Cynanchum komarovii extract for the treatment of rheumatoid arthritis by acting on synovial cells in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Cynanchum komarovii (CK), the northwest Chinese region's common medicinal herb, was traditionally utilized to treat arthritis, toothache, bald sores and cholecystitis. Various forms of arthritis can be treated with CK, based on "Medicinal Plants of Chinese Desert Areas". However, the exact mechanism of action in rheumatoid arthritis (RA) is uncertain.

AIM OF THE STUDY

To evaluate the in vitro and in vivo effects of CK extracts on RA and to preliminarily investigate its anti-RA mechanism of action.

MATERIALS AND METHODS

The main components of CK extract were analyzed by HPLC method. The effects of CK on the proliferation and apoptosis of human rheumatoid arthritis fibroblast-like synoviocytes (HFLS-RA) cells and the expression of apoptosis-related proteins in HFLS-RA cells were evaluated by CCK8 assay, flow cytometry and WB assay. To verify the anti-RA effect of CK extracts in vivo, a collagen-induced arthritis (CIA) rat model was established. The rats were divided into six groups: normal group, model group, CK high-dose group (1000 mg/kg, CK-H), CK medium-dose group (500 mg/kg, CK-M), CK low-dose group (250 mg/kg, CK-L) and methotrexate-positive drug group (MTX); the drug was administered continuously for 28 days. Body weight changes, joint swelling, arthritis index, bone density, ankle lesions, immune organ index, splenic lesions and inflammatory factor expression were used to evaluate the in vivo anti-RA activity of the extract.

RESULTS

The findings of in vitro experiments showed that 10% CK-containing serum decreased the expression level of Bcl-2, increased the expression levels of Bax and Cleaved Caspase-3 in synovial cells, and prevented TNF-α induced aberrant proliferation and apoptotic antagonism in HFLS-RA cells. According to in vivo studies, CK extract at doses above 250 mg/kg was effective in controlling the levels of inflammatory factors, lowering the arthritis index, and improving foot swelling in CIA rats. When administered at doses up to 1000 mg/kg, CK extract significantly improved synovial lesions, increased bone density, and decreased abnormally elevated immune organ index in CIA rats.

CONCLUSIONS

CK has significant anti-RA activity, and its anti-RA mechanism of action may be related to the regulation of the expression levels of apoptosis related proteins and the promotion of apoptosis in synovial cells.

Iljinski

ETHNOPHARMACOLOGICAL RELEVANCE

Cynanchum komarovii Al. Iljinski is a ethnomedicinal herb and this ethno-medicine is used mainly to treat arthritis, toothache, reducing phlegm, relieving cough. Total alkaloids of Cynanchum komarovii Al. Iljinski (TACKI) is the main active compound of Cynanchum komarovii Al. Iljinski. Previous investigations have revealed that TACKI can significantly inhibit rat foot swelling caused by carrageenan; it has a significant inhibitory effect on granulation tissue proliferation. Pharmacology study showed that Cynanchum komarovii Al. Iljinski has analgesia, anti-inflammatory, antibacterial, anti-tumor, relieving cough and relieving asthma. However, there is no any investigation on the mechanism of analgesia and anti-inflammation.

AIM OF THE STUDY

To clarify the analgesic effect and material basis of Cynanchum komarovii Al. Iljinski, determine the analgesic effect of TACKI, and provide experimental data support for its traditional application in the treatment of various pains.

MATERIALS AND METHODS

TACKI were prepared by the traditional acid extraction and alkaline precipitation method, and TACKI was analyzed through classic animal models of acute antinociceptive animal models and chronic antinociceptive. Evaluation of analgesic effects, and preliminary discussion of the mechanism of its analgesic effects were performed in this work.

RESULTS

Acute toxicity experiments showed that the LD₅₀ of TACKI mice was 2960.88 mg/kg, and symptoms of poisoning appeared. Patholog of liver and kidney studies have shown that TACKI reduces eosinophils and increases basophils in kidney glomeruli. In the study of analgesic effects, TACKI had analgesic activity through the PWL, formalin test, and acetic acid writhing test. In the chronic inflammatory antinociceptive study, the latency of the withdrawal reflex in the TACKI group was prolonged, and the mechanical withdrawal reflex threshold was significantly increased. The protein expression of NMDA, GFAP and Iba-1 in rat brain tissue can be reduced significantly byTACKI. Meanwhile, the content of TNF-α and IL-6 in rat brain tissue is reduced.

CONCLUSION

TACKI has a significant analgesic activities. It may be related to inhibiting the activation of astrocytes and reducing the content of inflammatory mediators.

Two new C21 steroidal glycosides isolated from Cynanchum komarovii

The present study was designed to further investigate the C₂₁ steroidal glycosides in Cynanchum plants. Two new steroidal glycosides based on a 13, 14:14, 15-disecopregnane-type aglycone, komaroside P (1) and komaroside Q (2), together with three known compounds (3-5) were isolated from the whole herbs of Cynanchum komarovii. The aglycones of compounds 1 and 2 were two new disecopregnane. Their structures were elucidated on the basis of 1D, 2D NMR spectroscopic data and acid hydrolysis. All the compounds (1-5) showed potent inhibitory activities against human leukemia cell lines (HL-60) with IC₅₀ values ranging from 16.6 to 26.3 μmol·L^-1, compared to the positive control 5-fluorouracil (6.4 μmol·L^-1).