Efficacy and safety of curcuminoids alone in alleviating pain and dysfunction for knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

Background

Curcuminoids (CURs) are the principal ingredients of Curcuma longa L. [Zingiberaceae] (CL)—an herbal plant used in east Asia to alleviate pain and inflammation. Thus far, the therapeutic effects of CURs for knee osteoarthritis (OA) uncovered by multiple reviews remained uncertain due to broadly involving trials with different agents-combined or CURs-free interventions. Therefore, we formed stringent selection criteria and assessment methods to summarize current evidence on the efficacy and safety of CURs alone in the treatment of knee OA.

Methods

A series of databases were searched for randomized controlled trials (RCTs) evaluating the efficacy and safety of CURs for knee OA. Clinical outcomes were evaluated using meta-analysis and the minimum clinically important difference (MCID) for both statistical and clinical significance.

Results

Fifteen studies with 1670 patients were included. CURs were significantly more effective than placebo in the improvements of VAS for pain ( WMD: − 1.77, 95% CI: − 2.44 to − 1.09), WOMAC total score ( WMD: − 7.06, 95% CI: − 12.27 to − 1.84), WOMAC pain score ( WMD: − 1.42, 95% CI: − 2.41 to − 0.43), WOMAC function score ( WMD: − 5.04, 95% CI: − 7.65 to − 2.43), and WOMAC stiffness score ( WMD: − 0.54, 95% CI: − 1.03 to − 0.05). Meanwhile, CURs were not inferior to NSAIDs in the improvements of pain- and function-related outcomes. Additionally, CURs did not significantly increase the incidence of adverse events (AEs) compared with placebo ( RR: 1.03, 95% CI: 0.69 to 1.53, P = 0.899, I² = 23.7%) and NSAIDs (RR: 0.71 0.65, 95% CI: 0.57 0.41 to 0.90 1.03).

Conclusions

CURs alone can be expected to achieve considerable analgesic and functional promotion effects for patients with symptomatic knee OA in short term, without inducing an increase of adverse events. However, considering the low quality and substantial heterogeneity of present studies, a cautious and conservative recommendation for broader clinical use of CURs should still be made. Further high-quality studies are necessary to investigate the impact of different dosages, optimization techniques and administration approaches on long-term safety and efficacy of CURs, so as to strengthen clinical decision making for patients with symptomatic knee OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03740-9.

Botanical Drug Extracts Combined With Biomaterial Carriers for Osteoarthritis Cartilage Degeneration Treatment: A Review of 10 Years of Research

Osteoarthritis (OA) is a long-term chronic arthrosis disease which is usually characterized by pain, swelling, joint stiffness, reduced range of motion, and other clinical manifestations and even results in disability in severe cases. The main pathological manifestation of OA is the degeneration of cartilage. However, due to the special physiological structure of the cartilage, once damaged, it is unable to repair itself, which is one of the challenges of treating OA clinically. Abundant studies have reported the application of cartilage tissue engineering in OA cartilage repair. Among them, cell combined with biological carrier implantation has unique advantages. However, cell senescence, death and dedifferentiation are some problems when cultured in vitro. Botanical drug remedies for OA have a long history in many countries in Asia. In fact, botanical drug extracts (BDEs) have great potential in anti-inflammatory, antioxidant, antiaging, and other properties, and many studies have confirmed their effects. BDEs combined with cartilage tissue engineering has attracted increasing attention in recent years. In this review, we will explain in detail how cartilage tissue engineering materials and BDEs play a role in cartilage repair, as well as the current research status.

Rhizoma drynariae total flavonoids combined with calcium carbonate ameliorates bone loss in experimentally induced Osteoporosis in rats via the regulation of Wnt3a/β-catenin pathway

Background

Rhizoma drynariae, a traditional Chinese herb, is commonly used in treatment of bone healing in osteoporotic fractures. However, whether the Rhizoma drynariae total flavonoids (RDTF) can promote the absorption of calcium and enhance the bone formation is unclear. The aim of the present study was to investigate the preventive effects of RDTF combined with calcium carbonate (CaCO₃) on estrogen deficiency-induced bone loss.

Methods

Three-month-old Sprague–Dawley rats were ovariectomized (OVX) and then treated with CaCO_3, RDTF, and their admixtures for ten weeks, respectively. The bone trabecular microstructure, bone histopathological examination, and serum biomarkers of bone formation and resorption were determined in the rat femur tissue. The contents of osteoprotegerin (OPG), receptor activator of the NF-κB (RANK), and its ligand (RANKL) in marrow were analyzed by ELISA, and the protein expressions of Wnt3a, β-catenin, and phosphorylated β-catenin (p-β-catenin) were analyzed by Western blot. Statistical analysis was conducted by using one-way analysis of variance (ANOVA) followed by LSD post hoc analysis or independent samples t test using the scientific statistic software SPSS version 20.0

Results

RDTF combined with CaCO₃ could promote osteosis and ameliorate bone loss to improve the repair of cracked bone trabeculae of OVX rats. Furthermore, RDTF combined with CaCO₃ also could prevent OVX-induced decrease in collagen fibers in the femoral tissue of ovariectomized rats and promote the regeneration of new bone or cartilage tissue, while CaCO₃ supplementation promoted the increase in bone mineral content. Nevertheless, there was no difference in the expression of Wnt3a, β-catenin and p-β-catenin between osteopenic rats and RDTF treated rats, but RDTF combined with CaCO₃ could activate the Wnt3a/β-catenin pathway.

Conclusions

RDTF combined with CaCO₃ could ameliorate estrogen deficiency-induced bone loss via the regulation of Wnt3a/β-catenin pathway.

Total flavonoids of Rhizoma Drynariae combined with calcium attenuate osteoporosis by reducing reactive oxygen species generation

In the present study, the effects of total flavonoids of Rhizoma Drynariae (TFRD) and calcium carbonate (CaCO₃) on osteoporosis (OP) were assessed in a rat model of OP. For this purpose, 36 Sprague-Dawley rats, aged 3 months, were randomly divided into a group undergoing sham surgery (sham-operated group), model group (OP group), CaCO₃ group (OP + CaCO₃ group), TFRD group (OP + TFRD group), TFRD combined with CaCO₃ group (OP + TFRD + CaCO₃ group) and TFRD and CaCO₃ combined with N-acetyl cysteine group (OP + TFRD + CaCO₃ + NAC group). The rat model of OP was established by bilateral ovariectomy. The changes in bone mineral density (BMD), bone volume parameters and bone histopathology in the rats from each group were observed. The levels of serum reactive oxygen species, superoxide dismutase (SOD), malondialdehyde, glutathione peroxidase (GSH-Px), interleukin (IL)-6, IL-1β, TNF-α, and the levels of bone tissue runt-related transcription factor 2 (RUNX2), osteoprotegerin (OPG), osteocalcin (BGP), PI3K, p-PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR) and p-mTOR were measured in the rats of each group. The induction of OP was associated with a marked decrease in BMD, bone mineral content, bone volume fraction and trabecular thickness, and decreased serum levels of SOD and GSH-Px. Moreover, the expressions of RUNX2, OPG, BGP were downregulated and an upregulation of p-PI3K, p-AKT and p-mTOR were observed in osteoporotic rats. However, treatment with TFRD and CaCO₃ restored all the aforementioned parameters to almost normal values. Furthermore, the findings on histopathological evaluation were consistent with the biochemical observations. Taken together, the findings of the present study demonstrated that TFRD and CaCO₃ significantly increased the antioxidant capacity in rats with OP, increased BMD and reduced bone mineral loss, and may be useful for the prevention and treatment of OP.

Association of β-cell function and insulin sensitivity with fasting and 2-h plasma glucose in a large Chinese population

AIM

Our aim was to provide a quantitative analysis of the changes in the principal determinants of insulin sensitivity and secretion in relation to fasting plasma glucose (FPG) or 2-h plasma glucose (2h PG) in a Chinese population with a wide range of glucose tolerance.

METHODS

A total of 5728 adults spanning the entire range of glucose tolerance were included. Insulin sensitivity was measured by Matsuda insulin sensitivity index (ISI(M)) and homeostasis model assessment of 1/homeostasis model assessment of insulin resistance (HOMA-IR). β-Cell function adjusted by insulin sensitivity was assessed from disposition index (DI) at early-phase DI(30) and total DI(120). The exponential curve was established as the best fit for the relationship between insulin sensitivity or β-cell function and FPG or 2h PG.

RESULTS

Relative to the trend classified as increasing 2h PG, hepatic insulin sensitivity and insulin secretion showed a decreasing trend to a substantial degree as FPG increased. A 1 mmol/l increase in FPG and 2h PG concentration was associated with a -22 and -21% decline in ISI(M), -16 and -4% in 1/HOMA-IR, -38 and -35% in DI(30) and -36 and -26% in DI(120). The decay constant of ISI(M) and DI(30) in IFG or ISI(M), 1/HOMA-IR, DI(30) and DI(120) in IGT was lower than that in normal glucose tolerance. Significant interactions between sex and glucose levels determining DI were found.

CONCLUSIONS

We conclude that impairment of insulin sensitivity and insulin secretion contributes to both FPG or 2h PG hyperglycaemia in a Chinese population, but that the decline in insulin secretion is more pronounced with increasing fasting than 2h PG.

[QTL analysis of anther length and ratio of stigma exsertion, two key traits of classification for cultivated rice (Oryza sativa L.) and common wild rice (O. rufipogon Griff.)]

A genetic map including 120 RFLP markers covering 1418.2 cM has been constructed using a BC1 population derived from a cross between common wild rice (Oryza rufipogon Griff.) from Dongxiang, Jiangxi Province, China, and an elite Indica variety Guichao 2. The linkage orders and genetic distances of markers in this map are consistent with the map constructed by Rice Genome Program of Japan except the markers of short arm of Chromosome 1. The QTLs analysis of anther length and ratio of stigma exsertion, two key traits of classification for cultivated rice and common wild rice indicated that there are two QTLs controlling anther length located at the region of C424-G39 of Chromosome 2, and C2807-C1263 of Chromosome 9 respectively. It was also found that there are two QTLs controlling ratio of stigma exsertion, and located at the region of C2289-R1553 of Chromosome 5 and G1149-R1963 of Chromosome 8 respectively. The detected QTLs affecting the key traits of classification for wild rice and cultivated rice will be useful for study of molecular evolution mechanism of cultivated rice.

[Preparation of huichun zhibao oral liquid (HZOL)]

The formulation, preparing method, quality standards, pharmacodynamic experinents and toxicological experiments of HZOL are described. The content of icariin, which is and effective component of epimedium herb as well as one of the main ingredients in HZOL, was successfully determined through HPLC, with an average recovery of 98.98% and RSD = 1.53%.