Osteoprotective effect of cordycepin on estrogen deficiency-induced osteoporosis in vitro and in vivo

Effect of Cordyceps spp. and Cordycepin on Functions of Bones and Teeth and Related Processes: A Review

Cordyceps spp. (belonging to the Ascomycota group) are entomopathogenic mushrooms that have traditionally been used in ethnomedicine in Asian countries such as China, Japan, Korea, and India. They are unique parasites of larvae of selected species of moths. Cordyceps militaris is one of the best sources of cordycepin. Worldwide, osteoporosis is one of the most common bone diseases, whose pharmacotherapy includes various medical interventions; however, the research and development of new molecules and new drugs is required. The impact of adenosine receptors (ARs) on the purinergic signaling pathway may regulate proliferation, differentiate dental pulp stem cells and bone marrow, and modulate osteogenesis and bone repair. The aim of the review was to collect and analyze the available data on the effects of Cordyceps spp. or cordycepin on bone function and related processes. To the best of our knowledge, this is the first systematic review in this perspective, not necessarily using mushroom raw material or even the isolated parent compound cordycepin, but new molecules that are analogs of nucleosides, such as those from C. militaris. This review found that Cordyceps spp. or isolated cordycepin interacts via the AR, 5' adenosine monophosphate-activated protein kinase (AMPK), and adenosine-5'-triphosphate (ATP) signaling pathway and evaluated their impact on bones, teeth, and dental pulp. Cordyceps spp. was found to have the potential to develop regenerative medicines, thus providing an opportunity to expand the treatment or intervention methods in the recovery after traumatic injuries, convalescence, and terminal-stage or devastating diseases.

A Systematic Review of the Biological Effects of Cordycepin

We conducted a systematic review of the literature on the effects of cordycepin on cell survival and proliferation, inflammation, signal transduction and animal models. A total of 1204 publications on cordycepin were found by the cut-off date of 1 February 2021. After application of the exclusion criteria, 791 papers remained. These were read and data on the chosen subjects were extracted. We found 192 papers on the effects of cordycepin on cell survival and proliferation and calculated a median inhibitory concentration (IC50) of 135 µM. Cordycepin consistently repressed cell migration (26 papers) and cellular inflammation (53 papers). Evaluation of 76 papers on signal transduction indicated consistently reduced PI3K/mTOR/AKT and ERK signalling and activation of AMPK. In contrast, the effects of cordycepin on the p38 and Jun kinases were variable, as were the effects on cell cycle arrest (53 papers), suggesting these are cell-specific responses. The examination of 150 animal studies indicated that purified cordycepin has many potential therapeutic effects, including the reduction of tumour growth (37 papers), repression of pain and inflammation (9 papers), protecting brain function (11 papers), improvement of respiratory and cardiac conditions (8 and 19 papers) and amelioration of metabolic disorders (8 papers). Nearly all these data are consistent with cordycepin mediating its therapeutic effects through activating AMPK, inhibiting PI3K/mTOR/AKT and repressing the inflammatory response. We conclude that cordycepin has excellent potential as a lead for drug development, especially for age-related diseases. In addition, we discuss the remaining issues around the mechanism of action, toxicity and biodistribution of cordycepin.

Cordycepin for Health and Wellbeing: A Potent Bioactive Metabolite of an Entomopathogenic Cordyceps Medicinal Fungus and Its Nutraceutical and Therapeutic Potential

Cordyceps is a rare naturally occurring entomopathogenic fungus usually found at high altitudes on the Himalayan plateau and a well-known medicinal mushroom in traditional Chinese medicine. Cordyceps contains various bioactive components, out of which, cordycepin is considered most vital, due to its utmost therapeutic as well as nutraceutical potential. Moreover, the structure similarity of cordycepin with adenosine makes it an important bioactive component, with difference of only hydroxyl group, lacking in the 3′ position of its ribose moiety. Cordycepin is known for various nutraceutical and therapeutic potential, such as anti-diabetic, anti-hyperlipidemia, anti-fungal, anti-inflammatory, immunomodulatory, antioxidant, anti-aging, anticancer, antiviral, hepato-protective, hypo-sexuality, cardiovascular diseases, antimalarial, anti-osteoporotic, anti-arthritic, cosmeceutical etc. which makes it a most valuable medicinal mushroom for helping in maintaining good health. In this review, effort has been made to bring altogether the possible wide range of cordycepin’s nutraceutical potential along with its pharmacological actions and possible mechanism. Additionally, it also summarizes the details of cordycepin based nutraceuticals predominantly available in the market with expected global value. Moreover, this review will attract the attention of food scientists, nutritionists, pharmaceutical and food industries to improve the use of bioactive molecule cordycepin for nutraceutical purposes with commercialization to aid and promote healthy lifestyle, wellness and wellbeing.

A novel nucleoside rescue metabolic pathway may be responsible for therapeutic effect of orally administered cordycepin

Although adenosine and its analogues have been assessed in the past as potential drug candidates due to the important role of adenosine in physiology, only little is known about their absorption following oral administration. In this work, we have studied the oral absorption and disposition pathways of cordycepin, an adenosine analogue. In vitro biopharmaceutical properties and in vivo oral absorption and disposition of cordycepin were assessed in rats. Despite the fact that numerous studies showed efficacy following oral dosing of cordycepin, we found that intact cordycepin was not absorbed following oral administration to rats. However, 3′-deoxyinosine, a metabolite of cordycepin previously considered to be inactive, was absorbed into the systemic blood circulation. Further investigation was performed to study the conversion of 3′-deoxyinosine to cordycepin 5′-triphosphate in vitro using macrophage-like RAW264.7 cells. It demonstrated that cordycepin 5′-triphosphate, the active metabolite of cordycepin, can be formed not only from cordycepin, but also from 3′-deoxyinosine. The novel nucleoside rescue metabolic pathway proposed in this study could be responsible for therapeutic effects of adenosine and other analogues of adenosine following oral administration. These findings may have importance in understanding the physiology and pathophysiology associated with adenosine, as well as drug discovery and development utilising adenosine analogues.

The polyadenylation inhibitor cordycepin reduces pain, inflammation and joint pathology in rodent models of osteoarthritis

Clinically, osteoarthritis (OA) pain is significantly associated with synovial inflammation. Identification of the mechanisms driving inflammation could reveal new targets to relieve this prevalent pain state. Herein, a role of polyadenylation in OA synovial samples was investigated, and the potential of the polyadenylation inhibitor cordycepin (3’ deoxyadenosine) to inhibit inflammation as well as to reduce pain and structural OA progression were studied. Joint tissues from people with OA with high or low grade inflammation and non-arthritic post-mortem controls were analysed for the polyadenylation factor CPSF4 and inflammatory markers. Effects of cordycepin on pain behavior and joint pathology were studied in models of OA (intra-articular injection of monosodium iodoacetate in rats and surgical destabilisation of the medial meniscus in mice). Human monocyte-derived macrophages and a mouse macrophage cell line were used to determine effects of cordycepin on nuclear localisation of the inflammatory transcription factor NFĸB and polyadenylation factors (WDR33 and CPSF4). CPSF4 and NFκB expression were increased in synovia from OA patients with high grade inflammation. Cordycepin reduced pain behaviour, synovial inflammation and joint pathology in both OA models. Stimulation of macrophages induced nuclear localisation of NFĸB and polyadenylation factors, effects inhibited by cordycepin. Knockdown of polyadenylation factors also prevented nuclear localisation of NFĸB. The increased expression of polyadenylation factors in OA synovia indicates a new target for analgesia treatments. This is supported by the finding that polyadenylation factors are required for inflammation in macrophages and by the fact that the polyadenylation inhibitor cordycepin attenuates pain and pathology in models of OA.

The Antiosteoporosis Effects of Zhuanggu Guanjie Pill In Vitro and In Vivo

We investigated the beneficial effects and underlying mechanisms of Zhuanggu Guanjie (ZGGJ) pill in osteoporosis in vitro and in vivo. Bone marrow macrophages from 4–6-week-old mice were cultured in the presence of macrophage colony-stimulating factor (15 ng/mL) and receptor activator of nuclear factor-κB ligand (30 ng/mL). Osteoclast differentiation was determined by quantification of tartrate-resistant acid phosphatase activity. Gelatin zymography was used to detect the activity of matrix metalloproteinases in osteoclasts. Ovariectomized rats were administered orally with estradiol valerate or ZGGJ for 8 weeks. Blood was collected to measure serum indices. Tibiae were harvested to carry out bone microcomputed tomography scanning, histomorphological analysis, and bone strength determination. ZGGJ inhibited tartrate-resistant acid phosphatase activity, matrix metalloproteinase 9 expression, and bone resorption in vitro. At doses of 0.55, 1.1, and 2.2 g/kg, ZGGJ exerted significant osteoprotective effects including inhibition of bone turnover markers and improved tibia bone strength in ovariectomized rats. Microcomputed tomographic analysis showed that ZGGJ improved the trabecular architecture with increased connectivity density and trabecular thickness and decreased trabecular spacing. These results revealed that ZGGJ prevents bone loss induced by ovariectomy in rats and that inhibition of bone resorption is involved in the bone-protective effects of ZGGJ.

Effect of Black Tea Extract and Thearubigins on Osteoporosis in Rats and Osteoclast Formation in vitro

Background: Osteoporosis is a major health problem that is closely related to substantial morbidity, mortality and decline in life quality for the aging population. Although previous studies and epidemiological evidence have demonstrated an association between black tea consumption and the prevention of bone loss, the underlying mechanism remains unclear. So, the effect of black tea extract (BTE) and thearubigins (TRs) on osteoporosis in rats and osteoclast formation in vitro were investigated.

Methods:In vivo, ovariectomized (OVX) rats were used to establish osteoporosis models. To validate the model and study the effects of BTE and TRs on osteoporosis, the female Wistar rats were divided into a sham-operated group and five OVX groups including model, Xian-Ling-Gu-Bao (XLGB) (as a positive control), BTE, TRs low-dose, and TRs high-dose group. The rats in the four treatment groups were given the corresponding test sample for 12 weeks. Then, the body weight, femur indices, and serum biomarkers were examined and analyzed. In vitro, RAW264.7 murine macrophages were used as model of osteoclast formation. The effects of BTE and TRs on osteoclasts formation and the specific genes and protein levels of osteoclasts were determined.

Results: Although there was no significant effect on the OVX-induced body weight gain by BTE or TRs, the levels of maximum bending force, cortical bone thickness and biomarker of bone resorption (acid phosphatase) can be significantly ameliorated by BTE or TRs in OVX rats. Furthermore, both of BTE and TRs can inhibit the osteoclastogenesis and diminish the expression levels of the related genes and proteins.

Effects of the Phosphodiesterase-5 (PDE-5) Inhibitors, Avanafil and Zaprinast, on Bone Remodeling and Oxidative Damage in a Rat Model of Glucocorticoid-Induced Osteoporosis

Background

The aim of this study was to evaluate the effects of the phosphodiesterase-5 (PDE-5) inhibitors, zaprinast and avanafil, on NO signalling pathway, bone mineral density (BMD), epiphyseal bone width, bone marrow angiogenesis, and parameters of oxidative stress in a rat model of glucocorticoid-induced osteoporosis (GIOP).

Material/Methods

Twenty-four 8-month-old male rats in four groups were given a single daily treatment during a 30-day period: an (untreated) control group (n=6): a dexamethasone-treated group (120 μ/kg) (n=6); a group treated with dexamethasone (120 μ/kg) and zaprinast (10 mg/kg) (n=6): and a group treated with dexamethasone (120 μ/kg) and avanafil (10 mg/kg) (n=6). Rat whole body bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA), and bone histology was performed. Also, selected oxidative stress parameters by HPLC method and the other biochemical parameters by ELISA method were measured.

Results

The GIOP model rats treated with zaprinast and avanafil showed a significant increase in NO, cyclic guanosine monophosphate (cGMP), and protein kinase G (PKG) (NO/cGMP/PKG) signaling-pathway components, and in C-terminal telopeptide of type I collagen (CTX-1), bone marrow angiogenesis, BMD, and epiphyseal bone width, compared with the (untreated) control rats (p<0.05). Levels of pyridinoline (PD) and deoxypyridinoline (DPD) were significantly reduced in the dexamethasone + zaprinast, and dexamethasone + avanafil treatment groups (p<0.05). Malondialdehyde (MDA), ubiquinone-10 (CoQ10), ubiquinol CoQ10 (CoQ10H), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) were significantly increased in the dexamethasone-treated group, compared with the (untreated) controls (p<0.05).

Conclusions

In the GIOP rat model, markers of oxidative stress and bone atrophy were significantly reduced by treatment with the PDE-5 inhibitors, zaprinast and avanafil.

Cordycepin prevents oxidative stress-induced inhibition of osteogenesis

Oxidative stress is known to be involved in impairment of osteogenesis and age-related osteoporosis. Cordycepin is one of the major bioactive components of Cordyceps militaris that has been shown to exert antioxidant and anti-inflammatory activities. However, there are few reports available regarding the effects of cordycepin on osteogenesis and the underlying mechanism. In this study, we investigated the potential osteoprotective effects of cordycepin and its mechanism systematically using both in vitro model as well as in vivo mouse models. We discovered that hydrogen peroxide (H2O2)-induced inhibition of osteogenesis which was rescued by cordycepin treatment in human bone marrow mesenchymal stem cells (BM-MSCs). Cordycepin exerted its protective effects partially by increasing or decreasing expression of osteogenic and osteoclastogenesis marker genes. Treatment with cordycepin increased Wnt-related genes' expression whereas supplementation of Wnt pathway inhibitor reversed its protective effects. In addition, administration of cordycepin promoted osteogenic differentiation of BM-MSCs by reducing oxidative stress in both ovariectomized and aged animal models. Taken together, these results support the protective effects of cordycepin on oxidative stress induced inhibition of osteogenesis by activation of Wnt pathway.

Natural Products from Chinese Medicines with Potential Benefits to Bone Health

Osteoporosis is a progressive, systemic bone disorder characterized by loss of bone mass and microstructure, leading to reduced bone strength and increased risk of fracture. It is often associated with reduced quality of life and other medical complications. The disease is common in the aging population, particularly among postmenopausal women and patients who receive long-term steroidal therapy. Given the rapid growth of the aging population, increasing life expectancy, the prevalence of bone loss, and financial burden to the healthcare system and individuals, demand for new therapeutic agents and nutritional supplements for the management and promotion of bone health is pressing. With the advent of global interest in complementary and alternative medicine and natural products, Chinese medicine serves as a viable source to offer benefits for the improvement and maintenance of bone health. This review summarizes the scientific information obtained from recent literatures on the chemical ingredients of Chinese medicinal plants that have been reported to possess osteoprotective and related properties in cell-based and/or animal models. Some of these natural products (or their derivatives) may become promising leads for development into dietary supplements or therapeutic drugs.

Mulberry water extract regulates the osteoblast/osteoclast balance in an ovariectomic rat model

Mulberry has favorable antioxidant ability.