Type 2 diabetes mellitus (T2DM) is the most widespread form of diabetes, characterized by chronic hyperglycaemia, insulin resistance, and inefficient insulin secretion and action. Primary care in T2DM is pharmacological, using drugs of several groups that include insulin sensitisers (e.g., biguanides, thiazolidinediones), insulin secretagogues (e.g., sulphonylureas, meglinides), alpha-glucosidase inhibitors, and the newest incretin-based therapies and sodium–glucose co-transporter 2 inhibitors. However, their long-term application can cause many harmful side effects, emphasising the importance of the using natural therapeutic products. Natural health substances including non-flavonoid polyphenols (e.g., resveratrol, curcumin, tannins, and lignans), flavonoids (e.g., anthocyanins, epigallocatechin gallate, quercetin, naringin, rutin, and kaempferol), plant fruits, vegetables and other products (e.g., garlic, green tea, blackcurrant, rowanberry, bilberry, strawberry, cornelian cherry, olive oil, sesame oil, and carrot) may be a safer alternative to primary pharmacological therapy. They are recommended as food supplements to prevent and/or ameliorate T2DM-related complications. In the advanced stage of T2DM, the combination therapy of synthetic agents and natural compounds with synergistic interactions makes the treatment more efficient. In this review, both pharmaceutical drugs and selected natural products, as well as combination therapies, are characterized. Mechanisms of their action and possible negative side effects are also provided.

Osteoporosis is considered an age-related disorder of the skeletal system, characterized primarily by decreased bone mineral density (BMD), microstructural quality and an elevated risk of fragility fractures. This silent disease is increasingly becoming a global epidemic due to an aging population and longer life expectancy. It is known that nutrition and physical activity play an important role in skeletal health, both in achieving the highest BMD and in maintaining bone health. In this review, the role of macronutrients (proteins, lipids, carbohydrates), micronutrients (minerals—calcium, phosphorus, magnesium, as well as vitamins—D, C, K) and flavonoid polyphenols (quercetin, rutin, luteolin, kaempferol, naringin) which appear to be essential for the prevention and treatment of osteoporosis, are characterized. Moreover, the importance of various naturally available nutrients, whether in the diet or in food supplements, is emphasized. In addition to pharmacotherapy, the basis of osteoporosis prevention is a healthy diet rich mainly in fruits, vegetables, seafood and fish oil supplements, specific dairy products, containing a sufficient amount of all aforementioned nutritional substances along with regular physical activity. The effect of diet alone in this context may depend on an individual’s genotype, gene-diet interactions or the composition and function of the gut microbiota.

BackgroundThe study investigated the associations of rs9340799:A > G (XbaI) and rs2234693:T > C (PvuII) polymorphisms in the estrogen receptor 1 gene (ESR1) with femoral neck (BMD-FN) and lumbar spine bone mineral density (BMD-LS), biochemical markers of bone turnover, calcium and phosphate levels, fracture prevalence, and a response to two types of anti-osteoporotic therapy in postmenopausal women from southern Slovakia.MethodsWe analysed 343 postmenopausal Slovak women (62.40 ± 0.46 years). The influence of rs9340799 (AA vs. AG + GG) and rs2234693 (TT vs. TC + CC) genotypes on BMD and biochemical markers was evaluated by covariance analysis adjusted for age and BMI. Binary logistic regression was used to evaluate the genotype effect on fracture prevalence. Pharmacogenetic part of the study included women who received a regular therapy of HT (17ß estradiol with progesterone; 1 mg/day for both; N = 76) or SERMs/raloxifene (60 mg/day; N = 64) during 48 months. The genotype-based BMD change was assessed by variance analysis for repeated measurements.ResultsWomen with AA genotype of rs9340799 had higher BMD-FN (+ 0.12 ± 0.57 of T-score) and BMD-LS (+ 0.17 ± 0.08 of T-score) in comparison with AG + GG. The rs2234693 polymorphism did not affect any of the monitored parameters. No effect of any ESR1 polymorphisms was found on fracture prevalence. Both types of anti-osteoporotic therapy had a positive effect on BMD improvement in FN and LS sites. Considering the effect of the ESR1 gene within the HT, the subjects with rs9340799/AA genotype showed worse response than those with GG genotype (− 0.26 ± 0.10 of BMD-FN T-score; − 0.35 ± 0.10 of BMD-LS T-score) and also with AG genotype (− 0.22 ± 0.08 of BMD-LS T-score). The rs2234693/TT genotype responded poorer in BMD-LS in comparison with TC (− 0.22 ± 0.08 of T-score) and CC (− 0.35 ± 0.09 of T-score). The effect of the ESR1 gene on raloxifene therapy was reported only in BMD-LS. Subjects with rs9340799/AA genotype had a − 0.30 ± 0.11 of T-score worse response compared to AG genotype. The rs2234693/TT genotype showed − 0.39 ± 0.11 and − 0.46 ± 0.15 lower T-scores in comparison with TC and CC genotypes, respectively.ConclusionsThe rs9340799 polymorphism may contribute to decreased BMD in postmenopausal women from southern Slovakia; however, this is not related to higher fracture prevalence. Concurrently, both polymorphisms affected a response to analysed anti-osteoporotic therapies.Electronic supplementary materialThe online version of this article (10.1186/s12881-018-0684-8) contains supplementary material, which is available to authorized users.

Cornelian cherry (Cornus mas L.) is a medicinal plant with a range of biological features. It is often used as a nutritional supplement in the treatment of diabetes mellitus. Our study was aimed to first investigate the effects of Cornelian cherry pulp on bone quality parameters in Zucker diabetic fatty (ZDF) rats. Moreover, lipid-lowering properties of this fruit were also evaluated. Adult rats (n = 28) were assigned into four groups of seven individuals each: L group (non-diabetic lean rats), C group (diabetic obese rats), and E1 and E2 groups (diabetic obese rats receiving 500 and 1000 mg/kg body weight of Cornelian cherry pulp, respectively, for 10 weeks). Significantly lower levels of triglyceride, total cholesterol and alkaline phosphatase activity were determined in the E2 group versus the C group. A higher dose of Cornus mas also had a beneficial impact on femoral weight, cortical bone thickness, relative volume of trabecular bone and trabecular thickness. We observed elevated density of Haversian systems and accelerated periosteal bone apposition in both treated groups (E1 and E2). Our results clearly demonstrate that Cornelian cherry pulp has a favorable effect on lipid disorder and impaired bone quality consistent with type 2 diabetes mellitus in a suitable animal model.

This study examined for the first time whether bee bread (BB, consisting of monofloral rape bee pollen) could alleviate lipid derangements and reduced bone quality in Zucker diabetic fatty (ZDF) rats, which are considered an appropriate animal model for type 2 diabetes mellitus (T2DM) investigation. Adult ZDF rats were segregated into four groups: lean non-diabetic rats (L group), obese diabetic rats untreated (C group), and those treated with the BB at two doses (500 and 700 mg/kg body weight, respectively, B1 and B2 groups) for 10 weeks. Significantly reduced levels of total cholesterol and triglyceride were recorded in the B2 group versus the C group. In both BB-treated groups, significantly increased relative volume of trabecular bone and trabecular thickness, enhanced density of secondary osteons, accelerated periosteal bone apposition, and improved blood flow were observed. A positive effect of higher dose of BB on femoral weight and cortical bone thickness was also demonstrated. Our results suggest a promising potential of BB to ameliorate T2DM-related complications associated with lipid and bone damages.