Anthocyanins from purple passion fruit (Passiflora edulia Sims) rind-An innovative source for nonbleachable pigment production.

Passion fruit rind is a waste product from the beverage industry that is rich in anthocyanins that can be potentially applied as a natural colorant. However, the inherent instability of anthocyanins causes rapid discoloration. In this study, the cyanidin-3-glucoside (C-3-G) in passion fruit rind was extracted using 50% ethanol and converted into nonbleachable pigments by reaction with Oolong tea extracts and acetaldehyde. Reactions over 70 days formed high concentrations of stable nonbleachable pigments (3.07-6.68 absorbance unit [A.U.], in total) such as pyranoanthocyanins, as well as oligomeric and polymeric pigments with ethyl-linked bridges. In C-3-G and acetaldehyde reaction, positive relations were found among acetaldehyde concentration, color density, and nonbleachable pigment concentrations. As for reactions with C-3-G and Oolong tea extract combined with acetaldehyde, greater color density and greater concentrations of nonbleachable pigments (10.80-12.34, 4.25-4.40 A.U., respectively) were formed compared with acetaldehyde alone. In addition, the antioxidant capabilities of the extracts were enhanced after reaction with Oolong tea extracts. The results of this study show a useful method to enhance the stability of anthocyanins from passion fruit rind and also provide greater economic value to this waste product. PRACTICAL APPLICATION: Ripened passion fruits contain a high concentration of anthocyanins in their rind. These anthocyanins can be optimally extracted by ultrasonic assisted solvent extraction to provide stable pigments by inducing acetaldehyde (a volatile compound often found in foods and beverages) into the anthocyanins. These stable pigments have a greater reddish hue in solution than the anthocyanin extracted from the rind and are more stable over a greater pH range. In addition, these stable pigments can be potentially used as colorant throughout the food and cosmetic industry to provide high economical values.

Virus-Like Fe3O4@Bi2S3 Nanozymes with Resistance-Free Apoptotic Hyperthermia-Augmented Nanozymitic Activity for Enhanced Synergetic Cancer Therapy.

Nanomaterials with intrinsic peroxidase-like activities are able to catalyze the oxidation of the substrate with the peroxide, which have been widely considered as artificial enzymatic agents in cancer therapy. However, current peroxidase catalytic oxidation treatments generating reactive oxygen species rely highly on hydrogen peroxide and pH, which limit greatly their therapeutic efficiency in the tumor microenvironment. Here, we report a strategy to construct the complex virus-like Fe3O4@Bi2S3 nanocatalysts (F-BS NCs) by connecting typical peroxidase Fe3O4 (MNPs) with a narrow band gap semiconductor Bi2S3 (BS) to enhance the enzymatic activity resorting to the limited intratumoral peroxide and efficient external photothermal stimuli. In this formulation, the integrated F-BS NCs induce cancer-cell death through mild photothermal treatment and sequential photothermal-stimulative catalysis of H2O2 into highly toxic •OH under 808 nm laser, which successfully realize a remarkable synergistic anticancer achievement.

Effect of Grape Seed and Skin Tannin Molecular Mass and Composition on the Rate of Reaction with Anthocyanin and Subsequent Formation of Polymeric Pigments in the Presence of Acetaldehyde.

Polymeric pigments formed via ethyl linkages between grape tannins and anthocyanins are important to the development of stable red wine color. To determine the effect of tannin structure on the stability and color properties of ethyl-linked polymeric pigments, tannin fractions with average polymerization between 4 and 43 units were prepared from grape skins and seeds and combined with malvidin-3-glucoside (M3G) in model wine containing acetaldehyde. As tannin molecular mass increased, the reaction rate with M3G increased. Compared with skin tannins of comparable molecular mass, seed tannins reacted more rapidly with M3G but were prone to precipitation. This resulted in a loss of polymeric pigments formed from seed tannins, which was greater as tannin molecular mass increased. Aggregation occurred following the reaction of seed tannin with M3G, concomitant with precipitation. The aggregation-precipitation phenomenon was not observed for skin tannin-derived pigments, indicating a greater stability in solution than those formed from seed tannins.

Large-Pore Mesoporous-Silica-Coated Upconversion Nanoparticles as Multifunctional Immunoadjuvants with Ultrahigh Photosensitizer and Antigen Loading Efficiency for Improved Cancer Photodynamic Immunotherapy.

Reported immunoadjuvants still have many limitations, such as inferior cellular uptake capacity and biocompatibility, overly large particle sizes, single function, and unsatisfactory therapeutic efficacy. Here, large-pore mesoporous-silica-coated upconversion nanoparticles (UCMSs) with a size of less than 100 nm are successfully prepared by a typical silica sol-gel reaction using mesitylene as a pore-swelling agent and are applied as a novel immunoadjuvant. The obtained UCMSs not only show significantly higher loadings for the photosensitizers merocyanine 540 (MC540), model proteins (chicken ovalbumin (OVA)), and tumor antigens (tumor cell fragment (TF)), but also are successfully employed for highly efficient in vivo vaccine delivery. The prepared UCMSs-MC540-OVA under 980 nm near-infrared irradiation shows the best synergistic immunopotentiation action, verified by the strongest Th1 and Th2 immune responses and the highest frequency of CD4+ , CD8+ , and effector-memory T cells. Additionally, nanovaccines UCMSs-MC540-TF can more effectively inhibit tumor growth and increase the survival of colon cancer (CT26)-tumor-bearing BALB/c mice compared with either photodynamic therapy or immunological therapy alone, suggesting the enhanced immunotherapy efficacy and clinical potential of UCMSs as immunoadjuvants for cancer immunotherapy.

20(s)-Protopanaxadiol (PPD) increases the radiotherapy sensitivity of laryngeal carcinoma.

Laryngeal carcinoma (LC) is one of the most prevalent malignant tumors in the head and neck area. Due to its high morbidity and mortality, LC poses a serious threat to human life and health. Even with surgical removal, some patients were not sensitive to radiotherapy or experienced transfer or recurrence. 20(s)-Protopanaxadiol (PPD), a natural product from Panax ginseng, has been reported to have cytotoxic effects against several cancer cell lines. However, whether it can improve the radiation sensitivity and the underlying mechanism of PPD's sensitization effect is still unknown. Herein, from in vitro and in vivo experiments, we found that the combination of PPD and radiation not only significantly inhibited proliferation and induced apoptosis, but also suppressed the tumor growth in mouse models. These findings confirmed the role of PPD in enhancing the sensitivity of radiotherapy. Moreover, our work showed that the expression levels of mTOR and its downstream effectors decreased remarkably after PPD addition when compared to radiation only. This result suggested that PPD's excellent synergistic effects with radiation might be associated with the down-regulation of the mTOR signaling pathway in Hep-2 cells.

Activation of neuronal Kv7/KCNQ/M-channels by the opener QO58-lysine and its anti-nociceptive effects on inflammatory pain in rodents.

AIM: The aim of this study was to examine the activation of neuronal Kv7/KCNQ channels by a novel modified Kv7 opener QO58-lysine and to test the anti-nociceptive effects of QO58-lysine on inflammatory pain in rodent models. METHODS: Assays including whole-cell patch clamp recordings, HPLC, and in vivo pain behavioral evaluations were employed. RESULTS: QO58-lysine caused instant activation of Kv7.2/7.3 currents, and increasing the dose of QO58-lysine resulted in a dose-dependent activation of Kv7.2/Kv7.3 currents with an EC50 of 1.2±0.2 µmol/L. QO58-lysine caused a leftward shift of the voltage-dependent activation of Kv7.2/Kv7.3 to a hyperpolarized potential at V1/2=-54.4±2.5 mV from V1/2=-26.0±0.6 mV. The half-life in plasma (t1/2) was derived as 2.9, 2.7, and 3.0 h for doses of 12.5, 25, and 50 mg/kg, respectively. The absolute bioavailabilities for the three doses (12.5, 25, and 50 mg/kg) of QO58-lysine (po) were determined as 13.7%, 24.3%, and 39.3%, respectively. QO58-lysine caused a concentration-dependent reduction in the licking times during phase II pain induced by the injection of formalin into the mouse hindpaw. In the Complete Freund's adjuvant (CFA)-induced inflammatory pain model in rats, oral or intraperitoneal administration of QO58-lysine resulted in a dose-dependent increase in the paw withdrawal threshold, and the anti-nociceptive effect on mechanical allodynia could be reversed by the channel-specific blocker XE991 (3 mg/kg). CONCLUSION: Taken together, our findings show that a modified QO58 compound (QO58-lysine) can specifically activate Kv7.2/7.3/M-channels. Oral or intraperitoneal administration of QO58-lysine, which has improved bioavailability and a half-life of approximately 3 h in plasma, can reverse inflammatory pain in rodent animal models.