Catalpol ameliorates type II collagen-induced arthritis in rats and inhibits LPS-stimulated inflammatory response in SW982 human synovial cells

Protective effects of Catalpol to attenuate TNF- α and collagen-induced inflammation in vitro HFLS-RA cells and in vivo mice models for the treatment of rheumatoid arthritis

BACKGROUND/RATIONALE

Rheumatoid Arthritis (RA) is a prolonged autoimmune condition marked by persistent inflammation, causing joint damage and bone erosion. Catalpol (CAT), an iridoid glycoside, offers anti-inflammatory benefits, warranting its study in RA models.

OBJECTIVE

To investigate the anti-inflammatory effects of CAT in RA by evaluating its impact on cellular and animal RA models.

METHODS

In vitro biological actions of CAT were investigated by the methods of cell viability, proliferation, migration, invasion, apoptosis, ROS generation, double luciferase reporter assay for NF-κB-p65 activity, Nitrite release detection, and RT-qPCR for gene expression in Tumor Necrosis Factor-alpha (TNF-α)-induced Human Fibroblast-Like Synoviocytes from RA patients (HFLS-RA) (cellular RA model). Arthritis severity, joint cellular structure, gene expression, inflammatory factors, and joint inflammation studies were investigated in mice with collagen-induced arthritis (CIA) (animal RA model).

KEY RESULTS

CAT treatment groups showed significant improvements (P < 0.001) in cell viability, migration, invasion, and apoptosis compared to the TNF-α-induced group. ROS generation and the activity of NF-κB-p65 were significantly reduced (P < 0.001). Nitrite release was decreased (P < 0.01, P < 0.001) in CAT-treatment groups. Pro-inflammatory and bone-metabolizing cytokine gene expression was markedly downregulated (P < 0.05, P < 0.001) in the cellular RA model. CIA mice treated with CAT exhibited significantly reduced arthritis severity, paw edema, and arthritis index (P < 0.05, P < 0.01). Joint pathology scores showed improvement (P < 0.001) in CAT-treatment groups. In the animal RA model, bone-metabolizing and inflammatory cytokine gene expression was significantly reduced in CAT-treatment groups (P < 0.01, P < 0.001).

CONCLUSION

CAT effectively reduces RA's inflammation and bone metabolism issues, suggesting its potential as a therapeutic agent for RA treatments. Key Points • Plant-derived Catalpol compound is an effective choice for rheumatoid arthritis treatment due to its anti-inflammatory potential. • CAT's effects were tested on TNF-α-induced HFLS-RA cells and in CIA mice, assessing cell viability, apoptosis, ROS generation, arthritis severity, inflammatory factors, and joint inflammation studies. • The administration of CAT could greatly enhance cell health and reduce inflammation markers and arthritis symptoms. • Observed significant reduction of RA inflammation and bone issues, confirming CAT as a therapeutic agent in RA treatment.

Mesua assamica (King & Prain) kosterm. bark ethanolic extract attenuates rheumatoid arthritis via down-regulating TLR4/NF-κB/COX-2/iNOS and activation of Nrf2/HO-1 pathways: A comprehensive study on in-vitro and in-vivo models

ETHNOPHARMACOLOGICAL RELEVANCE

Rheumatoid arthritis (RA) is a multifactorial, polygenic inflammatory disease. Mesua assamica (King & Prain) Kosterm. (MA) is an endangered medicinal plant indigenous to South Asia, primarily to Assam in India. The tree bark is claimed to possess anti-inflammatory, anti-diabetic, anti-cancer, and anti-malarial properties; nevertheless, its role in RA has not been elucidated. Hence, this study aims to investigate the in-vitro and in-vivo anti-arthritic effects of Mesua assamica bark ethanolic extract (MAE).

AIM OF THE STUDY

This study aims to investigate the anti-rheumatic potential of MAE in-vitro on RAW 264.7 cells for its anti-oxidant and anti-inflammatory activities and in-vivo on the CFA-induced adjuvant arthritis in the rat model.

MATERIALS AND METHODS

We investigated the possible therapeutic effects of MAE in-vitro using RAW 264.7 cells triggered by LPS. Meanwhile, adult Wistar rats were injected intradermally with 100 μl of CFA to induce arthritis, and they were given MAE orally at doses of 100 and 200 mg/kg for up to 28 days. Paw volume analysis, X-ray radiography, anti-oxidant levels analysis, gene and protein expression studies, and histological analysis were carried out to assess the effects of MAE in-vivo.

RESULTS

MAE significantly mitigated the inflammation by reducing ROS levels and dropped the nitrite, PGE2, and COX-2 levels enhanced by LPS in-vitro. At the same time, MAE treatment reduced the paw and joint inflammation and increased the immune organ index in the CFA rats. Histopathology data revealed that MAE mitigated the CFA-induced lesions of the ankle joints and synovial tissues. Similarly, MAE significantly abated the secretion of pro-inflammatory cytokines, inhibited the protein expression of TLR4, NF-кB, COX-2, and iNOS, as well as improved the Nrf2 and HO-1 levels in-vitro and in-vivo.

CONCLUSION

All the results highlighted the anti-rheumatic potential of MAE in RA in-vitro and in-vivo by inhibiting the TLR4/NF-кB/COX-2/iNOS and promoting the Nrf2/HO-1 signaling axis.

Clinical research on the effectiveness and safety of Uchasingihwan for low back pain with radiculopathy caused by herniated intervertebral disc of the lumbar spine: A multicenter, randomized, controlled equivalence trial

Background

This study aimed to establish the clinical evidence regarding the effectiveness and safety of Uchasingihwan (UCSGH) in improving pain, function, and quality of life in patients with lumbar herniated intervertebral disc (LHIVD).

Methods

This was a multicenter, randomized, controlled, equivalence trial with two parallel arms. Seventy-four participants with LHIVD were recruited and randomly allocated to the experimental and control groups. The participants in each group took 2.5 g of UCSGH granule or loxoprofen 60 mg tablet three times a day for six weeks. Additionally, both groups received the same acupuncture treatment once a week for six weeks. Outcomes about effectiveness and safety were assessed at baseline and 3, 6, and 10 weeks after screening.

Results

As the primary outcome, the mean differences with a 95 % confidence interval (CI) of changes in low back pain between the two groups at weeks 6 (95 % CI:9.26, 8.37) and 10 (95 % CI:9.03, 9.62) from baseline were within the equivalence limit. Also, changes in radiating pain at weeks 6 (95 % CI:1.70, 15.69) and 10 (95 % CI:4.72, 13.75) were within the equivalence limit. Outcome measures for function and quality of life also showed no statistical difference. Regarding safety, the frequency of adverse events related to intervention was lower in UCSGH.

Conclusion

UCSGH showed the equivalent level of effectiveness as loxoprofen in reducing low back and radiating pain in LHIVD patients and showed sufficient safety to be used as a complementary treatment option.

Trial registration

ClinicalTrials.gov (NCT03386149), CRIS (KCT0002848).

Catalpol from Rehmannia glutinosa Targets Nrf2/NF-κB Signaling Pathway to Improve Renal Anemia and Fibrosis

Rehmannia glutinosa is widely recognized as a prominent medicinal herb employed by practitioners across various generations for the purpose of fortifying kidney yin. Within Rehmannia glutinosa, the compound known as catalpol (CAT) holds significant importance as a bioactive constituent. However, the protective effects of CAT on kidneys, including ameliorative effects on chronic kidney disease - most prominently renal anemia and renal fibrosis - have not been clearly defined. In this study, the kidney injury model of NRK-52E cells and C57BL/6N male mice was prepared by exposure to aristolochic acid I (AA-I), and it was discovered that CAT could ameliorate oxidative stress injury, inflammatory injury, apoptosis, renal anemia, renal fibrosis, and other renal injuries both in vivo and in vitro. Further treatment of NRK-52E cells with Nrf2 inhibitors (ML385) and activators (ML334), as well as NF-κB inhibitors (PDTC), validated CAT's ability to target Nrf2 activation. Furthermore, the expression of phosphorylated NF-κB p65, IL-6, and Cleaved-Caspase3 protein was inhibited. CAT also inhibited NF-κB, and then inhibited the expression of IL-6, p-STAS3, TGF-β1 protein. Therefore, CAT can regulate Nrf2/NF-κB signaling pathway, significantly correct renal anemia and renal fibrosis, and is conducive to the preservation of renal structure and function, thus achieving a protective effect on the kidneys.

Anti-inflammatory effect and mechanism of catalpol in various inflammatory diseases

Catalpol is a kind of iridoid glucoside, widely found in a variety of plants, mostly extracted from the rhizome of the traditional medicinal herb rehmanniae. It has various biological activities such as anti-inflammatory, antioxidant, and antitumor. The anti-inflammatory effects of catalpol have been demonstrated in a variety of diseases, such as neurological diseases, atherosclerosis, renal diseases, respiratory diseases, digestive diseases, bone and joint diseases, eye diseases, and periodontitis. The purpose of this review is to summarize the existing literature on the anti-inflammatory effects of catalpol in a variety of inflammatory diseases over the last decade and to focus on the anti-inflammatory mechanisms of catalpol.