In degenerative joint disease like osteoarthritis (OA), bioactive compounds like resveratrol, epigallocatechin gallate, curcumin, and other polyphenols often target various signalling pathways, including NFκB, TGFβ, and Wnt/β-catenin by executing epigenetic-modifying activities. Epigenetic modulation can target genes of disease pathophysiology via histone modification, promoter DNA methylation, and non-coding RNA expression, some of which are directly involved in OA but have been less explored. OA patients often seek options that can improve the quality of their life in addition to existing treatment with nonsteroidal anti-inflammatory drugs (NSAIDs). Although bioactive and natural compounds exhibit therapeutic potential against OA, several disadvantages loom, like insolubility and poor bioavailability. Nanoformulated bioactive compounds promise a better way to alleviate OA since they also control systemic events, including metabolic, immunological, and inflammatory responses, by modulating host gut microbiota that can regulate OA pathogenesis. Recent data suggest gut dysbiosis in OA. However, limited evidence is available on the role of bioactive compounds as epigenetic and gut modulators in ameliorating OA. Moreover, it is not known whether the effects of polyphenolic bioactive compounds on gut microbial response are mediated by epigenetic modulatory activities in OA. This narrative review highlights the nanotherapeutic strategies utilizing bioactive compounds, reporting their effects on chondrocyte growth, metabolism, and epigenetic modifications in osteoarthritis amelioration.

The pathogenesis of knee osteoarthritis (OA) is multifaceted and involves the complete joint microenvironment. Despite beneficial evidence of curcumin, the mechanistic insights of nanoemulsified curcumin (n-Cur) delivery to the knee-OA microenvironment are limited. The study aimed to establish localized delivery of curcumin nanoemulsion in the knee joint of OA rats and to examine detailed histopathological changes. n-Cur was prepared using a neutral dietary oil and a surfactant. Adult (5 mo) male SD rats were intra-articularly delivered 40 mg/mL of monoiodoacetate (MIA) to induce OA in the left knee and further treated with n-Cur (30 mg/mL). The effect of n-Cur on macrophage recruitment was evaluated using a co-culture model of CHON 001 and RAW 264.7 cells. In the MIA model, localized delivery of n-Cur significantly reduced knee joint edema and joint space narrowing in the target site. Curcumin ameliorated cartilage degeneration by reducing fibrillation, hypocellularity, and restoring matrix proteoglycan, as evidenced by histology. Reduced synovial inflammation displays the effect of curcumin on the synovium, possibly by lowering the recruitment of macrophages in chemoattractant-stimulated chondrocytes. Thus, curcumin nanoemulsion can act as a chondroprotective agent, modulating the OA microenvironment by reducing joint edema, synovial inflammation, and oxidative stress in the OA model.

Bioactive like resveratrol, epigallocatechin gallate, curcumin, and other polyphenols often target various signalling pathways, including NFκB, TGFβ, and Wnt/β-catenin in a degenerative joint disease like osteoarthritis (OA), by executing epigenetic-modifying activities. Epigenetic modu-lation can target genes of disease pathophysiology by histone modifications, promoter DNA methylation, and non-coding RNA expression, some of which are directly involved but less ex-plored in OA. OA patients often explore options that can improve the quality of their life in ad-dition to existing treatment with nonsteroidal anti-inflammatory drugs (NSAIDs). Although bi-oactive and natural compounds exhibited therapeutic potential against OA, several disadvantages loom, like insolubility and poor bioavailability. Nanoformulated bioactives promise a better way to alleviate OA since they also control systemic events, including metabolic, immunological, and inflammatory responses, by modulating host gut microbiota that can regulate OA pathogenesis. Recent data suggest gut dysbiosis in OA. However, limited evidence is available on the role of bioactive as epigenetic and gut modulators in ameliorating OA. Moreover, the question of whether polyphenolic bioactive modulates gut microbial response that results in epigenetic-controlling activities of OA pathogenesis is not known. This narrative review explored the interplay of nanoformulated bioactive and host gut microbiota on chondrocyte growth, metabolism, and epigenetic alteration linked with OA progression and pathogenesis.

Bioactive like resveratrol, epigallocatechin gallate, curcumin, and other polyphenols often target various signalling pathways, including NFκB, TGFβ, and Wnt/β-catenin in osteoarthritis (OA) pathogenesis, by executing epigenetic-modifying activities. Epigenetic modulation by bioactive is gaining traction with the onset of nutrigenomics. Such modulations can target genes by histone modifications, promoter DNA methylation, and non-coding RNA expression, some of which are directly involved in disease pathophysiology but less explored in OA. OA patients often explore options that can improve the quality of their life in addition to existing treatment with nonsteroidal anti-inflammatory drugs (NSAIDs). Although bioactive and natural compounds exhibited therapeutic potential against OA, several disadvantages loom over them, like insolubility and poor bioavailability. Nanoformulated bioactives promise a better way to alleviate OA since they also control systemic events, including metabolic, immunological, and inflammatory responses, by modulating host gut microbiota that can regulate OA pathogenesis. Recent data suggest gut dysbiosis in OA. However, limited evidence is available on the role of bioactive as epigenetic and gut modulators in ameliorating OA. Moreover, the question of whether polyphenolic bioactive modulates gut microbial response that results in epigenetic-controlling activities of OA pathogenesis is not known. This narrative review explored the interplay of nanoformulated bioactive and host gut microbiota on chondrocyte growth, metabolism, and epigenetic alteration linked with OA progression and pathogenesis.

The pathogenesis of knee osteoarthritis (OA) is multifaceted and involves the complete joint microenvironment. Despite beneficial evidence of curcumin, the mechanistic insights of nanoemulsified curcumin (n-Cur) delivery to the knee-OA microenvironment are limited. A detailed histological change that occurs in the knee joint of the OA model after localized delivery of curcumin was examined. n-Cur was prepared using a neutral dietary oil and a surfactant. Adult (5 mo) male SD rats were intra-articularly delivered 40 mg/ml of monoiodoacetate (MIA) to induce OA in the left knee and further treated with n-Cur (30 mg/ml). The effect of n-Cur on macrophage recruitment was evaluated using a co-culture model of CHON 001 and RAW 264.7 cells. In the MIA-model, localized delivery of n-Cur significantly reduced knee-joint edema, and articular cavity stenosis in the target site. Curcumin ameliorated cartilage degeneration by reducing fibrillation, hypocellularity, and restoring matrix proteoglycan, as evidenced by histology. Reduced synovial inflammation displays the effect of curcumin on the synovium, possibly by lowering the recruitment of macrophages in chemoattractant-stimulated chondrocytes. Thus, curcumin nanoemulsion can act as a chondroprotective agent, modulating the OA microenvironment by reducing joint edema, synovial inflammation, and oxidative stress in the OA model.