Sida tuberculata reduces oxidative stress and pain caused by the knee osteoarthritis

The protective role of Achyranthes aspera extract against cisplatin-induced nephrotoxicity by alleviating oxidative stress, inflammation, and PANoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Achyranthes aspera, a widely recognized medicinal plant, is used in various cultures for treating different ailments, including renal dysfunction; however, there is a lack of comprehensive understanding of its protective effects and the underlying signaling networks involved.

AIM OF THE STUDY

This study aimed to investigate the molecular mechanisms of the action of A. aspera by employing an integrative approach including functional and tissue imaging as well as comprehensive genomics analysis.

MATERIALS AND METHODS

Cisplatin-induced nephrotoxicity is a well-established animal model for acute kidney injury (AKI). In this study, we investigated the protective effects and underlying mechanisms of the action of A. aspera water-soluble extract (AAW) on a murine model of cisplatin-induced AKI. The evaluation includes measurements of blood urea nitrogen (BUN) and serum creatinine (SCr) levels, histology examination, and transcriptome analysis using RNA sequencing.

RESULTS

In male ICR mice, oral administration of AAW at doses of 0.5-1.0 g/kg significantly reduced cisplatin-induced nephrotoxicity. This effect included the amelioration of tubular injury, renal fibrosis, and the lowering of BUN and SCr levels. AAW also effectively decreased oxidative markers, such as malondialdehyde (MDA) and nitrotyrosine (NT), along with inflammation markers, including COX-2, iNOS, NLRP3, and pP65NFκB. Moreover, AAW administration induced a dose-dependent increase in the expression of two protective factors, Nrf2 and BcL2, and suppressed apoptosis, as evidenced by reduced levels of truncated caspase 3 (t-Casp3). To explore the underlying molecular mechanisms and signaling networks, next-generation sequencing (NGS) analysis was employed. The results revealed that AAW mitigated apoptosis, necroptosis, and PANoptosis pathways by inhibiting inflammation signaling pathways, such as the TNFα-, NFκB-, NETs-, and leukocyte transendothelial migration pathways. Additionally, AAW was found to enhance protective signaling pathways, including the cGMP/PKG-, cAMP-, AMPK-, and mTOR-dependent activation of autophagy and mitophagy pathways. The primary bioactive compound found in AAW was identified as 20-hydroxyecdysone (0.36%).

CONCLUSION

Our study demonstrates that AAW reduces cisplatin-induced nephrotoxicity. The protective effects of AAW are attributed to its modulation of multiple molecular signaling networks. Specifically, AAW downregulates genes and signaling pathways associated with oxidative stress and endoplasmic reticulum (ER) stress, inflammation, and PANoptosis. Simultaneously, it upregulates genes and signaling pathways associated with cell survival, including autophagy and mitophagy pathways.

An Integrated View of Stressors as Causative Agents in OA Pathogenesis

Cells in the body are exposed to dynamic external and internal environments, many of which cause cell damage. The cell's response to this damage, broadly called the stress response, is meant to promote survival and repair or remove damage. However, not all damage can be repaired, and sometimes, even worse, the stress response can overtax the system itself, further aggravating homeostasis and leading to its loss. Aging phenotypes are considered a manifestation of accumulated cellular damage and defective repair. This is particularly apparent in the primary cell type of the articular joint, the articular chondrocytes. Articular chondrocytes are constantly facing the challenge of stressors, including mechanical overloading, oxidation, DNA damage, proteostatic stress, and metabolic imbalance. The consequence of the accumulation of stress on articular chondrocytes is aberrant mitogenesis and differentiation, defective extracellular matrix production and turnover, cellular senescence, and cell death. The most severe form of stress-induced chondrocyte dysfunction in the joints is osteoarthritis (OA). Here, we summarize studies on the cellular effects of stressors on articular chondrocytes and demonstrate that the molecular effectors of the stress pathways connect to amplify articular joint dysfunction and OA development.

P66shc in the spinal cord is an important contributor in complete Freund's adjuvant induced inflammatory pain in mice

PURPOSE

The aim of this study is to investigate whether p66shc is involved in inflammatory pain and the potential molecular mechanisms of p66shc in inflammatory pain.

METHODS

Inflammatory pain model was established by complete Freund's adjuvant (CFA) injection. Paw withdrawal latency (PWL) and paw withdrawal frequency (PWF) was recorded. The expression of spinal p66shc were determined by immunohistochemical staining, immunofluorescence staining. P66shc knockdown was performed by an adeno-associated virus (AAV) vector infusion. NLRP3 inflammasome complexes were determined by Western blot. DHE staining was used to evaluate reactive oxygen species (ROS) generation.

RESULTS

P66Shc expression was progressively elevated in spinal cord of inflammatory pain mice, and p66Shc knockdown in vivo significantly attenuated CFA injection triggers hyperalgesia. Furthermore, knockdown of p66Shc significantly inhibited ROS production and NOD-like receptor protein 3 (NLRP3) inflammasome activation, which were reversed by a ROS donor (t-BOOH). However, post-treatment with nigericin, a agonist of NLRP3, reversed AAV-shP66shc analgesic effect.

CONCLUSION

Spinal p66shc may facilitate the development of inflammatory pain by promoting the activation of NLRP3 inflammasome through ROS.

Medicinal plants and their secondary metabolites in alleviating knee osteoarthritis: A systematic review

BACKGROUND

With the increasing ages of the general population, the incidence of knee osteoarthritis (KOA) is also rising, and KOA has become a major health problem worldwide. Recently, medicinal plants and their secondary metabolites have gained interest due to their activity in treating KOA. In this paper, a comprehensive systematic review of the literature was performed concerning the effects of medicinal plant extracts and natural compounds against KOA in recent years. The related molecular pathways of natural compounds against KOA were summarized, and the possible crosstalk among components in chondrocytes was discussed to propose possible solutions for the current situation of treating KOA.

PURPOSE

This review focused on the molecular mechanisms by which medicinal plants and their secondary metabolites act against KOA.

METHODS

Literature searches were performed in the PUBMED, Embase, Science Direct, and Web of Science databases for a 10-year period from 2011 to 2022 with the search terms "medicinal plants," "bioactive compounds," "natural products," "phytochemical," "knee osteoarthritis," "knee joint osteoarthritis," "knee osteoarthritis," "osteoarthritis of the knee," and "osteoarthritis of knee joint."

RESULTS

According to the results, substantial plant extracts and secondary metabolites show a positive effect in fighting KOA. Plant extracts and their secondary metabolites can affect the diagnostic and prognostic biomarkers of KOA. Natural products inhibit the expression of MMP1, MMP3, MMP19, syndecan IV, ADAMTS-4, ADAMTS-5, iNOS, COX-2, collagenases, IL-6, IL-1β, and TNF-α in vitro and in vivo and . Cytokines also upregulate the expression of collagen II and aggrecan. The main signaling pathways affected by the extracts and isolated compounds include AMPK, SIRT, NLRP3, MAPKs, PI3K/AKT, mTOR, NF-κB, WNT/β-catenin, JAK/STAT3, and NRF2, as well as the cell death modes apoptosis, autophagy, pyroptosis, and ferroptosis.

CONCLUSION

The role of secondary metabolites in different signaling pathways supplies a better understanding of their potential to develop further curative options for KOA.

The role of oxidative stress in the development of knee osteoarthritis: A comprehensive research review

Knee osteoarthritis (KOA) is one of the most common degenerative diseases, and its core feature is the degeneration and damage of articular cartilage. The cartilage degeneration of KOA is due to the destruction of dynamic balance caused by the activation of chondrocytes by various factors, with oxidative stress playing an important role in the pathogenesis of KOA. The overproduction of reactive oxygen species (ROS) is a result of oxidative stress, which is caused by a redox process that goes awry in the inherent antioxidant defence system of the human body. Superoxide dismutase (SOD) inside and outside chondrocytes plays a key role in regulating ROS in cartilage. Additionally, synovitis is a key factor in the development of KOA. In an inflammatory environment, hypoxia in synovial cells leads to mitochondrial damage, which leads to an increase in ROS levels, which further aggravates synovitis. In addition, oxidative stress significantly accelerates the telomere shortening and ageing of chondrocytes, while ageing promotes the development of KOA, damages the regulation of redox of mitochondria in cartilage, and stimulates ROS production to further aggravate KOA. At present, there are many drugs to regulate the level of ROS, but these drugs still need to be developed and verified in animal models of KOA. We discuss mainly how oxidative stress plays a part in the development of KOA. Although the current research has achieved some results, more research is needed.

Sida tuberculata: In vitro cytotoxicity and in vivo anti-inflammatory effect

ETHNOPHARMACOLOGICAL RELEVANCE

Sida tuberculata R. E. Fries (Malvaceae) is a pioneer species considered a weed in farm fields in Southern Brazil. Widely distributed in South Brazil, S. tuberculata is popularly used to treat inflammatory conditions.

AIMS OF THE STUDY

The current study aimed to assess the in vitro cytotoxic and in vivo anti-inflammatory properties of S. tuberculata.

MATERIALS AND METHODS

Initially, extracts obtained from leaves (STLE) and roots (STRE) were submitted to cytotoxicity tests using human leukocytes (non-malignant cell line) and HepG2 and MCF-7 (tumor cell lines). In sequence, anti-inflammatory properties were investigated against carrageenan-induced peritonitis model.

RESULTS

In vitro analyses displayed a significant decrease in human leukocytes viability without genotoxic damage. IC₅₀ results from tumor cells presented significant decrease in cell viability, slightly more pronounced for STRE. In addition, STLE significantly inhibited the inflammatory and oxidative parameters (TBARS, NPSH, SOD, MPO activity, cell influx, and cytokines release).

CONCLUSION

Our findings indicate S. tuberculata extracts have cytotoxic potential more pronounced on tumor cell lines, as well as leaves extract shows a significant reduction in acute inflammation process, as already reported for Sida genus and specifically for this species.

Effects of quercetin on apoptosis and extracellular matrix degradation of chondrocytes induced by oxidative stress-mediated pyroptosis

Quercetin has been preliminarily proven to serve as a potential agent for the treatment of osteoarthritis (OA). However, its effects and potential mechanisms on the pathological process of OA are not very clear. This study aimed to study the protective effect of quercetin on OA. Lipopolysaccharide (LPS)-treated chondrocytes (C28/I2 cell) and anterior cruciate ligament transection with partial medial meniscectomy-treated Wistar rats were used as models of OA in vitro and in vivo. Cell counting kit-8 (CCK-8 kit), flow cytometry, enzyme-linked immunosorbent assay (ELISA) kit, western blot, dichlorodihydrofluorescein diacetate (DCFH-DA) kit, thiobarbituric acid (TBA) test, toluidine blue staining, Hematoxylin eosin (HE) staining and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) staining were used to evaluate cell viability, cell apoptosis, inflammatory cytokines level, protein expression, reactive oxygen species (ROS) level, malondialdehyde (MDA) content, morphological changes, and chondrocyte apoptosis of cartilage, respectively. Results showed that quercetin could reduce LPS-induced C28/I2 cell apoptosis, extracellular matrix (ECM) degradation, and cell pyroptosis, and overexpression of nucleotide-binding domain and leucine-rich-repeat-containing (NLR) family, pyrin domain-containing 3 (NLRP3) revealed that quercetin reduced chondrocyte apoptosis and ECM degradation by inhibiting NLRP3-mediated pyroptosis. Furthermore, quercetin could reduce chondrocyte apoptosis and ECM degradation, and inhibit NLRP3-mediated pyroptosis through blocking oxidative stress. It was further confirmed in the rat OA model that quercetin alleviated OA by blocking oxidative stress, reduces chondrocyte pyroptosis, apoptosis, and ECM degradation. In conclusion, quercetin inhibited OA via blocking oxidative stress-induced chondrocyte pyroptosis in models of OA in vitro and in vivo.

Preclinical safety assessment of the crude extract from Sida rhombifolia L. aerial parts in experimental models of acute and repeated-dose 28 days toxicity in rats

Sida rhombifolia (Malvaceae) is popularly used as a treatment for several pathological conditions; however, there is a lack of studies that identify its compounds and that evaluate comprehensively the safety of its consumption. Therefore, the aim of this study was to determinate the phytochemical constitution of the crude extract of Sida rhombifolia (CESR), and its safety in models of acute and repeated doses (28 days) toxicity. The tested dose for the model of acute toxicity was 2000 mg/kg doses for the repeated dose model were 150, 300 e 600 mg/kg. Hematological, biochemical, histopathological and oxidative markers were investigated. HPLC-DAD-MS analysis evidenced the presence of caffeic acid, coumarin, and rutin. In the acute toxicity model the only altered parameters were tissue ROS, and AST and BUN in serum. As for the repeated dose experiment both hematological and biochemical markers remained within the values of reference for the species. Obtained results demonstrate that the CESR did not present significant toxic effects when administrated orally to male and female rats in acute and repeated doses.

Biosynthesis of gold nanoparticles for the treatment of osteoarthritis alone or in combination with Diacerein® in a rat model

Gold (Au) compounds were used as an effective therapeutic agent for various inflammatory diseases; however, the use of Au compounds becomes limited because of its association with several side effects. Hence, gold nanoparticles (AuNPs) were developed as a new option for the medical proposes. However, the safety evaluation of gold nanoparticles (AuNPs) in osteoarthritis (OA) treatment remains vague. This study aimed to biosynthesize, characterize and evaluate the therapeutic effects of biosynthesized AuNPs and/or Diacerein^® (DIA) in experimental OA. OA was induced by a single injection of monosodium iodoacetate (3 mg/joint) in the intra-articular knee of female rats. Normal rats (N-rats) and OA-rats were treated orally for 5 weeks as follow: untreated N-rats; untreated OA-rats; N-rats received DIA (50 mg/kg b.w); N-rats received AuNPs (30 μg/kg b.w.); N-rats received AuNPs plus DIA; OA-rats received DIA; OA-rats received AuNPs, and OA-rats received AuNPs plus DIA. Blood, knee cartilage, liver and kidney samples were collected for biochemical and histological analysis. The synthesized AuNPs were nearly spherical with average size of 20 nm and zeta potential of 33 mV. AuNPs and DIA induced a significant improvement in serum inflammatory cytokines, biochemical parameters, estrogen level, hepatic and renal oxidative markers, hepatic DNA fragmentation, genomic template stability and cartilage joint histology of OA-rats. AuNPs were more effective than DIA and the combined treatment was more effective than the single treatment. It could be concluded that AuNPs are promising for the treatment of OA alone or in combination with DIA.

Photobiomodulation and Sida tuberculata combination declines the inflammation's markers in knee-induced osteoarthritis

The aim of this study was to assess potential combination effects of photobiomodulation therapy (PBMT) with Sida tuberculata extracts on the oxidative stress and antioxidant activity, as well as on the inflammatory process. Rats with knee osteoarthritis (OA) were treated with S. tuberculata extracts and PBMT (904 nm, 18 J/cm²). The animals were evaluated for nociception and edema. The blood, knee lavage and structures, spinal cord, and brainstem were collected for biochemical analyses (lipid peroxidation, protein carbonyl content, superoxide dismutase activity, non-protein thiol levels, and measurement of nitrite/nitrate). The knee structures were also used to measure cytokine levels. PBMT lowered the damage due to oxidative stress in the knee and at distant sites from the lesion. PBMT also reduced the levels of nitric oxide and cytokines, which could explain the nociception reduction mechanism. Similarly, S. tuberculata decreased the damage by oxidative stress, levels of nitrite/nitrate, and cytokines. The therapy combination reduced levels of cytokines and nitrite/nitrate. PBMT and S. tuberculata extracts reduced the oxidative stress and inflammation. It is noteworthy that PBMT increased the antioxidant activity in the knee and at sites distant from the lesion, contributing to a more significant decrease in nociception. The combination of therapies did not present significant effects on the analyzed parameters. Therefore, it is suggested that PBM is sufficient to minimize the signs and symptoms of the knee OA in our rat model.

Laquinimod Mitigated IL-1β-Induced Impairment of the Cartilage Extracellular Matrix in Human ATDC5 Chondrocytes

To date, a safe and reliable treatment of osteoarthritis (OA) has not yet been announced. Inflammatory response and degradation of the articular extracellular matrix (ECM) induced by IL-1β are important pathological characteristics of OA. Laquinimod is a quinoline-3-carboxamide and a novel oral immunomodulatory compound in clinical use. However, whether laquinimod has a beneficial effect in OA is not known. In our research, we found that laquinimod could ameliorate IL-1β-induced generation of ROS and improve mitochondrial function by increasing mitochondrial membrane potential (ΔΨm). Furthermore, treatment with laquinimod suppressed IL-1β-induced production of TNF-α and IL-6. Notably, laquinimod prevented the degradation of type II collagen by inhibiting MMP-3 and MMP-13. Meanwhile, the presence of laquinimod attenuated the reduction in aggrecan by mediating ADAMTS-4 and ADAMTS-5. Mechanistically, laquinimod ameliorated IL-1β-induced inflammation and degeneration of ECM by suppressing the activation of NF-κB. Taken together, our findings reveal that laquinimod possesses a beneficial effect against IL-1β insults in human chondrocytes, implying an important role of laquinimod in OA.