In vitro inhibitory effects on free radicals, pigmentation, and skin cancer cell proliferation from Dendrobium hybrid extract: A new plant source of active compounds.

Orchidaceae are diverse plants whose bioactive compounds have various biological activities. New hybrids of Dendrobium have been generated to gain characteristics shared with their ancestors. Dendrobium Pearl Vera (designated as DH) is derived from parents used for dermatological treatments and cosmetics. However, the phytoconstituents and biological properties of DH have not been reported. The current study investigated extracts from DH plants using four solvents (water, methanol, ethanol, or 2-propanol). The propanolic extract (DH-P) contained the highest phenolic and flavonoid contents, along with a high scavenging performance for free radicals. In total, 25 tentative constituents in the DH-P matrix were identified, consisting of amino acids, nucleotides, and three types of secondary metabolites: furan, phenolics, and alkaloids. The DH-P inhibited human tyrosinase in vitro in a concentration-dependent manner of the phenolic content. Furthermore, there was no significant difference between DH-P with 10 µg/ml phenolic content and 0.75 mM kojic acid (a commercial whitening agent) on the inhibition of human tyrosinase. Incubation with DH-P containing at least 15 µg/ml phenolic content greatly inhibited the proliferation of human melanoma; however, the cell viability was not affected by the phenolic content at 5 µg/ml or less. The half-maximal inhibitory concentration (IC50) of the phenolic content in DH-P on melanoma viability was 12.90 ± 1.04 µg/ml. Melanin production in vivo by human melanoma incubated with 5 µg/ml phenolic content in DH-P was reduced significantly, compared to 2.5 µg/ml phenolic content in DH-P, 100 µg/ml arbutin, and in control. The identified components, including 5-hydroxymethyl-2-furaldehyde, salicylic acid, nicotinamide, acetophenone, cytidine, adenosine, proline, or valine, have been reported to be associated with depigmentation, antioxidant, and anticancer. This research revealed, for the first time, the tentative phytoconstituents of Dendrobium Pearl Vera and their biological activities, thus demonstrating the potential use of DH-P in dermal applications.

Selection, alkaline phosphatase fusion, and application of single-chain variable fragment (scFv) specific to NT-proBNP as electrochemical immunosensor for heart failure.

Heart failure has a high global prevalence, with symptoms such as breathlessness, fatigue, and swelling. Early detection is crucial, as the condition worsens over time and can be fatal. This study identified the single-chain variable fragment (scFv) that specifically binds to the heart failure biomarker N-terminal pro B-type natriuretic peptide (NT-proBNP) using biopanning techniques for the development of an alternative diagnostic tool. Ten clones were identified that bound to the target peptide, with two clones (scFv-16 and scFv-36) selected for further analysis. Soluble scFv-16 and scFv-36 were produced and fused with alkaline phosphatase (AP) for potential applications. The binding efficiency and specificity levels of scFv to natriuretic peptides were evaluated using surface plasmon resonance (SPR) analysis. The values of the dissociation constant (KD) for NT-proBNP of scFv-16, scFv-36, scFv-16-AP, and scFv-36-AP were in the range 3.72 × 10-7-3.42 × 10-8 M with high specificity. All constructed scFvs had specificity to NT-proBNP, while not binding to A-type (ANP) and C-type (CNP) natriuretic peptides. When AP was combined, the scFv had a slightly higher yield of expression. The enzyme activity of scFv-36-AP was observed first by the absorption at 405 nm at a minimum of 44 nM and then by the naked eye at a minimum of 88 nM. Additionally, the potential application of NT-proBNP binding scFv was preliminarily investigated using an electrochemical technique to directly detect NT-proBNP in phosphate buffer saline. The results revealed the limit of detection at 69.09 pg/mL, which was less than the cutoff value (150 pg/mL) to discharge patients or healthy people. These findings provided promising biomolecules for the development of a reliable and sensitive diagnostic tool for heart failure.

Comparative Proteomic Profiling of Cisplatin-resistant Nasopharyngeal Carcinoma Cell Lines: Novel Biomarkers for Improving Chemotherapy of NPC.

BACKGROUND/AIM: Nasopharyngeal carcinoma (NPC) originates in the hidden nasopharynx, causing NPC patients to be diagnosed at a late stage and develop drug resistance. Therefore, the identification of drug-resistance biomarkers is indispensable to improve NPC detection and treatment. Hence, this study aimed to identify novel cisplatinresistance biomarkers using comparative proteomic profiles of cisplatin-resistant (CDDP/NPC) cell lines. MATERIALS AND METHODS: Two cisplatin-resistant NPC cell lines (CDDP/5-8F and CDDP/6-10B) were established by a continuous cisplatin treatment. Then, morphology, proliferation, and migration of all NPC cells were evaluated, followed by the examination of protein profiles using 1D in-gel digestion coupled with mass spectrometry. The potential drugresistance biomarkers were transcriptionally and translationally validated by qPCR and western blotting, respectively. RESULTS: CDDP/5-8F and CDDP/6-10B cells were successfully developed with a resistance index of 8.42 and 2.46, respectively. Furthermore, both CDDP/NPC cells demonstrated relatively altered morphology, retarded growth, and decreased migration. Additionally, the comparative proteomic analysis of CDDP/NPC revealed 92 differentially expressed proteins (DEPs). Specifically, up-regulated DEPs were notably enriched in cellular metabolic processes, while down-regulated DEPs were predominantly enriched in actin filament-based movement, methylation, and programmed cell death. Six up-regulated, namely ALPI, CKB, HMGB1, KHSRP, PDIA4, and STMN1, and three down-regulated proteins, FUBP1, YWHAZ, and PLEC, were validated at the transcriptional level. CKB and FUBP1 were further validated at the translational level and demonstrated corresponding expression levels at both protein and gene levels. CONCLUSION: Our findings suggest novel biomarkers to indicate cisplatin resistance in NPC, expanding the drug resistance knowledge and paving the way for in-depth mechanism studies in NPC.

Biosensors for the detection of organophosphate exposure by a new diethyl thiophosphate-specific aptamer.

OBJECTIVE: An aptamer specifically binding to diethyl thiophosphate (DETP) was constructed and incorporated in an optical sensor and electrochemical techniques to enable the specific measurement of DETP as a metabolite and a biomarker of organophosphate exposure. RESULTS: A DETP-bound aptamer was selected from the library using capillary electrophoresis-systematic evolution of ligands by exponential enrichment (CE-SELEX). A colorimetric method revealed that the aptamer had the highest affinity for DETP, with a mean Kd value (± SD) of 0.103 ± 0.014 µM. The docking results and changes in resistance showed that the selectivity of the aptamer for DETP was higher than that for the similar structures of dithiophosphate (DEDTP) and diethyl phosphate (DEP). The altered amplitude of cyclic voltammetry showed a linear range of DETP detection covering 0.0001-10 µg/ml with a limit of detection of 0.007 µg/ml. The recovery value of a real sample of pH 7 was 97.2%. CONCLUSIONS: The current method showed great promise in using the DETP-specific aptamer to detect the exposure history to organophosphates by measuring their metabolites, although degradation of organophosphate parent compounds might occur.