The Effects of Natural Product-Derived Extracts for Longitudinal Bone Growth: An Overview of In Vivo Experiments.

Approximately 80% of children with short stature are classified as having Idiopathic Short Stature (ISS). While growth hormone (GH) treatment received FDA approval in the United States in 2003, its long-term impact on final height remains debated. Other treatments, like aromatase inhibitors, metformin, and insulin-like growth factor-1 (IGF-1), have been explored, but there is no established standard treatment for ISS. In South Korea and other Asian countries, East Asian Traditional Medicine (EATM) is sometimes employed by parents to potentially enhance their children's height growth, often involving herbal medicines. One such product, Astragalus membranaceus extract mixture HT042, claims to promote height growth in children and has gained approval from the Korean Food and Drug Administration (KFDA). Research suggests that HT042 supplementation can increase height growth in children without skeletal maturation, possibly by elevating serum IGF-1 and IGF-binding protein-3 levels. Preclinical studies also indicate the potential benefits of natural products, including of EATM therapies for ISS. The purpose of this review is to offer an overview of bone growth factors related to ISS and to investigate the potential of natural products, including herbal preparations, as alternative treatments for managing ISS symptoms, based on their known efficacy in in vivo studies.

Hydrolyzed Collagen Tripeptide Promotes Longitudinal Bone Growth in Childhood Rats via Increases in Insulin-Like Growth Factor-1 and Bone Morphogenetic Proteins.

Previous studies have reported that collagen tripeptide (CTP) derived from collagen hydrolysate has various beneficial effects on health by protecting against skin aging and improving bone formation and cartilage regeneration. Collagen-Tripep20TM (CTP20), which is a low-molecular-weight CTP derived from fish skin, contains a bioactive CTP, Gly-Pro-Hyp >3.2% with a tripeptide content >20%. Herein, we investigated the osteogenic effects and mechanisms of CTP20 (<500 Da) on MG-63 osteoblast-like cells and SW1353 chondrocytes. And we measured promoting ratio of the longitudinal bone growth in childhood rats. First, CTP20 at 100 µg/mL elevated the proliferation (15.0% and 28.2%), alkaline phosphatase activity (29.3% and 32.0%), collagen synthesis (1.25- and 1.14-fold), and calcium deposition (1.18- and 1.15-fold) in MG-63 cells and SW1353, respectively. In addition, we found that CTP20 could promote the longitudinal growth and height of the growth plate of the tibia in childhood rats. CTP20 enhanced the protein expression of insulin-like growth factor-1 (IGF-1) in MG-63 and SW1353 cells, and in the growth plate of childhood rats, along with Janus Kinase 2, and signal transducer and activator of transcription 5 activation in MG-63 and SW1353 cells. CTP20 also elevated the expression levels of bone morphogenetic proteins (BMPs) in MG-63 and SW1353 cells and in the growth plates of childhood rats. These results indicate that CTP20 may promote the endochondral ossification and longitudinal bone growth, through enhancing of IGF-1 and BMPs. (Clinical Trial Registration number: smecae 19-09-01).

Proteomic Identification of Plasma Components in Tachypleus tridentatus and Their Effects on the Longitudinal Bone Growth Rate in Rats.

Tachypleus tridentatus (T. tridentatus) is a marine animal and traditional Chinese medicine. T. tridentatus plasma is a valuable resource for important medical and health-based functions. In this experiment, in order to evaluate the effect and mechanism of T. tridentatus plasma with respect to the promotion of bone tissue growth in rats, the processes of ultrafiltration and mass spectrometry were first used to separate and identify the components of T. tridentatus plasma. Then, a comparison of the effects of the T. tridentatus plasma samples, which each possessed different molecular weights, regarding the growth of the long bones of rats was conducted. Finally, transcriptomics, proteomics, and bioinformatics were all used to analyze the biological functions and related signaling pathways of the T. tridentatus plasma in order to promote rat bone growth. The results showed that the contents of amino acid residues in peptides are related to the growth promotion that was contained in the 10-30 kDa plasma group. Moreover, the T. tridentatus plasma samples were found to be higher in this respect than those in the whole plasma group. In addition, the 10-30 kDa plasma group could significantly promote bone growth activity in rats. The proteomic analysis showed that the proteins that were differentially expressed in the 10-30 kDa plasma group were mainly enriched in the PI3K-AKT signal pathway. Our study suggested that the T. tridentatus plasma possesses promising potential for the purposes of clinical use, whereby it can serve the role of a growth-promoting agent.

Effects of a Mixture of Humulus japonicus on Longitudinal Bone Growth in Hypophysectomized Rats.

Previously, we reported that the administration of a mixture of Humulus japonicus (MH) increased the longitudinal bone growth rate in Sprague Dawley rats. In this study, we investigated the effects of the dietary administration of MH on longitudinal bone growth in growth hormone (GH)-deficient hypophysectomized male and female rats to determine whether the effect of MH was similar to that of GH. We measured the nose-to-anus and nose-to-tail length gain, femur and tibia lengths, growth plate zones, and expression of insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) after the dietary administration of MH or the injection of GH into hypophysectomized rats for 4 weeks. Results demonstrated that the dietary administration of MH had no effect on longitudinal bone growth, whereas the injection of GH increased the nose-to-tail length gain and femur and tibia lengths in hypophysectomized rats. In addition, MH did not affect the growth plate, bone mineralization, and expression of IGF-1 and IGFBP-3. These findings indicate that MH does not exert a GH-like effect and that the effects of MH and GH on longitudinal bone growth involve different pathways.

A Mixture of Humulus japonicus Increases Longitudinal Bone Growth Rate in Sprague Dawley Rats.

The aim of this study was to investigate the effects of administration of a mixture of Humulus japonicus (MH) on longitudinal bone growth in normal Sprague Dawley (SD) rats. We measured the femur and tibia length, growth plate area, proliferation of chondrocytes, and expression of insulin-like growth factor-1 (IGF-I) and IGF binding protein-3 (IGFBP-3), and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 5 (STAT5) phosphorylation after dietary administration of MH in SD rats for four weeks. The nose-tail length gain and length of femur and tibia increased significantly in the group that received MH for a period of four weeks. We performed H&E staining and Bromodeoxyuridine/5-Bromo-2'-Deoxyuridine (BrdU) staining to examine the effect of dietary administration of MH on the growth plate and the proliferation of chondrocytes and found that MH stimulated the proliferation of chondrocytes and contributed to increased growth plate height during the process of longitudinal bone growth. In addition, serum levels of IGF-1 and IGFBP-3 and expression of IGF-1 and IGFBP-3 mRNAs in the liver and bone were increased, and phosphorylation of JAK2/STAT5 in the liver was increased in the MH groups. Based on these results, we suggest that the effect of MH on longitudinal bone growth is mediated by increased JAK2/STAT5-induced IGF-1 production.

Variation of bone acquisition during growth hormone treatment in children can be explained by proteomic biomarkers, bone formation markers, body composition and nutritional factors.

OBJECTIVE: Growth hormone (GH) regulates both longitudinal growth and bone acquisition in children, and has profound metabolic effects. The aim was to investigate the association between proteomic biomarkers, body fat, nutrition and bone formation markers, and longitudinal growth in response to GH during the first year of treatment. The degree to which changes in these factors could explain variations in GH-dependent longitudinal growth and bone mineralization was also assessed. METHODS: The individualized GH dose trial included 128 short prepubertal children with either normal (non-GH-deficient) or reduced levels of GH secretion (GH-deficient) (mean age ±â€¯SD, 8.6 ±â€¯2.6 years; 90 boys), i.e., with a broad range of GH-secretion and GH-responsiveness, receiving GH treatment (mean 43 µg/kg/day). Blood samples were taken and dual-energy X-ray absorptiometry (DXA) measured at baseline and 1 year of treatment. Step-wise multiple regression models were constructed including three steps with different independent variables added at each step to explain the variance in outcome variables (heightSDS, bone mineral content (BMC) and bone mineral density (BMD). Independent variables included in Step I were previously identified proteomic markers related to GH treatment response, bone formation markers (intact PINP, bone-specific alkaline phosphatase and osteocalcin), variables at treatment start (GH dose mU/kg/day, GH maximum secretion, and difference between child's current and mid-parental heightSDS). Step II explored the added influence of body composition data (body mass index or DXA). Step III explored the added influence of serum nutritional markers and hormones. RESULTS: Step I variables explained 71% of the variation in first year heightSDS gain, median (minimum-maximum) 0.8 (0.24-1.67); and the proportion explained rose to 73% following inclusion of step II variables and 75% following step III. Corresponding values for total body BMC were 58%, 78%, and 80%, respectively. Proportions fell by approximately 20% when BMC was adjusted for height; 33%, 57%, and 57% for steps I, II, and III, respectively. Corresponding values for total body BMD were 29%, 39%, and 45%, respectively. CONCLUSION: For total BMC, as much as 80% of the variation during the first year of GH treatment could be explained by proteomic biomarkers, body fat, nutrition and bone formation markers, whereas for height-adjusted BMC 57% could be explained. The inclusion of information about either body composition (fat/lean mass) or nutritional markers contributed with approximately 20%. The variation in heightSDS gain could be explained to 75%. Hence, information of fat or nutrition markers was needed for explaining the variation in bone acquisition to the same magnitude as explaining the variation in height response.

The Korean herbal formulation Yukmijihwangtang stimulates longitudinal bone growth in animal models.

BACKGROUND: Yukmijihwangtang (YJT) is a traditional Korean medicine that has been used to treat kidney-yin deficiency symptoms such as dizziness and tinnitus. In addition, because it is also thought to nourish kidney-yin, it has been used to treat short stature from congenital deficiency. This study evaluated the effects of YJT on longitudinal bone growth in rats. METHODS: Female adolescent rats were randomly assigned to groups that received distilled water (per os [p.o.] twice a day; control), recombinant human growth hormone (rhGH; 20 µg/kg, subcutaneous [s.c.] once a day), or two different doses of YJT (100 or 300 mg/kg, p.o. twice a day). In each group, treatment was maintained for 4 days. Rats were injected intraperitoneally with 5-bromo-2'-deoxyuridine (BrdU; 50 mg/kg) to label proliferating chondrocytes on days 2 - 4. Tetracycline hydrochloride (20 mg/kg) was injected intraperitoneally to form fluorescent bands on the growth plates on day 3 for measuring the longitudinal bone growth rate. Expression of insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) in the growth plate was identified using immunohistochemistry. RESULTS: There was a significant increase in the rate of bone growth in the 300 mg/kg YJT group (523.8 ± 23.7 µm/day; P < 0.05) compared to the control group (498.0 ± 23.8 µm/day), while the 100 mg/kg YJT group exhibited a non-significant increase. The number of BrdU-positive cells in the chondrocytes of the rhGH-treated group exhibited a significant increase (103.8 ± 34.2 cells/mm2) compared to that of the control group (70.3 ± 19.7 cells/mm2), while the 300 mg/kg YJT group had a non-significant increase. Additionally, IGF-1 and BMP-2 were highly expressed in the growth plate in the 300 mg/kg YJT and rhGH groups. CONCLUSIONS: YJT increased the longitudinal bone growth rate by stimulating chondrocyte proliferation with increasing increments of local IGF-1 and BMP-2 expression. Based on these findings, YJT may be a therapeutic candidate for the treatment of growth retardation during adolescence.

Soy isoflavone supplementation improves longitudinal bone growth and bone quality in growing female rats.

OBJECTIVES: The aim of this study was to investigate the effects of soy isoflavone on tibia length, bone mineral density (BMD), and structural parameters in growing female rats. METHODS: Three-week-old female Sprague-Dawley rats were randomly assigned to four experimental groups: control (CON: distilled water gavage); low-dose isoflavone (low-IF: 10 mg/kg body weight [BW]/d gavage); high-dose isoflavone (high-IF: 50 mg/kg BW/d gavage); and 17 ß-estradiol (E2: subcutaneous injection of 10 µg). All animals received a soy-free diet and vaginal opening was monitored daily. After an 8-wk treatment period, bone-related parameters (alkaline phosphatase [ALP], osteocalcin [OC], N-terminal telopeptide [NTx], bone length, failure load, stiffness, BMD, and structural parameters) were analyzed. RESULTS: Serum ALP levels of the high-IF group were higher than those of the CON group (P < 0.05); however, serum OC levels of the high-IF group were lower than those of the CON, low-IF, and E2 groups (P < 0.05). The tibias and femurs of the low-IF group were longer than those of the CON and high-IF groups (P < 0.05). Bone volume, trabecular number, and BMD of trabecular bone of the high-IF and E2 groups were higher than those of the CON and low-IF groups (P < 0.05). The trabecular thickness of the high-IF group was higher than that of the CON and low-IF groups (P < 0.05). The failure load of the high-IF group was higher than those of the CON group (P < 0.05). Age and body weight at vaginal opening of the E2 group were significantly lower than those of the CON, low-IF, and high-IF groups (P < 0.05). CONCLUSIONS: This study suggests that 8 wk of low-dose supplementation with soy isoflavone stimulates longitudinal bone growth. Additionally, high-dose supplementation with soy isoflavone may improve bone quality (BMD and structural parameters) in growing female rats.

Effects of Eucommia ulmoides extract on longitudinal bone growth rate in adolescent female rats.

Eucommia ulmoides is one of the popular tonic herbs for the treatment of low back pain and bone fracture and is used in Korean medicine to reinforce muscles and bones. This study was performed to investigate the effects of E. ulmoides extract on longitudinal bone growth rate, growth plate height, and the expressions of bone morphogenetic protein 2 (BMP-2) and insulin-like growth factor 1 (IGF-1) in adolescent female rats. In two groups, we administered a twice-daily dosage of E. ulmoides extract (at 30 and 100 mg/kg, respectively) per os over 4 days, and in a control group, we administered vehicle only under the same conditions. Longitudinal bone growth rate in newly synthesized bone was observed using tetracycline labeling. Chondrocyte proliferation in the growth plate was observed using cresyl violet dye. In addition, we analyzed the expressions of BMP-2 and IGF-1 using immunohistochemistry. Eucommia ulmoides extract significantly increased longitudinal bone growth rate and growth plate height in adolescent female rats. In the immunohistochemical study, E. ulmoides markedly increased BMP-2 and IGF-1 expressions in the proliferative and hypertrophic zones. In conclusion, E. ulmoides increased longitudinal bone growth rate by promoting chondrogenesis in the growth plate and the levels of BMP-2 and IGF-1. Eucommia ulmoides could be helpful for increasing bone growth in children who have growth retardation.