Current Insights on the Photoprotective Mechanism of the Macular Carotenoids, Lutein and Zeaxanthin: Safety, Efficacy and Bio-Delivery.

Ocular health has emerged as one of the major issues of global health concern with a decline in quality of life in an aging population, in particular and rise in the number of associated morbidities and mortalities. One of the chief reasons for vision impairment is oxidative damage inflicted to photoreceptors in rods and cone cells by blue light as well as UV radiation. The scenario has been aggravated by unprecedented rise in screen-time during the COVID and post-COVID era. Lutein and Zeaxanthin are oxygenated carotenoids with proven roles in augmentation of ocular health largely by virtue of their antioxidant properties and protective effects against photobleaching of retinal pigments, age-linked macular degeneration, cataract, and retinitis pigmentosa. These molecules are characterized by their characteristic yellow-orange colored pigmentation and are found in significant amounts in vegetables such as corn, spinach, broccoli, carrots as well as fish and eggs. Unique structural signatures including tetraterpenoid skeleton with extensive conjugation and the presence of hydroxyl groups at the end rings have made these molecules evolutionarily adapted to localize in the membrane of the photoreceptor cells and prevent their free radical induced peroxidation. Apart from the benefits imparted to ocular health, lutein and zeaxanthin are also known to improve cognitive function, cardiovascular physiology, and arrest the development of malignancy. Although abundant in many natural sources, bioavailability of these compounds is low owing to their long aliphatic backbones. Under the circumstances, there has been a concerted effort to develop vegetable oil-based carriers such as lipid nano-emulsions for therapeutic administration of carotenoids. This review presents a comprehensive update of the therapeutic potential of the carotenoids along with the challenges in achieving an optimized delivery tool for maximizing their effectiveness inside the body.

Lutein and zeaxanthin are the two most abundant natural xanthophylls (oxygenated carotenoids) with a linear C40 tetraterpene/isoprenoid lycopene-based backbone.Presence of extensive conjugation (more than 10 double bonds) enable these molecules to act as accessory light harvesting pigments apart from chlorophyll.More importantly, the xanthophylls prevent photobleaching of the pigments and proteins in the Light Harvesting Complex (LHC) by sequestering the excess unutilized blue light and preventing triplet chlorophyll associated formation of Reactive Oxygen Species.In human eye, lutein, zeaxanthin along with mesozeaxanthin constitute the three macular pigments forming the so called "yellow spot" of the macula and are implicated in maintaining the redox balance, homeostasis and normal physiology of the eyes.However, unlike plants, xanthophylls must be acquired from dietary sources such as colored leafy vegetables and egg yolk.Increase in the number of eye diseases in the aging population coupled with insufficient bioavailability of xanthophylls has mandated the industrial production of supplements enriched in xanthophylls.The bioavailability and delivery of xanthophylls can be significantly enhanced by suspension in a blend of extra-virgin olive oil and other vegetable oils.

Phytochemicals in Cancer Immune Checkpoint Inhibitor Therapy.

The interaction of immune checkpoint molecules in the tumor microenvironment reduces the anti-tumor immune response by suppressing the recognition of T cells to tumor cells. Immune checkpoint inhibitor (ICI) therapy is emerging as a promising therapeutic option for cancer treatment. However, modulating the immune system with ICIs still faces obstacles with severe immunogenic side effects and a lack of response against many cancer types. Plant-derived natural compounds offer regulation on various signaling cascades and have been applied for the treatment of multiple diseases, including cancer. Accumulated evidence provides the possibility of efficacy of phytochemicals in combinational with other therapeutic agents of ICIs, effectively modulating immune checkpoint-related signaling molecules. Recently, several phytochemicals have been reported to show the modulatory effects of immune checkpoints in various cancers in in vivo or in vitro models. This review summarizes druggable immune checkpoints and their regulatory factors. In addition, phytochemicals that are capable of suppressing PD-1/PD-L1 binding, the best-studied target of ICI therapy, were comprehensively summarized and classified according to chemical structure subgroups. It may help extend further research on phytochemicals as candidates of combinational adjuvants. Future clinical trials may validate the synergetic effects of preclinically investigated phytochemicals with ICI therapy.

Differential effects of thymoquinone on lysophosphatidic acid-induced oncogenic pathways in ovarian cancer cells.

Thymoquinone, a therapeutic phytochemical derived from Nigella sativa, has been shown to have a potent anticancer activity. However, it has been identified that the tumor microenvironment (TME) can attenuate the anticancer effects of thymoquinone (TQ) in ovarian cancer. Lysophosphatidic acid (LPA), a lipid growth factor present in high concentration in the TME of ovarian cancer, has been shown to regulate multiple oncogenic pathways in ovarian cancer. Taking account of the crucial role of LPA in the genesis and progression of ovarian cancer, the present study is focused on assessing the efficacy of TQ in inhibiting LPA-stimulated oncogenic pathways in ovarian cancer cells. Our results indicate that TQ is unable to attenuate LPA-stimulated proliferation or metabolic reprogramming in ovarian cancer cells. However, TQ potently inhibits the basal as well as LPA-stimulated migratory responses of the ovarian cancer cells. Furthermore, TQ abrogates the invasive migration of ovarian cancer cells induced by Gαi2, through which LPA stimulates cell migration. TQ also attenuates the activation of JNK, Src, and FAK, the downstream signaling nodes of LPA-LPAR-Gαi2 signaling pathway. In addition to establishing the differential effects of TQ in ovarian cancer cells, our results unravel the antitherapeutic role of LPA in the ovarian cancer TME could override the inhibitory effects of TQ on cell proliferation and metabolic reprogramming of ovarian cancer cells. More importantly, the concomitant finding that TQ could still sustain its inhibitory effect on LPA-stimulated invasive cell migration, points to its potential use as a response-specific therapeutic agent in ovarian cancer.

Resveratrol as a Tumor-Suppressive Nutraceutical Modulating Tumor Microenvironment and Malignant Behaviors of Cancer.

Tumor-suppressive effects of resveratrol have been shown in various types of cancer. However, regulation of tumor microenvironment by resveratrol is still unclear. Recent findings suggest resveratrol can potentiate its tumor-suppressive effect through modulation of the signaling pathways of cellular components (fibroblasts, macrophages and T cells). Also, studies have shown that resveratrol can suppress malignant phenotypes of cancer cells acquired in response to stresses of the tumor microenvironment, such as hypoxia, oxidative stress and inflammation. We discuss the effects of resveratrol on cancer cells in stress environment of tumors as well as interactions between cancer cells and non-cancer cells in this review.

Effect of Red Ginseng on Genotoxicity and Health-Related Quality of Life after Adjuvant Chemotherapy in Patients with Epithelial Ovarian Cancer: A Randomized, Double Blind, Placebo-Controlled Trial.

We evaluated the effect of red ginseng on toxicity, health-related quality of life (HRQL) and survival after adjuvant chemotherapy in patients with epithelial ovarian cancer (EOC). A total of 30 patients with EOC were randomly assigned to placebo (n = 15) and red ginseng groups (n = 15). All patients took placebo or red ginseng (3000 mg/day) for three months. Then, we compared changes of genotoxicity, HRQL and survival between the two groups. As a result, red ginseng reduced micronuclei yield in comparison with placebo despite no difference of binucleated cells index. Although red ginseng increased serum levels of alanine aminotransferase and aspartate aminotransferase significantly, they were within the normal value. Moreover, there were no differences in adverse events between placebo and red ginseng groups. In terms of HRQL, red ginseng was associated with improved emotional functioning and decreased symptoms of fatigue, nausea and vomiting, and dyspnea, reduced anxiety and interference affecting life and improved daytime somnolence. However, there was no effect of red ginseng on prognosis of EOC. Conclusively, red ginseng may be safe and effective to reduce genotoxicity and improve HRQL despite no benefit of survival in patients with EOC who received chemotherapy.

An Alternative Triage Strategy Based on Preoperative MRI for Avoiding Trimodality Therapy in Stage IB Cervical Cancer.

PURPOSE: Adjuvant chemoradiation following primary surgery is frequently indicated in patients with stage IB cervical cancer. The aim of this study is to evaluate the role of a magnetic resonance imaging (MRI)-based strategy in avoiding trimodality therapy. MATERIALS AND METHODS: We retrospectively reviewed all patients with stage IB cervical cancer treated initially with primary surgery at Seoul National University Hospital. We suggest an alternative triage strategy in which the primary treatment modality is determined based on preoperative MRI findings. Using this strategy, primary surgery is only indicated when there is no evidence of parametrial involvement (PMI) and lymph node metastasis (LNM) in the MRI results; when there is evidence of either or both of these factors, primary chemoradiation is selected. Assuming that this strategy is applied to our cohort, we evaluate how the rate of trimodality therapy is affected. RESULTS: Of the 254 patients in our sample, 77 (30.3%) had at least one category 1 risk factor (PMI, LNM, positive resection margin) upon pathologic examination. If the MRI-based strategy had been applied to our cohort, 168 patients would have undergone primary surgery and 86 would have undergone primary chemoradiation. Only 25 patients (9.8%) would have required trimodality therapy based on an indication of at least one category 1 pathologic risk factor following radical hysterectomy. CONCLUSION: The inclusion of MRI in the decision-making process for primary treatment modality could have reduced the number of patients requiring trimodality therapy based on the indication of a category 1 risk factor from 30.3% to 9.8% in our cohort.

20 year experience of postoperative radiotherapy in IB-IIA cervical cancer patients with intermediate risk factors: impact of treatment period and concurrent chemotherapy.

OBJECTIVE: To compare the long-term clinical outcomes of adjuvant radiotherapy (RT) versus concurrent chemoradiotherapy (CCRT) in cervical cancer patients with intermediate risk factors. METHODS: Between 1990 and 2010, 110 cervical cancer patients with 2 or more intermediate risk factors (deep stromal invasion, lymphovascular space invasion, and large tumor size) underwent adjuvant RT (n=56) or CCRT (n=54) following radical surgery. Because CCRT had been performed since 2000, patients were divided into 3 groups regarding treatment period and the addition of chemotherapy, RT 1990-1999 (n=39), RT 2000-2010 (n=17) and CCRT 2000-2010 (n=54). Majority of concurrent chemotherapeutic regimens were carboplatin and paclitaxel (n=48). RESULTS: Five-year relapse-free survival (RFS) rates for RT 1990-1999, RT 2000-2010 and CCRT 2000-2010 were 83.5%, 85.6% and 93.8%, respectively. CCRT 2000-2010 had a significant decrease in pelvic recurrence (p=0.012) and distant metastasis (p=0.027). There were no significant differences in overall survival and RFS between RT 1990-1999 and RT 2000-2010. Acute grade 3 and 4 hematologic toxicities were more frequently observed in CCRT 2000-2010 (p<0.001). However, acute grade 3 and 4 gastrointestinal (GI) and chronic toxicities did not differ between the groups. CONCLUSIONS: This study shows that the addition of concurrent chemotherapy to postoperative RT in cervical cancer patients with intermediate risk factors may improve RFS without increasing acute GI and chronic toxicities, although hematologic toxicities increased significantly.

Genistein as a Potential Anticancer Agent against Ovarian Cancer.

Genistein is known as the major component of isoflavone, which is present in high-soy diets. Genistein has received much attention because of its chemopreventive and therapeutic effects on various types of cancers. Numerous studies have shown that genistein has antineoplastic effects against ovarian cancer. Several epidemiological studies have shown that women who have high consumption of isoflavones have a relatively low incidence of ovarian cancer. Genistein inhibits ovarian carcinogenesis by pleiotropic mechanisms. A higher affinity to estrogen receptor ß is one probable explanation for its ability to reduce the risk of ovarian cancer. Genistein also targets multiple cellular signal transduction pathways associated with cell cycle regulation and apoptosis. In addition, genistein has been suggested to have antiangiogenic and antioxidant activities. Herein, we summarize recent results from epidemiological and experimental studies to identify the role of genistein in ovarian cancer. Further studies are needed to achieve conclusive results and determine the clinical applications of genistein.

Treatment of stage IB2, IIA bulky cervical cancer: a single-institution experience of neoadjuvant chemotherapy followed by radical hysterectomy and primary radical hysterectomy.

INTRODUCTION: The aim of this study was to compare the efficacy and safety of neoadjuvant chemotherapy (NAC) followed by radical hysterectomy (NAC group) with primary radical hysterectomy (RH group). METHODS: We reviewed all patients with bulky stage IB-IIA cervical cancer treated at Seoul National University Hospital from January 1, 2000 to December 31, 2006. Thirty-three patients were treated with NAC prior to radical hysterectomy, and 41 patients were treated with radical hysterectomy. RESULTS: Clinical characteristics were not significantly different between the two groups. The response rate in the NAC group was 81.8%. Operation time, estimated blood loss, and complication rate were not significantly different between the two groups. Pathologic outcomes were improved in the NAC group. Adjuvant therapy was less frequently performed in the NAC group (51.6%) than in the RH group (82.9%) (P = 0.005). The 5-year progression-free survival was 90.7% in the NAC group and 81.3% in the RH group, but the difference was not statistically significant (P = 0.297). CONCLUSION: The results of this study suggest that NAC may improve pathologic outcomes, decrease the need for adjuvant radiation therapy and have a comparable operation feasibility without affecting progression-free survival.

Matched-case comparison for the efficacy of neoadjuvant chemotherapy before surgery in FIGO stage IB1-IIA cervical cancer.

OBJECTIVE: To evaluate whether neoadjuvant chemotherapy before surgery (NCS) is more efficient than primary surgical treatment (PST) for improving clinical outcomes in FIGO stage IB1-IIA cervical cancer. METHODS: We conducted a matched-case comparison where 61 patients treated with NCS were matched to 183 treated with PST. We compared intermediate- and high-risk factors, the need of adjuvant radiotherapy, disease recurrence and survivals between NCS and PST. Patients with ≥2 intermediate- or ≥1 high-risk factors received adjuvant concurrent chemoradiation using cisplatin-based chemotherapy. RESULTS: NCS reduced more definitely intermediate- and high-risk factors than PST in stage IIA disease in spite of little difference of them in stage IB disease (large tumor size, 25% vs. 52.4%; deep stromal invasion, 57.1% vs. 82.1%; lymphovascular space invasion, 35.7% vs. 65.5%; parametrial invasion, 17.9% vs. 41.7%; p<0.05). Moreover, ≥2 intermediate-risk factors were less common in NCS than PST despite no difference of the number of high-risk factors between the 2 treatments, which decreased the need of adjuvant radiotherapy in patients with stage IIA disease who received NCS (46.4% vs. 84.5%, p<0.01). Although there were no differences in progression-free survival and disease recurrence between the 2 treatments, NCS led to poorer overall survival than PST in stage IIA disease with no difference of it in stage IB disease. CONCLUSIONS: The efficacy between NCS and PST may be similar in FIGO stage IB cervical cancer. However, NCS can lead to poor prognosis despite the reduction of intermediate-risk factors and the need of adjuvant radiotherapy in FIGO stage IIA disease.

XRCC1 Arginine194Tryptophan and GGH-401Cytosine/Thymine polymorphisms are associated with response to platinum-based neoadjuvant chemotherapy in cervical cancer.

OBJECTIVE: The objective of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) of genes which are involved in DNA synthesis and repair with the response to platinum-based neoadjuvant chemotherapy (NAC) and disease-free survival (DFS) in patients with cervical cancer who were treated with NAC followed by radical hysterectomy. METHODS: A retrospective review was performed on 66 patients with cervical cancer who were treated with NAC followed by radical hysterectomy in our institute between January 1999 and February 2007. DNA was extracted from the paraffin-embedded, formalin-fixed tissue blocks of hysterectomy specimens. The genotypes of SNPs (MTHFR 677Cytosine/Thymine, XRCC1 Arginine194Tryptophan, GGH-401Cytosine/Thymine, and GSTP1 Isoleucine105Valine) were determined using a single base primer extension assay. The association of SNP genotypes with the response to NAC, which was measured by physical and colposcopic examinations, was evaluated. In addition, DFS based on SNP genotypes was examined. RESULTS: The genotypes of XRCC1 Arginine194Tryptophan and GGH-401Cytosine/Thymine were significantly associated with the response to NAC (P=0.023 for XRCC1 Arginine194Tryptophan; P=0.046 for GGH-401Cytosine/Thymine). However, the genotypes of MTHFR 677Cytosine/Thymine and GSTP1 Isoleucine105Valine were not associated with the response to NAC. In subgroup analysis with 39 patients who were treated with regimens containing 5-fluorouracil (5-FU), the genotypes of GGH-401Cytosine/Thymine were significantly associated with the response to NAC (P=0.039). In multifactor dimensionality reduction (MDR) analysis, the combination of XRCC1 Arginine194Tryptophan and GGH-401Cytosine/Thymine genotypes was associated with the response to NAC (P<0.001). However, no SNP genotypes were associated with DFS, but the cisplatin dose intensity of NAC was associated with DFS. CONCLUSIONS: The genotypes of XRCC1 Arginine194Tryptophan and GGH-401Cytosine/Thymine were associated with the response to NAC in patients with cervical cancer. However, no SNP genotypes were associated with DFS.

Predictive value of individualized tumor response testing by ATP-based chemotherapy response assay in ovarian cancer.

The aim of this study is to investigate the correlation between ATP-based chemotherapy response assay (ATP-CRA) results and clinical outcomes in ovarian cancer. Twenty-nine fresh tumor specimens were collected. Tumor cells were isolated and cultured for 48 hrs in medium containing anticancer drugs. The median age of patients was 56 years. The sensitivity, positive predictive value, and accuracy of ATP-CRA were respectively 94.1%, 94.1%, and 90.0%. There was a significant relationship between ATP-CRA results and clinical responses (p = 0.046). This study suggests that ATP-CRA has high sensitivity, positive predictive value, and accuracy for predicting response to chemotherapy in ovarian cancer.

Curcumin inhibits phorbol ester-induced expression of cyclooxygenase-2 in mouse skin through suppression of extracellular signal-regulated kinase activity and NF-kappaB activation.

Recently, there have been considerable efforts to search for naturally occurring substances for the intervention of carcinogenesis. Many components derived from dietary or medicinal plants have been found to possess substantial chemopreventive properties. Curcumin, a yellow coloring ingredient of turmeric (Curcuma longa L., Zingiberaceae), has been shown to inhibit experimental carcinogenesis and mutagenesis, but molecular mechanisms underlying its chemopreventive activities remain unclear. In the present work, we assessed the effects of curcumin on 12-O- tetradecanoylphorbol-13-acetate (TPA)-induced expression of cyclooxygenase-2 (COX-2) in female ICR mouse skin. Topical application of the dorsal skin of female ICR mice with 10 nmol TPA led to maximal induction of cox-2 mRNA and protein expression at approximately 1 and 4 h, respectively. When applied topically onto shaven backs of mice 30 min prior to TPA, curcumin inhibited the expression of COX-2 protein in a dose-related manner. Immunohistochemical analysis of TPA-treated mouse skin revealed enhanced expression of COX-2 localized primarily in epidermal layer, which was markedly suppressed by curcumin pre-treatment. Curcumin treatment attenuated TPA- stimulated NF-kappaB activation in mouse skin, which was associated with its blockade of degradation of the inhibitory protein IkappaBalpha and also of subsequent translocation of the p65 subunit to nucleus. TPA treatment resulted in rapid activation via phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein (MAP) kinases, which are upstream of NF-kappaB. The MEK1/2 inhibitor U0126 strongly inhibited NF-kappaB activation, while p38 inhibitor SB203580 failed to block TPA-induced NF-kappaB activation in mouse skin. Furthermore, U0126 blocked the IkappaBalpha phosphorylation by TPA, thereby blocking the nuclear translocation of NF-kappaB. Curcumin inhibited the catalytic activity of ERK1/2 in mouse skin. Taken together, suppression of COX-2 expression by inhibiting ERK activity and NF-kappaB activation may represent molecular mechanisms underlying previously reported antitumor promoting effects of this phytochemical in mouse skin tumorigenesis.