The mechanism of Epimedin B in treating osteoporosis as revealed by RNA sequencing-based analysis

Epimedin B exerts an anti-inflammatory effect by regulating the MAPK/NF-κB/NOD-like receptor signalling pathways

Epimedin B (EB), a predominant compound found in Herba Epimedii, has been shown to be effective in the treatment of osteoporosis and peripheral neuropathy. However, the anti-inflammatory effect of EB has not yet been reported. The anti-inflammatory activity of EB was evaluated in a zebrafish inflammation model induced by copper sulfate (CuSO4) and tail cutting. Our findings demonstrated that EB effectively inhibited acute inflammation, mitigated the accumulation of reactive oxygen species (ROS), and ameliorated the neuroinflammation-associated impairment of locomotion in zebrafish. Moreover, EB regulates several genes related to the mitogen-activated protein kinase (MAPK)/nuclear factor-κB (NF-κB)/Nod-like receptor signalling pathways (mapk8b, src, mmp9, akt1, mapk14a, mapk14b, mapk1, egfra, map3k4, nfκb2, iκbαa, pycard, nlrp3 and caspase1) and inflammatory cytokine (stat6, arg1, irfɑ, stat1ɑ, il-1β, il-4, il-6, il-8, cox-2, ptges, tnf-α and tgf-β). Therefore, our findings indicate that EB could serve as a promising therapeutic candidate for treating inflammation.

Epimedin B exhibits pigmentation by increasing tyrosinase family proteins expression, activity, and stability

Epimedin B (EB) is one of the main flavonoid ingredients present in Epimedium brevicornum Maxim., a traditional herb widely used in China. Our previous study showed that EB was a stronger inducer of melanogenesis and an activator of tyrosinase (TYR). However, the role of EB in melanogenesis and the mechanism underlying the regulation remain unclear. Herein, as an extension to our previous investigation, we provide comprehensive evidence of EB-induced pigmentation in vivo and in vitro and elucidate the melanogenesis mechanism by assessing its effects on the TYR family of proteins (TYRs) in terms of expression, activity, and stability. The results showed that EB increased TYRs expression through microphthalmia-associated transcription factor-mediated p-Akt (referred to as protein kinase B (PKB))/glycogen synthase kinase 3β (GSK3β)/β-catenin, p-p70 S6 kinase cascades, and protein 38 (p38)/mitogen-activated protein (MAP) kinase (MAPK) and extracellular regulated protein kinases (ERK)/MAPK pathways, after which EB increased the number of melanosomes and promoted their maturation for melanogenesis in melanoma cells and human primary melanocytes/skin tissues. Furthermore, EB exerted repigmentation by stimulating TYR activity in hydroquinone- and N-phenylthiourea-induced TYR inhibitive models, including melanoma cells, zebrafish, and mice. Finally, EB ameliorated monobenzone-induced depigmentation in vitro and in vivo through the enhancement of TYRs stability by inhibiting TYR misfolding, TYR-related protein 1 formation, and retention in the endoplasmic reticulum and then by downregulating the ubiquitination and proteolysis processes. These data conclude that EB can target TYRs and alter their expression, activity, and stability, thus stimulating their pigmentation function, which might provide a novel rational strategy for hypopigmentation treatment in the pharmaceutical and cosmetic industries.

Advancements in the Biotransformation and Biosynthesis of the Primary Active Flavonoids Derived from Epimedium

Epimedium is a classical Chinese herbal medicine, which has been used extensively to treat various diseases, such as sexual dysfunction, osteoporosis, cancer, rheumatoid arthritis, and brain diseases. Flavonoids, such as icariin, baohuoside I, icaritin, and epimedin C, are the main active ingredients with diverse pharmacological activities. Currently, most Epimedium flavonoids are extracted from Epimedium plants, but this method cannot meet the increasing market demand. Biotransformation strategies promised huge potential for increasing the contents of high-value Epimedium flavonoids, which would promote the full use of the Epimedium herb. Complete biosynthesis of major Epimedium flavonoids by microbial cell factories would enable industrial-scale production of Epimedium flavonoids. This review summarizes the structures, pharmacological activities, and biosynthesis pathways in the Epimedium plant, as well as the extraction methods of major Epimedium flavonoids, and advancements in the biotransformation and complete microbial synthesis of Epimedium flavonoids, which would provide valuable insights for future studies on Epimedium herb usage and the production of Epimedium flavonoids.

Chinese Proprietary Medicine Xianling Gubao Capsule for Osteoporosis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

OBJECTIVE

To assess the benefit and harm of Chinese medicine Xianling Gubao (XLGB) capsule compared to conventional medication or placebo to inform clinical practice.

METHODS

We included randomized controlled trials (RCTs) with Jadad score ≥3 of XLGB capsule compared to pharmaceutical medication, placebo, or no treatment for primary osteoporosis. We conducted searches in EMBASE, Cochrane CENTRAL, MEDLINE, China National Knowledge Infrastructure, VIP, Wanfang, and Chinese Biomedical Literature Database (Sino-Med) from their inception till November 13^th, 2021. Study selection and data extraction were done by two authors independently. The methodological quality of the RCTs was assessed using Cochrane's risk of bias tool. The effect size was presented as risk ratio (RR) or mean difference (MD) with their 95% confidence interval (CI).

RESULTS

Our searches identified 2292 records and after exclusions, eight trials involving 846 participants were included. There was no statistically significant difference between conventional medications with or without XLGB on new fracture (RR: 0.50, 95% CI: [0.13, 1.87]). Quality of life by SF-36 questionnaire of XLGB plus calcium carbonate, vitamin D₃, and calcitriol was improved than that of without XLGB (MD: 6.72 scores, 95% CI: [2.82, 10.62]). XLGB increased bone mineral density similarly as calcium carbonate plus vitamin D₃ (MD: 0.21, 95% CI: [-0.16, 0.58]) or as alendronate sodium, calcium carbonate plus vitamin D₃ (MD: 0.00, 95% CI: [-0.10, 0.10]), but it had no additional effect as an add-on treatment to conventional medications (MD: 0.13, 95% CI: [-0.12, 0.37]). XLGB relieved pain via visual analog scale more effectively when combined with medications (MD: -1.55 score, 95% CI: [-2.47, -0.63]). XLGB as monotherapy did not increase adverse events (RR: 0.63, 95% CI: [0.28, 1.41]), or as an add-on treatment (RR: 0.25, 95% CI: [0.03, 2.16]).

CONCLUSION

This systematic review shows that XLGB capsule appears to be safe and has a beneficial effect on the quality of life and pain relief when used alone or in combination with conventional medications in osteoporosis patients. Further large, rigorous trials are warranted to test its long-term benefit.