Aqueous Extraction of Citrus unshiu Peel Induces Proangiogenic Effects Through the FAK and ERK1/2 Signaling Pathway in Human Umbilical Vein Endothelial Cells

Antioxidative, Metabolic and Vascular Medicinal Potentials of Natural Products in the Non-Edible Wastes of Fruits Belonging to the Citrus and Prunus Genera: A Review

Diabetes mellitus and related metabolic and vascular impairments are notable health problems. Fruits and vegetables contain phenolics that are beneficial to metabolic and oxidative health and useful in preventing associated disease. Scientific evidence has shown that some bioactive phenolics are more abundant in the non-edible parts (especially the peels) of many fruits than in their respective edible tissues. Fruits belonging to the Citrus and Prunus genera are commonly consumed worldwide, including in South Africa, and their non-edible wastes (peel and seed) have been shown to have antioxidative, metabolic and vascular pharmacological potentials and medicinal phytochemistry. It is therefore imperative to evaluate the pharmacological actions and phytochemical properties of the non-edible wastes of these fruits and understand how they could potentially be of medicinal relevance in oxidative, metabolic and vascular diseases, including diabetes, oxidative stress, obesity, hypertension and related cardiovascular impairments. In the absence of a previous review that has concomitantly presented the medicinal potentials of fruits wastes from both genera, this review presents a critical analysis of previous and recent perspectives on the medicinal potential of the non-edible wastes from the selected Citrus and Prunus fruits in metabolic, vascular and oxidative health. This review further exposes the medicinal phytochemistry, while elucidating the underlying mechanisms through the fruit wastes potentiates their therapeutic effects. A literature search was carried out on "PubMed" to identify peer-reviewed published (mostly 2015 and beyond) studies reporting the antidiabetic, antioxidative, antihypertensive, anti-hyperlipidemic and anti-inflammatory properties of the non-edible parts of the selected fruits. The data of the selected studies were analyzed to understand the bioactive mechanisms, bioactive principles and toxicological profiles. The wastes (seed and peel) of the selected fruits had antioxidant, anti-obesogenic, antihypertensive, anti-inflammatory, antidiabetic and tissue protective potentials. Some phenolic acids and terpenes, as well as flavonoids and glycosides such as narirutin, nobiletin, hesperidin, naringin, naringenin, quercetin, rutin, diosmin, etc., were the possible bioactive principles. The peel and seed of the selected fruits belonging to the Citrus and Prunus genera are potential sources of bioactive compounds that could be of medicinal relevance for improving oxidative, metabolic and vascular health. However, there is a need for appropriate toxicological studies.

Novel role of Dipterocarpus tuberculatus as a stimulator of focal cell adhesion through the regulation of MLC2/FAK/Akt signaling pathway

To investigate a novel function of Dipterocarpus tuberculatus on focal cell adhesion stimulation, alterations to the regulation of focal cell adhesion-related factors were analyzed in NHDF cells and a calvarial defect rat model after treatment with methanol extracts of D. tuberculatus (MED). MED contained gallic acid, caffeic acid, ellagic acid, and naringenin in high concentrations. The proliferation activity, focal cell adhesion ability, adhesion receptors-mediated signaling pathway in NHDF cells were increased by MED. Also, a dense adhered tissue layer and adherent cells on MED-coated titanium plate (MEDTiP) surfaces were detected during regeneration of calvarial bone. The results of the present study provide novel evidence that MED may stimulate focal cell adhesion in NHDF cells and a calvarial defect rat model.

Protective effects of total flavonoids from Qu Zhi Qiao (fruit of Citrus paradisi cv. Changshanhuyou) on OVA-induced allergic airway inflammation and remodeling through MAPKs and Smad2/3 signaling pathway

Allergic asthma is one of the inflammatory diseases, which has become a major public health problem. Qu zhi qiao (QZQ), a dry and immature fruit of Citrus paradisi cv. Changshanhuyou, has various flavonoids with pharmacological properties. However, there is a knowledge gap on the pharmacological properties of QZQ on allergic asthma. Therefore, here, we explored the efficacy and mechanism of total flavonoids from QZQ (TFCH) on allergic asthma. We extracted and purified TFCH and conducted animal experiments using an Ovalbumin (OVA)-induced mice model. Bronchoalveolar lavage fluid and Swiss-Giemsa staining were used to count different inflammatory cells in allergic asthma mice. We conducted histopathology and immunohistochemistry to evaluate the changes in the lungs of allergic asthma mice. Moreover, we used ELISA assays to analyze chemokines and inflammatory cytokines. Furthermore, western blot analyses were conducted to elucidate the mechanism of TFCH on allergic asthma. We established that TFCH has anti-inflammatory effects and inhibits airway remodeling, providing a potential therapeutic strategy for allergic asthma.

Association of Jagged1 expression with malignancy and prognosis in human pancreatic cancer

PURPOSE

Pancreatic cancer is one of the most aggressive cancers. Preclinical and clinical data indicate that Notch 1 ligand jagged1 (JAG1) plays a pro-oncogenic role in several malignant cancers. As yet, however, the role of JAG1 in pancreatic cancer is poorly understood. The objective of the present study was to investigate JAG1 as a therapeutic target in human pancreatic cancer.

METHODS

Expression levels of Notch signaling molecules were assessed using GEO datasets and Western blot analysis, respectively. Anti-tumor effects following JAG1 silencing were evaluated using in vitro and in vivo assays. Prognostic implications were assessed using GEO datasets.

RESULTS

Using GEO datasets and Western blot analysis we detected significantly higher JAG1 mRNA and protein expression levels in pancreatic cancer compared to normal pancreatic tissues. JAG1 silencing significantly restrained the growth, migration and invasion of pancreatic cancer cells through the induction of apoptosis and blockade of various kinases independent of the Notch1 pathway. Combined JAG1 silencing and gemcitabine treatment showed synergistic anti-viability effects in human pancreatic cancer cells. JAG1 silencing also resulted in significant anti-cancer effects in vivo and high JAG1 expression was found to be associated with an adverse prognosis in pancreatic cancer patients.

CONCLUSIONS

From our data we conclude that JAG1 may be a promising therapeutic target in pancreatic cancer.

Phenolic composition, antioxidant potential and health benefits of citrus peel

Citrus peel (CP) forms around 40-50% of the total fruit mass but is generally thought to be a waste. However, it is a substantial source of naturally occurring health enhancing compounds, particularly phenolic compounds and carotenoids. Phenolic compounds in CP mainly comprise phenolic acids (primarily caffeic, p-coumaric, ferulic and sinapic acid), flavanones (generally naringin and hesperidin) and polymethoxylated flavones (notably nobiletin and tangeretin). It has also been noted that CP's contain more amounts of these compounds than corresponding edible parts of the fruits. Phenolic compounds present in CP act as antioxidants (by either donation of protons or electrons) and protect cells against free radical damage as well as help in reducing the risk of many chronic diseases. Owing to the more abundance of polyphenols in CP's, their antioxidant activity is also higher than other edible fruit parts. Therefore, peels from citrus fruits can be used as sources of functional compounds and preservatives for the development of newer food products, that are not only safe but also have health-promoting activities. The present review provides in-depth knowledge about the phenolic composition, antioxidant potential and health benefits of CP.

Improvement of chemotherapy through reducing of cachexia by using Citrus unshiu peel extract

.Colorectal cancer (CRC) is now one the fourth cause of mortality and morbidity due to cancer throughout the globe. Cachexia is more prevalent in patients with this cancer and has a negative effect on response to chemotherapy and radiotherapy. Inflammatory cytokines such as TNF-α, IL-1β, and IL-6 could play a key role in cachexia. Moreover strong chemotherapy medications such as doxorubicin have complications such as toxicity and cachexia. Citrus unshiu Peel have been used as traditional herbal drugs for the treatment of cancer in traditional oriental medicine (TOM). Since its main components have anti-inflammatory effects, we evaluated the anti-cachexia activity in order to support the traditional usage of Citrus unshiu peel. Aim of the study; We aimed to assess the preventive or therapeutic effect of Citrus unshiu Peel Extract (CUPE) on cachexia by reducing of inflammatory cytokines in mice bearing C26 tumor. Also the contribution role of CUPE has evaluated on improvement of chemotherapy through reducing of inflammatory cytokines. Materials and Methods; The CUPE was prepared by Soxhlet extractor and quantitative and qualitative analysis of aqua extract was performed by high performance liquid chromatography (HPLC). C26 tumor bearing BALB/c male mice were immunized with different formulation of oral Prophylactic-therapeutic CUPE and/or intraperitoneal doxorubicin and then were monitored for weight gain, food intake and tumor size throughout the study. On the 32nd day after tumor injection, inflammatory cytokines levels, IL6, TNF-α and IL-1β were evaluated by Enzyme-linked Immunosorbent Assay (ELISA) and Malondialdehyde- Thiobarbituric acid (MDA) levels were measured by standard method. Results; Oral administration of CUPE in both prophylactic and therapeutic formulation to C26 adenocarcinoma bearing mice reduced the weight loss, tumor volume, and serum MDA levels compared with untreated tumor-bearing mice and Doxorubicin (Dox) groups. Also, the combination therapy of (CUPE + Dox) leads to reducing the levels of serum IL-6, TNF-α, IL-1β and tumor volume compared with untreated tumor-bearing mice and Dox groups. Serum MDA levels were considerably reduced by combination therapy of (CUPE + Dox) compared with Dox groups. Conclusions; These findings confirm the safety and efficacy of CUPE on C26 adenocarcinoma bearing mice as pure and adjuvant therapy, the results of which might be used in further human studies as a valuable natural anticancer agent alone or in combination with chemotherapy. Also the results showed that simultaneous application of CUPE and Dox leads to significant reduction of cachexia from the Dox chemotherapy.

Scattered DUSP28 is a novel biomarker responsible for aggravating malignancy via the autocrine and paracrine signaling in metastatic pancreatic cancer

Pancreatic cancer remains one of the most dangerous cancers with a grave prognosis. We have reported that dual specificity phosphatise 28 (DUSP28) could be secreted in pancreatic cancer cells. However, its biological function is poorly understood. Here, we distinguish the function of scattered DUSP28 in human pancreatic cancer. DUSP28 was specifically secreted to cultured medium in metastatic pancreatic cancer cells. Treatment with recombinant DUSP28 significantly increased the migration, invasion, and viability of metastatic pancreatic cancer cells through the activation of CREB, AKT, and ERK1/2 signaling pathways. In addition, administration of recombinant DUSP28 elicited pro-angiogenic effects in human umbilical vein endothelial cells. Injection of recombinant DUSP28 also produced tumor growth in vivo. Of interest, DUSP28 formed an autocrine loop with integrin α1 (ITGα1) by transcriptional regulation and recombinant DUSP28 acted as an oncogenic reagent through the interaction with ITGα1. Notably, scattered DUSP28 could be detected in whole blood samples of pancreatic cancer patients by accessible immunoassay. These results provide the basis for DUSP28 as a promising therapeutic target and a biomarker for metastatic pancreatic cancer.

Combined administration of naringenin and hesperetin with optimal ratio maximizes the anti-cancer effect in human pancreatic cancer via down regulation of FAK and p38 signaling pathway

BACKGROUND

We have previously reported the functional anti-cancer effects of the products of enzymatic hydrolysis of Citrus unshiu peel (εCUP) and fermented extraction of Citrus unshiu peel (ƒCUP) in human pancreatic cancer. Despite their different characteristics and effects, the underlying mechanism remains elusive.

PURPOSE

In this study, we further demonstrate the impact of ingredient contents of Citrus unshiu peel on the cancer's natural features.

METHODS

Anti-pancreatic cancer activities following combined treatment of naringenin and hesperetin were demonstrated in vitro and in vivo experiments.

RESULTS

Combined treatment with naringenin and hesperetin inhibited the growth of human pancreatic cancer cells (εCUP mimic condition, p < 0.001 for Miapaca-2 cells) through induction of caspase-3 cleavage compared to separate treatment with naringenin or hesperetin. Combined treatment with naringenin and hesperetin also inhibited the migration (εCUP mimic condition, p < 0.001 for Panc-1 cells) of human pancreatic cancer cells. The εCUP mimic condition had the most effective anti-cancer features; in contrast, which had no inhibitory effect on growth and migration of normal cells (HUVECs and Detroit551 cells). In addition, εCUP mimic condition inhibited the phosphorylation of focal adhesion kinase (FAK) and p38 signaling compared with separate treatment with naringenin or hesperetin. Of note, εCUP mimic condition showed a prominent anti-growth effect (p < 0.001) compared with control or ƒCUP mimic condition in vivo xenograft models.

CONCLUSION

These results suggest that combined treatment with naringenin and hesperetin might be a promising anti-cancer strategy for pancreatic cancers without eliciting toxicity on normal cells.

Fermented Extraction of Citrus unshiu Peel Inhibits Viability and Migration of Human Pancreatic Cancers

Pancreatic cancer is one of the most dangerous cancers with high mortality rates. Despite continuous efforts, there has been limited improvement in its prognosis. In this study, we prepared fermented extract of Citrus unshiu peel (fCUP) from the by-product after juice processing and then examined the anticancer effects of fCUP on human pancreatic cancer cells. Treatment with fCUP inhibited the growth of human pancreatic cancer cells through induction of caspase-3 cleavage both in vitro and in vivo. Treatment with fCUP also blocked the migration of human pancreatic cancer cells through activation of intracellular signaling pathways such as MKK3/6 and P38. In contrast, treatment with fCUP did not inhibit growth and migration of human umbilical vein endothelial cells. In addition, we found that fCUP mainly consisted of aboriginal compounds, narirutin and hesperidin, as well as newly generated compounds, naringenin and hesperetin. In silico analysis showed that naringenin and hesperetin were the unique modules related to anticancer effect. Furthermore, fCUP exhibited the anticancer effects in in vivo xenograft models. Collectively, these results suggest that fCUP might have the potential to be developed into an effective anticancer drug for pancreatic cancers without causing adverse side-effects.

In vitro and in vivo evaluation of systemic and genetic toxicity of Citrus unshiu peel

ETHNOPHARMACOLOGICAL RELEVANCE

The peel of Citrus unshiu Markovich fruits (CUP), called "Jinpi" in Korea, and "Chenpi" in China, has been used for the treatment of respiratory and blood circulation disorders in traditional oriental medicine (TOM). Despite its widespread uses in TOM, no information on the safety of CUP has been reported. Thus, genotoxicity and systemic toxicity of CUP were evaluated in the current studies.

MATERIALS AND METHODS

We conducted a toxicological evaluation of CUP water extracts using acute and subchronic (13-week repeated-dose) toxicity tests and three genotoxicity assays (bacterial reverse mutation, mammalian chromosomal aberration, and micronuclei formation).

RESULTS

In acute and subchronic toxicity tests, both the median lethal dose (LD₅₀) and no-observed-adverse-effect level (NOAEL) were more than 4000mg/kg/day in rats. None of the genotoxicity assays revealed any mutagenicity or clastogenicity in in vitro and in vivo systems.

CONCLUSION

CUP water extracts were found to be nongenotoxic under our testing conditions and had low acute and subchronic toxicity.

Extraction, characterization and biological activity of citrus flavonoids

Citrus is one of the largest and most popular fruit crops commercially grown across the globe. It is not only important in terms of economy but is also popular for its nutritional benefits to human and farm animals. Citrus is available in several varieties, all with attractive colors. It is consumed either fresh or in processed form. After processing, approximately 50% of the fruit remains unconsumed and discarded as waste. The latter includes fruit pith residue, peels and seeds. Direct disposal of these wastes to the environment causes serious problems as these contain bioactive compounds. Release of these bioactive compounds to the open landfills cause bad odor and spread of diseases, and disposal to water bodies or seepage to the underground water table deteriorates water quality and harms aquatic life. In this regard, a number of research are being focused on the development of better reuse methods to obtain value-added phytochemicals as well as for safe disposal. The important phytochemicals obtained from citrus include essential oils, flavonoids, citric acid, pectin, etc., which have now become popular topics in industrial research, food and synthetic chemistry. The present article reviews recent advances in exploring the effects of flavonoids obtained from citrus wastes, the extraction procedure and their usage in view of various health benefits.

Autocrine DUSP28 signaling mediates pancreatic cancer malignancy via regulation of PDGF-A

Pancreatic cancer remains one of the most deadly cancers with a grave prognosis. Despite continuous efforts to improve remedial values, limited progress has been made. We have reported that dual specificity phosphatase 28 (DUSP28) has a critical role of chemo-resistance and migration in pancreatic cancers. However, its mechanism remains unclear. Here, we further clarify the function of DUSP28 in pancreatic cancers. Analysis using a public microarray database and in vitro assay indicated a critical role of platelet derived growth factor A (PDGF-A) in pancreatic cancer malignancy. PDGF-A was positively regulated by DUSP28 expression at the mRNA and protein levels. Enhanced DUSP28 sensitized pancreatic cancer cells to exogenous PDGF-A treatment in migration, invasion, and proliferation. Transfection with siRNA targeting DUSP28 blunted the influence of administered PDGF-A by inhibition of phosphorylation of FAK, ERK1/2, and p38 signalling pathways. In addition, DUSP28 and PDGF-A formed an acquired autonomous autocrine-signaling pathway. Furthermore, targeting DUSP28 inhibited the tumor growth and migratory features through the blockade of PDGF-A expression and intracellular signaling in vivo. Our results establish novel insight into DUSP28 and PDGF-A related autonomous signaling pathway in pancreatic cancer.