Inhibition of triiodothyronine production by fenugreek seed extract in mice and rats

A Review on Extraction, Characterization, and Applications of Bioactive Peptides From Pressed Black Cumin Seed Cake

Plenty of black cumin cake was generated as a natural waste material after pressing the oil. Nigella sativa (black cumin) seeds and cakes are of precious nutritional value as they contain proteins, phenolics, essential amino acids, and bioactive compounds. Owing to their antioxidant properties, scientists and food manufacturers have extensively developed them. Notably, global awareness among consumers about the benefits of innovative food ingredients has been increased. Meanwhile, it has to be noted that vast amounts of cake by-products are not effectively utilized, which might cause economic loss and environmental consequences. This review aimed to highlight the antioxidant abilities, extraction, characterization, functional characteristics, and utilization of active peptides acquired from black seed oil cake. This overview would critically evaluate black seed cake proteins, plentiful in bioactive peptides that might be utilized as valuable additives in feed, food, pharmaceutical, and cosmetic industries. The addition of bioactive peptides to restrain the oxidation of fat-based products and preserve food safety is also addressed.

Oral galactagogues (natural therapies or drugs) for increasing breast milk production in mothers of non-hospitalised term infants

BACKGROUND

Many women express concern about their ability to produce enough milk, and insufficient milk is frequently cited as the reason for supplementation and early termination of breastfeeding. When addressing this concern, it is important first to consider the influence of maternal and neonatal health, infant suck, proper latch, and feeding frequency on milk production, and that steps be taken to correct or compensate for any contributing issues. Oral galactagogues are substances that stimulate milk production. They may be pharmacological or non-pharmacological (natural). Natural galactagogues are usually botanical or other food agents. The choice between pharmacological or natural galactagogues is often influenced by familiarity and local customs. Evidence for the possible benefits and harms of galactagogues is important for making an informed decision on their use.

OBJECTIVES

To assess the effect of oral galactagogues for increasing milk production in non-hospitalised breastfeeding mother-term infant pairs.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), Health Research and Development Network - Phillippines (HERDIN), Natural Products Alert (Napralert), the personal reference collection of author LM, and reference lists of retrieved studies (4 November 2019).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (including published abstracts) comparing oral galactagogues with placebo, no treatment, or another oral galactagogue in mothers breastfeeding healthy term infants. We also included cluster-randomised trials but excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane Pregnancy and Childbirth methods for data collection and analysis. Two to four review authors independently selected the studies, assessed the risk of bias, extracted data for analysis and checked accuracy. Where necessary, we contacted the study authors for clarification.

MAIN RESULTS

Forty-one RCTs involving 3005 mothers and 3006 infants from at least 17 countries met the inclusion criteria. Studies were conducted either in hospitals immediately postpartum or in the community. There was considerable variation in mothers, particularly in parity and whether or not they had lactation insufficiency. Infants' ages at commencement of the studies ranged from newborn to 6 months. The overall certainty of evidence was low to very low because of high risk of biases (mainly due to lack of blinding), substantial clinical and statistical heterogeneity, and imprecision of measurements. Pharmacological galactagogues Nine studies compared a pharmacological galactagogue (domperidone, metoclopramide, sulpiride, thyrotropin-releasing hormone) with placebo or no treatment. The primary outcome of proportion of mothers who continued breastfeeding at 3, 4 and 6 months was not reported. Only one study (metoclopramide) reported on the outcome of infant weight, finding little or no difference (mean difference (MD) 23.0 grams, 95% confidence interval (CI) -47.71 to 93.71; 1 study, 20 participants; low-certainty evidence). Three studies (metoclopramide, domperidone, sulpiride) reported on milk volume, finding pharmacological galactagogues may increase milk volume (MD 63.82 mL, 95% CI 25.91 to 101.72; I² = 34%; 3 studies, 151 participants; low-certainty evidence). Subgroup analysis indicates there may be increased milk volume with each drug, but with varying CIs. There was limited reporting of adverse effects, none of which could be meta-analysed. Where reported, they were limited to minor complaints, such as tiredness, nausea, headache and dry mouth (very low-certainty evidence). No adverse effects were reported for infants. Natural galactagogues Twenty-seven studies compared natural oral galactagogues (banana flower, fennel, fenugreek, ginger, ixbut, levant cotton, moringa, palm dates, pork knuckle, shatavari, silymarin, torbangun leaves or other natural mixtures) with placebo or no treatment. One study (Mother's Milk Tea) reported breastfeeding rates at six months with a concluding statement of "no significant difference" (no data and no measure of significance provided, 60 participants, very low-certainty evidence). Three studies (fennel, fenugreek, moringa, mixed botanical tea) reported infant weight but could not be meta-analysed due to substantial clinical and statistical heterogeneity (I² = 60%, 275 participants, very low-certainty evidence). Subgroup analysis shows we are very uncertain whether fennel or fenugreek improves infant weight, whereas moringa and mixed botanical tea may increase infant weight compared to placebo. Thirteen studies (Bu Xue Sheng Ru, Chanbao, Cui Ru, banana flower, fenugreek, ginger, moringa, fenugreek, ginger and turmeric mix, ixbut, mixed botanical tea, Sheng Ru He Ji, silymarin, Xian Tong Ru, palm dates; 962 participants) reported on milk volume, but meta-analysis was not possible due to substantial heterogeneity (I² = 99%). The subgroup analysis for each intervention suggested either benefit or little or no difference (very low-certainty evidence). There was limited reporting of adverse effects, none of which could be meta-analysed. Where reported, they were limited to minor complaints such as mothers with urine that smelled like maple syrup and urticaria in infants (very low-certainty evidence). Galactagogue versus galactagogue Eight studies (Chanbao; Bue Xue Sheng Ru, domperidone, moringa, fenugreek, palm dates, torbangun, moloco, Mu Er Wu You, Kun Yuan Tong Ru) compared one oral galactagogue with another. We were unable to perform meta-analysis because there was only one small study for each match-up, so we do not know if one galactagogue is better than another for any outcome.

AUTHORS' CONCLUSIONS

Due to extremely limited, very low certainty evidence, we do not know whether galactagogues have any effect on proportion of mothers who continued breastfeeding at 3, 4 and 6 months. There is low-certainty evidence that pharmacological galactagogues may increase milk volume. There is some evidence from subgroup analyses that natural galactagogues may benefit infant weight and milk volume in mothers with healthy, term infants, but due to substantial heterogeneity of the studies, imprecision of measurements and incomplete reporting, we are very uncertain about the magnitude of the effect. We are also uncertain if one galactagogue performs better than another. With limited data on adverse effects, we are uncertain if there are any concerning adverse effects with any particular galactagogue; those reported were minor complaints. High-quality RCTs on the efficacy and safety of galactagogues are urgently needed. A set of core outcomes to standardise infant weight and milk volume measurement is also needed, as well as a strong basis for the dose and dosage form used.

Impact of Fenugreek on Milk Production in Rodent Models of Lactation Challenge

Fenugreek, a herbal remedy, has long been used as galactologue to help mothers likely to stop breastfeeding because of perceived insufficient milk production. However, few studies highlight the efficacy of fenugreek in enhancing milk production. The aims of our study were to determine whether fenugreek increased milk yield in rodent models of lactation challenge and if so, to verify the lack of adverse effects on dam and offspring metabolism. Two lactation challenges were tested: increased litter size to 12 pups in dams fed a 20% protein diet and perinatal restriction to an 8% protein diet with eight pups’ litter, with or without 1 g.kg⁻¹.day⁻¹ dietary supplementation of fenugreek, compared to control dams fed 20% protein diet with eight pups’ litters. Milk flow was measured by the deuterium oxide enrichment method, and milk composition was assessed. Lipid and glucose metabolism parameters were assessed in dam and offspring plasmas. Fenugreek increased milk production by 16% in the litter size increase challenge, resulting in an 11% increase in pup growth without deleterious effect on dam-litter metabolism. Fenugreek had no effect in the maternal protein restriction challenge. These results suggest a galactologue effect of fenugreek when mothers have no physiological difficulties in producing milk.

A review of Algerian medicinal plants used in the treatment of diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Plants are traditionally used in Algeria to treat many disorders, including diabetes mellitus. Knowledge of the plants that are used may provide insight on their properties, for further exploration. This study reviewed all the available published and unpublished reports concerning the use of herbal medicines in the treatment of diabetes in Algeria.

AIM OF THE STUDY

To describe the plants used in Algeria to treat diabetes, as reported in the literature.

MATERIAL AND METHODS

Systematic review of ethnobotanical papers published in the medical literature, from literature databases (Pubmed, Web of Science), as well as Google, for English, French and Arabic -language publication, and a manual search of local libraries and bookshops, as well as the university repository of PhD and master's theses. The reference lists of the papers retrieved were also examined for further papers.

RESULTS

Many plants are cited in the ethnobotanical surveys, but only very few pharmacological studies were found. In the ethnobotanical surveys, 171 plants were reported, from 58 families of which the most often cited were Asteraceae, Lamiaceae and Apiaceae. The plants with the best evidence of use and activity are: Anabasis articulata (Forssk.) Moq., Trigonella foenum-graecum L., Centaurium erythraea Rafn, Artemisia herba-alba Asso, Marrubium vulgare L., Agathophora alopecuroides (Delile) Fenzl ex Bunge, Anabasis articulata (Forssk.) Moq., Hammada elegans (Bunge) Botsch., Helianthemum kahiricum Delile, Salsola baryosma (Schult.) Dandy, Salsola vermiculata L., Olea europaea L.

CONCLUSION

Traditional herbal medicines are still very much used in Algeria to control diabetes. However they are generally poorly characterized and none have been properly tested in man. There is a need for systematic evaluation of the more commonly used plants to confirm their antidiabetic activity, identify possible mechanimss of action, and recommend best use.

A systematic literature review of fenugreek seed toxicity by using ToxRTool: evidence from preclinical and clinical studies

Fenugreek (Trigonella foenum graecum) seed extract is a bioactive ingredient of many food supplements. Hence, there is a need for systematic assessment of the quality of published toxicological studies for its use in human health, hazard consideration, and risk assessment. The aim of the present investigation was to determine the reliability of published toxicological studies of fenugreek seed by using ToxRTool (Toxicological data reliability assessment tool). A comprehensive systematic literature search was conducted in PubMed, EMBASE, Cochrane Library, CPCI-S, ICTRP, Ovid, and Google Scholar till October 2018. Each identified study was evaluated for its quality using the ToxRTool with outcomes such as combined score, weighted score, and reliability category by three independent raters. Correlations of various criteria groups with the combined score were evaluated by Pearson correlation and Kendall rank correlation coefficient. Inter-rater consistency was measured by Cronbach's alpha coefficient. The database searches initially yielded 436 results, of which 391 (89.67%) studies were “not assignable”. The remaining 45 studies were included for quantitative analysis by ToxRTool. Based on the weighted score, 17 in-vivo, and 3 in-vitro studies were determined to be “Reliable Without Restriction” which were conducted according to international guidelines such as GLP. These studies have a significant difference (p < 0.05) for the combined and weighted score as compared to non-GLP studies. Remaining 28 in-vivo and 2 in-vitro studies were determined to be “Not Reliable.” The GLP studies conducted with “identified study material” have a significant difference (p < 0.0001) between combined and weighted score as compared to studies which used “non-identified study material”. For criteria group of ToxRTool I, III and V, the Pearson correlation with the combined score was found to be 0.875, 0.734 and 0.905, respectively and Kendall rank correlation coefficient was found to be 0.764, 0.551 and 0.752, respectively. Cronbach's alpha coefficient for combined score and weighted score were 0.920 and 0.887, respectively. In conclusion, the ToxRTool was found useful to identify seventeen toxicity studies of fenugreek seeds as “Reliable without Restrictions”. These studies showed a broad margin of safety for the standardized extract of fenugreek seeds and can form a basis for toxicological risk assessment with reasonable certainty.

Diosgenin and Its Fenugreek Based Biological Matrix Affect Insulin Resistance and Anabolic Hormones in a Rat Based Insulin Resistance Model

Fenugreek is known since ancient times as a traditional herbal medicine of its multiple beneficial effects. Fenugreek's most studied and employed effect is its hypoglycemic property, but it can also be useful for the treatment of certain thyroid disorders or for the treatment of anorexia. The regulation of glucose homeostasis is a complex mechanism, dependent on the interaction of different types of hormones and neurotransmitters or other compounds. For the study of how diosgenin and fenugreek seeds modify insulin sensitivity, we used a rat insulin resistance model induced by high-fat diet. Diosgenin in three different doses (1mg/bwkg, 10mg/bwkg, and 50 mg/bwkg, respectively) and fenugreek seed (0.2 g/bwkg) were administered orally for 6 weeks. Insulin sensitivity was determined by hyperinsulinemic euglycemic glucose clamp method. Our research group found that although glucose infusion rate was not significantly modified in either group, the increased insulin sensitivity index and high metabolic clearance rate of insulin found in the 1 mg/kg diosgenin and the fenugreek seed treated group suggested an improved peripheral insulin sensitivity. Results from the 10 mg/kg diosgenin group, however, suggest a marked insulin resistance. Fenugreek seed therapy results on the investigated anabolic hormones support the theory that, besides insulin and gastrointestinal peptides, the hypothalamic-hypopituitary axis regulated hormones synchronized action with IGF-1 also play an important role in the maintaining of normal glucose levels. Both diosgenin and fenugreek seeds are capable of interacting with substrates of the above-mentioned regulatory mechanisms, inducing serious hormonal disorders. Moreover, fenugreek seeds showed the ability to reduce the thyroid hormone levels at the periphery and to modify the T4/T3 ratio. It means that in healthy people this effect could be considered a severe side effect; however, in hypothyroidism this effect represents a possibility of alternative natural therapy.

Engineering a short-chain dehydrogenase/reductase for the stereoselective production of (2S,3R,4S)-4-hydroxyisoleucine with three asymmetric centers

Fenugreek is a dietary supplement for anti-aging and human health. (2S,3R,4S)-4-hydroxyisoleucine (4-HIL), which is extracted from fenugreek seeds, is expected to be a promising orally active drug for diabetes and diabetic nephropathy because of its insulinotropic effect. Although several chemical synthesis methods of 4-HIL have been proposed, these methods require multistep reactions to control the stereochemistry of 4-HIL. In this study, we modified the key enzyme 4-HIL dehydrogenase (HILDH) to overcome the biggest limitation in commercial-scale production of 4-HIL. As a result, an effective one-step carbonyl reduction to produce (2S,3R,4S)-4-HIL was successfully accomplished with strict stereoselectivity (>99% de). Mass production of (2S,3R,4S)-4-HIL by our synthetic method could have a significant contribution to the prevention of diabetes, dyslipidemia, and Alzheimer's disease. (120 words/200 words).

Toxicological properties of fenugreek (Trigonella foenum graecum)

Fenugreek (Trigonella foenum graecum), used as traditional medicine and natural additive food, has been shown to exert significant antiatherogenic, antidiabetic, antianorexic, antioxidant, anticarcinogenic, antihyperlipidemic, galactogogue and anti-inflammatory effects in several human and animal models. Besides, several medicinal pharmaceutical and nutraceutical properties, fenugreek have toxic effects as well. The aim of this review is discuss the cumulative evidence, which suggests that consumption of fenugreek induced some serious toxicological side effects. In this review, many teratogenic effects of fenugreek, from congenital malformations to death, were reported in human, rodent, rabbit, and chick. Moreover, results obtained in rats, mice and rabbits show a testicular toxicity and anti-fertility effects in male associated with oxidative stress and DNA damage, as well as anti-fertility, antiimplantation and abortifacient activity in females related to saponin compound of fenugreek which suggest that fenugreek is not recommended for use during pregnancy. Indeed, the consumption of fenugreek should be avoided for persons having peanut and chickpeas allergy because of possible cross-reactivity as well as chronic asthma. Accumulating evidence suggest also that fenugreek may have neurodevelopmental, neurobehavioral and neuropathological side effects. It is suggested that future studies would be conducted to identify molecular and cellular mechanisms underlying the fenugreek toxicological properties.

Investigating Therapeutic Potential of Trigonella foenum-graecum L. as Our Defense Mechanism against Several Human Diseases

Current lifestyle, stress, and pollution have dramatically enhanced the progression of several diseases in human. Globally, scientists are looking for therapeutic agents that can either cure or delay the onset of diseases. Medicinal plants from time immemorial have been used frequently in therapeutics. Of many such plants, fenugreek is one of the oldest herbs which have been identified as an important medicinal plant by the researchers around the world. It is potentially beneficial in a number of diseases such as diabetes, hypercholesterolemia, and inflammation and probably in several kinds of cancers. It has industrial applications such as synthesis of steroidal hormones. Its medicinal properties and their role in clinical domain can be attributed to its chemical constituents. The 3 major chemical constituents which have been identified as responsible for principle health effects are galactomannan, 4-OH isoleucine, and steroidal saponin. Numerous experiments have been carried out in vivo and in vitro for beneficial effects of both the crude chemical and of its active constituent. Due to its role in health care, the functional food industry has referred to it as a potential nutraceutical. This paper is about various medicinal benefits of fenugreek and its potential application as therapeutic agent against several diseases.

Urine Metabolomics by (1)H-NMR Spectroscopy Indicates Associations between Serum 3,5-T2 Concentrations and Intermediary Metabolism in Euthyroid Humans

CONTEXT

3,5-Diiodo-L-thyronine (3,5-T2) is a thyroid hormone metabolite which exhibited versatile effects in rodent models, including the prevention of insulin resistance or hepatic steatosis typically forced by a high-fat diet. With respect to euthyroid humans, we recently observed a putative link between serum 3,5-T2 and glucose but not lipid metabolism.

OBJECTIVE

The aim of the present study was to widely screen the urine metabolome for associations with serum 3,5-T2 concentrations in healthy individuals.

STUDY DESIGN AND METHODS

Urine metabolites of 715 euthyroid participants of the population-based Study of Health in Pomerania (SHIP-TREND) were analyzed by (1)H-NMR spectroscopy. Multinomial logistic and multivariate linear regression models were used to detect associations between urine metabolites and serum 3,5-T2 concentrations.

RESULTS

Serum 3,5-T2 concentrations were positively associated with urinary levels of trigonelline, pyroglutamate, acetone and hippurate. In detail, the odds for intermediate or suppressed serum 3,5-T2 concentrations doubled owing to a 1-standard deviation (SD) decrease in urine trigonelline levels, or increased by 29-50% in relation to a 1-SD decrease in urine pyroglutamate, acetone and hippurate levels.

CONCLUSION

Our findings in humans confirmed the metabolic effects of circulating 3,5-T2 on glucose and lipid metabolism, oxidative stress and enhanced drug metabolism as postulated before based on interventional pharmacological studies in rodents. Of note, 3,5-T2 exhibited a unique urinary metabolic profile distinct from previously published results for the classical thyroid hormones.

Metabolic and molecular action of Trigonella foenum-graecum (fenugreek) and trace metals in experimental diabetic tissues

Diabetes mellitus is a heterogeneous metabolic disorder characterized by hyperglycaemia resulting in defective insulin secretion, resistance to insulin action or both. The use of biguanides, sulphonylurea and other drugs are valuable in the treatment of diabetes mellitus; their use, however, is restricted by their limited action, pharmacokinetic properties, secondary failure rates and side effects. Trigonella foenum-graecum, commonly known as fenugreek, is a plant that has been extensively used as a source of antidiabetic compounds from its seeds and leaf extracts. Preliminary human trials and animal experiments suggest possible hypoglycaemic and antihyperlipedemic properties of fenugreek seed powder taken orally. Our results show that the action of fenugreek in lowering blood glucose levels is almost comparable to the effect of insulin. Combination with trace metal showed that vanadium had additive effects and manganese had additive effects with insulin on in vitro system in control and diabetic animals of young and old ages using adipose tissue. The Trigonella and vanadium effects were studied in a number of tissues including liver, kidney, brain peripheral nerve, heart, red blood cells and skeletal muscle. Addition of Trigonella to vanadium significantly removed the toxicity of vanadium when used to reduce blood glucose levels. Administration of the various combinations of the antidiabetic compounds to diabetic animals was found to reverse most of the diabetic effects studied at physiological, biochemical, histochemical and molecular levels. Results of the key enzymes of metabolic pathways have been summarized together with glucose transporter, Glut-4 and insulin levels. Our findings illustrate and elucidate the antidiabetic/insulin mimetic effects of Trigonella, manganese and vanadium.

Molecular spectroscopic study of acid treated fenugreek seeds

Fenugreek seeds were subjected to acid treatment in order to activate its surface. XRF indicated that there was no change in the level of metals and metal oxides as a result of the treatment. FTIR of the treated fenugreek showed no change in the characteristic bands and/or structure of the fenugreek. A shift in both OH and metal oxide bands suggest a role for metal, hydrated metal and metal oxide in fenugreek seed. Molecular modeling suggests that metal oxides such as Al16O24 offer its surface for the adsorption of gases. The interaction of gases with metal oxide is depending on the type of gas rather than the type of coordination. Finally results indicate that fenugreek could be used safely to control the level of gases in stomach.

A novel phytochemical, digoxigenin-3-O-rutin in the amelioration of isoproterenol-induced myocardial infarction in rat: a comparison with digoxin

INTRODUCTION

The commonly used cardiac glycoside, digoxin (DIG), has a narrow therapeutic window. Although some investigations were made to counteract its toxic effects, no alternate phytochemical is available till date that is more potent and safer than DIG.

AIMS

Our main aim was to isolate a novel cardenolide from the seeds of Trigonella foenum graceium and to evaluate its relative potential in comparison to that of DIG.

EXPERIMENTAL DESIGN

In one experiment effects of the isolated compound at 2.5, 5.0, and 10 mg/kg (p.o.) were evaluated in isoproterenol (ISO)-induced cardiovascular problems in rats. As the test drug (TDR) reversed most of the ISO-induced changes, it was subjected to the phytochemical analyses and was identified as digoxigenin-3-O-rutin. In another experiment effects of DIG and rutin (Rtn) were compared with those of TDR or DIG alone. The hydroxyl radical scavenging activity was also measured by electron spin resonance (EPR).

RESULTS

digoxigenin-3-O-rutin at 10 mg/kg markedly reduced the ISO-induced increase in cardiac lipid peroxidation and in the levels of serum creatinine phosphokinase-MB, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, lactate dehydrogenase, and creatinine. It also reversed the ISO-induced changes in the cardiac histomorphology. Interestingly TDR appeared to be more effective than DIG alone or DIG and Rtn in combination.

CONCLUSION

The newly isolated digoxigenin-3-O-rutin appears to be more potent and safe than digoxin. Its higher efficacy could be due to its structural specificity and might have been mediated through its better free radical scavenging action.

Fenugreek (Trigonella foenum-graecum L. Leguminosae): an evidence-based systematic review by the natural standard research collaboration

An evidence-based systematic review including written and statistical analysis of scientific literature, expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology and dosing.

Annona squamosa seed extract in the regulation of hyperthyroidism and lipid-peroxidation in mice: possible involvement of quercetin

Annona squamosa (Custard apple) seeds are generally thrown away as waste materials. The extract of these seeds was evaluated for its possible ameliorative effect in the regulation of hyperthyroidism in mouse model. Serum triiodothyronine (T(3)), thyroxine (T(4)) concentrations, hepatic glucose-6-phospatase (G-6-Pase) and 5'-mono-deiodinase (5'DI) activity were considered as the end parameters of thyroid function. Simultaneously hepatic lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activities were investigated to observe its hepatotoxic effect, if any. L-T(4) administration (0.5 mg/kg/d for 12 days, i.p.) increased the levels of serum T(3) and T(4), activity of hepatic G-6-Pase, 5'DI and LPO with a parallel decrease in SOD and CAT activities. However, simultaneous administration of the Annona seed extract (200 mg/kg) or quercetin (10 mg/kg) to T(4)-induced hyperthyroid animals for 10 days, reversed all these effects indicating their potential in the regulation of hyperthyroidism. Further, the seed extract did not increase, but decreased the hepatic LPO suggesting its safe and antiperoxidative nature. Quercetin also decreased hepatic LPO. When relative efficacy was compared with that of propyl thiouracil (PTU), a standard antithyroidic drug, experimental seed extract appeared to be more effective. Phytochemical analyses including HPLC revealed the presence of quercetin in the seed extract and the results on the effects of quercetin suggested the involvement of this phytochemical in the mediation of antithyroidal activity of Annona squamosa seed extract.

Mitigation of thyroxine-induced hyperglycaemia by two plant extracts

Extracts of Trigonella foenum-graecum (TFG) seed and Allium sativum (AS) bulb were evaluated for their efficacy to ameliorate l-thyroxine (l-T4) induced hyperglycaemia in rats. Simultaneously, the serum cholesterol concentration, a supporting parameter for thyroid function, was also estimated. Thyroxine treatment in rats (300 microg/kg b. wt./day) increased the levels of both the thyroid hormones, namely thyroxine (T4) and tri-iodothyronine (T3) with a concomitant elevation in serum glucose concentration and a reduction in serum cholesterol level. Administration of TFG (220 mg/kg/day) and AS (500 mg/kg/day) extracts in hyperthyroid animals decreased the serum glucose concentration as well as the serum thyroid hormones. For comparison, propyl thiouracil (PTU), an antithyroid compound, was used as the standard at a daily dose of 10 mg/kg. The reductions in serum glucose and thyroid hormone concentrations in the plant extract treated groups were comparable to that in PTU treated animals. Our findings indicate that TFG seed and AS bulb extracts may prove to be effective in the treatment of thyroxine-induced hyperglycaemia.

Relative efficacy of three medicinal plant extracts in the alteration of thyroid hormone concentrations in male mice

Relative importance of Bacopa monnieri (200 mg/kg), Aegle marmelos (1.00 g/kg) and Aloe vera (125 mg/kg) leaf extracts in the regulation of thyroid hormone concentrations in male mice was investigated. While serum levels of both T(3) and T(4) were inhibited by A. vera, A. marmelos extract could decrease only T(3) concentration. On the other hand, T(4) concentration was increased by B. monnieri extract suggesting its thyroid-stimulating role. When the relative potency of each plant extract was calculated in terms of percent increase or decrease in thyroid hormones, as compared to the control value, the decrease in T(3) concentration by A. marmelos was about 62% indicating its possible use in the regulation of hyperthyroidism. B. monnieri could increase T(4) concentration by 41% without enhancing hepatic lipid peroxidation (LPO) suggesting that it can be used as a thyroid-stimulating drug. In fact, hepatic LPO was decreased and superoxide dismutase (SOD) and catalase (CAT) activities were increased by B. monnieri and A. marmelos leaf extracts showing their antiperoxidative role. It is thus suggested that A. marmelos and A. vera may be used in the regulation of hyperthyroidism, while B. monnieri in hypothyroidism.

How safe is neem extract with respect to thyroid function in male mice?

In this investigation we attempted to find out the hitherto unstudied adverse effects of neem (Azardirachta indica) leaf extract on the thyroid function of male mice. Neem leaf extract was orally administered in two different doses (40 mg and 100 mg kg(-1)day(-1)for 20 days). The extract exhibited differential effects. While the higher dose decreased serum tri-iodothyonine (T(3)) and increased serum thyroxine (T(4)) concentrations, no significant alterations of levels were observed in the lower dose group, indicating that the high concentrations of neem extract can be inhibitory to thyroid function, particularly in the conversion of T(4)to T(3), the major source of T(3)generation. A concomitant increase in hepatic lipid peroxidation (LPO) and a decrease in glucose-6-phosphatase (G-6-Pase) activity in the higher dosed group also indicated the adverse effect of neem extract despite an enhancement in the activities of two defensive enzymes, superoxide dismutase (SOD) and catalase (CAT). Thus, it appears that the higher concentration of neem extract may not be safe with respect to thyroid function and lipid peroxidation.

Role of Moringa oleifera leaf extract in the regulation of thyroid hormone status in adult male and female rats

The role of Moringa oleifera aqueous leaf extract in the regulation of thyroid hormone status, was studied in adult Swiss rats. Other than the thyroid hormone concentrations, hepatic lipid peroxidation (LPO) and the activities of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) were evaluated. In the first experiment, effects of the leaf extract (175 mg kg(-1)body wt. day(-1)for 10 days) were studied both in male and female animals. Following the administration of the extract, serum triiodothyronine (T(3)) concentration and hepatic LPO decreased with a concomitant increase in the serum thyroxine (T(4)) concentration, in female rats, while in males no significant changes were observed, suggesting that Moringa oleifera leaf extract is more effective in females than in the males. To evaluate the impact of a higher dose, in the second experiment, the study was repeated in female rats, with 350 mg kg(-1)body wt. day(-1)for the same duration. Almost similar reduction in the serum T(3)concentration (approx. 30%) and an increase in the T(4)concentration were observed suggesting the inhibiting nature of Moringa oleifera leaf extract in the peripheral conversion of T(4)to T(3), the principal source of the generation of latter hormone. As the antiperoxidative effects were exhibited only by the lower dose and percent decrease in T(3)concentration was nearly the same by both the doses, it is suggested that the lower concentration of this plant extract may be used for the regulation of hyperthyriodism. 2000 Academic Press@p$hr