FTY720 increases paclitaxel efficacy in cisplatin-resistant oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma has high recurrence and cisplatin resistance. As cancer stem cells, autophagy, and sphingolipids have been appointed as associated with chemotherapy resistance, we tested combined treatments targeting autophagy and/or sphingolipid metabolism with paclitaxel using cisplatin-resistant oral squamous cell carcinoma cells. METHODS: Cisplatin-resistant oral squamous cell carcinoma cells were maintained under exposition to FTY720 and chloroquine combined with paclitaxel and submitted to viability, clonogenicity, and spheres formation assays. The xenograft tumor model using cisplatin-resistant CAL27 cells was adopted to examine the drug combinations' potential antitumoral efficacy. Using an animal model, sphingolipids profiles from plasma and tissue samples were obtained by liquid chromatography coupled to mass spectrometry to identify potential lipids associated with drug response. RESULTS AND DISCUSSION: Our results showed higher autophagic flux in cisplatin-resistant Ooral squamous cell carcinoma (CAL27 and SCC9) cells than in parental cells. The combinations of an autophagy inhibitor (chloroquine) or an autophagy inducer/sphingosine kinase 1 antagonist (FTY720) with paclitaxel (PTX) had a synergistic antitumor effect. Treated CisR cells lost clonogenicity and tumor sphere abilities and reduced proteins associated with proliferation, survival, and cancer stem cells. FTY720 plus PTX had higher antitumor efficacy than PTX against CAL27 CisR xenograft tumor formation. Additionally, increases in glucosylceramide, dehydroglucosylceramide, and sphingomyelin were presented in responsive tumors. CONCLUSION: FTY720 sensitizes cisplatin-resistant oral squamous cell carcinoma cells for paclitaxel.

Topical gel containing phenolic-rich extract from Ipomoea pes-capre leaf (Convolvulaceae) has anti-inflammatory, wound healing, and antiophidic properties.

The growing use of phytotherapy in clinical practice arouses interest in studies using medicinal plants as active ingredients for new medicines. Ipomoea pes-caprae has a wide medicinal use in the treatment of inflammatory disorders, skin wounds, stings, and painful rheumatic processes. Assayed in this study are the physicochemical characterization of a gel developed with this extract and the evaluation of its anti-inflammatory and healing efficacy, in addition to its antiedematogenic action on Bothrops snake envenoming in mice. The qualitative and quantitative analyses of the hydroethanolic extract by mass spectrometry showed 18 phenolic compounds, highlighting a high content of chlorogenic acid (0.92 µg/g), neochlorogenic acid (6.07 µg/g), and isochlorogenic acid (0.80 µg/g) compounds. The formulation was stable in relation to the physical-chemical characteristics during the time of analysis and was considered safe for topical treatment in animals, causing no skin irritation. Although the results have shown an absence of activity in the model of ear edema induced by croton oil (acute inflammation), the herbal gel efficiently inhibited carrageenan paw edema and chronic ear edema induced by multiple applications of croton oil, which may indicate the possible performance under the kinin pathway such as bradykinin, histamine, and serotonin. Wound healing in the group treated with the I. pes-caprae gel was accelerated compared with the placebo group, also confirmed through histological data. Edema induced by Bothrops erythromelas snake venom was efficiently reduced in the treatment with I. pes-caprae gel associated with the antibothropic-crotalic serum, whereas the antivenom alone was not effective. This approach presents a promising formulation based on I. pes-caprae with potential therapeutic use for inflammatory disorders.

In vitro-in vivo availability of metformin hydrochloride-PLGA nanoparticles in diabetic rats in a periodontal disease experimental model.

CONTEXT: Metformin is an important oral anti-hyperglycemic used in diabetes. Polylactic-co-glycolic acid (PLGA) has been widely used due to its reliability in controlling the release of drugs. OBJECTIVE: This study evaluates the in vitro-in vivo availability of metformin hydrochloride-loaded polylactic-co-glycolic acid. MATERIAL AND METHODS: In vitro metformin release (Met-free or PLGA + Met-12.5 mg/mL per 360 min) was evaluated using static Franz vertical diffusion cells. The in vivo study was performed with two control groups (validation bioanalytical method) and two experimental groups of diabetic male Wistar rats treated with PLGA + Met 10 mg/kg or Met 100 mg/kg by oral gavage. Diabetes was induced by streptozotocin (40 mg/kg) through the penile vein. Blood samples were collected 0.5, 1, 4, 7, 10, 12, 18, 24, 36, 48 and 72 h and analysed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). RESULTS: PLGA + Met 10 mg/kg was released in the in vitro assay suggesting a parabolic diffusion kinetic model (K -0.0619-0.5h) with a 100% release profile in 10 h by controlled diffusion. The in vivo assay showed the apparent volume of distribution Vz/F (PLGA + Met 10 mg/kg, 40971.8 mL/kg vs. Met 100 mg/kg, 2174.58 mL/kg) and mean residence time MRTinf (PLGA + Met 10 mg/kg, 37.66 h vs. Met 100 mg/kg, 3.34 h). DISCUSSION AND CONCLUSIONS: The formulation modifies pharmacokinetics parameters such as apparent distribution volume and mean residence time. The PLGA + Met 10 mg/kg had a slower elimination rate compared to Met 100 mg/kg in diabetic rats in a periodontal disease experimental model.

Hypoglycemic and Vasorelaxant Effect of Passiflora edulis Fruit Peel By-Product.

Passiflora edulis fo. flavicarpa (Passifloraceae) is popularly known as yellow passion fruit and its fruit peels are considered a rich by-product in bioactive compounds which has greatly beneficial health properties. The objective of this study was to evaluate the effects of P. edulis fruit peel extracts in a type 1 diabetes model and the potential vasorelaxant effect. The aqueous and hydroethanolic extracts were obtained from P. edulis fruit peels and orientin and isorientin flavonoids were identified in both extracts through ultra-high performance liquid chromatography. Pectin was only identified in the aqueous extract by high-performance steric exclusion chromatography and nuclear magnetic resonance. Regarding the vascular system, the hydroethanolic extract showed better vasorelaxant effects in the mesenteric artery rings when compared to the aqueous extract. These effects mainly occur by opening the potassium channels. In the type 1 diabetes model, extracts at doses of 400 and 600 mg/kg were able to restore the effect of insulin in diabetic rats which were not responding to its action. The antidiabetic effect was more significant for the aqueous extract. Thus, the results suggest that the hydroethanolic and aqueous extracts have greater potential to be used to treat cardiovascular diseases such as hypertension and as a hypoglycemic agent, respectively. Taken together, P. edulis fruit peel extracts proved to be a source of valuable bioactive raw material to produce nutraceuticals or pharmaceutical products.

In Vivo Antidepressant Effect of Passiflora edulis f. flavicarpa into Cationic Nanoparticles: Improving Bioactivity and Safety.

A variety of neuroactive flavonoids can be found in the species of the Passiflora genus; however, their difficulty in crossing the blood-brain barrier limits their in vivo neuropharmacological activity. In this study, cationic nanoparticles were developed as a novel nanocarrier for improving the antidepressant activity of Passiflora edulis f. flavicarpa leaf extract. Formulations obtained using Eudragit E PO polymethylmethacrylate copolymer, as polymeric matrix had their physicochemical properties investigated. The analytical content of the flavonoids vicenin-2, orientin, isoorientin, vitexin, and isovitexin was determined in the plant extract. Small-sized and spherical nanoparticles loaded with Passiflora edulis f. flavicarpa were obtained with positive zeta potential and high encapsulation efficiency. In addition, the nanosystems were shown to be stable for at least 6 months. The antidepressant activity of P. edulis extract (50 and 100 mg/kg) as well as the extract-loaded nanoparticles (5 mg/kg) were investigated in mice using the forced swimming test, where the latter increased the potency of the former by 10-fold. In addition, histopathological and biochemical analysis confirmed the biocompatibility of the extract-loaded nanoparticles. This study demonstrated that the Eudragit cationic nanoparticles were able to improve the antidepressant activity of P. edulis in the central nervous system of mice.

Isolation and Identification of the Five Novel Flavonoids from Genipa americana Leaves.

Genipa americana is a medicinal plant popularly known as "jenipapo", which occurs in Brazil and belongs to the Rubiaceae family. It is a species widely distributed in the tropical Central and South America, especially in the Cerrado biome. Their leaves and fruits are used as food and popularly in folk medicine to treat anemias, as an antidiarrheal, and anti-syphilitic. Iridoids are the main secondary metabolites described from G. americana, but few studies have been conducted with their leaves. In this study, the aim was to chemical approach for identify the main compounds present at the extract of G. americana leaves. The powdered leaves were extracted by maceration with EtOH: water (70:30, v/v), following liquid-liquid partition with petroleum ether, chloroform, ethyl acetate and n-butanol. A total of 13 compounds were identified. In addition three flavonoids were isolated from the ethyl acetate fraction: quercetin-3-O-robinoside (GAF 1), kaempferol-3-O-robinoside (GAF 2) and isorhamnetin-3-O-robinoside (GAF 3) and, from n-butanol fraction more two flavonoids were isolated, kaempferol-3-O-robinoside-7-O-rhamnoside (robinin) (GAF 4) and isorhamnetin-3-O-robinoside-7-rhamnoside (GAF 5). Chemical structures of these five flavonoids were elucidated using spectroscopic methods (MS, ¹H and 13C-NMR 1D and 2D). These flavonoids glycosides were described for the first time in G. americana.

Phytochemical Analysis by HPLC-HRESI-MS and Anti-Inflammatory Activity of Tabernaemontana catharinensis.

Tabernaemontana catharinensis (Apocynaceae) has been popularly used by folk medicine because of its anti-inflammatory, analgesic, and antiophidic properties. This study aims to analyze the flavonoids composition of the hydroethanolic extract and of the ethyl acetate (EtOAc) and butanol (BuOH) fractions of T. catharinensis leaves, as well as to evaluate their anti-inflammatory activity using in vivo models. The phytochemical profile, determined by High-Performance Liquid Chromatography-High-Resolution Electrospray Ionization-Mass Spectrometry (HPLC-HRESI-MS), showed the presence of flavonoids mainly having an isorhamnetin nucleus. The anti-inflammatory activity was evaluated in carrageenan-induced paw edema (pre- and post-treatment) with oral administration of a T. catharinensis hydroethanolic extract (50, 100, and 150 mg/kg) and of organic fractions (50 mg/kg). The extract and fractions showed antiedematogenic activity by decreasing myeloperoxidase (MPO) production. In the zymosan-air-pouch model, the extract and fractions inhibited leukocyte migration and significantly decreased the levels of various proteins, such as MPO, interleukin (IL)-1ß, and tumor necrosis factor (TNF)-α. The cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed no cytotoxicity of the extract and the fractions. These results suggest that the hydroethanolic extract and organic fractions of T. catharinensis leaves have sufficient anti-inflammatory activity to support the popular use of this plant in the treatment of inflammatory disorders.