Ginger Root Extract Increases Mitochondrial Fission and Mitophagy in Diabetes Mellitus Rats

Diabetes (DM) is accompanied by mitochondrial dysfunction (i.e., mitochondria fission/fusion and mitophagy) in which result in an accumulation of damaged mitochondria and further impaired insulin resistance. Ginger root extract (GRE) has been shown to improve mitochondrial biogenesis and decreased respiratory coefficient in DM model, however, the effect of GRE on the basal mitochondria fission/fusion and mitophagy state is limited. PURPOSE: To determine the effect of GRE on mitochondria fission/fusion and mitophagy transcript abundance in rats with diabetes induced by high-fat diet (HFD) with streptozotocin (STZ). METHOD: Sprague-Dawley rats were randomly divided into 3 groups: standard diet (STD; n=11), HFD with 35 mg/kg of STZ (DM; n=11), and HFD+STZ with 0.75% w/w GRE (GRE; n=10). After 7 weeks, soleus samples were collected and analyzed for gene expression for fission/fusion (DRP, MFN) and mitophagy (PINK1, PARKIN, BECN1, LC3A, LC3B, P62). RESULT: A significant (p\u3c0.05) condition effect was found for PINK1, DRP, LC3A, LC3B, P62, and autophagic flux. For fission/fusion, GRE had significantly greater DRP (2.27±0.9-fold vs. 0.47±0.1-fold) than DM and no difference was found for MFN. For mitophagy, GRE had significantly greater PINK1 (1.59±0.55-fold vs. 0.31±0.06-fold), LC3A (1.81±0.65-fold vs. 0.13±0.02-fold), LC3B (2.71±0.92-fold vs. 0.66±0.25-fold), P62 (3.25±1.24-fold vs. 0.43±0.12-fold), and autophagy flux (4.5±1.06-fold vs. 2.41±0.36-fold) than DM and greater LC3B (2.71±0.92-fold vs. 1±0.06-fold), P62 (3.25±1.24-fold vs. 1±0.21-fold), and autophagic flux (4.5±1.06-fold vs. 1±0.26-fold) than STD. No difference was found for PARKIN and BECN1. CONCLUSION: In DM rats, GRE increased basal expression of mitochondria fission, degradation tag (PINK1), and autophagolysosome (LC3A, LC3B, P62, autophagic flux) markers, suggesting a potential increased in mitochondrial fission and mitophagy capacity

Curcumin Mitigates Neuropathic-Induce Muscle Atrophy by Suppressing CaMK2/NF-kB Pathway

Neuropathy can induce inflammation that results in muscle atrophy. Curcumin has been shown to exert an anti-inflammatory effect, preserving muscle mass in diabetic rats. However, the mechanism of curcumin to preserve muscle mass in neuropathy is not known. PURPOSE: To examine the effect of curcumin on the intramuscular inflammation and muscle cross-sectional area (CSA) in a neuropathy rodent model. METHODS: Twelve rats were randomly assigned to three groups: sham (CON), spinal nerve ligation (SNL), and SNL+100curcumin/kg BW (100CUR). The right (R) lumbosacral section (i.e., L5/L6) of the spinal cord was ligated (SNL and 100CUR) or sham surgery (CON) was performed, whereas the contralateral side (left: L) was served as their own control. Rats were fed with a control diet without (i.e., CON and SNL) or with (i.e., 100CUR) curcumin supplementation for 4 weeks. Plantaris (left and right) and tibialis anterior (TA; right) muscles were collected. TA was stained for dystrophin to measure CSA. Left and right plantaris were analyzed for protein content for AChR, CaMK2, CaMK2Thr286, CaMK2Thr286/CaMK2, NF-κB, NF-κBSer536, NF-κBSer536/NF-κB, IL-1β, and GAPDH. Each protein was normalized to GAPDH then to the CON. RESULTS: A significant (p ≤ 0.05) group effect was observed for TA CSA and a group x leg interaction effect was observed for CaMK2Thr286/CaMK2, NF-κBSer536, IL-1β protein content. For muscle CSA, CON (9027.33 ± 603.39 μm2) and 100CUR (8853.68 ± 696.73 μm2) were larger than SNL (4771.01 ± 539.69 μm2). No difference was observed in CSA between CON and 100CUR. Additionally, when compared between left and right plantaris muscles, only SNL had greater CaMK2Thr286/CaMK2 (R: 2.63 ± 1.87 vs. L: 1.56 ± 1.65), NF-κBSer536 (R: 1.85 ± 0.83 vs. L: 0.55 ± 0.33), and IL-1β (R: 2.11 ± 1.32 vs. L: 0.65 ± 0.29) protein content in the right than the left leg, whereas, no difference was observed for left leg among groups. For NF-κBSer536, SNL (1.85 ± 0.83) was greater than 100CUR (0.91 ± 0.52) in the right leg. No significant differences were observed for AChR, CaMK2, CaMK2Thr286, and NF-κBSer536/NF-κB. CONCLUSION: In a neuropathic model, muscle atrophy was observed with concomitant increase in CaMK2/NF-κB/IL-1β activation in the ipsilateral plantaris. Curcumin supplementation appears to mitigate this inflammatory response and muscle mass loss

Green Tea Polyphenols Reduce Body Weight in Rats by Modulating Obesity-Related Genes

Beneficial effects of green tea polyphenols (GTP) against obesity have been reported, however, the mechanism of this protection is not clear. Therefore, the objective of this study was to identify GTP-targeted genes in obesity using the high-fat-diet-induced obese rat model. A total of three groups (n = 12/group) of Sprague Dawley (SD) female rats were tested, including the control group (rats fed with low-fat diet), the HF group (rats fed with high-fat diet), and the HF+GTP group (rats fed with high-fat diet and GTP in drinking water). The HF group increased body weight as compared to the control group. Supplementation of GTP in the drinking water in the HF+GTP group reduced body weight as compared to the HF group. RNA from liver samples was extracted for gene expression analysis. A total of eighty-four genes related to obesity were analyzed using PCR array. Compared to the rats in the control group, the rats in the HF group had the expression levels of 12 genes with significant changes, including 3 orexigenic genes (Agrp, Ghrl, and Nr3c1); 7 anorectic genes (Apoa4, Cntf, Ghr, IL-1β, Ins1, Lepr, and Sort); and 2 genes that relate to energy expenditure (Adcyap1r1 and Adrb1). Intriguingly, the HF+GTP group restored the expression levels of these genes in the high-fat-induced obese rats. The protein expression levels of IL-1β and IL-6 in the serum samples from the control, HF, and HF+GTP groups confirmed the results of gene expression. Furthermore, the protein expression levels of superoxide dismutase-1 (SOD1) and catechol-O-methyltransferase (COMT) also showed GTP-regulated protective changes in this obese rat model. Collectively, this study revealed the beneficial effects of GTP on body weight via regulating obesity-related genes, anti-inflammation, anti-oxidant capacity, and estrogen-related actions in high-fat-induced obese rats

Geranylgeraniol Increases Autophagy and Mitophagy Gene Expression in Soleus of Rats with Diabetes

The autophagy and mitophagy (selective autophagy for mitochondria) processes are important in maintaining muscle homeostasis, e.g., removing damaged mitochondria. With diabetes, skeletal muscle autophagy decreases. Geranylgeraniol (GG) has been shown to reduce mitochondrial damage; however, the effect of GG on basal autophagy and mitophagy in diabetic rats is not known. PURPOSE: To determine the effect of GG on selective autophagy and mitophagy genes in rats with diabetes induced by a high-fat diet (HFD) with streptozotocin (STZ). METHODS: Sprague-Dawley rats were divided into three groups: normal diet (CON; n=11), HFD with 35 mg/kg body weight of STZ (HFD; n=9), and HFD/STZ with 800 mg/kg body weight of GG (GG; n=9). On the 7th week, soleus muscles were collected and analyzed for gene expression of LC3A, LC3B, P62, PINK1, PARKIN, DRP, and MFN. Gene data were normalized to CON. RESULTS: A significant (p \u3c 0.05) condition effect was found for autophagy (LC3A, LC3B, and P62) and mitophagy (PINK1, DRP, and MFN) gene expression. For autophagy, HFD (0.14 ± 0.03-fold) had significantly lower LC3A than CON (1.00 ± 0.22-fold), lower LC3B (0.67 ± 0.26-fold vs. 2.37 ± 0.72-fold) and P62 (0.44 ± 0.13-fold vs. 1.70 ± 0.35-fold) than GG. HFD trended to have lower LC3A than GG (0.14 ± 0.03-fold vs. 0.86 ± 0.26-fold; p = 0.066) while CON trended to have lower LC3B than GG (1.00 ± 0.07-fold vs. 2.37 ± 0.72-fold; p = 0.078). For mitophagy, HFD (0.32 ± 0.07-fold) and GG (0.51 ± 0.15-fold) had significantly lower PINK1 than CON (1.00 ± 0.13-fold). Further, HFD had lower MFN than GG (0.31 ± 0.08-fold vs. 1.46 ± 0.25-fold) and lower DRP than CON (0.48 ± 0.11-fold vs. 1.00 ± 0.15-fold). HFD trended to have lower PARKIN than GG (0.46 ± 0.08-fold vs. 1.38 ± 0.38-fold; p = 0.053) with no difference between GG and CON. CONCLUSION: In comparison to HFD, GG consumption improved the basal transcript abundance of the selective skeletal muscle autophagic and mitophagic genes, which could indicate an increased capacity to remove damaged mitochondria in diabetic rats

Geranylgeraniol Supplementation Mitigates Muscle Atrophy with Mitochondrial Quality Improvement in Diabetic Rats

With diabetes, skeletal muscle mitochondrial quality control (mitochondrial fusion, fission & macro-autophagy) is impaired. Geranylgeraniol (GG) is shown to have a protective effect on preventing mitochondrial damage and muscle health; however, the effect of GG on a diabetic model is not known. PURPOSE: To determine the effect of GG on mitochondrial quality control and muscle cross-sectional area (CSA) in diabetic rats. METHODS: Thirty-five Sprague-Dawley rats were divided into three diet groups: control diet (CON), high-fat diet with 35 mg/kg body weight of streptozotocin (HFD), and HFD with 800 mg/kg body weight of GG (GG). Due to the limited sample, a total of 21 (CON: n = 7; HFD: n = 7; GG: n = 7) rats’ muscle samples were used for this report. The soleus muscles were harvested after 7-weeks of feeding and were analyzed for OPA1, MFN2, DRP1, pDRP, PINK1, Parkin, LC3A, and LC3B protein content using western blot analysis. Muscle CSA were assessed using Image J. RESULTS: A significant (p \u3c 0.05) condition effect was observed for MFN2, DRP, LC3A, and LC3B protein contents and muscle CSA. For mitochondrial fusion, GG (0.21 ± 0.08) had lower MFN2 than CON (0.43 ± 0.04; p = 0.007) and HFD (0.65 ± 0.08; p = 0.010). For mitochondrial fission, GG (0.26 ± 0.07) had lower DRP than HFD (0.59 ± 0.07; p = 0.019). For macro-autophagy, GG (1.08 ± 0.28) had lower LC3A than CON (2.81 ± 0.55; p = 0.028) and HFD (3.99 ± 0.57; p = 0.010); whereas GG (0.63 ± 0.21) had lower LC3B than HFD (1.93 ± 0.24; p = 0.012). No significant differences were observed for OPA1, pDRP, PINK1, Parkin, and LC3B/A. For muscle size, CON (10,092.88 ± 104.67µm2) had larger CSA than GG (7284.69 ± 70.91µm2, p = 0.001) and HFD (5615.59 ± 59.97µm2; p = 0.001), whereas GG (7284.69 ± 70.91µm2) had larger CSA than HFD (5615.59 ± 59.97µm2; p = 0.001). CONCLUSION: GG supplementation could prevent mitochondrial fragmentation (reduction in DRP), thus, potentially resulting in a decreased demand for mitochondrial fusion (reduction in MFN2). In addition, a greater rate of autophagosome degradation than formation (reduction in LC3A and LC3B) was observed (indicative of an increase in macro-autophagy). Improvement in mitochondrial quality could potentially contribute to attenuating the reduction of muscle size in diabetic rats with GG supplementation

Effects of bariatric surgery on adipokine-induced inflammation and insulin resistance

Over a third of the US population is obese and at high risk for developing type 2 diabetes, insulin resistance, and other metabolic disorders. Obesity is considered a chronic lowgrade inflammatory condition that is primarily attributed to expansion and inflammation of adipose tissues. Indeed, adipocytes produce and secrete numerous proinflammatory and anti-inflammatory cytokines known as adipokines.When the balance of these adipokines is shifted toward higher production of proinflammatory factors, local inflammation within adipose tissues and subsequently systemic inflammation occur. These adipokines including leptin, visfatin, resistin, apelin, vaspin, and retinol binding protein-4 can regulate inflammatory responses and contribute to the pathogenesis of diabetes.These effects are mediated by key inflammatory signaling molecules including activated serine kinases such as c-Jun N-terminal kinase and serine kinases inhibitor κB kinase and insulin signaling molecules including insulin receptor substrates, protein kinase B (PKB, also known as Akt), and nuclear factor kappa B. Bariatric surgery can decrease body weight and improve insulin resistance in morbidly obese subjects. However, despite reports suggesting reduced inflammation and weight-independent effects of bariatric surgery on glucose metabolism, mechanisms behind such improvements are not yet well understood. This review article focuses on some of these novel adipokines and discusses their changes after bariatric surgery and their relationship to insulin resistance, fat mass, inflammation, and glucose homeostasis

The Effect of Geranylgeraniol on Satellite Cells Myogenic State in Type 2 Diabetic Rats

Type 2 Diabetes (T2D) is associated with chronic inflammation, which can contribute to impaired satellite cells (SC) myogenic state that may result in muscle atrophy. Geranylgeraniol (GGOH) has shown to prevent muscle atrophy, reduce inflammatory markers, and increase SC content; however, the effect of GGOH on SC myogenic state in T2D rats is not known. PURPOSE: To examine the effects of GGOH on SC myogenic state and muscle cross-sectional area (CSA) in T2D rats. METHODS: 21 Sprague-Dawley rats were fed a control diet (CON; n=7), a high-fat diet with 35 mg/kg of streptozotocin (HFD; n=7), and HFD with 800mg/kg body weight of GGOH (GG; n=7). In the 8th week, the right soleus muscle was analyzed for protein expression for Pax7, MyoD, myostatin, and GAPDH, and protein content was normalized to GAPDH. The left soleus muscle was co-stained with Pax7, MyoD, and myostatin using immunohistochemistry and analyzed for muscle CSA. Counted SC were normalized to 100 fibers. RESULTS: A significant (p \u3c 0.05) condition effect was observed for MyoD and myostatin protein expression. For MyoD, HFD (1.41 ± 0.09 A.U.) was lower than CON (2.24 ± 0.21 A.U.) and GG (2.62 ± 0.43 A.U.). For myostatin, HFD (0.42 ± 0.06 A.U.) was lower than CON (0.91 ± 0.09 A.U.). Additionally, a significant condition effect was observed for the number of cells that presented Pax7+/MyoD- and Pax7+/myostatin+. For Pax7+/MyoD-, HFD (0.039 ± 0.004) and GG (0.035 ± 0.004) had lower cell counts than CON (0.064 ± 0.010). For Pax7+/myostatin+, HFD (0.034 ± 0.003) had lower cell counts than GG (0.065 ± 0.010) and CON (0.057 ± 0.004). A significant condition effect was observed for CSA where CON (7099.89 ± 187.33 μm2) was larger than HFD (4351.02 ± 127.46 μm2) and GG (5584.61 ± 208.01 μm2), while GG (5584.61 ± 208.01 μm2) was larger than HFD (4351.02 ± 127.46 μm2). CONCLUSION: GGOH supplementation to T2D rats mitigated muscle mass loss (increased MyoD expression with no change in MyoD+ SC). Despite no differences in SC myogenic state (proliferative and differentiation) among groups, GGOH appeared to mitigate the reduction in the quiescent SC pool (Pax7+/myostatin+) observed in HFD. Given the importance of quiescent SC pool on retaining myogenic potential, which is essential for muscle hypertrophy and regeneration, supplementing GGOH to T2D rats could improve muscle health

Complementary and Alternative Exercises for Management of Osteoarthritis

Osteoarthritis (OA) is a chronic condition characterized by degeneration of cartilage and its underlying bone within a joint. With no cure currently available, the goals of treating OA are to alleviate pain, maintain, or improve joint mobility, increase the muscle strength of the joints, and minimize the disabling effects of the disease. Recent research has suggested that complementary and alternative medicine (CAM) exercises may improve OA symptoms. This paper covers CAM mind-body exercises—Tai Chi, qigong, and yoga—for OA management and evaluates their benefits in pain reduction, muscle strength, physical function, stiffness, balance, fear of falling, self-efficacy, quality of life, and psychological outcomes in patients with OA, based on randomized controlled trials published. Findings from the literature suggest that CAM exercises demonstrate considerable promise in the management of OA. Future studies require rigorous randomized controlled trials with larger sample sizes

Green tea polyphenols and Tai Chi for bone health: Designing a placebo-controlled randomized trial

BACKGROUND: Osteoporosis is a major health problem in postmenopausal women. Evidence suggests the importance of oxidative stress in bone metabolism and bone loss. Tea consumption may be beneficial to osteoporosis due to its antioxidant capability. However, lack of objective data characterizing tea consumption has hindered the precise evaluation of the association between tea ingestion and bone mineral density in previous questionnaire-based epidemiological studies. On the other hand, although published studies suggest that Tai Chi (TC) exercise can benefit bone health and may reduce oxidative stress, all studies were conducted using a relatively healthy older population, instead of a high-risk one such as osteopenic postmenopausal women. Therefore, this study was designed to test an intervention including green tea polyphenol (GTP) and TC exercise for feasibility, and to quantitatively assess their individual and interactive effects on postmenopausal women with osteopenia. METHODS/DESIGN: One hundred and forty postmenopausal women with osteopenia (defined as bone mineral density T-score at the spine and/or hip between 1 to 2.5 SD below the reference database) were randomly assigned to 4 treatment arms: (1) placebo group receiving 500 mg medicinal starch daily, (2) GTP group receiving 500 mg of GTP per day, (3) placebo+TC group receiving both placebo treatment and TC training (60-minute group exercise, 3 times per week), and (4) GTP+TC group receiving both GTP and TC training for 24 weeks. The outcome measures were bone formation biomarker (serum bone alkaline phosphatase), bone resorption biomarker (serum tartrate resistant acid phosphatase), and oxidative DNA damage biomarker (urinary 8-hydroxy-2'-deoxyguanosine). All outcome measures were determined at baseline, 4, 12, and 24 weeks. Urinary and serum GTP concentrations were also determined at baseline, 4, 12, and 24 weeks for bioavailability. Liver function was monitored monthly for safety. A model of repeated measurements with random effect error terms was applied. Traditional procedures such as ANCOVA, chi-squared analysis, and regression were used for comparisons. DISCUSSION: We present the rationale, design, and methodology of a placebo-controlled randomized trial to investigate a new complementary and alternative medicine strategy featuring a dietary supplement and a mind-body exercise for alleviating bone loss in osteopenic postmenopausal women. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT0062539

The Potential of Isoprenoids in Adjuvant Cancer Therapy to Reduce Adverse Effects of Statins

The mevalonate pathway provides sterols for membrane structure and nonsterol intermediates for the post-translational modification and membrane anchorage of growth-related proteins, including the Ras, Rac, and Rho GTPase family. Mevalonate-derived products are also essential for the Hedgehog pathway, steroid hormone signaling, and the nuclear localization of Yes-associated protein and transcriptional co-activator with PDZ-binding motif, all of which playing roles in tumorigenesis and cancer stem cell function. The phosphatidylinositol-4,5-bisphosphate 3-kinase-AKT-mammalian target of rapamycin complex 1 pathway, p53 with gain-of-function mutation, and oncoprotein MYC upregulate the mevalonate pathway, whereas adenosine monophosphate-activated protein kinase and tumor suppressor protein RB are the downregulators. The rate-limiting enzyme, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), is under a multivalent regulation. Sterol regulatory element binding protein 2 mediates the sterol-controlled transcriptional downregulation of HMGCR. UbiA prenyltransferase domain-containing protein-1 regulates the ubiquitination and proteasome-mediated degradation of HMGCR, which is accelerated by 24, 25-dihydrolanosterol and the diterpene geranylgeraniol. Statins, competitive inhibitors of HMGCR, deplete cells of mevalonate-derived intermediates and consequently inhibit cell proliferation and induce apoptosis. Clinical application of statins is marred by dose-limiting toxicities and mixed outcomes on cancer risk, survival and mortality, partially resulting from the statin-mediated compensatory upregulation of HMGCR and indiscriminate inhibition of HMGCR in normal and tumor cells. Tumor HMGCR is resistant to the sterol-mediated transcriptional control; consequently, HMGCR is upregulated in cancers derived from adrenal gland, blood and lymph, brain, breast, colon, connective tissue, embryo, esophagus, liver, lung, ovary, pancreas, prostate, skin, and stomach. Nevertheless, tumor HMGCR remains sensitive to isoprenoid-mediated degradation. Isoprenoids including monoterpenes (carvacrol, L-carvone, geraniol, perillyl alcohol), sesquiterpenes (cacalol, farnesol, β-ionone), diterpene (geranylgeranyl acetone), “mixed” isoprenoids (tocotrienols), and their derivatives suppress the growth of tumor cells with little impact on non-malignant cells. In cancer cells derived from breast, colon, liver, mesothelium, prostate, pancreas, and skin, statins and isoprenoids, including tocotrienols, geraniol, limonene, β-ionone and perillyl alcohol, synergistically suppress cell proliferation and associated signaling pathways. A blend of dietary lovastatin and δ-tocotrienol, each at no-effect doses, suppress the growth of implanted murine B16 melanomas in C57BL6 mice. Isoprenoids have potential as adjuvant agents to reduce the toxicities of statins in cancer prevention or therapy