aβ1-42 significantly (p<0.05) increases pTau-181. This effect was significantly (p<0.05) attenuated by arils, peels, and punicalagin and drastically reduced by ellagic acid treatments. Conclusion. Our results are attributed to PP's anti-inflammatory, antioxidant, anti-apoptotic, and anti-Tau pathology potential. Future studies should aim to extend our knowledge of the potential role of PP on A1-42-induced neurodegeneration, mainly its association with the tauopathy involved in AD.