Bupivacaine in combination with sildenafil (Viagra) and vitamin D3 have anti-inflammatory effects in osteoarthritic chondrocytes

Abstract

Aims To treat osteoarthritic chondrocytes and thereby reduce the inflammation with a drug combination that primarily affects 5-HT- and ATP-evoked Ca 2+ signaling. In osteoarthritic chondrocytes, Ca 2+ signaling is elevated, resulting in increased production of ATP and inflammatory mediators. The expression of TLR4 and Na + /K + -ATPase was used to evaluate the inflammatory status of the cells. Main methods Equine chondrocytes were collected from joints with mild structural osteoarthritic changes and cultured in monolayers. The cells were treated with a combination of bupivacaine (1 pM) and sildenafil (1 ​μM) in combination with vitamin D3 (100 ​nM). A high-throughput screening system, the Flexstation 3 microplate reader, was used to measure intra- and extracellular Ca 2+ signaling after exposure to 5-HT, glutamate, or ATP. Expression of inflammatory receptors was assessed by Western blotting. Key findings Drug treatment substantially reduced 5-HT- and ATP-evoked intracellular Ca 2+ release and TLR4 expression compared to those in untreated chondrocytes. The combination of sildenafil, vitamin D3 together with metformin, as the ability to take up glucose is limited, increased Na + /K + -ATPase expression. Significance The combination of these three therapeutic substances at concentrations much lower than usually used, reduced expression of the inflammatory receptor TLR4 and increased the cell membrane enzyme Na + /K + -ATPase, which regulates cell volume and reduces increased intracellular Ca 2+ concentrations. These remarkable results indicate that this drug combination has disease-modifying osteoarthritis drug (DMOAD) properties and may be a new clinical therapy for osteoarthritis (OA).

A randomized, triple-blinded controlled clinical study with a novel disease-modifying drug combination in equine lameness-associated osteoarthritis

“…In addition, we found low concentrations of bupivacaine decreased the inflammation-induced interleukin-1β (IL-1 β ) release in astrocytes [ 39 ]. The same results were seen in OA chondrocytes [ 14 ]. These results support the anti-inflammatory properties of bupivacaine in low concentrations.…”

“…The TC drug primarily acts by restoring cell-to-cell signalling which is essentially impaired in OA. Studying basic cellular mechanisms, which is mostly similar in many inflamed cell types (chondrocytes, fibroblast and astrocytes) has been crucial in understanding how different drugs can restore the derailed cellular networks [ 14 , [25] , [26] , [27] , [28] ]. Gap junction-coupled cells forming networks in different organs in the body are another focus point [ 29 , 30 ].…”

“…Our proof of concept preclinical research has identified that low concentrations of sildenafil and mepivacaine, when combined with glucose, target basic cellular mechanisms by affecting the inflammatory system [ 13 ]. A patented combination of these three substances addressed as treatment combination (TC) in this study exerted an anti-inflammatory effect while restoring Ca 2+ signalling in gap junction coupled cells [ 13 , 14 ]. We speculate the effect exerted by low concentrations of sildenafil and mepivacaine for OA treatment in vivo differs from their normal pharmacological effect.…”

Role of hydrogels in osteoarthritis: A comprehensive review

“…31 Bupivacaine combined with vitamin D3 is anti-inflammatory in osteoarthritic chondrocytes by reducing concentrations of toll-like receptor 4 (TLR4), increasing the cell membrane enzyme Na + /K + -ATPase, and maintaining cell volume. 62 Intra-articular administrating hydrogel containing bupivacaine on OA rats decreased weight load and paw withdrawal threshold. 48 Rapamycin is promising in OA amelioration by elevating autophagy, preventing senescence, and sustaining sulfated glycosaminoglycan generation in primary articular chondrocytes.…”

“…Surgery‐induced OA mice administrated simvastatin‐conjugated gelatin hydrogel will attenuate OA progression, including reduced levels of IL‐1β, MMP‐13, elevated levels of collagen II, and an autophagic marker called light chain 3 (LC3) in the articular cartilage 31 . Bupivacaine combined with vitamin D3 is anti‐inflammatory in osteoarthritic chondrocytes by reducing concentrations of toll‐like receptor 4 (TLR4), increasing the cell membrane enzyme Na + /K + ‐ATPase, and maintaining cell volume 62 . Intra‐articular administrating hydrogel containing bupivacaine on OA rats decreased weight load and paw withdrawal threshold 48 .…”