Prevention of retinoic acid-induced osteoporosis in mice by isoflavone-enriched soy protein

Yak milk improves retinoic acid-induced osteoporosis by promoting intestinal calcium absorption

Yak milk is a unique nutritional quality milk with health-promoting benefits. In this study, we investigated the effect of yak milk on intestinal calcium absorption in mice with retinoic acid-induced osteoporosis (OP) and in the Caco-2 cell model. Results showed that compared with the model group, the apparent calcium absorption rate increased from 35.93% to 51.84% and 49.41% for the low-dose yak milk group (L-YM) and high-dose yak milk group (H-YM), respectively, and the calcium accumulation rate increased from 26.14% to 44.09% and 42.66%, respectively. However, no improvement was observed in the alendronate sodium (ALN) group. The expression of the transient receptor potential vanilloid 6 (TRPV6) calcium channel in the yak milk treatment group was 2.7 (L-YM) and 3.5 (H-YM) times higher than that in the model group, implying that TRPV6 channel was the main transport pathway in the small intestine. Furthermore, in vitro calcium absorption assays indicated that yak milk enhanced intestinal Ca2+ absorption more effectively than CaCl2 by regulating the TRPV6 channel. These data suggest that yak milk promotes calcium absorption by upregulating the expression of the TRPV6 calcium channel, thereby improving OP. This study highlights the importance of yak milk as a dietary factor for bone health.

Mongolian medicine Sugemule-7 decoction prevents osteoporosis via Erk1/2 and p38 MAPK signaling pathways according to network pharmacology analysis

Osteoporosis (OP) is a significant global public health concern that requires the development of safe and effective drugs for prevention and treatment. Sugemule-7 (SGML-7) decoction, a traditional Mongolian herbal prescription, has long been used for treating OP, but its components and mechanisms of action remain unclear. The study identified the main compounds of SGML-7 using UHPLC-Q Exactive MS and explored the multi-target mechanisms of SGML-7 in OP through network pharmacology and molecular docking. A retinoic acid (RA)-induced mouse OP model was utilized to confirm the therapeutic effects and potential mechanism of SGML-7. Additionally, mouse pre-osteoblastic (MC3T3-E1) cells treated with SGML-7 medicated serum were employed to delve deeper into the molecular mechanisms. The UHPLC-Q Exactive MS analysis, network pharmacology, and molecular docking suggested that the synergistic effect of multiple active compounds could be the main contributor to SGML-7 for its anti-OP activities. Moreover, MAPK1, JUN, ESR1, TP53, AKT1, NCOA1, FOS, and NR3C1 were identified as potential key targets, and the MAPK signaling pathway was among the signaling pathways possibly involved in the anti-OP activities of SGML-7. Consistent with these findings, experimental studies confirmed that SGML-7 prevented bone loss, enhanced bone quality in OP mice, and promoted osteoblastic activity and bone formation in MC3T3-E1 cells by modulating MAPK-associated targets. Taken together, SGML-7 shows promise as an effective and appealing anti-OP drug candidate.

Lacticaseibacillus paracasei JM053 alleviates osteoporosis in rats by increasing the content of soy isoflavone aglycones in fermented soymilk

Lacticaseibacillus paracasei JM053 has a significant ability to convert soy isoflavones and can be used as a fermentation strain to ferment soymilk, thereby increasing the content of free aglycones in soymilk and thus providing an effective method to alleviate osteoporosis symptoms. This study aims to establish a rat model of osteoporosis induced by dexamethasone (DEX) and clarify the alleviating effect of soymilk fermented with Lacticaseibacillus paracasei JM053 on osteoporosis. Research has shown that fermented soymilk with Lacticaseibacillus paracasei JM053 can inhibit weight loss in rats caused by DEX, regulate the expression of inflammatory factors such as tumor necrosis factor-α (TNF-α) towards normal levels, and increase levels of alkaline phosphatase (ALP) and osteocalcin (OCN) to promote bone synthesis. By observing the microstructure of bone tissue through microCT and Goldner staining, it was found that, compared with the model group, fermented soymilk with Lacticaseibacillus paracasei JM053 can alleviate the damage to bone tissue structure caused by DEX by increasing the number of bone trabeculae and reducing fracture. Fermented soymilk with Lacticaseibacillus paracasei JM053 can alleviate bone metabolism disorders by regulating gut microbiota and metabolite content. This study provides theoretical and data-based support for developing functional products that can alleviate osteoporosis.

Epimedii Folium decoction ameliorates osteoporosis in mice through NLRP3/caspase-1/IL-1β signalling pathway and gut-bone axis

AIM OF THE STUDY

This study aimed to determine the effect of Epimedium brevicornu Maxim. (EF) on osteoporosis (OP) and its underlying molecular mechanisms, and to explore the existence of the "Gut-Bone Axis".

MATERIAL AND METHODS

The impact of EF decoction (EFD) on OP was evaluated using istopathological examination and biochemical assays. Targeted metabolomics was employed to identify key molecules and explore their molecular mechanisms. Alterations in the gut microbiota (GM) were evaluated by 16S rRNA gene sequencing. The role of the GM was clarified using an antibiotic cocktail and faecal microbiota transplantation.

RESULTS

EFD significantly increased the weight (14.06%), femur length (4.34%), abdominal fat weight (61.14%), uterine weight (69.86%), and insulin-like growth factor 1 (IGF-1) levels (59.48%), while reducing serum type I collagen cross-linked carboxy-terminal peptide (CTX-I) levels (15.02%) in osteoporotic mice. The mechanism of action may involve the regulation of the NLRP3/cleaved caspase-1/IL-1β signalling pathway in improving intestinal tight junction proteins and bone metabolism. Additionally, EFD modulated the abundance of related GM communities, such as Lactobacillus, Coriobacteriaceae, bacteria of family S24-7, Clostridiales, and Prevotella, and increased propionate and butyrate levels. Antibiotic-induced dysbiosis of gut bacteria disrupted OP regulation of bone metabolism, which was restored by the recovery of GM.

CONCLUSIONS

Our study is the first to demonstrate that EFD works in an OP mouse model by utilising GM and butyric acid. Thus, EF shows promise as a potential remedy for OP in the future.

Protective effect of isoflavone enriched soy β-conglycinin on osteoporosis in ovariectomized rats

Research shows that the consumption of soybean foods can reduce the incidence rate of bone fractures in women after menopause. The aim of this study was to investigate the effects of different complex of soy β-conglycinin (7S) and isoflavones (7S-ISO) on osteoporosis in ovariectomized rats. All treatments were administrated intragastrically to the groups every afternoon for 3 months. The treatments were administrated at 1 mL·(100 g)^-1 , the animals were given 50 mg·kg^-1 ·d^-1 ISO, and the concentration of protein was about 2 wt. %. The bone mineral density (BMD) and the bone biomechanics results of left tibia' maximum load in the 7S-ISO group is significantly higher than in the ovariectomized group and the 7S group (p < .05). Otherwise, the serum tartrate-resistant acid phosphatase (s-TRACP), serum osteocalcin (s-BGP), and serum estradiol (s-E₂ ) levels in 7S-ISO were all significantly different from the OVX, OVX + casein, and the OVX + 7S group (p < .05). The serum calcium (s-Ca) level was not significantly different among all the groups. 7S-ISO may exhibit moderate estrogenic activities and as compared to 7S and ISO in osteoporosis (OP) of ovariectomized rats. PRACTICAL APPLICATIONS: The effects of soy proteins on the health of females have always been a concern. It has been extensively reported soy 7S globulin (7S) as a type of trimer glycoprotein can depress blood fats. The aim of this study was to investigate the effects of different complex of soy β-conglycinin and isoflavones (ISO), the main storage proteins and polyphenols in soy, on osteoporosis in ovariectomized rats.

Bone Regeneration in Osteoporosis via Carbon Nanotube-Based Bone Morphogenetic Protein-2

We constructed a bone morphogenetic protein 2 (BMP-2)@Carbon nanotube (CNT) delivery system to explore the feasibility of a nanodrug delivery system in the treatment of osteoporosis (OP). Osteoblasts were cultured and OP mouse models were constructed to evaluate the osteogenesis of nano-BMP-2 in OP therapy. In physicochemical property tests, we found that BMP-2 was effectively loaded into CNT to form nanoparticles (NPs) with a particle size of 100 nm. Additionally, we found that nano-BMP-2 had good stability and could effectively prolong BMP-2 release time. In cellular experiments, we found that nano-BMP-2 could penetrate osteoblasts more effectively than BMP-2 alone, and with the increase of BMP-2 loading, the amount of BMP-2 penetrating osteoblasts increased with an optimal loading of 100 μg. We determined that nano-BMP-2 could increase proliferation activity of osteoblasts to better promote OP repair. In our vivo experiments, we found that nano-BMP-2 was effectively excreted through the kidney and mainly distributed in bone tissue. Moreover, CNT effectively prolonged the half-life of BMP-2 and was safe to introduce through intramuscular injection and did not cause obvious inflammatory reactions. Following treatment, nano-BMP-2 increased body weight, femur weight, and femoral head diameter in OP mouse models. Furthermore, bone trabecular was arranged in a close and orderly fashion and was uniform in thickness in OP mice treated with nano-BMP-2. OP mice had improved bone mineral density, trabecular thickness, trabecular number, and cortical bone thickness in their metaphyseal regions, implying nano-BMP-2 treatment led to improved OP symptoms. Therefore, BMP-2@CNT may be a beneficial choice for treatment of OP.

Near-Infrared Light-Controlled and Real-Time Detection of Osteogenic Differentiation in Mesenchymal Stem Cells by Upconversion Nanoparticles for Osteoporosis Therapy

Osteoporosis (OP) is one of the most common diseases in the elderly, and it is not effectively solved by current treatments. Mesenchymal stem cells (MSCs) have multiple differentiation potentials, which can induce osteogenic differentiation to treat OP; however, it is important to understand how to remotely control and detect osteogenic differentiation in vivo in real time. Here, we developed an upconversion nanoparticle (UCNP)-based photoresponsive nanoplatform for near-infrared (NIR) light-mediated control of intracellular icariin (ICA) release to regulate the osteogenic differentiation of MSCs for OP therapy. We simultaneously detected osteogenic differentiation in vivo in real time to evaluate the treatment effects. The Tm/Er-doped UCNPs were synthesized and coated with mesoporous silica (UCNP@mSiO₂) first. Then, the photocaged linker 4-(hydroxymethyl)-3-nitrobenzoic acid (ONA) and the PEG linker (OH-PEG4-MAL) were linked to the surface of UCNP@mSiO₂ to conjugate to the cap β-cyclodextrin (β-CD) and the Arg-Gly-Asp (RGD)-targeted peptide/matrix metalloproteinase 13 (MMP13)-sensitive peptide-BHQ (CGPLGVRGK-BHQ₃) to form the UCNP nanoplatform (UCNP@mSiO₂-peptide-BHQ-ONA-CD) for drug loading. Under 980 nm NIR light, the upconverted UV from the UCNPs triggered the cleavage of cap β-CD and the intracellular release of ICA to induce the osteogenic differentiation of MSCs for OP therapy. Meanwhile, MMP13, which was produced by osteogenic differentiation of MSCs, cleaved the MMP13-sensitive peptide to remove BHQ and recover the fluorescence of UCNPs, allowing real-time detection of osteogenic differentiation and the evaluation of the OP treatment effect. This photoresponsive UCNP nanoplatform has the potential to be used for the remote control and real-time detection of osteogenic differentiation of MSCs for OP therapy by NIR.

Microbial Composition of a Traditional Fermented Wheat Preparation—Nishasta and Its Role in the Amelioration of Retinoic Acid-Induced Osteoporosis in Rats

Fermented foods have a long history of human use. The purpose of this study was to characterize the microbial composition of a traditional fermented wheat preparation—Nishasta— and to explore its effect in retinoic acid-induced osteoporosis in Wistar rats. The sample was suspended in sterile water (10% w/v), mixed thoroughly, filtered, and gradually diluted. Aliquots of dilutions were cultured in MRS (DeMan–Rogosa–Sharpe) medium, and colonies with similar morphologies were subjected to DNA extraction. The 16S rRNA gene of the isolates was amplified by polymerase chain reaction, checked by agarose gel electrophoresis, and finally identified by sequencing. Anti-osteoporosis screening of Nishasta was carried out in female Wistar rats using retinoic acid as an inducer (70 mg/kg, p.o. once a day for 14 days). Its effect on bone health parameters was determined. The bone metabolism markers such as hydroxyproline (HOP), tartrate-resistant acid phosphatase (TRACP), and alkaline phosphatase (ALP) were evaluated. The results of microbial characterization revealed the presence of ten clones of Lactobacillus plantarum in the fermented preparation with L. plantarum NF3 as the predominant strain. The average microbial count was 2.4 × 103 CFU/g. Retinoic acid administration led to a marked disorder of various bone health markers in rats. It also increased the levels of urine calcium and phosphorus, indicating increased bone destruction. Treatment with fermented wheat (at 200, 100, and 50 mg/kg doses, p.o. daily for 42 days after the induction of osteoporosis) improved bone mineral density in a dose-dependent manner. It also improved the bone microstructure and reduced the levels of ALP, TRACP, and HOP. Micro-CT revealed that it reduced trabecular separation and increased the percent bone volume, trabecular numbers, trabecular thickness, and bone mineral density in the rats. The results showed that the fermented wheat promoted bone formation and prevented bone resorption. Our findings clearly established the effectiveness of Nishasta against osteoporosis in Wistar rats that can be partly attributed to the improved gut calcium absorption and microbiota composition.

Antioxidative and Anti-Inflammatory Activities of Chrysin and Naringenin in a Drug-Induced Bone Loss Model in Rats

Oxidative stress (OS) mediators, together with the inflammatory processes, are considered as threatening factors for bone health. The aim of this study was to investigate effects of flavonoids naringenin and chrysin on OS, inflammation, and bone degradation in retinoic acid (13cRA)-induced secondary osteoporosis (OP) in rats. We analysed changes in body and uterine weight, biochemical bone parameters (bone mineral density (BMD), bone mineral content (BMC), markers of bone turnover), bone geometry parameters, bone histology, OS parameters, biochemical and haematological parameters, and levels of inflammatory cytokines. Osteoporotic rats had reduced bone Ca and P levels, BMD, BMC, and expression of markers of bone turnover, and increased values of serum enzymes alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Malondialdehyde (MDA) production in liver, kidney, and ovary was increased, while the glutathione (GSH) content and activities of antioxidant enzymes were reduced and accompanied with the enhanced release of inflammatory mediators TNF-α, IL-1β, IL-6, and RANTES chemokine (regulated on activation normal T cell expressed and secreted) in serum. Treatment with chrysin or naringenin improved bone quality, reduced bone resorption, and bone mineral deposition, although with a lower efficacy compared with alendronate. However, flavonoids exhibited more pronounced antioxidative, anti-inflammatory and phytoestrogenic activities, indicating their great potential in attenuating bone loss and prevention of OP.

Lactobacillus Fermentum ZS40 prevents secondary osteoporosis in Wistar Rat

Using retinoic acid to inducer, we successfully established a rat model of secondary osteoporosis and verified the preventive effect of Lactobacillus fermentum ZS40 (ZS40) on secondary osteoporosis. Serum biochemical indicators showed that ZS40 can effectively slow down bone resorption caused by retinoic acid, increase blood content of calcium, phosphorus, bone alkaline phosphatase, bone gla protein, and insulin-like growth factor 1, and decrease blood content of tartrate-resistant acid phosphatase (TRAP) 5b. qRT-PCR results showed that ZS40 could upregulate mRNA expressions of β-catenin, Wnt10b, Lrp5, Lrp6, Runx2, ALP, RANKL, and OPG, and downregulate mRNA expression of DKK1, RANK, TRACP, and CTSK in the rats' spinal cord. Results following TRAP staining showed that ZS40 could slow down retinoic acid-induced formation of osteoclasts. Micro-CT results showed that ZS40 could reduce Tb.Sp, increase BV/TV, Tb.N, Tb.Th, and ultimately increase bone mineral density of rats in vivo. These findings indicate that ZS40 might have a potential role in preventing retinoic acid-induced secondary osteoporosis in vivo.

Colonization Potential to Reconstitute a Microbe Community in Pseudo Germ-Free Mice After Fecal Microbe Transplant From Equol Producer

Human intestinal microbiota plays a crucial role in the conversion of isoflavones into equol. Usually, human microbiota-associated (HMA) animal models are used, since it is difficult to establish the mechanism and causal relationship between equol and microbiota in human studies. Currently, several groups have successfully established HMA animal models that produce equol through germ-free mice or rats; however, the HMA model of producing equol through pseudo germ-free mice has not been established. The objective of this study is to establish an HMA mice model for equol production through pseudo germ-free mice, mimicking the gut microbiota of an adult human equol producer. First, a higher female equol producer was screened as a donor from 15 volunteers. Then, mice were exposed to vancomycin, neomycin sulfate, metronidazole, and ampicillin for 3 weeks to obtain pseudo germ-free mice. Finally, pseudo germ-free mice were inoculated with fecal microbiota of the equol producer for 3 weeks to establish HMA mice of producing equol. The results showed that (i) the ability to produce equol was partially transferred from the donor to the HMA mice. (ii) Most of the original intestinal microbiota of mice were eliminated after broad-spectrum antibiotic administration. (iii) The taxonomy data from HMA mice revealed similar taxa to the donor sample, and the species richness returned to the level close to the donor. (iv) The family Coriobacteriaceae and genera Collinsella were successfully transferred from the donor to HMA mice. In conclusion, the HMA mice model for equol production, based on pseudo germ-free mice, can replace the model established by germ-free mice. The model also provides a basis for studying microbiota during the conversion from isoflavones into equol.

Melatonin prevents bone destruction in mice with retinoic acid-induced osteoporosis

BACKGROUND

The protective effect of melatonin against bone metabolism imbalance in osteoporosis (OP) induced by drugs such as retinoic acid (RA) is unclear. The aim of this study was to explore the role of melatonin in bone destruction based on a mouse model.

METHODS

RA-induced OP model mice were established. To assess the effect of melatonin on these mice, micro-CT was used to characterize the trabecular structure of normal mice and those treated with RA (model), RA + low-dose melatonin (Mlt-L), RA + high-dose melatonin (Mlt-H), and RA + alendronate sodium (positive control). The shape of the trabecular bone, the length and diameter of the femoral head and the height and diameter of vertebra(L1) of each group were also measured and the number of osteoclasts was determined by Tartrate-resistant acid phosphatase (TRACP) staining. Meanwhile, the expression of alkaline phosphatase (ALP) was evaluated by immunohistochemistry assays. The differences between groups in terms of liver and kidney oxidation-related indexes and serum and urinary indicators related to bone metabolism were also analyzed. Furthermore, qRT-PCR and western blotting were used to evaluate the effect of melatonin on osteogenic and osteoclastic differentiation in MC3T3-E1 and RAW264.7 cells, respectively.

RESULTS

RA induction led to a decrease in the amount and density of trabecular bone, a decrease in the length and diameter of the femur and height, diameter of the vertebra (L1), a decrease in bone mass and density and the expression of ALP, and an increase in the number of osteoclasts. Melatonin treatment alleviated these effects induced by RA, increasing the amount of trabecular bone in OP mice, improving the microstructure of the femur and vertebra(L1) and increasing bone mass bone density and the expression of ALP, as well as decreasing the number of osteoclasts. Additionally, blood and urinary bone metabolism-related indicators showed that melatonin promoted bone formation and inhibited bone resorption. Determination of oxidant and antioxidant biomarkers in the livers and kidneys of the mice revealed that melatonin promoted the antioxidant level and suppressed the level of oxidant molecules in these organs. In vitro, RA promoted osteoclasts and inhibit osteogenesis by increasing oxidative stress levels in the RAW264.7 and MC3T3-E1 cells, but melatonin reversed this effect. Melatonin may, therefore, play a role in the ERK/SMAD and NF-κB pathways.

CONCLUSIONS

Melatonin can alleviate bone loss in RA-induced OP model mice, repair the trabecular microstructure, and promote bone formation. These effects may be related to reducing oxidation levels in vivo and vitro through the ERK/SMAD and NF-κB pathways.

Ursolic Acid Prevents Retinoic Acid-Induced Bone Loss in Rats

OBJECTIVE

To examine the effects of ursolic acid (UA) on mitigating retinoic acid (RA)-induced osteoporosis in rats.

METHODS

Fifty female Sprague-Dawley rats were randomly divided into the control group (n=10) and the osteoporosis group (n=40). The 40 osteoporosis rats were induced by 75 mg/(kg•d) RA once daily for 2 weeks, and then were randomly assigned to vehicle control (model), low-, middle-, and high-dose UA [(UA-L, UA-M, UA-H; 30, 60, 120 mg/(kg•d), respectively] groups (10 rats each). UA were administered once daily to the rats from the 3rd weeks for up to 4 weeks by gavage. Bone turnover markers [serum alkaline phosphatase (ALP), osteocalcin (OCN), urine deoxypyridinoline (DPD)] and other parameters, including serum calcium (S-Ca), serum phosphorus (S-P), urine calcium (U-Ca), urine phosphorus (U-P), and bone mineral density (BMD) of the femur, 4th lumbar vertebra and tibia, bone biomechanical properties and trabecular microarchitecture, were measured.

RESULTS

The osteoporosis in rats was successfully induced by RA. Compared with the model group, UA-M and UA-H significantly reversed the RA-induced changes in S-P, U-Ca, U-P, ALP, OCN and urine DPD ratio and markedly enhanced the BMD of right femur, 4th lumbar vertebra and tibia (Plt;0.05 or Plt;0.01). Further, biomechanical test and microcomputed tomography evaluation also showed that UA-H drastically improved biomechanical properties and trabecular microarchitecture (Plt;0.05 or Plt;0.01).

CONCLUSION

UA could promote bone formation, increase osteoblastic activity and reduce osteoclastic activity in rats, indicating that UA might be a potential therapeutic of RA-induced acute osteoporosis.

Synthesis and cytotoxicity evaluation of 3-amino-2-hydroxypropoxygenistein derivatives

Soy isoflavones exhibit various biological activities, such as antioxidant, anti-tumor, anti-inflammatory, and cardiovascular protective effects. The present study was designed to investigate the effects of sixteen synthesized 3-amino-2-hydroxypropoxy genistein derivatives on cell proliferation and activation of Nrf2 (Nuclear factor erythroid 2-related factor 2)/ARE (antioxidant response elements) pathway in human cancer cell lines. Most of the tested compounds exerted greater cytotoxic activity than genistein, as measured by MTT assay. Moreover, compound 8c showed the highest ARE-luciferase reporter activity among the test compounds. It strongly promoted Nrf2 nuclear translocation and up-regulated the expression of total Nrf2 and downstream targets NQO-1 and HO-1 at protein level. The present study may provide a basis for the application of isoflavone derivatives as Nrf2/ARE pathway inducers for cancer therapy and cancer prevention.

Dietary Soy Isoflavone: A Mechanistic Insight

Soy, a major component of the diet for centuries contains the largest concentration of isoflavones, a class of phytoestrogens. A variety of health benefits are associated with the consumption of soy primarily because of the isoflavones genistein, daidzein, and glycitein with a potential protective effect against a number of chronic diseases. Owing to the pharmaceutical and nutraceutical properties allied with isoflavonoids and their use in functional foods, there is a growing interest in these compounds. This review throws light on the chemistry, and significant pharmacological and biopharmaceutical aspects of soy isoflavones. This article critically describes the mechanisms of action, infers conclusions and shows opportunity for future research.

The Cooperative Effect of Genistein and Protein Hydrolysates on the Proliferation and Survival of Osteoblastic Cells (hFOB 1.19)

Chum salmon skin gelatin, de-isoflavoned soy protein, and casein were hydrolyzed at two degrees of hydrolysis. Genistein, the prepared hydrolysates, and genistein-hydrolysate combinations were assessed for their proliferative and anti-apoptotic effects on human osteoblasts (hFOB 1.19) to clarify potential cooperative effects between genistein and these hydrolysates in these two activities. Genistein at 2.5 μg/L demonstrated the highest proliferative activity, while the higher dose of genistein inhibited cell growth. All hydrolysates promoted osteoblast proliferation by increasing cell viability to 102.9%–131.1%. Regarding etoposide- or NaF-induced osteoblast apoptosis, these hydrolysates at 0.05 g/L showed both preventive and therapeutic effects against apoptosis. In the mode of apoptotic prevention, the hydrolysates decreased apoptotic cells from 32.9% to 15.2%–23.7% (etoposide treatment) or from 23.6% to 14.3%–19.6% (NaF treatment). In the mode of apoptotic rescue, the hydrolysates lessened the extent of apoptotic cells from 15.9% to 13.0%–15.3% (etoposide treatment) or from 13.3% to 10.9%–12.7% (NaF treatment). Gelatin hydrolysates showed the highest activities among all hydrolysates in all cases. All investigated combinations (especially the genistein-gelatin hydrolysate combination) had stronger proliferation, apoptotic prevention, and rescue than genistein itself or their counterpart hydrolysates alone, suggesting that genistein cooperated with these hydrolysates, rendering greater activities in osteoblast proliferation and anti-apoptosis.

Synthesis and cytotoxicity evaluation of 3-amino-2-hydroxypropoxyisoflavone derivatives

Soy isoflavones exert a wide variety of biological activities, such as antioxidant, anti-inflammatory and anti-cancer properties. Nuclear factor erythroid 2-related factor 2 (Nrf2), a bZip transcription factor, plays a key role in soy isoflavones induced protection against oxidative stress and cancer. To obtain more effective isofavones, a series of 7,4'-bis-(3-amino-2-hydroxypropoxy), 7 or 4'-(3-amino-2-hydroxypropoxy) isoflavone derivatives have been synthesized as potential antitumor agents and Nrf2/ARE (antioxidant response element) activators. The cytotoxicity of these compounds in human cancer cell lines MDA-MB-231, HT-29, HCT116, HepG2 and 7402 was tested by MTT assay. In this study, the cytotoxicity of compound 3b exhibited highest cytotoxic activity and at the safety dose range, it also strongly up-regulated antioxidant response element (ARE)-luciferase reporter activity. In addition, compound 3b induced Nrf2 nuclear translocation and upregulated its downstream target genes NQO-1 and HO-1 at protein level. Taken together, our results suggest that compound 3b could be a potential agent for cancer themotherapy or cancer chemoprevention.