Selected polyphenolic compounds and their use as a supportive therapy in metabolic syndrome.

Metabolic syndrome is diagnosed mainly in people of economically developed parts of the world and it affects 20-25% of the adult population worldwide. Nowadays, it is also more frequently diagnosed in children and adolescents. In addition to standard treatment that often involves polypharmacotherapy, and thus increases risk of side effects caused by drugdrug interactions, it is appropriate to look for alternative tools to support the treatment of metabolic syndrome components. Natural polyphenolic compounds, usually present in the so-called functional foods, are suitable candidates for that matter, due to the bioactivity and beneficial effects on the human body. Quercetin, troxerutin, diosmin, hesperidin or silybin are among the currently studied and used natural polyphenolic compounds with a positive effect on aspects of the metabolic syndrome. In addition to their antioxidant and anti-inflammatory effects, these compounds have other positive properties that very often outweigh their side effects whilst their usage in the pharmacotherapy.

Diosmin, a citrus fruit-derived phlebotonic bioflavonoid protects rats from chronic kidney disease-induced loss of bone mass and strength without deteriorating the renal function.

Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline has recommended treatment decisions for patients with chronic kidney disease (CKD) with osteoporosis and/or high risk of fracture. Bisphosphonates, the first-line anti-osteoporosis drugs have the concern of worsening kidney functions. Moreover, despite impaired bone formation in CKD patients, teriparatide, the formation-stimulating drug is not recommended. Thus, there is an urgent need for safe and effective treatment of osteoporosis in CKD patients. Here, in CKD rats, we tested the osteoprotective effect of diosmin, a citrus-derived bioflavonoid used as a phlebotonic in chronic venous insufficiency and has a renoprotective effect. CKD was developed by 5/6th nephrectomy and diosmin at the human equivalent dose (100 mg kg-1) did not advance renal failure but reduced blood pressure to the level of sham control. Fibroblast growth factor-23 and parathyroid hormone were increased in CKD and diosmin suppressed both. CKD reduced bone mass and deteriorated the microarchitecture of trabecular bones, and diosmin maintained both to control levels. Bone formation and strength were impaired in the CKD and diosmin maintained these levels to control levels. Nanoindentation of bone showed that diosmin significantly increased tissue hardness over the control. Diosmetin, the metabolic surrogate of diosmin had comparable pharmacokinetic profiles between the control and CKD groups. Furthermore, diosmetin (50 mg kg-1) protected against CKD-induced bone loss. These data suggest that diosmin and its metabolic surrogate, diosmetin protect against CKD-induced osteopenia. Since diosmin has no renal adverse effect and protected bone mass and strength in CKD rats, we propose assessing its anti-osteoporosis effect in CKD patients.

Is There a Difference in the Clinical Efficacy of Diosmin and Micronized Purified Flavonoid Fraction for the Treatment of Chronic Venous Disorders? Review of Available Evidence.

Flavonoids are oral venoactive drugs frequently prescribed to relieve the symptoms of chronic venous disorders (CVD). Among venoactive drugs, diosmin is a naturally occurring flavonoid glycoside that can be isolated from various plant sources; it can also be obtained after conversion of hesperidin extracted from citrus rinds. Micronized purified flavonoid fraction (MPFF) is a preparation that contains mainly diosmin and a small fraction of hesperidin. We performed a state-of-the-art literature review to collect and analyze well-conducted randomized clinical studies comparing diosmin - also called non-micronized or hemisynthetic diosmin - 600 mg a day and MPFF, 1000 mg a day. Three clinical studies met the criteria and were included for this literature review. These clinical studies showed a significant decrease of CVD symptom intensity (up to approximately 50%) and global patient satisfaction after one-to-six-month treatment with diosmin or MPFF, without statistical differences between these two forms of diosmin. Both treatments were well tolerated with few mild adverse drug reactions reported. Overall, based on this literature review, there is no clinical benefit to increase the dose of diosmin beyond 600 mg per day, to use the micronized form, or to add hesperidin, since clinical efficacy on venous symptomatology is achieved with 600 mg per day of pure non-micronized diosmin. This challenges the status of diosmin - 600 mg a day - in guidelines for the management of CVD, which is currently categorized 2C (weak recommendations for use and poor quality of evidence), while the most widely used and assessed preparation MPFF is rated 1B (strong recommendation for use and moderate quality of evidence).

Dual modulatory effects of diosmin on calcium oxalate kidney stone formation processes: Crystallization, growth, aggregation, crystal-cell adhesion, internalization into renal tubular cells, and invasion through extracellular matrix.

Diosmin is a natural flavone glycoside (bioflavonoid) found in fruits and plants with several pharmacological activities. It has been widely used as a dietary supplement or therapeutic agent in various diseases/disorders. Although recommended, evidence of its protective mechanisms against kidney stone disease (nephrolithiasis/urolithiasis), especially calcium oxalate (CaOx) monohydrate (COM) that is the most common type, remained unclear. In this study, we thus systematically evaluated the effects of diosmin (at 2.5-160 nM) on various stages of kidney stone formation processes, including COM crystallization, crystal growth, aggregation, crystal-cell adhesion, internalization into renal tubular cells and invasion through extracellular matrix (ECM). The results showed that diosmin had dose-dependent modulatory effects on all the mentioned COM kidney stone processes. Diosmin significantly increased COM crystal number and mass during crystallization, but reduced crystal size and growth. While diosmin promoted crystal aggregation, it inhibited crystal-cell adhesion and internalization into renal tubular cells. Finally, diosmin promoted crystal invasion through the ECM. Our data provide evidence demonstrating both inhibiting and promoting effects of diosmin on COM kidney stone formation processes. Based on these dual modulatory activities of diosmin, its anti-urolithiasis role is doubtful and cautions should be made for its use in kidney stone disease.

Therapeutic potential of diosmin, a citrus flavonoid against arsenic-induced neurotoxicity via suppression of NOX 4 and its subunits.

OBJECTIVES: Water contaminated with arsenic affected millions of people worldwide and arsenic exposure is related to various neurological disorders. Hence, the current study was planned to investigate the neuroprotective activity of diosmin (DSN) against arsenic induced neurotoxicity as an attempt to identify therapeutic intervention to combat arsenicism. MATERIALS AND METHODS: Sodium arsenite an inducer of neurotoxicity was administered orally (13 mg/kg) and DSN treatment at two selected doses (50 and 100 mg/kg) was done for 21 days. Behavioral and biochemical variations were examined by various parameters. Furthermore, histopathological and immunohistochemistry studies were done with the brain sections. RESULTS: The behavioral studies evidenced that arsenic has suppressed the exploratory behavior and motor coordination in rats and DSN treatment has recovered the behavioral changes to normal. Arsenic administration has also found to induce oxidative stress and DSN co-treatment has ameliorated the oxidative stress markers. Interestingly, depleted levels of neurotransmitters were observed with the arsenic and it was restored back by the DSN treatment. Histopathological alterations like pyknosis of the neuronal cells were identified with arsenic exposure and subsided upon DSN co administration. Immunohistochemical studies have revealed the expression of NOX4 and its gp91phox and P47phox subunits and its suppression by DSN treatment may be the key therapeutic factor of it. CONCLUSIONS: Treatment with DSN showed a beneficial effect in protecting against arsenic-induced neurotoxicity by suppressing the toxicity changes and the antioxidant effect of DSN might be attributed to its ability of suppressing NOX4 and its subunits.

Diosmin Mitigates Cyclophosphamide Induced Premature Ovarian Insufficiency in Rat Model.

The current study was designed to investigate the protective role of diosmin against cyclophosphamide-induced premature ovarian insufficiency (POI). Female Swiss albino rats received a single intraperitoneal dose of cyclophosphamide (200 mg/kg) followed by 8 mg/kg/day for the next 15 consecutive days either alone or in combination with oral diosmin at 50 or 100 mg/kg. Histopathological examination of ovarian tissues, hormonal assays for follicle stimulating hormone (FSH), estradiol (E2), and anti-Mullerian hormone (AMH), assessment of the oxidative stress status, as well as measurement of the relative expression of miRNA-145 and its target genes [vascular endothelial growth factor B (VEGF-B) and regulator of cell cycle (RGC32)] were performed. Diosmin treatment ameliorated the levels of E2, AMH, and oxidative stress markers. Additionally, both low and high diosmin doses significantly reduced the histopathological alterations and nearly preserved the normal ovarian reserve. MiRNA-145 expression was upregulated after treatment with diosmin high dose. miRNA-145 target genes were over-expressed after both low and high diosmin administration. Based on our findings, diosmin has a dose-dependent protective effect against cyclophosphamide-induced ovarian toxicity in rats.

Phlebotonics for venous insufficiency.

BACKGROUND: Chronic venous insufficiency (CVI) is a condition in which veins are unable to transport blood unidirectionally towards the heart. CVI usually occurs in the lower limbs. It might result in considerable discomfort, with symptoms such as pain, itchiness and tiredness in the legs. Patients with CVI may also experience swelling and ulcers. Phlebotonics are a class of drugs often used to treat CVI. This is the second update of a review first published in 2005. OBJECTIVES: To assess the efficacy and safety of phlebotonics administered orally or topically for treatment of signs and symptoms of lower extremity CVI. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and Clinicaltrials.gov trials register up to 12 November 2019. We searched the reference lists of the articles retrieved by electronic searches for additional citations. We also contacted authors of unpublished studies. SELECTION CRITERIA: We included randomised, double-blind, placebo-controlled trials (RCTs) assessing the efficacy of phlebotonics (rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, Centella asiatica, disodium flavodate, French maritime pine bark extract, grape seed extract and aminaftone) in patients with CVI at any stage of the disease. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed the quality of included RCTs. We estimated the effects of treatment by using risk ratios (RRs), mean differences (MDs) and standardized mean differences (SMDs), according to the outcome assessed. We calculated 95% confidence intervals (CIs) and percentage of heterogeneity (I2). Outcomes of interest were oedema, quality of life (QoL), assessment of CVI and adverse events. We used GRADE criteria to assess the certainty of the evidence. MAIN RESULTS: We identified three new studies for this update. In total, 69 RCTs of oral phlebotonics were included, but only 56 studies (7690 participants, mean age 50 years) provided quantifiable data for the efficacy analysis. These studies used different phlebotonics (28 on rutosides, 11 on hidrosmine and diosmine, 10 on calcium dobesilate, two on Centella asiatica, two on aminaftone, two on French maritime pine bark extract and one on grape seed extract). No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria. Moderate-certainty evidence suggests that phlebotonics probably reduce oedema slightly in the lower legs, compared with placebo (RR 0.70, 95% CI 0.63 to 0.78; 13 studies; 1245 participants); and probably reduce ankle circumference (MD -4.27 mm, 95% CI -5.61 to -2.93 mm; 15 studies; 2010 participants). Moderate-certainty evidence shows that phlebotonics probably make little or no difference in QoL compared with placebo (SMD -0.06, 95% CI -0.22 to 0.10; five studies; 1639 participants); and similarly, may have little or no effect on ulcer healing (RR 0.94, 95% CI 0.79 to 1.13; six studies; 461 participants; low-certainty evidence). Thirty-seven studies reported on adverse events. Pooled data suggest that phlebotonics probably increase adverse events slightly, compared to placebo (RR 1.14, 95% CI 1.02 to 1.27; 37 studies; 5789 participants; moderate-certainty evidence). Gastrointestinal disorders were the most frequently reported adverse events. We downgraded our certainty in the evidence from 'high' to 'moderate' because of risk of bias concerns, and further to 'low' because of imprecision. AUTHORS' CONCLUSIONS: There is moderate-certainty evidence that phlebotonics probably reduce oedema slightly, compared to placebo; moderate-certainty evidence of little or no difference in QoL; and low-certainty evidence that these drugs do not influence ulcer healing. Moderate-certainty evidence suggests that phlebotonics are probably associated with a higher risk of adverse events than placebo. Studies included in this systematic review provided only short-term safety data; therefore, the medium- and long-term safety of phlebotonics could not be estimated. Findings for specific groups of phlebotonics are limited due to small study numbers and heterogeneous results. Additional high-quality RCTs focusing on clinically important outcomes are needed to improve the evidence base.

Is hesperidin essential for prophylaxis and treatment of COVID-19 Infection?

SARS-CoV-2 or COVID-19 is representing the major global burden that implicated more than 4.7 million infected cases and 310 thousand deaths worldwide in less than 6 months. The prevalence of this pandemic disease is expected to rise every day. The challenge is to control its rapid spread meanwhile looking for a specific treatment to improve patient outcomes. Hesperidin is a classical herbal medicine used worldwide for a long time with an excellent safety profile. Hesperidin is a well-known herbal medication used as an antioxidant and anti-inflammatory agent. Available shreds of evidence support the promising use of hesperidin in prophylaxis and treatment of COVID 19. Herein, we discuss the possible prophylactic and treatment mechanisms of hesperidin based on previous and recent findings. Hesperidin can block coronavirus from entering host cells through ACE2 receptors which can prevent the infection. Anti-viral activity of hesperidin might constitute a treatment option for COVID-19 through improving host cellular immunity against infection and its good anti-inflammatory activity may help in controlling cytokine storm. Hesperidin mixture with diosmin co-administrated with heparin protect against venous thromboembolism which may prevent disease progression. Based on that, hesperidin might be used as a meaningful prophylactic agent and a promising adjuvant treatment option against SARS-CoV-2 infection.

The effect of diosmin against liver damage caused by cadmium in rats.

A total of 40, male Wistar Albino, 2-3-months-old rats were used and divided into four groups. Control group received the vehicle alone, diosmin group received 100 mg/kg.bw diosmin, the cadmium group received 200 ppm cadmium, cadmium plus diosmin group received 200 ppm cadmium, and 100 mg/kg.bw diosmin for 30 days. Some biochemical parameters (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase) and oxidative stress parameters (malondialdehyde [MDA], nitric oxide [NO], superoxide dismutase [SOD], catalase [CAT], gluthatione peroxidase [GSH-Px], and glutathione [GSH]) were analyzed in the samples. Histo-pathological findings were evaluated in the liver. The body weights and liver weights of the animals were measured. The MDA and NO levels and biochemical enzyme activities examined were increased, whereas SOD, CAT, and GSH-Px activities and GSH levels decreased in cadmium-exposed group. There were also negative changes in body weight, liver weight, and liver tissue histo-phathology. Positive improvements were observed in all these parameters evaluated of the group co-administered cadmium and diosmin. PRACTICAL APPLICATIONS: Cadmium is one of the common environmental pollutants. Diosmin is a type of flavonoid found mainly in citrus fruits. It can also be produced from hesperidine. This compound is used for medical purposes and also has strong antioxidant properties. One of the toxic effects mechanisms of cadmium is oxidative stress and causes liver damage with different pathways. This compound can be used as a supporting agent in addition to the main treatment options against liver damage in case of exposure to possible cadmium. This flavonoid can also be taken with food for prophylactic purposes.

The chondroprotective effect of diosmin on human articular chondrocytes under oxidative stress.

Excessive oxidative stress, which can amplify inflammatory responses, is involved in the pathologic progression of knee osteoarthritis. Diosmin is known to possess a variety of biological functions such as antiinflammatory and antioxidant activities. We therefore demonstrated the chondroprotective potentials of diosmin on human articular chondrocytes under oxidative stress. The cytotoxicity of diosmin (5, 10, 50, and 100 µM) to chondrocytes was first evaluated. Subsequently, the cells were treated with diosmin (5 and 10 µM) after hydrogen peroxide (H2 O2 ) exposure. We found that the cytotoxicity of diosmin occurred in a dose-dependent manner (10, 50, and 100 µM), and low-dose diosmin (5 µM) slightly impaired cell viability. Diosmin supplementations (5 and 10 µM) did not show beneficial effects on mitochondrial activity, cytotoxicity, proliferation, and survival and the cell senescence was ameliorated in H2 O2 -exposed chondrocytes. On the other hand, diosmin down-regulated the mRNA levels of iNOS, COX-2, IL-1ß, COL1A1, MMP-3, and MMP-9; up-regulated TIMP-1 and SOX9; and improved COL2A1 in chondrocytes under oxidative stresses. Furthermore, diosmin also regulated glutathione reductase and glutathione peroxidase of H2 O2 -exposed chondrocytes. In conclusion, diosmin displayed a remarkable antiinflammatory effect compared with the antioxidant capacity on human chondrocytes. Diosmin can maintain the homeostasis of extracellular matrix of articular cartilage.

Dual-targeted casein micelles as green nanomedicine for synergistic phytotherapy of hepatocellular carcinoma.

In recent years, green nanomedicines have made transformative difference in cancer therapy researches. Herein, we propose dual-functionalized spray-dried casein micelles (CAS-MCs) for combined delivery of two phytochemicals; berberine (BRB) and diosmin (DSN) as targeted therapy of hepatocellular carcinoma (HCC). The nanomicelles enabled parenteral delivery of the poorly soluble DSN via its encapsulation within their hydrophobic core. Moreover, sustained release of the water soluble BRB was attained by hydrophobic ion pairing with sodium deoxycholate followed by genipin crosslinking of CAS-MCs. Dual-active targeting of MCs, via conjugating both lactobionic acid (LA) and folic acid (FA), resulted in superior cytotoxicity and higher cellular uptake against HepG2 cells compared to single-targeted and non-targeted CAS-MCs. The dual-targeted DSN/BRB-loaded CAS-MCs demonstrated superior in vivo anti-tumor efficacy in HCC bearing mice as revealed by down regulation of cell necrosis markers (NF-κB and TNF-α), inflammatory marker COX2, inhibition of angiogenesis and induction of apoptosis. Histopathological analysis and immunohistochemical Ki67 staining confirmed the superiority of the dual-targeted micelles. Ex-vivo imaging showed preferential liver-specific accumulation of dual-targeted CAS-MCs. Overall, this approach combined the benefits of traditional herbal medicine with nanotechnology via LA/FA-CAS-MCs loaded with BRB and DSN as a promising nanoplatform for targeted HCC therapy.

Diosmin, a Citrus Nutrient, Activates Imidazoline Receptors to Alleviate Blood Glucose and Lipids in Type 1-Like Diabetic Rats.

Diosmin is a nutrient that is widely contained in citrus and that has been indicated to improve glucose metabolism in diabetic disorders. Recently, we demonstrated that diosmin induces ß-endorphin to lower hyperglycemia in diabetic rats. However, the mechanisms of diosmin in opioid secretion were unclear. Therefore, we focused on the secretion of opioids from isolated adrenal glands induced by diosmin. The changes in the released ß-endorphin-like immunoreactivity (BER) were determined using ELISA. Diosmin increased the BER level in a dose-dependent manner, and this effect was markedly reduced in the absence of calcium ions. Activation of the imidazoline I-2 receptor (I-2R) has been introduced to induce opioid secretion. Interestingly, we observed that diosmin activates CHO cells expressing I-R. Additionally, diosmin-increased BER was inhibited by the blockade of I-2R in isolated adrenal glands. Additionally, an antagonist of I-2R blocked diosmin-induced effects, including the reduction in hyperglycemia and the increase in plasma BER in streptozotocin-induced diabetic rats (STZ-diabetic rats). Repeated treatment of STZ-diabetic rats with diosmin for one week induced changes in hepatic glycogen, lipid levels, and the expression of phosphoenolpyruvate carboxykinase (PEPCK). Furthermore, an antagonist of I-2R blocked the diosmin-induced changes. Additionally, plasma lipids modified by diosmin were also reversed by the blockade of I-2R in STZ-diabetic rats. Taken together, we suggest that diosmin may activate I-2R to enhance the secretion of ß-endorphin from adrenal glands and to influence metabolic homeostasis, resulting in alleviation of blood glucose and lipids in STZ-diabetic rats.

Antihyperglycaemic action of diosmin, a citrus flavonoid, is induced through endogenous ß-endorphin in type I-like diabetic rats.

Diosmin is one of the flavonoids contained in citrus and has been demonstrated to improve glucose metabolism in diabetic disorders. However, the mechanism(s) of diosmin in glucose regulation remain obscure. Therefore, we investigated the potential mechanism(s) for the antihyperglycaemic action of diosmin in streptozotocin-induced diabetic rats (STZ-diabetic rats). Diosmin lowered hyperglycaemia in a dose-dependent manner in STZ-diabetic rats. This action was inhibited by naloxone at a dose sufficient to block opioid receptors. Additionally, we determined the changes in plasma ß-endorphin-like immunoreactivity (BER) using enzyme-linked immunosorbent assay (ELISA). Diosmin also increased BER dose-dependently in the same manner. Repeated treatment of STZ-diabetic rats with diosmin for 1 week resulted in an increase in the expression of the glucose transporter subtype 4 (GLUT 4) in the soleus muscle and a reduction in the expression of phosphoenolpyruvate carboxykinase (PEPCK) in the liver. These effects were also inhibited by naloxone at a dose sufficient to block opioid receptors. Bilateral adrenalectomy in STZ-diabetic rats eliminated the actions of diosmin, including both the reduction in hyperglycemia and the elevation of plasma BER. In conclusion, our results suggest that diosmin may act on the adrenal glands to enhance the secretion of ß-endorphin, which can stimulate the opioid receptors to attenuate hepatic gluconeogenesis and increase glucose uptake in soleus muscle, resulting in reduced hyperglycemia in STZ-diabetic rats.

Effect of a mixture of diosmin, coumarin glycosides, and triterpenes on bleeding, thrombosis, and pain after stapled anopexy: a prospective, randomized, placebo-controlled clinical trial.

PURPOSE: We evaluated the efficacy of oral administration of a mixture of diosmin, coumarin glycosides, and Centella asiatica (Venoplant®) in preventing bleeding, pain, and thrombosis of internal and external hemorrhoids after stapled anopexy (SA). METHODS: SA was conducted in 182 patients with third-degree hemorrhoids. Preoperatively, patients were randomized evenly into two groups. Group A patients were administered Venoplant for 30 days post-SA, and group B received a placebo for 30 days post-SA. Patients received paracetamol for postoperative pain. Visit (v)1, v2, and v3 took place 7, 15, and 30 days postoperatively, respectively; bleeding (clinical examination), visual analog scale (VAS), thrombosis (clinical examination), and pain (paracetamol dosage, VAS) were evaluated. RESULTS: At v1, v2, and v3, the numbers of patients with bleeding in groups A and B were 21 and 46, 3 and 25, and 1 and 5, respectively (p < 0.05). At v1, v2, and v3, the numbers of patients in groups A and B with thrombosed internal hemorrhoids were 3 and 13, 2 and 11, and 1 and 8, respectively (p < 0.05). The number of patients who took at least one paracetamol tablet was similar in both groups at v1 but was significantly greater in group B than group A at v2 and v3 (p < 0.05); pain VAS scores were equivalent at v1 and significantly greater in group B than group A at v2 and v3 (p < 0.05). CONCLUSIONS: Venoplant effectively reduced bleeding after SA, decreased the incidence of thrombosed internal hemorrhoids, and decreased postoperative pain.

Effect of Pycnogenol on the Healing of Venous Ulcers.

BACKGROUND: Venous ulcers are common complications of chronic venous insufficiency that result in severe physical and mental suffering to patients. The oral administration of diosmin/hesperidin has been used as adjuvant therapy in the treatment of chronic venous insufficiency. The purpose of this study was to evaluate and compare the effect of pycnogenol and diosmin/hesperidin on the healing of venous ulcers. METHODS: This longitudinal, prospective, randomized clinical trial was conducted with 30 adult patients with venous ulcers from a vascular surgery outpatient clinic of a university hospital. The patients were randomly allocated to 2 groups: Group 1 (n = 15) was treated with pycnogenol (50 mg orally, 3 times daily) and Group 2 (n = 15) was treated with diosmin/hesperidin (450/50 mg orally, twice daily). They were assessed every 15 days for 90 days. During follow-up visits, photo-documentation was obtained and the ulcer area and circumference of the affected limb were measured. Friedman's test and Mann-Whitney test were used to compare ulcer areas and circumference of affected limbs between and within groups at different time points. The level of significance was set at 5% (P < 0.05) for all tests. RESULTS: Both the pycnogenol and diosmin/hesperidin treatments had a similar effect on the healing of venous ulcers and led to a significant decrease in the circumference of affected limbs (P < 0.0001). CONCLUSION: The results suggest that pycnogenol has an adjuvant effect on the healing of venous ulcers, similar to diosmin/hesperidin.

Phlebotonics for venous insufficiency.

BACKGROUND: Chronic venous insufficiency (CVI) is a common condition caused by valvular dysfunction with or without associated obstruction, usually in the lower limbs. It might result in considerable discomfort with symptoms such as pain, itchiness and tiredness in the legs. Patients with CVI may also experience swelling and ulcers. Phlebotonics are a class of drugs often used to treat CVI. This is an update of a review first published in 2005. OBJECTIVES: To assess the efficacy and safety of phlebotonics administered both orally and topically for treatment of signs and symptoms of lower extremity CVI. SEARCH METHODS: For this update, the Cochrane Vascular Trials Search Co-ordinator (TSC) searched the Specialised Register (August 2015), as well as the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 7). The reference lists of the articles retrieved by electronic searches were searched for additional citations. We also contacted pharmaceutical companies and searched the World Health Organization (WHO) International Clinical Trials Registry Platform Search Portal for ongoing studies (last searched in August 2015). SELECTION CRITERIA: Randomised, double-blind, placebo-controlled trials (RCTs) assessing the efficacy of rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, Centella asiatica, disodium flavodate, french maritime pine bark extract, grape seed extract and aminaftone in patients with CVI at any stage of the disease. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed the quality of included RCTs. We estimated the effects of treatment by using risk ratios (RRs), mean differences (MDs) and standardised mean differences (SMDs), according to the outcome assessed. We calculated 95% confidence interval (CIs) and percentage of heterogeneity (I(2)). Additionally, we performed sensitivity analyses. MAIN RESULTS: We included 66 RCTs of oral phlebotonics, but only 53 trials provided quantifiable data (involving 6013 participants; mean age 50 years) for the efficacy analysis: 28 for rutosides, 10 hidrosmine and diosmine, nine calcium dobesilate, two Centella asiatica, two aminaftone, two french maritime pine bark extract and one grape seed extract. No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria.Moderate-quality evidence suggests that phlebotonics reduced oedema in the lower legs compared with placebo. Phlebotonics showed beneficial effects among participants including reduced oedema (RR 0.70, 95% CI 0.63 to 0.78; I(2) = 20%; 1245 participants) and ankle circumference (MD -4.27 mm, 95% CI -5.61 to -2.93 mm; I(2) = 47%; 2010 participants). Low-quality evidence reveals no difference in the proportion of ulcers cured with phlebotonics compared with placebo (RR 0.94, 95% CI 0.79 to 1.13; I(2) = 5%; 461 participants). In addition, phlebotonics showed greater efficacy for trophic disorders, cramps, restless legs, swelling and paraesthesia, when compared with placebo. We identified heterogeneity for the variables of pain, itching, heaviness, quality of life and global assessment by participants. For quality of life, it was not possible to pool the studies because heterogeneity was high. However, high-quality evidence suggests no differences in quality of life for calcium dobesilate compared with placebo (MD -0.60, 95% CI -2.15 to 0.95; I(2) = 40%; 617 participants), and low-quality evidence indicates that in the aminaftone group, quality of life was improved over that reported in the placebo group (MD -10.00, 95% CI -17.01 to - 2.99; 79 participants). Moderate-quality evidence shows that the phlebotonics group had greater risk of non-severe adverse events than the placebo group (RR 1.21, 95% CI 1.05 to 1.41; I(2) = 0; 3975 participants). Gastrointestinal disorders were the most frequently reported adverse events. AUTHORS' CONCLUSIONS: Moderate-quality evidence shows that phlebotonics may have beneficial effects on oedema and on some signs and symptoms related to CVI such as trophic disorders, cramps, restless legs, swelling and paraesthesia when compared with placebo but can produce more adverse effects. Phlebotonics showed no differences compared with placebo in ulcer healing. Additional high-quality RCTs focused on clinically important outcomes are needed to improve the evidence base.

A flavonoid fraction purified from Rutaceae aurantiae (Daflon(R)) inhibiting AGE formation, reduces urinary albumin clearance and corrects hypoalbuminemia in normotensive and hypertensive diabetic rats.

AIM: Advanced glycation endproducts (AGEs) have been shown to contribute to alteration of glomerular permselectivity to proteins in diabetes. Oxidative stress is required for AGE formation. Therefore we studied the effect of an antioxidant micronized purified flavonoid fraction (MPFF, Daflon(R) 500 mg), on urinary albumin clearance in diabetic rats. METHODS: Hyperglycaemia was induced by streptozotocin 55 mg/kg IM at days 0 and 7 in normotensive Wistar rats (NWR, diabetes duration 5 months) or hypertensive Wistar Kyoto rats (SHR, diabetes duration 2 months). MPFF was administered at 300 mg/kg/day, from day -2 until sacrifice. RESULTS: After 5 months of diabetes in NWR, MPFF reduced albumin clearance from 729±92 to 392±60 nl/min/kg, p<0.01, and restored albuminemia from 20.4±0.9 to 24.0±1 g/l, p<0.05; albumin fractional clearance was significantly diminished in the flavonoid-treated diabetic rats (0.360±0.037‰ versus 1.335±0.430‰ in the diabetic controls, p<0.001); MPFF did not significantly modify blood glucose and plasma fructosamine levels. After 2 months of diabetes in SHR, MPFF reduced albumin clearance from 243±121 to 101±47 nl/min/kg, p<0.05, and restored albuminemia from 21.1±1.6 to 26.7±2.2 g/l (p<0.05); MPFF also decreased plasma fluorescence characteristic of AGEs (p<0.02). Besides hesperetin, a main metabolite of MPFF recovered in plasma, inhibited in vitro the formation of the crosslinking AGE pentosidine in collagen incubated with high glucose (p<0.001). CONCLUSION: Our results confirm the role of glycoxidative stress in diabetic nephropathy. MPFF might be useful as complementary treatment for preventing diabetic microangiopathy.

Long-term follow-up of oral administration of flavonoids, Centella asiatica and Melilotus, for diabetic cystoid macular edema without macular thickening.

PURPOSE: To evaluate long-term follow-up of the orally administered combination of flavonoids with Centella asiatica and Melilotus for treatment of diabetic cystoid macular edema (CME) without macular thickening. METHODS: Seventy consecutive patients with type 2 diabetes and CME without macular thickening at optical coherence tomography (OCT) were prospectively and randomly enrolled in two groups of 35 subjects each (treatment and control groups). Patients in the treatment group were treated with an oral combination of diosmin (300 mg/day), with C. asiatica (15 mg/day) and Melilotus (160 mg/day). All patients underwent a complete ophthalmologic examination, OCT (Spectralis HRA-OCT), and central microperimetry (SD-SLO/OCT) at baseline, month 3, month 6, month 12, month 24, and month 36. RESULTS: No differences in HbAc1 percentage, blood pressure, microalbuminuria, visual acuity, mean central retinal thickness, and stability of fixation were present between the two groups during follow up (p>0.05). Retinal sensitivity reduced in the control group only from month 6 until month 36 (p<0.001). In the treatment group, a greater retinal sensitivity was present at month 12, month 24, and month 36 (p=0.001). No side effects of treatment were observed. CONCLUSION: Oral administration of flavonoids, C. asiatica and Melilotus, in patients with CME without macular thickening provided preservation of retinal sensitivity during 36 months of follow up when compared with untreated patients.

Diosmin--isolation techniques, determination in plant material and pharmaceutical formulations, and clinical use.

Diosmin is a naturally occurring flavone glycoside used in the treatment of venous diseases. In this review, we present the clinical aspects of the use of diosmin preparations in venous stasis, hemorrheologic disorders and vein wall remodeling. Because of its multiple applications in biology and its many therapeutic activities, research on isolation and identification of diosmin is of high relevance. The aim of this review is to present an overview of techniques of isolation and separation of diosmin in plant material, pharmaceutical formulations such as Daflon, Diosed and Dioven tablets, and biological fluids.