In vitro evaluation of calcium oxalate monohydrate crystals influenced by Costus igneus aqueous extract

Investigations on melamine-based uric acid kidney stone formation and its prevention by inhibitors

Melamine (Mel) as a milk powder adulterant came to light in September 2008, when a kidney stone disease (KSD) outbreak struck China. The mechanism of the formation of Mel-associated uric acid (UA) stones is relatively unknown. Therefore, in the present study, Mel's influence was explored at comparatively higher and lower concentrations in artificial urine. The parameter optimization performed when the Mel concentration in artificial urine was low, which revealed that higher pH values and lower UA concentration considerably delayed the induction of UA crystallization. When Mel concentration was increased relative to UA concentration, the induction time of UA crystallization decreased dramatically. At the highest concentration of Mel investigated (at UA-Mel molar ratio 1:1), PXRD analysis and SEM revealed a change in crystalline structure of the samples. Based on FTIR analysis, it was determined that UA-Mel interactions are essentially physical, because no new characteristic bands developed. Two inhibitors, namely tri-potassium citrate (TPC) and 3, 7-dimethylxanthine (DMX), were investigated for their inhibitory action on UA crystallization in the presence of Mel. DMX was observed to be more promising than TPC in delaying the induction of crystallisation and hence inhibiting crystal formation.

Insights into the structure and composition of mineralized hard cocoons constructed by the oriental moth, Monema (Cnidocampa) flavescens Walker

Animals widely use minerals and organic components to construct biomaterials with excellent properties, such as teeth, bones, molluscan shells and eggshells. The larvae of the oriental moth, Monema (Cnidocampa) flavescens Walker, secrete silk proteins that combine closely with calcareous minerals to construct a hard cocoon, which is completely different from the mineral-free Bombyx mori cocoon. The cocoons of oriental moths are likely to be the hardest among the cocoons constructed by insect species. The cocoons of oriental moths were found to be mainly composed of calcium oxalates and Asx/Ser/Gly-rich cocoon proteins, but the types of calcium oxalates and cocoon proteins remain to be elucidated. In this study, we provide an in-depth explanation of the inorganic and organic components in the oriental moth cocoon. Microscopy and imaging technologies revealed that the cocoon is composed of mineral crystals, silk fibers and other organic matter. X-ray diffraction and infrared spectral analyses showed that the mineral crystals in the oriental moth cocoon were mainly CaC₂H₂O₄·H₂O. ICP-OES analysis suggested that the mineral crystals in the cocoons were mainly CaC₂H₂O₄·H₂O. LC-MS/MS-based proteomics allowed us to identify 467 proteins from the oriental moth cocoon, including 252 uncharacterized proteins, 87 enzymes, 36 small molecule binding proteins, and 5 silk proteins. Among the uncharacterized proteins, 25 of which were Asn-rich proteins because they contained a high proportion of Asn residues (19.1%-41.4%). Among the top 20 cocoon proteins with the highest abundance, 9 of which were Asn-rich proteins. The qPCR was used to investigate the expression patterns of the major cocoon protein-coding genes. Three fibroins and three Asn-rich proteins were expressed only in the silk gland but not in other tissues. The expression of Asn-rich proteins in the silk gland gradually increased from the anterior silk gland to the posterior silk gland. These findings provide important references for understanding the formation mechanism and mechanical properties of mineralized hard cocoons constructed by oriental moths.

Plants Used in Mexican Traditional Medicine for the Management of Urolithiasis: A Review of Preclinical Evidence, Bioactive Compounds, and Molecular Mechanisms

Urolithiasis (UL) involves the formation of stones in different parts of the urinary tract. UL is a health problem, and its prevalence has increased considerably in developing countries. Several regions use plants in traditional medicine as an alternative in the treatment or prevention of UL. Mexico has known about the role of traditional medicine in the management of urinary stones. Mexican traditional medicine uses plants such as Argemone mexicana L., Berberis trifoliata Hartw. ex Lindl., Costus mexicanus Liebm, Chenopodium album L., Ammi visnaga (L.) Lam., Eysenhardtia polystachya (Ortega) Sarg., Selaginella lepidophylla (Hook. & Grev.) Spring, and Taraxacum officinale L. These plants contain different bioactive compounds, including polyphenols, flavonoids, phytosterols, saponins, furanochromones, alkaloids, and terpenoids, which could be effective in preventing the process of stone formation. Evidence suggests that their beneficial effects might be associated with litholytic, antispasmodic, and diuretic activities, as well as an inhibitory effect on crystallization, nucleation, and aggregation of crystals. The molecular mechanisms involving these effects could be related to antioxidant, anti-inflammatory, and antimicrobial properties. Thus, the review aims to summarize the preclinical evidence, bioactive compounds, and molecular mechanisms of the plants used in Mexican traditional medicine for the management of UL.