Alloxan-induced diabetic thermal hyperalgesia, prophylaxis and phytotherapeutic effects of Rheum ribes L. in mouse model

Treatment of neuropathic pain by traditional Chinese medicine: An updated review on their effect and putative mechanisms of action

Neuropathic pain (NP) is a common chronic pain with heterogeneous clinical features, and consequent lowering of quality of life. Currently, although conventional chemical drugs can effectively manage NP symptoms in the short term, their long-term efficacy is limited, and they come with significant side effects. In this regard, traditional Chinese medicine (TCM) provides a promising avenue for treating NP. Numerous pharmacological and clinical studies have substantiated the effectiveness of TCM with multiple targets and mechanisms. We aimed to outline the characteristics of TCM, including compound prescriptions, single Chinese herbs, active ingredients, and TCM physical therapy, for NP treatment and discussed their efficacy by analyzing the pathogenesis of NP. Various databases, such as PubMed, Web of Science, China National Knowledge Infrastructure, and Wanfang database, were searched. We focused on recent research progress in NP treatment by TCM. Finally, we proposed the future challenges and emerging trends in the treatment of NP. TCM demonstrates significant clinical efficacy in NP treatment, employing multi-mechanisms. Drawing from the theory of syndrome differentiation, four types of dialectical treatments for NP by compound TCM prescriptions were introduced: promoting blood circulation and removing blood stasis; promoting blood circulation and promote Qi flow; warming Yang and benefiting Qi; soothing the liver and regulating Qi. Meanwhile, 33 single Chinese herbs and 25 active ingredients were included. In addition, TCM physical therapy (e.g., acupuncture, massage, acupoint injection, and fumigation) also showed good efficacy in NP treatment. TCM, particularly through the use of compound prescriptions and acupuncture, holds bright prospects in treating NP owing to its diverse holistic effects. Nonetheless, the multi-targets of TCM may result in possible disadvantages to NP treatment, and the pharmacological mechanisms of TCM need further evaluation. Here, we provide an overview of NP treatment via TCM, based on the pathogenesis and the potential therapeutic mechanisms, thus providing a reference for further studies.

The effects of the Rheum ribes plant extract on inflammation, extracellular matrix remodeling, and obesity suggest a therapeutic potential

BACKGROUND

The prevalence of obesity is increasing in the world, and the Type II diabetes associated with obesity led researchers to seek alternative methods to treat these two chronic diseases. In the case of obesity and diabetes, changes occur in the levels of inflammatory mediators. A study was conducted to investigate the molecular mechanism of the Rheum ribes L. plant regarding obesity and inflammation.

METHODS AND RESULTS

Differentiated 3T3-L1 mouse cell lines were used as an experimental model. A dose-response relationship was established to determine at what dose and time of treatment the R. ribes L. plant extract would act effectively. To assess expression on the transcriptional level, q-PCR analyses were performed. The primers to evaluate the expression levels of genes such as Dgat1, Lpl, Fasn, ColV, Il-6, and Mcp1, which are known to be associated with obesity and insulin resistance, inflammation, and cell skeletal restructuring was designed using NCBI sequences. 18S was chosen as the housekeeping gene for normalization.

CONCLUSION

It was found that applying 50 µg/mL and 100 µg/mL of R. ribes root extract to 3T3-L1 adipocyte cells for 24 and 48 h resulted in anti- obesity and anti-inflammatory effects on the genes examined at the transcriptional level. It is an effective study to understand the molecular mechanisms by which R. ribes, which is known to have anti-diabetic, anti-obesity and anti- inflammatory activities, and to establish a link between these activities.

Rodent models for diabetes

Diabetes mellitus (DM) is associated with many health complications and is potentially a morbid condition. As prevalence increases at an alarming rate around the world, research into new antidiabetic compounds with different mechanisms is the top priority. Therefore, the preclinical experimental induction of DM is imperative for advancing knowledge, understanding pathogenesis, and developing new drugs. Efforts have been made to examine recent literature on the various induction methods of Type I and Type II DM. The review summarizes the different in vivo models of DM induced by chemical, surgical, and genetic (immunological) manipulations and the use of pathogens such as viruses. For good preclinical assessment, the animal model must exhibit face, predictive, and construct validity. Among all reported models, chemically induced DM with streptozotocin was found to be the most preferred model. However, the purpose of the research and the outcomes to be achieved should be taken into account. This review was aimed at bringing together models, benefits, limitations, species, and strains. It will help the researcher to understand the pathophysiology of DM and to choose appropriate animal models.

The effects of aqueous and ethanolic extracts of Rheum ribes on insulin-resistance and apolipoproteins in patients with type 2 diabetes mellitus: a randomized controlled trial

BACKGROUND AND AIM

Previous studies have shown that Rheum ribes (R. ribes) could be effective in controlling the blood glucose levels. This study was conducted to determine the effects of R. ribes supplementation on glycemic indices and apolipoproteins in patients with type 2 diabetes mellitus (T2DM).

METHODS

In the present randomized double-blind controlled trial, 60 type 2 diabetic patients aged 30-60 years with a body mass index (BMI) of 20-30 kg/m² and hemoglobin A1c (HbA1c) of 6-8% were enrolled. Patients were randomly assigned to receive 450 mg of aqueous R. ribes extract (AG), 450 mg of ethanolic R. ribes extract (EG), or placebo (PG) three times daily for 6 weeks. At the baseline and at the end of the study, blood glucose levels, homeostatic model assessment of insulin resistance (HOMA-IR) and the homeostatic model assessment of β-cell dysfunction (HOMA-B), as well as apolipoprotein A-I (ApoA1) and apolipoprotein B (ApoB) were measured.

RESULTS

There was a significant decrease in the serum levels of insulin in AG and EG groups (P = 0.003 and P = 0.001, respectively), HOMA-IR (P = 0.01 and P = 0.001, respectively), HOMA-B (P = 0.002 and P = 0.001, respectively), ApoB (P = 0.006 and P = 0.03, respectively), ApoB/ApoA1 ratio (P = 0.016 and P = 0.04, respectively). However, a significant increase in ApoA1 (P = 0.08 and P = 0.05, respectively) with no significant changes in blood glucose, at the end of study compared to beginning values, were observed. None of the variables showed a significant change in PG. At the end of the study; while there were significant differences in insulin (P = 0.04), HOMA-IR (P = 0.03), HOMA-B (P = 0.01), ApoB (P = 0.02), and ApoB/ApoA1 ratio (P = 0.03) among the groups but ApoA1 had no significant change.

CONCLUSION

Consumption of R. ribes intake could have beneficial effects on insulin resistance and apolipoproteins in type 2 diabetic patients. (Registered at en.irct.ir, identification number: IRCT201410142709N31).

Exploration of the mechanisms underlying the beneficial effect of Luo Tong formula on retinal function in diabetic rats via the "gut microbiota-inflammation-retina" axis

BACKGROUND

Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Luo Tong formula (LTF), a classical traditional Chinese medicine (TCM) prescription, consists of four plants that have been widely and effectively used to treat DR. Previous work in our laboratory has confirmed that LTF can effectively ameliorate DR. However, the potential mechanism underlying the therapeutic effect of LTF on DR has not been fully elucidated. To explore the potential mechanism of action through which LTF prevents and alleviates DR from an inflammation and gut microbiota perspective.

MATERIALS AND METHODS

Metabolite profiling of LTF was performed using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). Type 1 diabetes was induced in male Sprague Dawley (SD) rats via tail vein injection of 45 mg/kg streptozotocin. Next, 100 SD rats were randomly divided into four groups, normal control; diabetic control; diabetic + insulin + calcium dobesilate; and diabetic + insulin + LTF. After 12 weeks of treatment, glucose metabolism, fundus oculi, blood-retinal barrier permeability, retinal thickness, microvascular damage, as well as cell junction expression in retinas were measured and the changes observed in different groups were compared. Finally, the alteration in gut microbiota and inflammatory cytokine expression in serum and tissues were monitored, and their correlation was analyzed.

RESULTS

A total of 1024 valid peaks were obtained for LTF using GC-MS. The HbA1c and fasting blood glucose (FBG) levels in the LTF group were slightly decreased. LTF exerted protective effects on fundus oculi and the retina structure to different degrees. LTF attenuated systemic and local retinal inflammation by significantly decreasing the levels of seven pro-inflammatory cytokines, including ICAM-1, IL-6, IL-8, MCP-1, VCAM-1, VEGF, and IL-1β. LTF restored the intestinal microbiota of diabetic rats to levels that were similar to those of normal rats. Further analysis revealed that Enterobacteriales, Prevotellaceae, Enterobacteriaceae, Bacteroides, and Klebsiella were significantly and positively correlated with the inflammatory factors in DR after LTF treatment.

CONCLUSIONS

Our results revealed the mechanisms underlying the preventive effects of LTF on DR development and progression. LTF inhibited pathological changes in retinal histopathology, cell composition, and cell junction proteins while effectively ameliorating systemic and local retinal inflammation via regulating pivotal gut microbiota.

Middle East Medicinal Plants in the Treatment of Diabetes: A Review

Diabetes is a global health problem, and the number of diabetic patients is in continuous rise. Conventional antidiabetic therapies are associated with high costs and limited efficiency. The use of traditional medicine and plant extracts to treat diabetes is gaining high popularity in many countries. Countries in the Middle East region have a long history of using herbal medicine to treat different diseases, including diabetes. In this review, we compiled and summarized all the in vivo and in vitro studies conducted for plants with potential antidiabetic activity in the Middle East region. Plants of the Asteraceae and Lamiaceae families are the most investigated. It is hoped that this review will contribute scientifically to evidence the ethnobotanical use of medicinal plants as antidiabetic agents. Work has to be done to define tagetes, mechanism of action and the compound responsible for activity. In addition, safety and pharmacokinetic parameters should be investigated.

Ethnobotanical Uses, Phytochemistry and Pharmacology of Different Rheum Species (Polygonaceae): A Review

Today, there is an increased tendency to use herbal remedies. Rhubarb refers to several species of the genus Rheum L. in the Polygonaceae family. This species-rich genus is mainly distributed in Asian countries. Several medicinal effects have been attributed to the Rheum spp. in the traditional and modern medicine such as healing lungs, liver, kidney, womb and bladder diseases, cancer, diabetes, insect bites, relapsing fevers, diarrhea and constipation. Various in vitro, in vivo and clinical studies have investigated the therapeutic effect of extracts, fractions and pure compounds isolated from different species of this genus. Considering the positive findings, several pharmaceutical formulations containing rhubarb extract like capsules, drops, mouthwashes and different topical formulations are now present in the market. However, there are other traditional therapeutic effects of rhubarb that have not been studied yet and it is of great importance to perform confirmatory experiments or clinical investigations. The current review summarizes general information regarding botany, phytochemistry, ethnobotany and pharmacological aspects of Rheum spp. It is hoped that the present review could motivate subsequent research on the other medicinal properties of these plants that have been neglected until today.

Depletion of senescent-like neuronal cells alleviates cisplatin-induced peripheral neuropathy in mice

Chemotherapy-induced peripheral neuropathy is among the most common dose-limiting adverse effects of cancer treatment, leading to dose reduction and discontinuation of life-saving chemotherapy and a permanently impaired quality of life for patients. Currently, no effective treatment or prevention is available. Senescence induced during cancer treatment has been shown to promote the adverse effects. Here, we show that cisplatin induces senescent-like neuronal cells in primary culture and in mouse dorsal root ganglia (DRG), as determined by the characteristic senescence markers including senescence-associated beta-galactosidase, accumulation of cytosolic p16^INK4A and HMGB1, as well as increased expression of p16Ink4a, p21, and MMP-9. The accumulation of senescent-like neuronal cells in DRG is associated with cisplatin-induced peripheral neuropathy (CIPN) in mice. To determine if depletion of senescent-like neuronal cells may effectively mitigate CIPN, we used a pharmacological ‘senolytic’ agent, ABT263, which inhibits the anti-apoptotic proteins BCL-2 and BCL-xL and selectively kills senescent cells. Our results demonstrated that clearance of DRG senescent neuronal cells reverses CIPN, suggesting that senescent-like neurons play a role in CIPN pathogenesis. This finding was further validated using transgenic p16-3MR mice, which permit ganciclovir (GCV) to selectively kill senescent cells expressing herpes simplex virus 1 thymidine kinase (HSV-TK). We showed that CIPN was alleviated upon GCV administration to p16-3MR mice. Together, the results suggest that clearance of senescent DRG neuronal cells following platinum-based cancer treatment might be an effective therapy for the debilitating side effect of CIPN.

The effect of Rheum ribes L. on oxidative stress in diabetic rats

Objectives Rheum ribes L. is a perennial plant that belongs to the family of Polygonaceae, which is often used in traditional therapy because it possesses many bioactivities, such as antioxidant and antibacterial ones. Here we examined the effect of different R. ribes L. extracts on oxidative stress in experimental diabetic rats. Methods Thirty-six rats were divided into six groups as follows: group I, control group; group II, diabetic rats; group III, diabetic rats treated with the aqueous extract of R. ribes L. by gavage at 50 mg/kg for 15 days; group IV, diabetic rats treated by gavage with the ethanolic extract of R. ribes L. at 50 mg/kg for 15 days; group V, nondiabetic rats treated by gavage with the aqueous extract of R. ribes L. at 50 mg/kg for 15 days; group VI, nondiabetic rats treated by gavage with the ethanol extract of R. ribes L. at 50 mg/kg for 15 days. After 15 days, the animals were sacrificed and the liver and kidney tissues of each animal were isolated. Superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) activities in the tissue samples were measured, and histopathologic examination was carried out. Results R. ribes L. was effective in reducing the oxidative stress and increasing the levels of the antioxidant enzymes. Increased levels of MDA and decreased levels of SOD, CAT and GSH-Px were observed in both the liver and kidney tissues in group II. Decreased levels of MDA and increased levels of SOD, CAT and GSH-Px were observed in group III compared with group II. In group IV, decreased levels of MDA and increased levels of SOD, CAT and GSH-Px were observed in comparison with group II. Conclusions Diabetes increases oxidative stress and causes a decrease in antioxidant enzyme levels. Both aqueous and ethanolic extracts of R. ribes L. decrease oxidative stress activity and increase the levels of antioxidant enzymes. The ethanol extract of R. ribes L. has a higher antioxidant effect than the aqueous extract.

Phytochemical Compositions and Antidiabetic Potentials of Salvia sclarea L. Essential Oils

Salvia sclarea (SS) is characterized by its valuable essential oils (Eos) and potent biological activities. This study aimed at investigating the phytochemical composition of SS Eos collected in within the same week, from two different regions in Lebanon, Beirut (SS-Bt) and Taanayel (SS-Tl), utilizing GC-MS methods, and to explore their acute and subchronic antidiabetic potentials. Moreover, studying the phytochemical diversity of twenty SS Eos established on our work and literature descriptions in order to recognize the origin of the Lebanese active chemotype(s). The Eos have been obtained by hydro-distillation and identified via GC-MS analyses. Five chemotypes of SS Eos have been identified. The Lebanese Eos, SS-Bt and SS-Tl, studied here have shown evidence to belong to two different chemotypes 1 and 5, respectively. SS-Bt has shown to belong to chemotype 1, which is characterized by high linalool (LL) concentration (average 40.2%). On the other hand, SS-Tl has shown to belong to chemotype 5, which is characterized by high linalyl acetate (LA) concentration (average 50.4%). The acute and subchronic antidiabetic activities of these EOs have been monitored along with LL and LA, in order to find the most active chemotype. Chemotypes 1 (owned to high LL content), present at low altitude places of Lebanon and Poland, has shown significantly higher acute and subchronic antidiabetic activities than that of chemotype 5 (owned to high LA content). In conclusion, Salvia sclarea Eos have shown potential antidiabetic activities, and their Eos might be used in the future as a complementary or an alternative medicine in the management of diabetes and related complications.

Chromane isolated from leaves of Dillenia indica improves the neuronal dysfunction in STZ-induced diabetic neuropathy

ETHNOPHARMACOLOGICAL RELEVANCE

According to the Indian traditional medicine, Dillenia indica L. has shown therapeutic efficacy in various diseases. Fruits and leaves of the plant possess anti-oxidant and anti-inflammatory properties. Reactive oxygen species, formation of advanced glycation end products (AGEs) and apoptosis are implicated in the pathogenesis of diabetic neuropathy.

AIM OF THE STUDY

The aim of the present study was to explore the effect of D. indica and its isolate, chromane (CR), on thermal and mechanical hyperalgesia, allodynia, MNCV and oxidative-nitrosative stress in streptozotocin-induced experimental diabetes.

MATERIAL AND METHODS

Diabetes was induced by intraperitoneal administration of Streptozotocin (STZ; 65mg/kg) for the development of diabetic neuropathy. Chronic treatment with DAE (100, 200 and 400mg/kg, p.o.) and CR (5 and 10mg/kg, p.o.) for 30 days was started from the 60th day of STZ administration. Development of neuropathy was evident from a marked hyperalgesia and allodynia; reduced MNCV associated with increased formation of AGEs and reactive oxygen species.

RESULTS

significantly attenuated behavioral and biochemical changes associated with diabetic neuropathy. Present study suggested that DAE and CR ameliorated hyperglycemia and diabetic neuropathic pain via modulation of oxidative-nitrosative stress and reduction in AGEs formation in the diabetic rats.

CONCLUSION

Thus D. indica might be beneficial in chronic diabetics, ameliorate the progression of diabetic neuropathy and may also find application in diabetic neuropathic pain.

Prunella vulgaris L. active components and their hypoglycemic and antinociceptive effects in alloxan-induced diabetic mice

Prunella vulgaris L. (Lamiaceae) (PV) is a herbaceous plant traditionally utilized in management of diabetes and it has immunomodulatory activity. In this study, acute and subchronic antidiabetic, in-vivo antioxidant and antinociceptive effects of PV were evaluated in alloxan-induced type 1 diabetes (T1D) in a mouse model. Bio-guided fractionation, isolation, RP-HPLC, and ¹H and ¹³C NMR identification of the active components responsible for PV effects were determined. RP-HPLC analysis showed that PV contained rosmarinic acid (RA) 4.5%, caffeic acid (CA) 9.8% and p-coumaric acid (pCA) 11.6%. Bio-guided fractionation showed that PV most active fraction was rich in caffeic acid, hence named, caffeic acid-rich fraction (CARF). RP-HPLC, and ¹H and ¹³C NMR experiments showed that CARF contained CA (93.4%) and RA (6.6%). CARF reduced blood glucose levels and improved in-vivo oxidative-stress. It also inhibited the carbohydrate-hydrolyzing enzymes (alpha-amylase and alpha-glucosidase) and reduced HbA1c levels more significantly (p≤0.05) than that of PV and equivalent amounts of CA or RA. For longer times, CARF had significantly (p≤0.05) increased serum-insulin, ameliorated thermal hyperalgesia and tactile allodynia more significantly (p≤0.05) than the effects of PV and equivalent amounts of CA or RA. Moreover, the tested compounds showed potential restoration of the lipid peroxide levels. Consequently, CARF and PV observed increase in serum-insulin, attenuation of alpha-amylase and alpha-glucosidase, and their antioxidant potentials might be responsible for their antidiabetogenic and antinociceptive properties. In conclusion, CARF isolated from PV could be a potential therapeutic agent to ameliorate T1D and related complications.

Phytotherapeutic activity of curcumol: Isolation, GC-MS identification, and assessing potentials against acute and subchronic hyperglycemia, tactile allodynia, and hyperalgesia

CONTEXT

Curcumol has recently attracted special attention due to its potential activities in many chronic disorders. Moreover, the traditional role of turmeric [Curcuma longa L. (Zingiberaceae)] in suppression of hyperglycemia is of great interest.

OBJECTIVES

The present work explores the potential acute and subchronic antihyperglycemic, antinociceptive, and in vivo antioxidant effects of curcumol in alloxan-diabetic mice.

MATERIALS AND METHODS

Bio-guided fractionation, column-chromatography, and GC-MS were utilized to identify the most active compound of turmeric (curcumol). Turmeric (25, 50, and 100 mg/kg), the curcumol rich fraction (CRF) (7 mg/kg), and curcumol (20, 30, and 40 mg/kg) were assessed for their acute (6 h) and subchronic (8 d) antihyperglycemic potentials and antinociceptive effects (8 weeks) were measured, using hot-plate and tail-flick latencies and von-Frey filaments method and in vivo antioxidant effects in alloxan-diabetic mice.

RESULTS

The most-active turmeric fraction was found to be rich in curcumol (45.5%) using GC-MS analysis method. The results proved that the highest dose levels of turmeric extract and curcumol exerted remarkable hypoglycemic activity with 41.4 and 39.3% drop in the mice glucose levels after 6 h, respectively. Curcumol (40 mg/kg) was found to be 9.4% more potent than turmeric extract (100 mg/kg) in subchronic management of diabetes. Curcumol also showed a significant improvement of peripheral nerve function as observed from the latency and tactile tests.

DISCUSSION

The antioxidant potential of curcumol may cause its ability to ameliorate diabetes and diabetes-related complications.

CONCLUSIONS

Curcumol, a natural metabolite with a good safety-profile, showed results comparable with tramadol in reversing diabetes-induced tactile allodynia and hyperalgesia.

Development of an efficient callus proliferation system for Rheum coreanum Nakai, a rare medicinal plant growing in Democratic People's Republic of Korea

A clonal mass propagation to obtain mountainous sources of Rheum coreanum Nakai, a rare medicinal plant in Democratic People’s Republic of Korea was established by rhizome tissue culture. Whole plants were selected and collected as a vigorous individual free from blights and harmful insects among wild plants of R. coreanum grown on the top of Mt. Langrim (1.540 m above the sea) situated at the northern extremity of Democratic People’s Republic of Korea. Induction of the callus was determined using four organs separated from the whole plant and different plant growth regulators. The callus was successfully induced from rhizome explant on MS medium containing 2.4-D (0.2–0.3 mg/l). In the MS medium supplemented with a combination of BAP (2 mg/l) and NAA (0.2 mg/l), single NAA (0.5 mg/l), or IBA (0.5 mg/l), a higher number of shoot, root and plantlets was achieved. The survival rate on the mountainous region of the plantlets successfully acclimatized (100%) in greenhouse reached 95%, and yields of crude drug and contents of active principles were higher than those obtained by sexual and vegetative propagation. This first report of R. coreanum tissue culture provides an opportunity to control extinction threats and an efficient callus proliferation system for growing resources rapidly on a large scale.

Anti-Inflammatory and Antioxidant Activities of Salvia fruticosa: An HPLC Determination of Phenolic Contents

Objectives. Salvia fruticosa Mill. (S. fruticosa) is widely used in folk medicine. Accordingly, the present study was designed to evaluate the antioxidant and anti-inflammatory activities of S. fruticosa, and to determine the phenolic constituents of its extracts. Methods. The antioxidant activity was determined using 2,2-diphenylpicrylhydrazyl assay. Total phenolic contents were estimated using Folin-Ciocalteu reagent, and high-performance liquid chromatography was performed to identify phenolic constituents. To evaluate the anti-inflammatory activity, carrageenan-induced mouse paw edema was determined plethysmographically. Key Findings. Different plant extracts demonstrated strong radical scavenging activity, where the ethyl acetate extract had the highest value in the roots and the lowest in the aerial parts. This antioxidant activity was correlated to the total phenolic content of different extracts, where rutin and luteolin were the most abundant constituents. Interestingly, both the roots and aerial parts revealed a significant anti-inflammatory activity comparable to diclofenac. Conclusions. This study is the first to demonstrate pharmacologic evidence of the potential anti-inflammatory activity of S. fruticosa. This activity may partly be due to the radical scavenging effects of its polyphenolic contents. These findings warrant the popular use of the East Mediterranean sage and highlight the potential of its active constituents in the development of new anti-inflammatory drugs.

Acute and subchronic in-vivo effects of Ferula hermonis L. and Sambucus nigra L. and their potential active isolates in a diabetic mouse model of neuropathic pain

Background

The prevalence of Diabetes mellitus (DM) is escalating rapidly worldwide, and associated with micro- and macrovascular complications. Diabetic neuropathy (DN) is a common complication of DM, and has a few approved therapies with limited efficacy and several side-effects. Herbal medicine is used worldwide as an effective alternative-medicine. The present study aims to investigate the activities of Ferula hermonis Boiss. EtAc (Ferula) and Sambucus nigra L. aqueous (Elder) extracts, and their potential active isolates; for acute (6 h) and subchronic (8 days) glucose homeostasis, in vivo antioxidant potential and DN amelioration in alloxan-induced DM mice model.

Methods

DM was induced experimentally by injection of freshly prepared alloxan every 48-h for three times at a dose of 180 mg/kg. Utilizing tail-flick, hot-plate latencies (accessing thermal hyperalgesia) and von Frey filaments test (accessing tactile allodynia), DN was evaluated for longer period of time (8 weeks).

Results

The most active isolates from Ferula was ferutinin, and Kaempferol from Elder utilizing bio-guided fractionation and RP-HPLC steeping methods. Compared to glibenclamide (GB) and tramadol (TRA), as positive controls, the highest doses of tested compounds exerted remarkable hypoglycemic and antinociceptive activities. The best acute hypoglycemic effect was observed with ferutinin (1.4 folds more effective than GB). Elder has shown the best subchronic hypoglycemic effect (2.6 folds more effective than GB) and the greatest efficacy against tactile allodynia following a single-administration, yet required repeated administration for improvement of thermal hyperalgesia.

Conclusions

Without the use-limiting-side-effects of existing therapies, Ferula, Elder and their active isolates have shown significant results in ameliorating DM and long standing diabetes-induced complications.

Amelioration of Diabetes and Painful Diabetic Neuropathy by Punica granatum L. Extract and Its Spray Dried Biopolymeric Dispersions

Aims. To evaluate the effect of Punica granatum (Pg) rind extract and its spray dried biopolymeric dispersions with casein (F1) or chitosan (F2) against Diabetes mellitus (DM) and diabetic neuropathy (DN). Methods. We measured the acute (6 h) and subacute (8 days) effect of various doses of Pg, F1, and F2 and the active compounds on alloxan-induced DM mouse model. We evaluated DN utilizing latency tests for longer period of time (8 weeks). In addition, the in vivo antioxidant activity was assessed utilizing serum catalase level. Results. The results proved that the highest dose levels of Pg extract, F1, F2 exerted remarkable hypoglycemic activity with 48, 52, and 40% drop in the mice glucose levels after 6 hours, respectively. The tested compounds also improved peripheral nerve function as observed from the latency tests. Bioguided fractionation suggested that gallic acid (GA) was Pg main active ingredient responsible for its actions. Conclusion. Pg extract, F1, F2, and GA could be considered as a new therapeutic potential for the amelioration of diabetic neuropathic pain and the observed in vivo antioxidant potential may be involved in its antinociceptive effect. It is highly significant to pay attention to Pg and GA for amelioration and control of DM and its complications.