Phytotherapy in reducing glycemic index and testicular oxidative stress resulting from induced diabetes: a review

Hibiscus sabdariffa in Diabetes Prevention and Treatment—Does It Work? An Evidence-Based Review

Diabetes is currently a global health problem that is already reported as an epidemic. This metabolic disease, characterized by a disturbance in the carbohydrate, protein, and lipid metabolism, is often accompanied by disorders of several organs. Its treatment is expensive and often difficult to control. Therefore, it seems necessary to search for new drugs and solutions to facilitate therapy and reduce treatment costs. Herbal medicines are becoming more and more popular. Hibiscus sabdariffa (roselle) is a plant that grows wild in a tropical climate. It has been used in folk medicine for thousands of years. Thanks to the numerous active compounds, including polyphenols, polysaccharides, organic acids, or pectins, it is reported to exhibit hypoglycemic, antioxidant, hypotensive, and anti-lipidemic activities and numerous indirect effects that are related to them. The aim of this review was to update the knowledge about the therapeutic effects of roselle in diabetes and its comorbidities based on in vitro, animal, and human studies. After a careful analysis of the scientific literature, it can be stated that roselle is a promising product that can be used either on its own or as an addition to the conventional treatment regimens to prevent or treat diabetes and its accompanying diseases.

Evaluation of testicular glycogen storage, FGF21 and LDH expression and physiological parameters of sperm in hyperglycemic rats treated with hydroalcoholic extract of Securigera Securidaca seeds, and Glibenclamide

Structural and physiological changes in sperm and semen parameters reduce fertility in diabetic patients. Securigera Securidaca (S. Securidaca) seed is a herbal medicine with hypoglycemic, antioxidant, and anti-hypertensive effects. The question now is whether this herbal medicine improves fertility in diabetic males. The study aimed to evaluate the effects of hydroalcoholic extract of S. Securidaca seeds (HESS), glibenclamide and a combination of both on fertility in hyperglycemic rats by comparing histological and some biochemical changes in testicular tissue and sperm parameters. The treatment protocol included administration of three doses of HESS and one dose of glibenclamide, as well as treatment with both in diabetic Wistar diabetic rats and comparison of the results with untrated groups. The quality of the testicular tissue as well as histometric parameters and spermatogenesis indices were evaluated during histopathological examination. Epididymal sperm analysis including sperm motility, viability, abnormalities, maturity, and chromatin structure were studied. The effect of HESS on the expression of LDH and FGF21 genes and tissue levels of glycogen, lactate, and total antioxidant capacity in testicular tissue was investigated and compared with glibenclamide. HESS improved sperm parameters in diabetic rats but showed little restorative effect on damaged testicular tissue. In this regard, glibenclamide was more effective than the highest dose of HESS and its combination with HESS enhanced its effectiveness so that histological tissue characteristics and sperm parameters were were comparable to those of healthy rats. The expression level of testicular FGF21 gene increased in diabetic rats, which intensified after treatment with HESS as well as glibenclamide. The combination of HESS and glibenclamide restored the expression level of testicular LDH gene, as well as tissue storage of glycogen, lactate and LDH activity, and serum testosterone to the levels near healthy control. S. Securidaca seeds can be considered as an effective supplement in combination with hypoglycemic drugs to prevent infertility complications in diabetes.

Antioxidant activity, antibacterial and inhibitory effect of intestinal disaccharidases of extracts obtained from Eugenia uniflora L. Seeds

Abstract The use of medicinal plants for disease prevention, treatment and cure is an ancient practice used by humanity, and many plants species are used in bioprospecting research. In this context, its stands out Eugenia uniflora L., populary known as pitangueira and belongs to the Myrtaceae family, with a wide geographic distribution and native of Brazil. In view of the therapeutic qualities of the plant and the lack of the studies on its seeds, the present study had as objective to evaluate the phytochemical profile of the extracts of Eugenia uniflora L. seeds, from different solvents, as well as their antibacterial activity, antioxidant and its inhibitory effect of intestinal disaccharidases. Results showed a high content of phenolic compounds and total flavonoids, thus characterizing antioxidant activity, also highlighting the best bacteriostatic action for the Gram positive strain of Staphylococcus aureus in the ethanolic fraction. Regarding the disaccharidases, a strong inhibitory action was observed for all concentrations, evidencing a antihyperglycemic potential. The present research allowed to concluded that Eugenia uniflora L. seeds have promising biological activities for the industrial sector, but a more detailed investigation is needed regarding their bioactive compounds.

Hesperidin alleviates insulin resistance by improving HG-induced oxidative stress and mitochondrial dysfunction by restoring miR-149

BACKGROUND

Hesperidin, a natural flavanone, has been proven to have multiple protective effects in diabetic rats, such as antioxidant, anti-inflammatory and anti-apoptotic effects. However, the molecular mechanisms underlying the effects of hesperidin are not well elucidated.

METHODS

LO2 cells were stimulated with high glucose (HG, 33 mM) for 24 h to establish a model of oxidative stress. Then, cell viability was determined using the MTT assay. The antioxidant activities, including the reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels, mitochondrial membrane potential (MMP) and adenosine-triphosphate (ATP) production, were measured with the corresponding kits. The levels of gene expression, protein expression and methylation were detected using qRT-PCR, western blotting and methylation-specific PCR (MSP) assays, respectively.

RESULTS

Compared to the NG treatment, hesperidin treatment increased the viability and improved the oxidative stress, mitochondrial dysfunction and insulin resistance of HG-treated LO2 cells, and these effects were correlated with heightened SOD and GPx activities, increased MMP level and ATP generation, reduced MDA, ROS and glucose levels, and activated GSK3β/AKT and inactivated IRS1 signals. Mechanistically, hesperidin treatment enhanced the miR-149 expression level by reducing its promoter methylation by inhibiting DNMT1. Importantly, knockdown of miR-149 obviously abolished the biological roles of hesperidin.

CONCLUSIONS

Our findings demonstrated that hesperidin treatment ameliorated HG-induced insulin resistance by reducing oxidative stress and mitochondrial dysfunction partly by suppressing DNMT1-mediated miR-149 silencing.

Ellagic acid improved diabetes mellitus-induced testicular damage and sperm abnormalities by activation of Nrf2

Diabetes mellitus induces testicular damage, increases sperm abnormalities, and impairs reproductive dysfunction due to induction of endocrine disturbance and testicular oxidative stress. This study evaluated the reproductive protective effect of ellagic acid (EA) against testicular damage and abnormalities in sperm parameters in Streptozotocin (STZ)-induced diabetic rats (T1DM) and examined some possible mechanisms of protection. Adult male rats were segregated into 5 groups (n = 12 rat/each) as control, control + EA (50 mg/kg/day), T1DM, T1DM + EA, and T1DM + EA + brusatol (an Nrf-2 inhibitor) (2 mg/twice/week). All treatments were conducted for 12 weeks, daily. EA preserved the structure of the seminiferous tubules, prevented the reduction in sperm count, motility, and viability, reduced sperm abnormalities, and downregulated testicular levels of cleaved caspase-3 and Bax in diabetic rats. In the control and diabetic rats, EA significantly increased the circulatory levels of testosterone, reduced serum levels of FSH and LH, and upregulated Bcl-2 and all steroidogenic genes (StAr, 3β-HSD1, and 11β-HSD1). Besides, it reduced levels of ROS and MDA but increased levels of GSH and MnSOD and the transactivation of Nrf2. All these biochemical alterations induced by EA were associated with increased activity and nuclear accumulation of Nrf2. However, all these effects afforded by EA were weakened in the presence of brusatol. In conclusion, EA could be an effective therapy to alleviated DM-induced reproductive toxicity and dysfunction in rats by a potent antioxidant potential mediated by the upregulation of Nrf2.

Tiliacora triandra extract and its major constituent attenuates diabetic kidney and testicular impairment by modulating redox imbalance and pro-inflammatory responses in rats

BACKGROUND

Literature has demonstrated that diabetes is associated with renal complication and testicular dysfunctions. The current study explored the potential of Tiliacora triandra extract and its major component against diabetic kidney and testicular damages in rats.

METHODS

Diabetes was induced by high fat diet/streptozotocin (HFD/STZ) and treated orally with Tiliacora triandra extract (TTE, 100 and 400 mg kg^-1 body weight) and its major component, 5,7-dihydroxy-6-oxoheptadecanoic acid (DHA, 25 mg kg^-1 body weight) for 30 consecutive days. Testicular activities of testicular enzymes, serum levels of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), sperm parameters and urinalysis for protein and albumin levels were evaluated. Renal and testicular biomarkers of oxidative stress and pro-inflammation were analysed along with histology.

RESULTS

The experimental diabetes induced significant alterations in the levels and activities of indices evaluated compared to non-diabetic normal rats. The 28-day treatment of diabetic rats with TTE and DHA markedly improved activities of testicular enzymes, restored levels of testosterone, LH and FSH and sperm parameters compared to untreated diabetic rats. TTE and DHA abrogated proteinuria and reversed urine albumin level. Testicular and renal oxidative stress and pro-inflammation were attenuated in diabetic rats treated with TTE and DHA. The diabetes-mediated histopathological damage was alleviated in the kidney and testis.

CONCLUSION

The protective effect of TTE and DHA against diabetes induced kidney and testicular damages may be related to its antioxidant and anti-inflammatory activities. © 2020 Society of Chemical Industry.

The influence of phytoestrogens on different physiological and pathological processes: An overview

Functional foods have nutritional properties and organic functions, which are beneficial to health. Certain types of functional food components are so-called phytoestrogens, non-steroidal compounds derived from the metabolism of precursors contained in plants, which originate secondary metabotypes known to induce biological responses and by mimicry or modulating the action of endogenous estrogen. These molecules are involved in several physiological and pathological processes related to reproduction, bone remodeling, skin, cardiovascular, nervous, immune systems, and metabolism. This review aimed to present an overview of phytoestrogens regarding their chemical structure, actions, and effects in the organism given several pathologies. Several studies have demonstrated beneficial phytoestrogen actions, such as lipid profile improvement, cognitive function, menopause, oxidative stress, among others. Phytoestrogens effects are not completely elucidated, being necessary future research to understand the exact action mechanisms, whether they are via estrogen receptor or whether other hidden mechanisms produce these effects. Thus, this review makes a general approach to the phytoestrogen actions, beneficial effects, risk and limitations. However, the complexities of biological effects after ingestion of phytoestrogens and the differences in their metabolism and bioavailability indicate that interpretation of either risk or benefits needs to be made with caution.

Possible therapeutic effects of vindoline on testicular and epididymal function in diabetes-induced oxidative stress male Wistar rats

OBJECTIVE

The study evaluated the effects of vindoline on testicular and epididymal oxidative stress in diabetes-induced male Wistar rats.

METHODS

Forty-eight (48), 6-week old male Wistar rats weighing between 190-230g were divided into 6 groups (n = 8) and used for this study. Group 1 was the normal control, group 2 comprised non-diabetic rats treated with vindoline, and group 3 was the non-diabetic group of rats treated with glibenclamide-the standard drug for the treatment of diabetes. Group 4 was the diabetic control, group 5 comprised diabetic rats treated with vindoline and group 6 was the diabetic rats treated with glibenclamide. Diabetes was induced in group 4, group 5 and group 6 rats by subjecting them to 10% fructose water over a period of 2 weeks, followed by administration of a single intraperitoneal injection of 40 mg/kg b.w streptozotocin (STZ). Testicular and epididymal lipid peroxidation levels, antioxidant enzymes, scavenging activity and total antioxidant capacity were measured.

RESULTS

Diabetes-induced male Wistar rats demonstrated chronic hyperglycaemia, oxidative stress and reduced oxygen radical absorption capacity in both testicular and epididymal tissues. Short-term treatment of diabetic rats with vindoline for 5 weeks significantly reduced fasting blood glucose levels, minimise testicular oxidative stress, increased testicular and epididymal catalase and epididymal SOD and increase total antioxidant activity capacity.

CONCLUSION

Treatment with vindoline showed protective effects against diabetes-induced oxidative stress in both testicular and epididymal tissues of male Wistar rats, hence can be considered potential agent in the management of diabetes-induced oxidative stress male sexual dysfunction.

In Vitro and In Vivo Antioxidant Properties of Taraxacum officinale in Nω-Nitro-l-Arginine Methyl Ester (L-NAME)-Induced Hypertensive Rats

Oxidative stress has gained attention as one of the fundamental mechanisms responsible for the development of hypertension. The present study investigated in vitro and in vivo antioxidant effects of 70% ethanol-water (v/v) leaf and root extracts of T. officinale (TOL and TOR, respectively). Total phenolic and flavonoid content of plant extracts were assessed using Folin Ciocalteau and aluminium chloride colorimetric methods; while, 2,2-diphenyl-1-picrlhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) protocols were used to determine the free radical scavenging and total antioxidant capacities (TAC), respectively. The in vivo total antioxidant capacity and malondialdehyde acid (MDA) levels for lipid peroxidation tests were performed on organ homogenate samples from Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats treated with leaf extract, TOL (500 mg/kg/day) and TOR (500 mg/kg/day) for 21 days. Results showed that compared to TOR, TOL possessed significantly higher (p < 0.01) polyphenol (4.35 ± 0.15 compared to 1.14 ± 0.01) and flavonoid (23.17 ± 0.14 compared to 3 ± 0.05) content; free radical scavenging activity (EC₅₀ 0.37 compared to 1.34 mg/mL) and total antioxidant capacities (82.56% compared to 61.54% ABTS, and 156 ± 5.28 compared to 40 ± 0.31 FRAP) and both extracts showed no toxicity (LD₅₀ > 5000 mg/kg). TOL and TOR significantly (p < 0.01) elevated TAC and reduced MDA levels in targets organs. In conclusion, T. officinale leaf extract possesses significant anti-oxidant effects which conferred significant in vivo antioxidant protection against free radical-mediated oxidative stress in L-NAME-induced hypertensive rats.

Comparative Effects of Estrogen and Phytoestrogen, Genistein on Testicular Activities of Streptozotocin-Induced Type 2 Diabetic Mice

The aim of this study was to compare the effect of synthetic estrogen (E2) with a phytoestrogen and genistein in ameliorating type 2 diabetes mellitus (T2D)-mediated testicular dysfunction in mice. The streptozotocin (STZ)-induced type 2 diabetic mice were treated exogenously with either E2 or genistein for 2 durations and compared their effects on testicular activities, serum glucose, and insulin level. Type 2 diabetic mice treated with E2 for only short term (14 days) improved regressive changes in the testicular histology by increasing testosterone synthesis and improving insulin sensitivity, whereas those treated for longer duration (28 days) failed to improve testicular dysfunctions. On the other hand, genistein treated for both short- and long term was useful in improving T2D-induced adverse effects on testicular functions. This study further suggests that treatment with genistein improves spermatogenesis in type 2 diabetic mice by increasing insulin-induced formation of lactate and antioxidative enzymes, which contributes to prevent germ cell apoptosis. Thus, genistein can be used to ameliorate T2D-induced testicular dysfunction.

Effects of electroacupuncture stimulation at different spinal segmental levels in a rat model of diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) is associated with high morbidity, mortality and economic cost. Studies have shown that acupuncture can improve many symptoms of DM.

OBJECTIVES

To examine for differences in effects of electroacupuncture (EA) stimulation at Weiwanxiashu, BL15 and BL23 in the streptozotocin (STZ)-induced DM rat model, to help guide clinical selection of acupuncture points.

METHODS

90 male rats weighing 160±5 g were used. 12 rats were control fed (Normal group) and 78 were fed a high-fat high-sugar diet for 8 weeks and underwent intraperitoneal STZ injection to model DM. 60 animals that met modelling criteria were randomly divided into an untreated DM group and four groups receiving EA at Weiwanxiashu (DM+WWX group), BL15 (DM+BL15 group), BL23 (DM+BL23 group) or a non-traditional acupuncture point on the tail (DM+Tail group). Fasting blood glucose, total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and insulin levels were determined and an oral glucose tolerance test (OGTT) performed.

RESULTS

EA at Weiwanxiashu had a glucose-lowering effect on the 21st and 28th days, decreased TC, TG and LDL-C levels, increase insulin levels and improved glucose tolerance. EA at BL15 had a glucose-lowering effect on the7th, 14th and 21st days of intervention but did not impact lipids, insulin or OGTT parameters. EA at BL23 or on the tail had no significant effects.

CONCLUSION

EA at Weiwanxiashu and BL15 had differential effects on metabolic markers in the STZ-induced rat model of DM. These effects may be explained neuroanatomically by variations in the segmental innervation of the tissues at these locations.