Immunomodulatory and cellular anti-oxidant activities of an aqueous extract of Limoniastrum guyonianum gall

Potential Therapeutic Implications of Caffeic Acid in Cancer Signaling: Past, Present, and Future

Caffeic acid (CA) has been present in many herbs, vegetables, and fruits. CA is a bioactive compound and exhibits various health advantages that are linked with its anti-oxidant functions and implicated in the therapy and prevention of disease progression of inflammatory diseases and cancer. The anti-tumor action of CA is attributed to its pro-oxidant and anti-oxidant properties. CA’s mechanism of action involves preventing reactive oxygen species formation, diminishing the angiogenesis of cancer cells, enhancing the tumor cells’ DNA oxidation, and repressing MMP-2 and MMP-9. CA and its derivatives have been reported to exhibit anti-carcinogenic properties against many cancer types. CA has indicated low intestinal absorption, low oral bioavailability in rats, and pitiable permeability across Caco-2 cells. In the present review, we have illustrated CA’s therapeutic potential, pharmacokinetics, and characteristics. The pharmacological effects of CA, the emphasis on in vitro and in vivo studies, and the existing challenges and prospects of CA for cancer treatment and prevention are discussed in this review.

Potential Therapeutic Implications of Caffeic Acid in Cancer Signaling: Past, Present, and Future

Caffeic acid (CA) has been present in many herbs, vegetables, and fruits. CA is a bioactive compound and exhibits various health advantages that are linked with its anti-oxidant functions and implicated in the therapy and prevention of disease progression of inflammatory diseases and cancer. The anti-tumor action of CA is attributed to its pro-oxidant and anti-oxidant properties. CA’s mechanism of action involves preventing reactive oxygen species formation, diminishing the angiogenesis of cancer cells, enhancing the tumor cells’ DNA oxidation, and repressing MMP-2 and MMP-9. CA and its derivatives have been reported to exhibit anti-carcinogenic properties against many cancer types. CA has indicated low intestinal absorption, low oral bioavailability in rats, and pitiable permeability across Caco-2 cells. In the present review, we have illustrated CA’s therapeutic potential, pharmacokinetics, and characteristics. The pharmacological effects of CA, the emphasis onin vitro and in vivostudies, and the existing challenges and prospects of CA for cancer treatment and prevention are discussed in this review.

Immunomodulatory effects of four polysaccharides purified from Erythronium sibiricum bulb on macrophages

Four neutral polysaccharides (ESBP1-1, ESBP1-2, ESBP2-1 and ESBP3-1) were successfully purified from the water extracted crude polysaccharides of Erythronium sibiricum bulbs through the combination of DEAE Sepharose CL-6B and Sephadex G-100 chromatography; their average molecular weights were 1.3 × 10⁴, 1.7 × 10⁴, 9.4 × 10⁵ and 4.1 × 10⁵ Da, respectively. Monosaccharide component analysis indicated that ESBP1-1 and ESBP1-2 were mainly composed of glucose (Glc). ESBP2-1 was composed of Glc, galactose (Gal) and arabinose, with a molar ratio of 24.3:1.1:1, whereas ESBP3-1 comprised Glc and Gal at a molar ratio of 14.8:1. In-vitro study showed that all of the four polysaccharides were able to considerably promote the proliferation and neutral red phagocytosis of RAW 264.7 macrophage cell. They could also stimulate the production of the cell lines' secretory molecules [nitric oxide, tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β)] in a dose-dependent manner. However, ESBP1-2 was not included in IL-1β. Overall, these results suggested that polysaccharides from E. sibiricum bulbs can be developed as immunomodulatory ingredients for complementary medicines or functional foods. However, further animal or clinical studies are required.

Platycodon grandifloras polysaccharides inhibit mitophagy injury induced by Cr (VI) in DF-1 cells

This study aimed to investigate the role of Platycodon grandiflorus polysaccharide (PGPS) in chromium (VI)-induced autophagy in a chicken embryo fibroblast cell lines (DF-1 cells). DF-1 cells were exposed to Cr (VI), PGPS_t, and Cr (VI) + PGPS_t, and their effects on cell viability, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and autophagy-related proteins were examined. The results showed that the cell viability was reduced after Cr (VI) treatment, and 3-MA, CsA or PGPS_t suppressed this decrease. Cr (VI) treatment increased the ROS levels and decreased the MMP, thereby enhancing the expression of mitochondrial autophagy marker proteins (PINK1, Parkin, and LC3-II), inhibiting mitophagy autophagy protein TOMM20 expression, and promoting the degradation of autophagy-related marker p62. These changes led to exceeding mitochondrial autophagy and cell trauma and could be mitigated by PGPS_t. Overall, our research showed that Cr (VI) can induce exceeding mitochondrial autophagy in DF-1 cells, whereas PGPS_t can improve Cr (VI)-induced mitochondrial autophagy by inhibiting ROS and restoring MMP.

Antitumor Effect of Bryonia dioïca Methanol Extract: In Vitro and In Vivo Study

Aim: A large number of plant-derived products have been approved for the treatment of numerous types of cancer, and these products have also shown to reduce the effects of metastatic cancer. The aim of this study is to evaluate the anticancer effects of a methanolic extract of Bryonia dioïca root (M extract) against B16F10 melanoma cancer cells in vitro as well as in vivo.Results: It was shown to induce apoptosis, in vitro, and to inhibit cell growth by arresting cell cycle progression in SubG1 phase. Mice bearing the melanoma cells were used to confirm any in vivo effectiveness of the M extract as an antitumor promoting agent. In mice dosed with 50 mg M/kg/d (for 28 days), tumor weight was inhibited by 65.03% compared to that in mice that did not receive the product. Our results demonstrate on the one hand, that this inhibition was accompanied by a drastic decrease regulation of complex FAK, Src, ERK, p130Cas and paxillin. On the other hand, it was marked by a measurable decrease of the metastatic descent in the lungs.Conclusions: These effects could be ascribed to the presence of bryoniosides and cucurbitacins such as cucurbitacin A and cucurbitacin G in M extract.

Trans-cinnamic acid application for rainbow trout (Oncorhynchus mykiss): I. Effects on haematological, serum biochemical, non-specific immune and head kidney gene expression responses

The present study investigated the effects of dietary trans-cinnamic acid (CA) on pre- and post-challenge haematological, serum biochemical, non-specific immune and head kidney gene expression responses of rainbow trout, Oncorhynchus mykiss juveniles. In this regard, fish with an average weight of 17.01 ± 0.05 g were divided into five groups, and fed daily with an additive free basal diet (control); 250, 500, 750 or 1500 mg kg^-1 CA for a 60-day period. Fish were sampled every 20 days during the experiment. On days 20, 40 and 60 (the pre-challenge period), the dietary CA especially at 250 and/or 500 mg kg^-1 significantly increased blood granulocyte percentage, and serum total protein, globulin, lysozyme and total immunoglobulin values. Furthermore, dietary CA increased activities of phagocytic activity, respiratory burst and potential killing, and increased the expression levels of immune related genes [serum amyloid A (SAA), interleukin 8 (IL-8), interleukin 1, beta (IL-1β), transforming growth factor beta (TGF-β), tumor necrosis factor (TNF-α), and immunoglobulin T (IgT)] in the head kidney of fish fed with 250 and/or 500 mg kg^-1 CA. Following 60 days of feeding, fish were challenged with Yersinia ruckeri and mortality was recorded for 20 days. Highest percentage survival (%) rate was found in the 250 and/or 500 mg kg^-1 CA-supplemented feeding groups. During the post-challenge period, red blood cell (RBC) count, hematocrit (%), respiratory burst activity, and total antiprotease activity increased in fish fed with feed containing 500 mg kg^-1 content. Moreover, markedly up-regulated the expression of related genes (SAA, IL-8, IL-1β, TGF-β, TNF-α, IFN-γ and IgM) in fish fed 250, 500 and/or 750 mg kg^-1 CA. Therefore, feeding O. mykiss for 60 days with dietary CA at 250-500 mg kg^-1 CA incorporation levels can be suggested as optimal to enhance the immunity and disease resistance against Y. ruckeri.

The relevance of folkloric usage of plant galls as medicines: Finding the scientific rationale

Galls, the abnormal growths in plants, induced by virus, bacteria, fungi, nematodes, arthropods, or even other plants, are akin to cancers in fauna. The galls which occur in a myriad of forms are phytochemically-distinct from the normal plant tissues, for these are the sites of tug-of-war, just like the granuloma in animals. To counter the stressors, in the form of the effector proteins of the invaders, the host plants elaborate a large repertoire of metabolites, which they normally will not produce. Perturbation of the jasmonic acid pathway, and the overexpression of auxin, and cytokinin, promote the tissue proliferation and the resultant galls. Though the plant family characteristics and the attackers determine the gall biochemistry, most of the galls are rich in bioactive phytochemicals such as phenolic acids, anthocyanins, purpurogallin, flavonoids, tannins, steroids, triterpenes, alkaloids, lipophilic components (tanshinone) etc. Throughout the long trajectory of evolution, humans have learned to use the galls as therapeutics, much like other plant parts. In diverse cultures, the evidence of folkloric usage of galls abound. Among others, galls from the plant genus like Rhus, Pistacia, Quercus, Terminalia etc. are popular as ethnomedicine. This review mines the literature on galling agents, and the medicinal relevance of galls.

A review of Tunisian medicinal plants with anticancer activity

Cancer is a major public health problem in the world. The use of the medicinal plants in cancer prevention and management is frequent in Africa, especially in Tunisia, and it is transmitted from generation to generation within cultures. Many previous studies showed that a wide range of Tunisian medicinal plants exerted cytotoxic and anticancer activity. A comprehensive review was conducted to collect information from scientific journal articles, including indigenous knowledge researches, about Tunisian medicinal plants used for the prevention and management of cancer. The aim of this review article is to provide the reader with information concerning the importance of Tunisian medicinal plants in the prevention and management of cancer and to open the door for the health professionals and scientists working in the field of pharmacology and therapeutics to produce new drug formulations to treat different types of cancer.

Protective mechanisms of purified polyphenols from pinecones of Pinus koraiensis on spleen tissues in tumor-bearing S180 mice in vivo

The present study was designed to evaluate the protective effects of the purified polyphenols from pinecones ofPinus koraiensis(PPP-40) on spleen tissues of S180 micein vivo.

Effect of heated naringenin on immunomodulatory properties and cellular antioxidant activity

Naringenin is one of the most popular flavonoids derived from citrus. It has been reported to be an effective anti-inflammatory compound. Citrus fruit may be used raw, cooked, stewed, or boiled. The present study was conducted to investigate the effect of thermal processes on naringenin in its immunomodulatory and cellular antioxidant activities. The effects of flavonoids on B and T cell proliferation were assessed on splenocytes stimulated or not with mitogens. However, their effects on cytotoxic T lymphocyte (CTL) and natural killer (NK) activities were assessed in splenocytes co-incubated with target cells. The amount of nitric oxide production and the lysosomal enzyme activity were evaluated in vitro on mouse peritoneal macrophages. Cellular antioxidant activity in splenocytes and macrophages was determined by measuring the fluorescence of the dichlorofluorescin (DCF). Our findings revealed that naringenin induces B cell proliferation and enhances NK activity. The highest concentration of native naringenin exhibits a significant proliferation of T cells, induces CTL activity, and inhibits cellular oxidation in macrophages. Conversely, it was observed that when heat-processed, naringenin improves the cellular antioxidant activity in splenocytes, increases the cytotoxic activity of NK cells, and suppresses the cytotoxicity of T cells. However, heat treatment maintains the anti-inflammatory potency of naringenin.

Walnut Polyphenol Extract Attenuates Immunotoxicity Induced by 4-Pentylphenol and 3-methyl-4-nitrophenol in Murine Splenic Lymphocyte

4-pentylphenol (PP) and 3-methyl-4-nitrophenol (PNMC), two important components of vehicle emissions, have been shown to confer toxicity in splenocytes. Certain natural products, such as those derived from walnuts, exhibit a range of antioxidative, antitumor, and anti-inflammatory properties. Here, we investigated the effects of walnut polyphenol extract (WPE) on immunotoxicity induced by PP and PNMC in murine splenic lymphocytes. Treatment with WPE was shown to significantly enhance proliferation of splenocytes exposed to PP or PNMC, characterized by increases in the percentages of splenic T lymphocytes (CD3+ T cells) and T cell subsets (CD4+ and CD8+ T cells), as well as the production of T cell-related cytokines and granzymes (interleukin-2, interleukin-4, and granzyme-B) in cells exposed to PP or PNMC. These effects were associated with a decrease in oxidative stress, as evidenced by changes in OH, SOD, GSH-Px, and MDA levels. The total phenolic content of WPE was 34,800 ± 200 mg gallic acid equivalents/100 g, consisting of at least 16 unique phenols, including ellagitannins, quercetin, valoneic acid dilactone, and gallic acid. Taken together, these results suggest that walnut polyphenols significantly attenuated PP and PNMC-mediated immunotoxicity and improved immune function by inhibiting oxidative stress.

Structural characterization and biological activities of two α-glucans from radix paeoniae alba

Radix Paeoniae Alba is widely used in Chinese traditional medicine to treat various diseases such as gastrointestinal disorders, cancer, and other diseases. In this study, two polysaccharides RPAPW1 and RPAPW2 were isolated from Radix Paeoniae Alba by DEAE-52 cellulose chromatography and G-25 sephadex. According to physicochemical methods, NMR and methylation analysis, RPAPW1 and RPAPW2 were established to be α-glucans consisting of predominant 4-linked α- Glc residues branched at O-6 and contained trace amount of protein and uronic acid. Immunological tests indicated that RPAPW1, RPAPW2 and could promote splenocyte proliferation and RAW264.7 phagocytic activity. In vitro, RPAPW1 and RPAPW2 elicited a week reducing power, DPPH scavenging activity and could not protect the PC12 cells from H2O2 damage. These data implied polysaccharides RPAPW1 and RPAPW2 had the potential to be a natural immunopotentiating and antioxidant supplement for preparing functional foods and nutraceuticals.

Immunomodulatory potencies of isolated compounds from Crataegus azarolus through their antioxidant activities

The search of natural immunomodulatory agents has become an area of great interest in order to reduce damage to the human body. In this study, the immunomodulatory potential of Crataegus azarolus and its isolated hyperoside on mouse lymphocytes and macrophages in vitro was assessed. The effect of C. azarolus natural compounds on splenocytes proliferation, natural killer (NK) and cytotoxic T lymphocytes (CTL) activities, and on macrophage-mediated cytotoxicity were assessed by MTT test. Phagocytic activity and inhibition of nitric oxide (NO) release by macrophages were also evaluated. The antioxidant capacity of these products was evaluated by determining their cellular antioxidant activity (CAA) in splenocytes and macrophages. Depending on the concentrations, both ethyl acetate (EA) extract and hyperoside (Hyp) from C. azarolus affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide release. Whereas, the above-mentioned products significantly promote LPS and lectin-stimulated splenocyte proliferation, implying a potential activation of lymphocytes B and T enhancing humoral and cellular immune responses. Moreover, EA extract and Hyp could enhance the activity of NK and T lymphocytes cells, as well as the macrophages-mediated cytotoxicity against B16F10 cells. The anti-inflammatory activity was concomitant with the cellular antioxidant effect of the tested compounds against macrophages and splenocytes. Collectively, C. azarolus and its isolated hyperoside exhibited an immunomodulatory effect through their antioxidant activity. These findings suggest that C. azarolus should be explored as a novel potential immunomodulatory agent for the treatment of inflammatory diseases.

Immunomodulatory and cellular antioxidant activities of pure compounds from Teucrium ramosissimum Desf

Evaluation of the immunomodulatory activity of plant compounds is an interesting and growing area of research. Teucrium ramosissimum Desf. is a native and endemic medicinal plant from the South of Tunisia traditionally used for the treatment of many diseases. The anti-inflammatory activity of apigenin-7-glucoside, genkwanin, and naringenin isolated from T. ramosissimum were assayed. The phagocytic activities of macrophage and lymphocyte proliferation were investigated in the absence and presence of mitogens (lipopolysaccharide [LPS] or lectin). Depending on the concentrations, the compounds affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide (NO) release. The tested compounds enhance significantly splenocyte proliferation, either with or without mitogen stimulation. In studies to assess any potential effects of apigenin-7-glucoside, genkwanin, and naringenin on innate immunity, the results showed that these compounds significantly enhanced the killing activity of natural killer (NK) cells and cytotoxic activity of the T lymphocyte (CTL) isolated from splenocytes. These results suggest that T. ramosissimum compounds such as apigenin-7-glucoside, genkwanin, and naringenin may be potentially useful for modulating immune cell functions in physiological and pathological conditions.

In Vitro and In Vivo Anti-Melanoma Effects of Pituranthos tortuosus Essential Oil Via Inhibition of FAK and Src Activities

A large number of plants used in traditional medicines have been shown to possess antitumor activities. The aims of this study were to evaluate any anticancer effect of the essential oil (EO) extracted from P. tortuosus against B16F10 melanoma cancer cells in vitro as well as in vivo. In vitro, EO was shown to induce apoptosis and to inhibit migration and invasion processes. Further investigation revealed that EO decreased focal adhesion and invadopodia formation which was accompanied by a drastic downregulation of FAK, Src, ERK, p130Cas and paxillin. Moreover, EO treatment decreased the expression level of p190RhoGAP, and Grb2, which impair cell migration and actin assembly. Mice bearing the melanoma cells were used to confirm any in vivo effectiveness of the EO as an anti-tumor promoting agent. In mice dosed with 100 mg EO/kg/d (for 27 days), tumor weight was inhibited by 98% compared to that in mice that did not receive the product. In conclusion, these data suggested to us that an EO of P. tortuosus could evolve to be a potential medicinal resource for use in the treatment of cancers.

Up-regulation of Hsp72 and keratin16 mediates wound healing in streptozotocin diabetic rats

Background

Impaired wound healing is a complication of diabetes and a serious problem in clinical practice. We previously found that whey protein (WP) was able to regulate wound healing normally in streptozotocin (STZ)-diabetic models. This subsequent study was designed to assess the effect of WP on heat shock protein-72 (Hsp72) and keratin16 (Krt16) expression during wound healing in diabetic rats.

Methods

WP at a dosage of 100 mg/kg of body weight was orally administered daily to wounded normal and STZ-diabetic rats for 8 days.

Results

At day 4, the WP-treated diabetic wound was significantly reduced compared to that in the corresponding control. Diabetic wounded rats developed severe inflammatory infiltration and moderate capillary dilatation and regeneration. Treated rats had mild necrotic formation, moderate infiltration, moderate to severe capillary dilatation and regeneration, in addition to moderate epidermal formation. Hsp72 and Krt16 densities showed low and dense activity in diabetic wounded and diabetic wounded treated groups, respectively. At day 8, WP-treatment of diabetic wounded animals revealed great amelioration with complete recovery and closure of the wound. Reactivity of Hsp72 and Krt16 was reversed, showing dense and low, or medium and low, activity in the diabetic wounded and diabetic wounded treated groups, respectively. Hsp72 expression in the pancreas was found to show dense reactivity with WP-treated diabetic wound rats.

Conclusion

This data provides evidence for the potential impact of WP in the up-regulation of Hsp72 and Krt16 in T1D, resulting in an improved wound healing process in diabetic models.

Immunomodulatory and anticancer effects of Pituranthos tortuosus essential oil

Many studies have been performed to assess potential utility of natural products as immunomodulants to enhance antitumor activity in situ. In this study, an essential oil (EO) from the aerial parts of Pituranthos tortuosus was prepared using hydrodistillation, its composition was characterized, and its immunomodulatory potential was assessed. The results indicated that the EO contained sabinene, α-pinene, limonene, and terpinen-4-ol as major constituents. EO was also found to be able to significantly promote lipopolysaccharide (LPS)-stimulated splenocyte proliferation, suggestive of a potential for activation of B cells and enhanced humoral immune responses in hosts given this product. Effects of EO on cell proliferation and apoptosis were also investigated in B16F10 melanoma cells. EO-induced tumor cell growth inhibition was associated with characteristic apoptotic changes in the cells, including nuclear condensation. In conclusion, these data suggested to us that an EO of P. tortuosus could evolve to be a potential medicinal resource for use in the treatment of cancers.

Anemone altaica Induces Apoptosis in Human Osteosarcoma Cells

In the past decade, no significant improvement has been made in chemotherapy for osteosarcoma (OS). To develop improved agents against OS, we screened 70 species of medicinal plants and treated two human OS cell lines with different agent concentrations. We then examined cell viability using the MTT assay. Results showed that a candidate plant, particularly the rhizomes of Anemone altaica Fisch. ex C. A. Mey aqueous extract (AAE), suppressed the viability of HOS and U2OS cells in a concentration-dependent manner. Flow cytometry analysis revealed that AAE significantly increased the amount of cell shrinkage (Sub-G1 fragments) in HOS and U2OS cells. Moreover, AAE increased cytosolic cytochrome c and Bax, but decreased Bcl-2. The amount of cleaved caspase-3 and poly-(ADP-ribose) polymerase-1 (PARP-1) were significantly increased. AAE suppressed the growth of HOS and U2OS through the intrinsic apoptotic pathway. Data suggest that AAE is cytotoxic to HOS and U2OS cells and has no significant influence on human osteoblast hFOB cells. The high mRNA levels of apoptosis-related factors (PPP1R15A, SQSTM1, HSPA1B, and DDIT4) and cellular proliferation markers (SKA2 and BUB1B) were significantly altered by the AAE treatment of HOS and U2OS cells. Results show that the anticancer activity of AAE could up-regulate the expression of a cluster of genes, especially those in the apoptosis-related factor family and caspase family. Thus, AAE has great potential as a useful therapeutic drug for human OS.

Correlation between the major components of Phyllanthus amarus and Phyllanthus urinaria and their inhibitory effects on phagocytic activity of human neutrophils

Background

Recently, we have highlighted the immunomodulatory activity of the standardized extracts of Phyllanthus amarus and P. urinaria. The present study was carried out to correlate between the prevalent constituents of the herbs and their inhibitory effects on phagocytic activity of human neutrophils.

Methods

The compounds, gallic acid, ellagic acid, corilagin, geraniin, phyllanthin and hypophyllanthin were identified and quantitatively analyzed in the extracts of Phyllanthus amarus and P. urinaria obtained from Malaysia and Indonesia by using a validated reversed phase high performance liquid chromatography (RP-HPLC) method. The standardized extracts and the pure compounds were evaluated for their effects on chemotaxis, β2 integrin (CD18) expression, phagocytosis and chemiluminescence of human phagocytes. Chemotactic activity was assessed using the Boyden chamber technique, inhibition of CD18 expression and phagocytic ability were tested with the aid of flow cytometry, while effect on the respiratory burst was investigated using a luminol-based chemiluminescence assay.

Results

All plant extracts strongly inhibited migration of the phagocytes with the Malaysian P. amarus depicting the highest inhibitory activity. Amongst the compounds tested, geraniin demonstrated the strongest inhibitory activity on chemotaxis of polymorphonuclear leukocytes (PMNs) and monocytes with IC₅₀ values of 1.09 and 1.69 μM, respectively, which were lower than that of ibuprofen. All plant extracts and pure compounds exhibited high inhibitory activity on the oxidative burst of zymosan and PMA stimulated leukocytes. Geraniin and corilagin exhibited exceptionally strong inhibition on the reactive oxygen species (ROS) activity with IC₅₀ values lower than aspirin. The plant extracts exhibited moderate inhibition of E. coli uptake by monocytes but weak effect on PMNs. Of all the compounds, phyllanthin at 50 μg/mL exhibited the highest engulfment inhibitory activity with percentage of phagocytizing cells of 14.2 and 27.1% for PMNs and monocytes, respectively. All plants and compounds tested possessed weak effect on CD18 expression on leukocytes except for hypophyllanthin and phyllanthin which exhibited significant inhibitory effect.

Conclusion

The strong inhibition of the extracts on the phagocytic activity of neutrophils was due to the presence of their major constituents especially geraniin, corilagin, phyllanthin and hypophllanthin which were able to modulate the innate response of phagocytes at different steps.

Limoniastrum guyonianum aqueous gall extract induces apoptosis in colorectal cancer cells by inhibiting calpain activity

Several studies have reported that plant-derived natural products have cancer chemopreventive and chemotherapeutic properties. The aim of the present study was to determine the antiproliferative and pro-apoptotic potential of Limoniastrum guyonianum aqueous gall extract (G extract) on human colorectal cancer BE cell line and, if so, to characterize the mechanism involved. The G extract-induced growth inhibitory effect was associated with an arrest of cell cycle progression in G2/M phase as shown by the cell phase distribution. In addition, G extract promoted in a concentration-dependent manner these cells towards apoptosis as indicated by the presence of cleaved poly(ADP-ribose) polymerase (PARP). In order to characterize the mechanism involved in the antiproliferative and pro-apoptotic signaling pathway activated by G extract, calpain activity and the expression of the cell cycle inhibitor p16(INK4A) were determined. The present findings indicated that G extract exhibited significant inhibitory activity against calpain and caused a marked and concentration-dependent upregulation of p16(INK4A). These effects could be ascribed to the presence of condensed tannins and polyphenols such as epicatechin and epigallocatechin gallate in G extract.

Immunopotentiation of Pleurotus eryngii (DC. ex Fr.) Quel

ETHNOPHARMACOLOGICAL RELEVANCE

Pleurotus eryngii (DC. ex Fr.) Quel has been collected from the wild, cultivated and used in traditional medicines to treat various disorders and diseases since antiquity. In traditional Chinese medicine, the powdered fruiting bodies of Pleurotus eryngii were used for immunostimulation, skin-care, wound-healing, cancer and lumbago treatment. In the current study, we investigated the antiproliferative activity of Pleurotus eryngii powder on A549, BGC-823, HepG2 and HGC-27 cancer cells and its immunomodulating activity on macrophage, RAW 264.7 cells based on its active compound.

MATERIALS AND METHODS

A novel bioactive protein (PEP) was extracted from Pleurotus eryngii fruiting bodies powder and purified on DEAE-52, CM-52 and Superdex 75 column chromatographies using an ÄKTA purifier. Its cytotoxicity on A549, BGC-823, HepG2, HGC-27 and RAW 267.4 cell lines was then evaluated using MTT, alamar blue (AB), trypan blue (TB), neutral red (NR), lactate dehydrogenase (LDH), Annexin V FITC/PI and morphological change assays. Moreover, lysosomal enzyme activity, pinocytosis, nitric oxide (NO) and hydrogen peroxide (H₂O₂) production assays were used to examine immunomostimulatory activity of PEP on RAW 267.4 cells.

RESULTS

Based on high performance gel permeation chromatography (HPGPC), Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) analyses, the isolated protein (PEP) had a molecular weight of 63 kDa, a secondary (α-helical) structure and was mainly composed of arginine, serine and glycine. PEP significantly (P<0.05) inhibited A549, BGC-823, HepG2 and HGC-27 tumor cells proliferation dose-dependently with an IC₅₀ range of 36.5 ± 0.84 to 229.0 ± 1.24 µg/ml. Contrarily, PEP stimulated the proliferation of macrophages.

CONCLUSION

Pleurotus eryngii fruiting bodies powder has a potential application as a natural antitumor agent with immunomodulatory activity, proposedly, by targeting the lysosomes of cancerous cells and stimulating macrophage-mediated immune responses.

Antioxidant, mutagenic and antimutagenic activities of an aqueous extract of Limoniastrum guyonianum gall

An aqueous extract of Limoniastrum guyonianum gall (G extract) was tested on Salmonella typhimurium to assess its mutagenic and antimutagenic effects. This extract showed no mutagenicity when tested with S. typhimurium strain TA104 either with or without exogenous metabolic activation mixture (S9), whereas our findings revealed that the aqueous gall extract induced a mutagenic effect in S. typhimurium TA1538 when tested in the presence, as well as in the absence, of S9 activation mixture at the concentration of 500 µg/mL. Thus, the same concentration produced a mutagenic effect, when incubated with S. typhimurium TA100 in the presence of metabolic activation mixture. In contrast, our results showed a weak antimutagenic potential of the same extract against sodium azide in the presence of S. typhimurium TA100 and S. typhimurium TA1538 without metabolic activation (S9), whereas, in the presence of S. typhimurium TA104, we obtained a significant inhibition percentage (76.39%) toward 3.25 µg/plate of methylmethanesulfonate. Antimutagenicity against aflatoxin B1, 4-nitro-o-phenylene-diamine and 2-aminoanthracène was significant, with an inhibition percentage of, respectively, 70.63, 99.3 and 63.37% in the presence of, respectively, S. typhimurium TA100, S. typhimurium TA1538 and S. typhimurium TA104 strains at a concentration of 250 µg/plate after metabolic activation (S9). Antioxidant capacity of the tested extract was evaluated using the enzymatic (xanthine/xanthine oxidase assay) and the nonenzymatic (2,2-diphenyl-1-picrylhydrazyl) system. G extract exhibited high antioxidant activity.

Limoniastrum guyonianum aqueous gall extract induces apoptosis in human cervical cancer cells involving p16 INK4A re-expression related to UHRF1 and DNMT1 down-regulation

Several reports have described the potential effects of natural compounds as anti-cancer agents in vitro as well as in vivo. The aim of this study was to evaluate the anti-cancer effect of Limoniastrum guyonianum aqueous gall extract (G extract) and luteolin in the human cervical cancer HeLa cell line, and, if so, to clarify the underlying mechanism. Our results show that G extract and luteolin inhibited cell proliferation and induced G2/M cell cycle arrest in a concentration and time-dependent manner. Both natural products induced programmed cell death as confirmed by the presence of hypodiploid G0/G1 cells. These effects are associated with an up-regulation of the expression of the tumor suppressor gene p16INK4A and a down-regulation of the expression of the anti-apoptotic actor UHRF1 and its main partner DNMT1. Moreover, G extract- and luteolin-induced UHRF1 and DNMT1 down-regulation is accompanied with a global DNA hypomethylation in HeLa cell line. Altogether our results show that G extract mediates its growth inhibitory effects on human cervical cancer HeLa cell line likely via the activation of a p16INK4A-dependent cell cycle checkpoint signalling pathway orchestrated by UHRF1 and DNMT1 down-regulation.