An Update on the Use of Natural Pigments and Pigment Nanoparticle Adducts for Metal Detection Based on Colour Response.

Natural pigments occur in plants as secondary metabolites and have been used as safe colourants in food. Studies have reported that their unstable colour intensity might be related to metal ion interaction, which leads to the formation of metal-pigment complexes. This underlines the need for further investigations on the use of natural pigments in metal detection using colorimetric methods, since metals are important elements and can be hazardous when present in large amounts. This review aimed to discuss the use of natural pigments (mainly betalains, anthocyanins, curcuminoids, carotenoids, and chlorophyll) as reagents for portable metal detection based on their limits of detection, to determine which pigment is best for certain metals. Colorimetric-related articles over the last decade were gathered, including those involving methodological modifications, sensor developments, and a general overview. When considering sensitivity and portability, the results revealed that betalains are best applied for copper, using a smartphone-assisted sensor; curcuminoids are best applied for lead, using a curcumin nanofiber; and anthocyanin is best applied for mercury, using anthocyanin hydrogel. This provides a new perspective on the use of colour instability for the detection of metals with modern sensor developments. In addition, a coloured sheet representing metal concentrations may be useful as a standard to support on-site detection with trials on masking agents to improve selectivity.

Active Antialopecia Chemical Identification of Merremia peltata Leaves and Computational Study toward Androgen Receptor Using Molecular Docking and Molecular Dynamic Simulation.

Alopecia is a health condition in which the hair loses its function in some or all of the body. Alopecia occurs due to various genetic, environmental, and nutritional factors. One of the methods developed to treat alopecia is through inhibition of the enzyme 5-α-reductase, which converts testosterone into its more potent metabolite, dihydrotestosterone (DHT). In ethnomedicine, the leaves of Merremia peltata are used by the people of Sulawesi as a remedy for baldness. Therefore, in this study, an in vivo study was conducted on rabbits to investigate the antialopecia activity of the ethanolic extract of M. peltata leaves. The purified M. peltata leaf extract was fractionated using vacuum liquid chromatography with several solvents to produce fractions F1-F5. Each fraction was then retested in vivo in rabbits, and its content was then analyzed by LC-MS. An in silico study was then carried out using minoxidil as a comparison ligand; 17 compounds derived from M. peltata leaves were identified as antialopecia compounds through prediction of molecular interactions and molecular dynamics simulation and prediction of absorption, distribution, metabolism, excretion, and toxicology (ADME-Tox). The assay results showed that fractions F2 and F3 had a better effect on hair growth compared to the positive control, and the test compound obtained from the LC-MS analysis, bufotalinin, had a strong binding energy to the receptor in the molecular docking interaction study: -5.99 kcal/mol compared to -4.8 kcal/mol for minoxidil. Molecular dynamics simulation analysis with complex stability parameters based on solvent-accessible surface area (SASA), principal component analysis (PCA), root mean square deviation (RMSD), and root mean square fluctuation (RMSF) showed that bufotalinin has good affinity for androgen receptors. ADME-Tox prediction for bufotalinin showed good results for the parameters of skin permeability, absorption, and distribution. Therefore, bufotalinin, a steroid compound, is a potential androgen receptor antagonist and could be useful in the treatment of alopecia.

Kahar Method: A Novel Calculation Method of Tonicity Adjustment.

BACKGROUND: Hypertonic and hypotonic conditions in pharmaceutical preparations decrease the drug's absorption and bioavailability. In addition, it can cause tissue damage. There are several calculation methods to regulate hypotonic preparations. However, there are no methods that can be used to regulate hypertonic preparations without causing dose-dividing problem. OBJECTIVE: This study aimed to develop a new calculation using basic principle of freezing point depression method (cryoscopic) that can solve hypotonic and hypertonic problems, especially for hypertonic preparations through reducing the levels of additional ingredients. METHODS: The calculation of Kahar method was successfully obtained by substitution and simplification in the basic principle equation of cryoscopic method, and then evaluated by resolving the problems in 42 sterile formula preparations and compared with White-Vincent method, cryoscopic method, equivalent NaCl method, and milliequivalent method through the analysis of its similarity and reliability. RESULTS: The results of similarity analysis between Kahar method and other methods showed good similarity values with more than 0.880. Kahar method and cryoscopic method have the highest similarity of the calculation result with a similarity value of 1. The reliability analysis obtained very good result with Cronbach α = 0.990. CONCLUSIONS: These results suggest that Kahar method provides reliable equation with complete and efficient solution to hypotonic and hypertonic problems.

Lactobacillus plantarum IS-10506 probiotic administration increases amlodipine absorption in a rabbit model.

OBJECTIVE: Probiotics are beneficial in human health. In this study, we investigated the effect of probiotics on absorption of amlodipine, a dihydropyridine calcium antagonist used in the treatment of angina and hypertension, in a rabbit model. METHODS: Lactobacillus plantarum IS-10506 probiotic was administered for 14 days to male New Zealand rabbits. Blood samples were collected before and after probiotic supplementation. Amlodipine (10 mg) was then administered to all groups. Blood samples from a marginal vein were withdrawn at 5, 15, 30, 60, and 120 minutes to determine amlodipine concentrations in rabbit plasma. RESULTS: Amlodipine concentrations in the L. plantarum IS-10506 group were 4.95 ± 1.22, 8.71 ± 0.69, and 12.48 ± 2.53 ng/ml, and those in the control group were 1.69 ± 0.31, 3.89 ± 1.23, and 7.17 ± 1.85 ng/ml at 30, 60, and 120 minutes, respectively after administration of amlodipine. Amlodipine concentrations in the L. plantarum IS-10506 group were significantly higher than those in the control group at 30, 60, and 120 minutes after amlodipine administration. CONCLUSION: Our results suggested that supplementation of L. plantarum IS-10506 significantly increases amlodipine plasma concentrations in rabbits.