Biomineralization of calcium carbonate in the cell wall of Lithothamnion crispatum (Hapalidiales, Rhodophyta): correlation between the organic matrix and the mineral phase

Disease-Modifying Adjunctive Therapy (DMAT) in Osteoarthritis-The Biological Effects of a Multi-Mineral Complex, LithoLexal® Joint-A Review

Modern advances in molecular medicine have led to the reframing of osteoarthritis as a metabolically active, inflammatory disorder with local and systemic contributing factors. According to the ‘inflammatory theory’ of osteoarthritis, immune response to an initial damage is the key trigger that leads to progressive joint destruction. Several intertwined pathways are known to induce and govern articular inflammation, cartilage matrix degradation, and subchondral bone changes. Effective treatments capable of halting or delaying the progression of osteoarthritis remain elusive. As a result, supplements such as glucosamine and chondroitin sulphate are commonly used despite the lack of scientific consensus. A novel option for adjunctive therapy of osteoarthritis is LithoLexal^® Joint, a marine-derived, mineral-rich extract, that exhibited significant efficacy in clinical trials. LithoLexal^® has a lattice microstructure containing a combination of bioactive rare minerals. Mechanistic research suggests that this novel treatment possesses various potential disease-modifying properties, such as suppression of nuclear factor kappa-B, interleukin 1β, tumor necrosis factor α, and cyclooxygenase-2. Accordingly, LithoLexal^® Joint can be considered a disease-modifying adjunctive therapy (DMAT). LithoLexal^® Joint monotherapy in patients with knee osteoarthritis has significantly improved symptoms and walking ability with higher efficacy than glucosamine. Preliminary evidence also suggests that LithoLexal^® Joint may allow clinicians to reduce the dose of nonsteroidal anti-inflammatory drugs in osteoarthritic patients by up to 50%. In conclusion, the multi-mineral complex, LithoLexal^® Joint, appears to be a promising candidate for DMAT of osteoarthritis, which may narrow the existing gap in clinical practice.

Coralline algal calcification: A morphological and process-based understanding

Research purpose and findings

Coralline algae are key biological substrates of many carbonate systems globally. Their capacity to build enduring crusts that underpin the formation of tropical reefs, rhodolith beds and other benthic substrate is dependent on the formation of a calcified thallus. However, this important process of skeletal carbonate formation is not well understood. We undertook a study of cellular carbonate features to develop a model for calcification. We describe two types of cell wall calcification; 1) calcified primary cell wall (PCW) in the thin-walled elongate cells such as central medullary cells in articulated corallines and hypothallial cells in crustose coralline algae (CCA), 2) calcified secondary cell wall (SCW) with radial Mg-calcite crystals in thicker-walled rounded cortical cells of articulated corallines and perithallial cells of CCA. The distinctive banding found in many rhodoliths is the regular transition from PCW-only cells to SCW cells. Within the cell walls there can be bands of elevated Mg with Mg content of a few mol% higher than radial Mg-calcite (M-type), ranging up to dolomite composition (D-type).

Model for calcification

We propose the following three-step model for calcification. 1) A thin (< 0.5 μm) PCW forms and is filled with a mineralising fluid of organic compounds and seawater. Nanometer-scale Mg-calcite grains precipitate on the organic structures within the PCW. 2) Crystalline cellulose microfibrils (CMF) are extruded perpendicularly from the cellulose synthase complexes (CSC) in the plasmalemma to form the SCW. 3) The CMF soaks in the mineralising fluid as it extrudes and becomes calcified, retaining the perpendicular form, thus building the radial calcite. In Clathromorphum, SCW formation lags PCW creating a zone of weakness resulting in a split in the sub-surface crust. All calcification seems likely to be a bioinduced rather than controlled process. These findings are a substantial step forward in understanding how corallines calcify.