Diuretic and potassium-sparing effect of isoquercitrin-an active flavonoid of Tropaeolum majus L

Phytochemical Composition of Ziziphus lotus (L.) Lam and Its Impact on the Metabolic Syndrome: A Review

The long-term pathological state known as metabolic syndrome is characterized by hypertension, insulin resistance diabetes, abdominal obesity, and hyperlipidemia. Seeking healthcare strategies with fewer side effects, such as herbal remedies, is preferable in terms of mitigating the negative consequences of synthetic medications. Ziziphus lotus (L.) (Rhamnaceae) or wild jujube, commonly known as "Sedra," is one of the best choices as it contains a variety of phytochemicals and biologically active compounds. Several flavonoids and stilbenes have been recognized as the primary bioactive components in wild jujube, including rutin, hyperin, isoquercitrin, and resveratrol. These polyphenols are pharmacologically active and have broad-spectrum beneficial effects for reducing the risk factors associated with metabolic syndrome. They exhibit antioxidant and anti-inflammatory properties, regulate lipid metabolism, and possess antiobesity, antihypertensive, and antidiabetic characteristics. However, there are certain limitations to their therapeutic application, such as low bioavailability. Various strategies have been proposed to enhance their pharmacokinetic profile and therapeutic potential for future use. The main goal of this review is to explore the underlying mechanisms related to the therapeutic effects of wild jujube and its active compounds in the treatment and prevention of metabolic syndrome.

Current insights and future perspectives of flavonoids: A promising antihypertensive approach

Hypertension, or high blood pressure (BP), is a complex disease influenced by various risk factors. It is characterized by persistent elevation of BP levels, typically exceeding 140/90 mmHg. Endothelial dysfunction and reduced nitric oxide (NO) bioavailability play crucial roles in hypertension development. L-NG-nitro arginine methyl ester (L-NAME), an analog of L-arginine, inhibits endothelial NO synthase (eNOS) enzymes, leading to decreased NO production and increased BP. Animal models exposed to L-NAME manifest hypertension, making it a useful design for studying the hypertension condition. Natural products have gained interest as alternative approaches for managing hypertension. Flavonoids, abundant in fruits, vegetables, and other plant sources, have potential cardiovascular benefits, including antihypertensive effects. Flavonoids have been extensively studied in cell cultures, animal models, and, to lesser extent, in human trials to evaluate their effectiveness against L-NAME-induced hypertension. This comprehensive review summarizes the antihypertensive activity of specific flavonoids, including quercetin, luteolin, rutin, troxerutin, apigenin, and chrysin, in L-NAME-induced hypertension models. Flavonoids possess antioxidant properties that mitigate oxidative stress, a major contributor to endothelial dysfunction and hypertension. They enhance endothelial function by promoting NO bioavailability, vasodilation, and the preservation of vascular homeostasis. Flavonoids also modulate vasoactive factors involved in BP regulation, such as angiotensin-converting enzyme (ACE) and endothelin-1. Moreover, they exhibit anti-inflammatory effects, attenuating inflammation-mediated hypertension. This review provides compelling evidence for the antihypertensive potential of flavonoids against L-NAME-induced hypertension. Their multifaceted mechanisms of action suggest their ability to target multiple pathways involved in hypertension development. Nonetheless, the reviewed studies contribute to the evidence supporting the useful of flavonoids for hypertension prevention and treatment. In conclusion, flavonoids represent a promising class of natural compounds for combating hypertension. This comprehensive review serves as a valuable resource summarizing the current knowledge on the antihypertensive effects of specific flavonoids, facilitating further investigation and guiding the development of novel therapeutic strategies for hypertension management.

Alibertia patinoi (Cuatrec.) Delprete & C.H.Perss. (Borojó): food safety, phytochemicals, and aphrodisiac potential

Although the western discovery of borojó [Alibertia patinoi Cuatrec. (Delprete & C.H.Perss.)] is as recent as 1948, its several traditional uses in gastronomy and medicine, and its fame as an aphrodisiac are long standing and strong: the “love juice” extracted from it is very appreciated in Colombia, Ecuador, and Panama. Its medicinal potential, though, is far wider. This literature review aims to summarize the knowledge about the fruit, its ethnomedical uses, its biological activity and phytochemical composition, to validate ethnomedical claims and to help envision future lines of research. Borojó extracts have confirmed antimicrobial and antioxidant, and potential anticancer activities, which can be at least partially explained by its phytochemical composition -compounds isolated and identified through Gas Chromatography, High Performance Liquid Chromatography and spectroscopic and spectrometric techniques- rich in phenolic compounds, some of which, for example oleuropein, chlorogenic acid and rutin, possess proven biological activity. There is potential for borojó products as a source of bioactive natural products, which have not been exhaustively identified despite phytochemical screenings that show the presence of unstudied compound families: terpenoids, alkaloids, steroids; and functional alimentary products. Although its aphrodisiac properties have not been confirmed, several compounds with confirmed aphrodisiac activity in other species, mainly flavonoids, are also found in borojó. These, coupled with its nutritional profile and perhaps compounds yet unidentified, could validate the claim.

Graphical abstract

Hepatorenal Protective Effects of Hydroalcoholic Extract of Solidago canadensis L. against Paracetamol-Induced Toxicity in Mice

Paracetamol (AKA acetaminophen) is a widely used drug and is used for mild to moderate pains, such as mild osteoarthritis, toothache, headache, and pain caused by minimally invasive surgeries. Despite being a harmless drug in lower doses, acetaminophen can be toxic to the liver and kidneys if overdosed and even results in death. In this study, the therapeutic effects of Solidago canadensis L. extract (SCE) were investigated. 48 adult male Swiss albino mice (20-30 grams) were randomly divided into six groups of 8. The control group was gavaged with normal saline every 12 hours for 6 days. The second group received paracetamol at a 500 mg/kg intraperitoneally (i.p) dose on the sixth day. The third, fourth, and fifth groups were gavaged doses of 125, 250, and 500 mg/kg of SCE every 12 hours for six days, respectively, and on the sixth day, we received paracetamol at a dose of 500 mg/kg i.p. The sixth group only received SCE every 12 hours at a dose of 1000 mg/kg via gavaging for six days. On the seventh day (24 hours after paracetamol injection), blood samples were collected to measure the serum level of creatinine, uric acid, blood urea nitrogen (BUN), total protein, albumin, alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and total and direct bilirubin, and liver and kidney tissues were also sampled for histopathological examination. It was observed that paracetamol caused a considerable increase in the ALT, AST, ALP, uric Acid, and BUN levels (P < 0.01), while those in SCE-treated groups were significantly lower. In addition, various lesions in the paracetamol group were observed, while in the SCE-receiving groups, receiving prophylactic SCE inhibited the high-intense lesions such as the infiltration of inflammatory cells, hyperemia, and vacuolar degeneration, which decreased significantly in the control group in comparison with that of the paracetamol group (P < 0.05). In conclusion, SCE can have substantial protective effects against paracetamol's hepatorenal toxicity.

Tropaeolum majus R2R3 MYB Transcription Factor TmPAP2 Functions as a Positive Regulator of Anthocyanin Biosynthesis

Anthocyanins are an important group of water-soluble and non-toxic natural pigments with antioxidant and anti-inflammatory properties that can be found in flowers, vegetables, and fruits. Anthocyanin biosynthesis is regulated by several different types of transcription factors, including the WD40-repeat protein Transparent Testa Glabra 1 (TTG1), the bHLH transcription factor Transparent Testa 8 (TT8), Glabra3 (GL3), Enhancer of GL3 (EGL3), and the R2R3 MYB transcription factor Production of Anthocyanin Pigment 1 (PAP1), PAP2, MYB113, and MYB114, which are able to form MYB-bHLH-WD40 (MBW) complexes to regulate the expression of late biosynthesis genes (LBGs) in the anthocyanin biosynthesis pathway. Nasturtium (Tropaeolum majus) is an edible flower plant that offers many health benefits, as it contains numerous medicinally important ingredients, including anthocyanins. By a comparative examination of the possible anthocyanin biosynthesis regulator genes in nasturtium varieties with different anthocyanin contents, we found that TmPAP2, an R2R3 MYB transcription factor gene, is highly expressed in "Empress of India", a nasturtium variety with high anthocyanin content, while the expression of TmPAP2 in Arabidopsis led to the overproduction of anthocyanins. Protoplast transfection shows that TmPAP2 functions as a transcription activator; consistent with this finding, some of the biosynthesis genes in the general phenylpropanoid pathway and anthocyanin biosynthesis pathway were highly expressed in "Empress of India" and the 35S:TmPAP2 transgenic Arabidopsis plants. However, protoplast transfection indicates that TmPAP2 may not be able to form an MBW complex with TmGL3 and TmTTG1. These results suggest that TmPAP2 may function alone as a key regulator of anthocyanin biosynthesis in nasturtiums.

A systematic review on nephron protective AYUSH drugs as constituents of NEERI-KFT (A traditional Indian polyherbal formulation) for the management of chronic kidney disease

Chronic Kidney Disease (CKD) is a major health problem characterized by kidney dysfunction with progressive segmental glomerulosclerosis to end-stage renal disease (ESRD). Due to lack of scientific data and comprehensive reports, the current systematic review provides an inclusive understanding and prospective associated with phytopharmacology of NEERI-KFT in CKD. The data was collected from more than five databases such as Science Direct, Google Scholar, Elsevier, PubMed, Springer, ACS publication etc using keywords like CKD/Kidney disease, epidemiology/prevalence, modern therapies for CKD management, NEERI-KFT and its role in kidney disease. The study was performed based on scientific reports screened by experts according to inclusion and exclusion criteria. The pre-clinical and clinical findings suggested that NEERI-KFT has promising effects as nephroprotective and considered safe and well effective in primary care of kidney against disease. Phytopharmacological evaluation of NEERI-KFT suggest that it exhibit substantial potential against oxidative and inflammatory stress induced apoptosis by exerting antioxidants, nephroprotective and immunomodulatory effects. Hence, it can be enlighten that NEERI-KFT have potential herbs which exerts significant antioxidants, nephroprotective and immunomodulatory effects in the patients associated with renal dysfunction or CKD thus improving altered renal architecture and renal physiology. Clinically, it is concluded that NEERI-KFT works kidney malfunction and cease ESRD progression or even reduce the number of dialysis.

Promising Medicinal Plants with Diuretic Potential Used in Brazil: State of the Art, Challenges, and Prospects

Medicinal plants are used in traditional medicine to treat a wide range of ailments. The knowledge of them is handed down from generation to generation and is described in several pharmacopoeia and in the general literature. The immense biodiversity of the Brazilian flora, covering about 25% of all plant species worldwide, makes Brazil a huge potential source of medicinal plants. Indeed, many of these plant species are already used in the Brazilian ethnopharmacology for their probable effect to induce diuresis, to reduce fluid retention, and to treat cardiovascular and renal disorders. This review article describes and discusses the main native Brazilian medicinal plants (including some of their isolated compounds) used as diuretics. It also gives a comprehensive analysis of the most relevant scientific studies presented to date, as well as addressing a special topic with future prospects for plant species that have not yet been scientifically studied. In brief, several plants can be indicated for more detailed study, with a view to obtain scientific subsidies for a new and effective diuretic medicine in the future. These include Bauhinia forficata, Leandra dasytricha, and Tropaeolum majus. Other species have reputed medicinal properties but lack experimental assays to demonstrate their pharmacological effects (e.g., Mikania hirsutissima, Phyllanthus niruri, and Tagetes minuta). Several active principles are indicated as responsible for the diuretic effects of the plants studied, with emphasis on phenolic compounds as flavonoids, phenolic acids, and xanthones. These results should encourage more detailed preclinical, clinical, and phytochemical investigations on Brazilian plants in the future.

Evaluation of Diuretic Activity and Phytochemical Contents of Aqueous Extract of the Shoot Apex of Podocarpus falcactus

Background

In Ethiopian folk medicine Podocarpus falcactus is used to treat stomachache, cancer, diabetes, and difficulty of urination. However, its diuretic activity has not been proven scientifically.

Objective

To determine the diuretic activity and phytochemical contents of the aqueous extract of the shoot apexes of Podocarpus falcactus.

Methods

The coarse powder of Podocarpus falcactus shoot apex was extracted by cold maceration using distilled water. Male rats were treated with distilled water, the standard drug (furosemide 10 mg/kg), and three different doses (100, 200, and 400 mg/kg) of the aqueous extract. The diuretic activity was determined by measuring parameters such as time to the first urination, volume, electrolyte concentration, and pH of urine. Electrolyte indices were calculated to elucidate the possible mechanism of diuresis. Additionally, qualitative and quantitative determination of phytochemicals in the plant extract was carried out.

Results

The aqueous extract induced diuresis, natriuresis, and kaliuresis in a dose- and time-dependent manner as compared to the negative control. The extract at 200 and 400 mg/kg doses produced significant diuresis (p<0.001) by the end of the fifth hour compared to the negative control. Excretion of sodium, potassium, and chloride also significantly (p<0.001) increased following extract administration. In addition, there was a significant change in the pH of urine samples of the extract-treated group compared with the negative control. Qualitative and quantitative determination of phytochemicals revealed the presence of alkaloids, flavonoids, phenolics, and tannins with the value of 128.4 mg atropine equivalents (AE)/g, 142.23 mg quercetin equivalents (QE)/g, 196.84 mg gallic acid equivalents (GAE)/g, and 25.5 mg tannic acid equivalents (TAE)/g, respectively. The aqueous extract exhibited significant diuretic activity due to its phytochemical content, which could be used as a starting point for further studies.

Conclusion

The aqueous extract showed significant diuretic activity and confirmed the folkloric use of Podocarpus falcactus.

Corallodiscus flabellata B.L. Burtt Extracts Stimulate Diuretic Activity and Regulate the Renal Expression of Aquaporins

Corallodiscus flabellata B. L. Burtt is a traditional Chinese medicine. Previous studies in our laboratory showed that C. flabellata alleviated symptoms of Alzheimer's disease (AD) in a rat model of AD and increased healthy rats' urine volume. The aims of this study were to explore the diuretic activity of different extracts from C. flabellata and to identify the underlying mechanisms of action. Different doses of a C. flabellata extract (CF-L, CF-M, and CF-H) were administered orally to male KM mice in a single dose. In another procedure, C. flabellata (CF), water extract, and 20%, 30%, and 40% ethanol extracts of C. flabellata (CF-WE, CF-20, CF-30, and CF-40) were administered orally daily for 5 days. The urinary excretion rate, osmolality, and electrolyte levels in urine and serum, renal expression of aquaporins (AQPs), apoptosis-related protein, and MAPK-related protein were analyzed. The results showed that single doses of CF-M and CF-H increased urinary volume significantly, as well as daily administration of CF, CF-WE, CF-20, CF-30, and CF-40. Furthermore, CF-20 and CF-30 increased the concentration of Na⁺ in the urine. Treatment with CF-40 increased the urine osmolality and Na⁺ and Cl⁻ concentrations and decreased the concentration of Na⁺ in the serum. Also, CF, CF-WE, CF-20, CF-30, and CF-40 decreased the renal expression of AQPs, as well as the ratios of Bcl-2/Bax, p-ERK/ERK, p-JNK/JNK, and p-p38/p38. In sum, the medium and high doses of the C. flabellata extract and CF-WE, CF-20, CF-30, and CF-40 were found to have a diuretic activity. They may inhibit the renal expression of AQPs and apoptosis-related proteins by inhibiting the MAPK signaling pathway, thereby achieving diuretic effects.

quareticctivity of S olidago canadensiscultivated ingypt and etermination of theostioactiveraction

Despite the traditional use of Solidago canadensis L. (Asteraceae) as a diuretic drug, there is a scarcity in scientific data concerning the activity of its different extracts and fractions as well as the class of constituents responsible for this diuretic action. A comparative study was carried out for the diuretic activities of the different standardized extracts and fractions of the flowering aerial parts of S. canadensis, as well as isolation of compounds from the most biologically active fraction. The ethanol extract and its ethyl acetate fraction (EA) showed the highest aquaretic activities (91 and 58% at a dose of 400 mg/Kg b.wt., respectively) compared to 100% of furosemide at 20 mg/Kg b.wt.. Their activities were higher than Cystinol® and spironolactone reference standards (74% and 59% of furosemide, respectively). EA showed the highest total phenolic and flavonoid contents among the tested fractions of the ethanol and aqueous extracts (9.38 ± 0.004 g GAE and 39.75 ± 0.005 g RE/100 g dried extract, respectively). Eight flavonoids, 2 phenolic acids and 1 nucleoside were isolated from EA. This is the first report of a comparative study between the aquaretic activities of the different extracts, fractions and essential oil of S. canadensis, as well as isolation of thyimidine (1), isorhamnetin-3-O-β-ᴅ-glucopyranoside (2), kaempferol-3-O-(6”-O-acetyl)-β-ᴅ-glucopyranoside (4), quercetin-3-O-(6”-O-acetyl)-β-ᴅ-glucopyranoside (5), and kaempferol-3-O-β-ᴅ-apiofuranoside (7) from genus Solidago.

90-Day Oral Toxicity Assessment of Tropaeolum majus L. in Rodents and Lagomorphs

Tropaeolum majus L., popularly known as nasturtium, is a species widely used in the form of infusions and salads. In the last years, the antihypertensive, diuretic, and calcium and potassium sparing activities of T. majus preparations were shown. Moreover, no preclinical 90-day oral toxicity studies were conducted. Thus, this study evaluated the toxicity of the hydroethanolic extract obtained from T. majus (HETM) leaves in female and male mice, rats, and rabbits. Swiss mice and Wistar rats were treated with HETM (75, 375, and 750 mg/kg). The doses of rabbits (30, 150, and 300 mg/kg) were calculated by allometric extrapolation. The control groups received vehicle. The animals were orally treated, daily, for 90 days. At the end, the animals were anesthetized, and body weight gain, relative weight of liver, kidney, and spleen, and histopathological changes were evaluated. Serum hematological and biochemical parameters were also analyzed. No alterations were found in body and organ weights or in histopathological and biochemical evaluation. Hematological analyses revealed small changes in lymphocytes and neutrophil counts in rats after administration of 750 mg/kg of HETM. These results showed that 90-day use of T. majus is safe in rodents and lagomorphs.

Ethnopharmacological Study of Medicinal Plants Used for Treating Dysuria: A Collection from Traditional Markets in Shiraz

Background: Data from the ethnopharmacological field on the treatment of dysuria are provided and analyzed with regard to traditional healers from Shiraz and in comparison to previous studies. Material and Methods: From April 21 to June 25, 2014, we visited traditional markets called Attari in Shiraz, and plants used in dysuria were collected. Questionnaires asking for general information on the traditional healers named Attars, local names of plant species, plant parts, preparation methods, etc. were prepared in order to gather data from Attars. Results: We visited 40 Attari, and 29 questionnaires were filled in by male Attars. Evaluation of our investigation revealed that Tribulus terrestris, Zea mays, and Cerasus avium were the most common plants suggested by Attars (24, 23, and 23, respectively). Infusion (37%) and decoction (34%) were the most common preparation methods for these plants. 50% of the main effects intended by the Attars were antimicrobial effects, while diuretic effects were reported at 35.7%. The temperament of the plants, as one aspect of the questionnaires, showed that more plants have a hot and dry temperament (47.9%). According to available studies about the plants, we found that flavonoids (78.3%), higher terpenoids (43.5%), and essential oils (39.1%) exist in higher amounts than other components in the plants. Conclusions: We analyzed the information gathered from the questionnaires and from previous studies and found that flavonoids are the most important constituents among the plants, especially those that exist in T. terrestris, Z. mays, and C. avium. Due to the useful effects of flavonoids in urological diseases, we suggest to evaluate and concentrate on the effects of flavonoids in dysuria treatments.

Inhibition of Lipoxygenase and Peroxidase Reaction by Some Flavonols and Flavones: The Structure-Activity Relationship

Some flavonoids were investigated for their effects on lipoxygenase and peroxidase. The strongest inhibitor of lipoxygenase was kaempferol with one hydroxyl group situated at the 4’ position in the B ring, with activity of 21.2±2.03 calculated per μmole of compound. The weakest inhibition was observed for diosmetin with a hydroxyl group at the 3′ position and a methoxyl group at 4′ in the B ring, with activity of 1.17±0.77 per μmole.

Peroxidase was most strongly inhibited by quercetin (22.7±0.05) with two hydroxyl groups in the B ring at 3′ and 4′. The weakest inhibitor of peroxidase was genkwanin (0±0.16) with one hydroxyl group at position 4′ in the B ring and methoxyl at position 7 in the A ring. The correlation coefficient between reduction of Fe3+ by flavonoids and inhibition of lipoxygenase by these compounds was 0.72 and the reduction of Fe3+ and inhibition of peroxidase was 0.24. The results show that inhibition of peroxidase is weakly associated with reducing properties of phenols and inhibition of lipoxygenase may be associated with antioxidant properties of flavonoids.

Chemical composition and diuretic, natriuretic and kaliuretic effects of extracts of Mimosa bimucronata (DC.) Kuntze leaves and its majority constituent methyl gallate in rats

Objectives

Some species of the genus Mimosa showed promising results in previous investigations, which include diuretic effect; however, no chemical analyses or animal model has been conducted so far to evaluate the biological properties of M. bimucronata.

Methods

Male Wistar rats received the oral treatment with vehicle; hydrochlorothiazide; methanolic extract from M. bimucronata (MEMB), dichloromethane (DCM) and ethyl acetate (EA) fractions or methyl gallate (MG). The cumulative urine volume, electrolytes excretion, pH and osmolality were determined at the end of the experiment.

Key findings

The chemical studies demonstrated that the phenolic compounds are the majorities in the plant, with the MG being the main substance identified. We showed that MEMB and EA fraction, but not DCM, exhibited diuretic and saluretic effects. Similarly, the MG also revealed diuretic, natriuretic and kaliuretic properties to both normotensive and spontaneously hypertensive rats. Atropine, a muscarinic receptor antagonist, fully prevented MG-induced diuresis and saluresis. In addition, MG did not alter the viability of A7r5 and L929 cell lines and neither stimulated nitric oxide generation.

Conclusions

These findings suggest that M. bimucronata extracts and its majority compound MG present diuretic, natriuretic and kaliuretic properties, which was dependent on the activation of muscarinic acetylcholine receptor.

Anti-adipogenic effects of Tropaeolum majus (nasturtium) ethanol extract on 3T3-L1 cells

Background: Edible flowers, Tropaeolum majus has been used as a disinfectant and an antibiotic, and for wound healing, but the anti-obesity effects of this plant have not been reported previously Objective: We investigated the anti-adipogenic effects of T. majus ethanol extract (TME) on 3T3-L1 cells. Design: 3T3-L1 cells were differentiated in the presence of different concentrations of TME. Lipid accumulation levels were determined using Oil-Red O staining and a triglyceride content assay. Changes in the expression of proteins related to adipocyte differentiation in 3T3-L1 cells were determined by SDS-PAGE and western blotting. Results: The highest inhibition of lipid accumulation was observed at a TME concentration of 300 µg/mL. Additionally, TME concentrations ranging from 20 µg/mL to 500 µg/mL led to a decrease in the expression of adipocyte differentiation regulators, peroxisome proliferator-activated receptor γ, CCAAT element binding protein α, and sterol regulatory element binding transcription factor 1. This decrease was shown to be concentration-dependent. Discussion: Taken together, the results of this study demonstrate that TME inhibits lipid accumulation and reduces the expression PPARG, CEBPA, and SREBF1, which regulate adipocyte differentiation in 3T3-L1 cells. Conclusions: TME may be a potential novel therapeutic agent for the prevention and treatment of obesity.

Evaluation of the diuretic activity of the aqueous and 80% methanol extracts of the root of Euclea divinorum Hiern (Ebenaceae) in Sprague Dawley rats

BACKGROUND

Diuretics are drugs that increase the formation of urine and are important for the treatment of various diseases including hypertension and edema. The root decoction of Euclea divinorum has been used as a diuretic agent in the traditional medicine. Therefore, this study was aimed to evaluate the diuretic activity of the crude extracts of the roots of Euclea divinorum in Sprague Dawley rats.

METHODS

The aqueous extract (AE) and 80% methanol extract (80ME) of the plant were prepared using decoction and maceration, respectively. Vehicle (distilled water, 10ml/kg), standard drug (hydrochlorothiazide, 10mg/kg) and three doses (100mg/kg, 200mg/kg and 400mg/kg) of the AE and 80ME were given to male rats by oral gavage. Parameters like urine volume (for 5h), electrolyte concentration and pH were measured (at 5^th h) and analyzed. Data were analyzed using one way analysis of variance (ANOVA) followed by Tukey post hoc test. Linear regression was also applied to show the dose dependency nature of the diuretic effect.

RESULTS

The result indicated that the 80ME of the plant significantly (p<0.05) produced diuresis at 200mg/kg and 400mg/kg. Furthermore, the AE produced significant diuresis (p<0.05) at all doses. With regard to the electrolyte excretion, the AE produced significant natriuresis and kaliuresis at all tested doses (p<0.001), while the 80ME showed significant natriuresis and kaliuresis at 200mg/kg (p<0.01) and 400mg/kg (p<0.001). Preliminary phytochemical screening revealed the presence of secondary metabolites, including saponins, flavonoids, glycosides, steroids, tannins and terpinoids in both extracts. These constituents might be responsible for the diuretic activity of Euclea divinorum. Both extracts were also found to be safe at 2000mg/kg on the acute toxicity study.

CONCLUSION

This finding provides a scientific support for the acclaimed traditional use of the roots of Euclea divinorum as a diuretic agent.

Biotransformation of Rutin Using Crude Enzyme from Rhodopseudomonas palustris

Rhodopseudomonas palustris was selected for the ability to grow in diglycosylated flavonoids-based media, exhibited deglycosylation activity. The present study aimed to investigate the ability of a crude enzyme from Rhodopseudomonas palustris to transform rutin. Our results showed the crude enzyme was found to transform rutin to quercetin via isoquercitrin. The maximum enzyme activities were observed at pH 7.0, 25 °C, and rutin concentration of 1.0 mg mL^- 1. Under optimal conditions, 13.11 μM rutin was biotransformed into 6.86 μM isoquercitrin and 11.64 μM quercetin after 11 and 21 h, respectively. The study demonstrates an eco-friendly and potential economically viable 'green' conversion route to convert rutin to isoquercitrin and quercetin, which is of great interest, considering the therapeutic applications of isoquercitrin and quercetin. The specific biotransformation of rutin to isoquercitrin and quercetin, using the crude enzyme from Rhodopseudomonas palustris, may potentially serve as a new method for industrial production of isoquercitrin and quercetin.

Analysis of Polyphenolic Compounds in Extracts from Leaves of Some Malus domestica Cultivars: Antiradical and Antimicrobial Analysis of These Extracts

In this study, methanol, ethyl acetate, water extracts, and precipitate were obtained from leaves of Malus domestica cultivars: Golden delicious, Jonagold, Elstar, Ligol, and Mutsu. Antiradical activity of these extracts was measured using the ABTS^+∙ radical, and antimicrobial activity was measured with the disk-diffusion method. Phenolic compounds were measured with the colorimetric method and identified with high performance liquid chromatography (HPLC). The highest antiradical activity was observed for the Jonagold variety, and in particular strong activity was noted for ethyl acetate extracts. Antimicrobial activity was observed against strains of Staphylococcus aureus, Enterococcus faecalis, and the fungus Candida glabrata. Particularly susceptible to the extracts activity appeared to be Staphylococcus aureus, but the growth of Candida glabrata was inhibited in the presence of ethyl acetate extracts. With the HPLC method we identified a high amount of phloridzin (above 500 mg per g of ethyl acetate extracts), lower amounts of hyperoside, isoquercitrin, and quercitrin, and traces of p-hydroxybenzoic and chlorogenic acids. The contribution of phloridzin to antiradical activity of methanol and ethyl acetate extracts was very high (above 90%). In water extract the contribution of phloridzin was between 38.9 and 55.2%, chlorogenic acid 22.7 and 36.1%, and hyperoside 12.2 and 13.3%.

Isoquercitrin Inhibits Hydrogen Peroxide-Induced Apoptosis of EA.hy926 Cells via the PI3K/Akt/GSK3β Signaling Pathway

Oxidative stress plays a critical role in endothelial injury and the pathogenesis of diverse cardiovascular diseases, including atherosclerosis. Isoquercitrin (quercetin-3-glucoside), a flavonoid distributed widely in plants, exhibits many biological activities, including anti-allergic, anti-viral, anti-inflammatory, and anti-oxidative effects. In the present study, the inhibitory effect of isoquercitrin on H₂O₂-induced apoptosis of EA.hy926 cells was evaluated. MTT assays showed that isoquercitrin significantly inhibited H₂O₂-induced loss of viability in EA.hy926 cells. Hoechst33342/PI and Annexin V-FITC/PI fluorescent double staining indicated that isoquercitrin inhibited H₂O₂-induced apoptosis of EA.hy926 cells. Western blotting demonstrated that isoquercitrin prevented H₂O₂-induced increases in cleaved caspase-9 and cleaved caspase-3 expression, while increasing expression of anti-apoptotic protein Mcl-1. Additionally, isoquercitrin significantly increased the expression of p-Akt and p-GSK3β in a dose-dependent manner in EA.hy926 cells. LY294002, a PI3K/Akt inhibitor, inhibited isoquercitrin-induced GSK3β phosphorylation and increase of Mcl-1 expression, which indicated that regulation of isoquercitrin on Mcl-1 expression was likely related to the modulation of Akt activation. These results demonstrated that the anti-apoptotic effect of isoquercitrin on H₂O₂-induced EA.hy926 cells was likely associated with the regulation of isoquercitrin on Akt/GSK3β signaling pathway and that isoquercitrin could be used clinically to interfere with the progression of endothelial injury-associated cardiovascular disease.

Identification of phenolic compounds in petals of nasturtium flowers (Tropaeolum majus) by high-performance liquid chromatography coupled to mass spectrometry and determination of oxygen radical absorbance capacity (ORAC)

The contents and profile of polyphenols were analyzed in edible petals of nasturtium flowers (Tropaeolum majus) of three colors, and their oxygen radical absorbance capacities (ORAC) were compared. Three primary anthocyanins (ACNs) and 15 non-ACN phenolic compounds including hydroxycinammic acids (HCAs) and flavonoids (myricetin, quercetin, and kaempferol derivatives) were detected. Anthocyanin concentration was within 31.9 ± 21.7 and 114.5 ± 2.3 mg cyanidin-3-glucoside (cy-3-glu)/100 g fresh weight (FW) in yellow and red petals, respectively. The concentration of HCAs varied between 33.3 ± 7.1 and 235.6 ± 8.1 mg chlorogenic acid equivalents/100 g FW for red and yellow flowers, respectively. Red flowers had the highest level of flavonoids (315.1 ± 2.4 mg myricetin equivalents/100 g FW) and the highest ORAC radical-scavenging activity. These results show the diversity and abundance of polyphenolic compounds in nasturtium flowers, which could be the basis for applications in functional foods, cosmetics, and pharmaceuticals.

Prolonged Diuretic Activity and Calcium-Sparing Effect of Tropaeolum majus: Evidence in the Prevention of Osteoporosis

Although several studies indicate high effectiveness in the use of the hydroethanolic extract from Tropaeolum majus (HETM) as a diuretic, the impact of its prolonged use in the presence of low estrogen levels remains unclear. Thus, the aim of this study was to investigate the diuretic effects of prolonged administration of HETM in ovariectomized rats and their interrelationship between calcium excretion and bone turnover. Forty-two female Wistar rats were ovariectomized (OVX) and treated orally with different doses of HETM (3, 30, and 300 mg/kg) for 4 weeks. On the first day of treatment and at weekly intervals for four weeks the diuretic activity was evaluated. Electrolyte concentrations and creatinine levels were estimated from urine sample of each rat. The serum lipids, urea, creatinine, and osteocalcin were also measured at the end of the experiment. The data revealed that the HETM was able to sustain its diuretic effect after prolonged treatment. Moreover, its use has not affected the urinary calcium or potassium excretion, reduces lipid levels, and maintains osteocalcin levels similarly to untreated rats. These findings support the potential of HETM as a candidate to be used in clinical conditions in which the renal loss of calcium is not desired.

Effects of Angiotensin-Converting Enzyme Inhibitor Derived from Tropaeolum majus L. in Rat Preimplantation Embryos: Evidence for the Dehydroepiandrosterone and Estradiol Role

Although several studies have shown the inhibitory effects of Tropaeolum majus extracts (HETM) on angiotensin-converting enzyme (ACE) activity, no studies have been carried out during the beginning of pregnancy, when humoral and hormonal imbalance may affect zygote and early embryo transport. This study investigates whether HETM can affect embryonic development when administered during the one-cell-blastocyst period. Pregnant Wistar rats received orally the HETM (3, 30, and 300 mg/kg/day) from the 1st to the 7th gestational day. Rats were killed on the 8th day of pregnancy and the following parameters were evaluated: clinical symptoms of toxicity (including organ weights), number of corpora lutea, implants per group, preimplantation losses ratio, and the serum levels of dehydroepiandrosterone (DHEA), estradiol, and progesterone. No clinical symptoms of maternal toxicity were evidenced. On the 8th day of pregnancy, the levels of DHEA and estradiol were increased and significant preimplantation losses were observed at all doses used. The present study reveals that the HETM can raise levels of DHEA and estradiol and induce difficulty in the embryo implantation in the early stages of pregnancy. The data contributes significantly to the safety aspects of using this natural product when trying to get pregnant or during pregnancy.

Diuretic activity and toxicity of some Verbascum nigrum extracts and fractions

CONTEXT

Verbascum nigrum L. (Scrophulariaceae) is a perennial plant used in folk medicine for the treatment of kidney diseases due to its presumable diuretic properties.

OBJECTIVE

We investigated the diuretic activity and toxicity of extracts from different parts of V. nigrum and identified a group of compounds responsible for the biological effect.

MATERIALS AND METHODS

Five ethanol extracts from herb, roots, flowers, leaves and stems as well as five fractions of polar compounds isolated from herb of V. nigrum were orally administrated as a single dose of 50 mg/kg to rats. Urinary excretion and electrolyte content were measured at 3 and 6 h after the treatment. The acute toxicity of the V. nigrum extracts and fractions was evaluated in mice.

RESULTS

All extracts, except the one prepared from the roots, showed a significant increase of the urine output within first 3 h after their administration. The extract from stems was the most active, inducing urine output of 14.6 ± 0.8 ml/kg BW versus 5.2 ± 1.4 ml/kg BW of the control. It also demonstrated saluretic activity with a natriuretic index 4.1 and a kaliuretic index 3.8. The diuretic activity was correlated with the flavonoid content in the plant organs. Flavonoid fractions demonstrated significant activity; the higher content of flavonoids (expressed as hesperidin) translated into more pronounced diuretic (35.9 ± 2.1 ml/kg BW) and saluretic effects (natriuretic index 4.5 and kaliuretic index 5.4).

CONCLUSION

The diuretic activity of traditionally used V. nigrum was validated experimentally. The pharmacological effect was attributed to flavonoids, which accumulated in aerial parts of the plant, mainly in stems.

Protective effects of flavonol isoquercitrin, against 6-hydroxy dopamine (6-OHDA)-induced toxicity in PC12 cells

BACKGROUND

Free radicals-induced neurodegeneration is one of the many causes of Parkinson's disease (PD). This study investigated the neuroprotective effects of flavonol isoquercitrin against toxicity induced by 6-hydroxy-dopamine (6-OHDA) in rat pheochromocytoma (PC12) cells.

METHODS

PC12 cells were pretreated with different concentrations of isoquercitrin for 4, 8 and 12 hours and incubated with 6-OHDA for 24 hours to induce oxidative cell damage.

RESULTS

A significant cytoprotective activity was observed in isoquercitrin pre-treated cells in a dose-dependent manner. There was a significant increase (P < 0.01) in the antioxidant enzymes namely superoxide dismutase, catalase, glutathione peroxidase, and glutathione in isoquercitrin pretreated cells compared to cells incubated with 6-OHDA alone. Isoquercitrin significantly reduced (P < 0.01) lipid peroxidation in 6-OHDA treated cells. These results suggested that isoquercitrin protects PC 12 cells against 6-OHDA-induced oxidative stress.

CONCLUSIONS

The present study suggests the protective role of isoquercitrin on 6-hydroxydopamine-induced toxicity by virtue of its antioxidant potential. Isoquercitrin could be a potential therapeutic agent against neurodegeneration in Parkinson's disease.

Evaluation of subchronic toxicity of the hydroethanolic extract of Tropaeolum majus in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

The use of medicinal plants for the treatment of diseases usually comes from the belief that they present low toxicity due their natural origin. However, it is necessary a toxicological and pharmacological evaluation for these plants. Tropaeolum majus is a medicinal plant used in popular medicine to treat several diseases, including cardiovascular disorders, urinary tract infections and asthma. Even though several studies proved its therapeutic effects, there are few toxicological studies with this species.

AIM OF THE STUDY

The present study was carried out to evaluate the subchronic toxicity of the hydroethanolic extract obtained from leaves of T. majus (HETM) in Wistar rats.

MATERIAL AND METHODS

Male and female Wistar rats received three doses of HETM (75, 375 and 750 mg/kg) for 28 days. After the treatments biochemical, hematological and histopathological parameters were analyzed.

RESULTS

No significant alterations in the animal's body weight gain, relative organs weight, serum biochemical analysis, hematological or histopathological analyses of liver, kidneys and spleen were observed.

CONCLUSIONS

These results demonstrate the absence of subchronic toxicity due to oral treatment with HETM for 28 days in Wistar rats. However, other toxicological studies are necessary to evaluate the total safety of this plant.

Mechanisms underlying the diuretic effects of Tropaeolum majus L. extracts and its main component isoquercitrin

ETHNOPHARMACOLOGICAL RELEVANCE

Previous studies have shown that the extracts obtained from Tropaeolum majus L., and its main compound isoquercitrin (ISQ), exhibit pronounced diuretic effects, supporting the ethnopharmacological use of this plant. The aim of this study was to evaluate the efficacy and mechanisms underlying the diuretic action of an ethanolic extract of Tropaeolum majus (HETM), its purified fraction (TMLR), and its main compound ISQ, in spontaneously hypertensive rats (SHR).

MATERIALS AND METHODS

The diuretic effects of HETM (300mg/kg; p.o.), TMLR (100mg/kg; p.o.), and ISQ (10mg/kg; p.o.), were compared with classical diuretics in 7days repeated-dose treatment. The urinary volume, sodium, potassium, chloride, bicarbonate, conductivity, pH and density were estimated in the sample collected for 15h. The plasmatic concentration of sodium, potassium, urea, creatinine, aldosterone, vasopressin, nitrite and angiotensin converting enzyme (ACE) activity were measured in samples collected at the end of the experiment (seventh day). Using pharmacological antagonists or inhibitors, we determine the involvement of bradykinin, prostaglandin and nitric oxide (NO) in ISQ-induced diuresis. In addition, reactive oxygen species (ROS) and the activity of erythrocytary carbonic anhydrase and renal Na(+)/K(+)/ATPase were evaluated in vitro.

RESULTS

HETM, TMLR and ISQ increased diuresis similarly to spironolactone and also presented K(+)-sparing effects. All groups presented both plasmatic aldosterone levels and ACE activity reduced. Previous treatment with HOE-140 (a B2-bradykinin receptor antagonist), or indomethacin (a cyclooxygenase inhibitor), or L-NAME (a NO synthase inhibitor), fully avoided the diuretic effect of ISQ. In addition, the 7days treatment with ISQ resulted in increased plasmatic levels of nitrite and reducing ROS production. Moreover, the renal Na(+)/K(+)/ATPase activity was significantly decreased by ISQ.

CONCLUSION

Our results suggest that the mechanisms through ISQ and extracts of Tropaeolum majus increase diuresis in SHR rats are mainly related to ACE inhibition, increased bioavailability of bradykinin, PGI2, and nitric oxide, besides an inhibitory effect on Na(+)/K(+)-ATPase.

Screening for in vivo (anti)estrogenic and (anti)androgenic activities of Tropaeolum majus L. and its effect on uterine contractility

ETHNOPHARMACOLOGICAL RELEVANCE

Tropaeolum majus L. (Tropaeolaceae) is a medicinal herb popularly used in Brazil for treatment of inflammatory and cardiovascular diseases. Despite some published data on its efficacy, there are still few toxicological data describing the safety of this plant. The aim of this study was to evaluate the (anti)estrogenic and (anti)androgenic activity of the hydroethanolic extract obtained from Tropaeolum majus L. (HETM), as well as its possible effects on uterine contractility.

MATERIALS AND METHODS

Three experimental protocols were performed, (a) uterotrophic assay, (b) Hershberger assay and (c) an ex vivo test to investigate the effects of maternal administration of HETM on uterine contractility at the end of pregnancy. In all protocols three doses of the HETM were administered to Wistar rats: 3, 30 and 300mg/kg.

RESULTS

In vivo tests for detection of (anti)androgenic and (anti)estrogenic activities did not show any significant alterations. Similarly, no alterations were observed on uterine contractility induced by oxytocin and arachidonic acid.

CONCLUSIONS

HETM was unable to produce (anti)estrogenic or (anti)androgenic activities in the short-term in vivo screening assays performed. In addition, there was no evidence that HETM can affect uterine contractility following gestational exposure of rats.

Diuretic Activity of Lophophytum leandri

A bioassay-oriented study was carried-out in order to validate the traditional uses of Lophophytum leandri, a parasitic plant used as a diuretic in traditional medical practices of Argentina. Four known flavonoids have been isolated from the active fraction. Quercetin-3- O-β-D-glucopyranoside was identified as the active principle of the fraction. However, the diuretic activity of the extract and of the most active fraction had greater activity than that of the pure isolated compounds.

Antihypertensive effects of isoquercitrin and extracts from Tropaeolum majus L.: evidence for the inhibition of angiotensin converting enzyme

AIM OF THE STUDY

Previous studies have shown that the extracts obtained from Tropaeolum majus L. exhibit pronounced diuretic properties. In the present study, we assessed whether the hypotensive and/or antihypertensive mechanism of hydroethanolic extract (HETM), semi-purified fraction (TMLR) obtained from T. majus and the flavonoids isoquercitrin (ISQ) and kaempferol (KPF) can be mediated by their interaction with angiotensin converting enzyme (ACE).

METHODS AND METHODS

Firstly, to evaluate changes in mean arterial pressure (MAP), different groups of normotensive and spontaneously hypertensive rats (SHR) were orally and intraduodenally treated with HETM (10-300 mg/kg) and TMLR (12.5-100mg/kg) and intravenously treated with ISQ and KPF being later anesthetized with ketamine (100mg/kg) and xylazine (20mg/kg). The left femoral vein and the right carotid artery were isolated, and polyethylene catheters were inserted for ISQ and KPF (0.5-4 mg/kg) administration and blood pressure recording, respectively. The plasmatic ACE activity was evaluated to indirect fluorimetry, in serum samples after orally treatment with HETM, TMLR, ISQ and KPF.

RESULTS

The oral administration of the HETM and its TMLR significantly reduced, in a dose-dependent manner, the MAP in both normotensive and SHR. In addition, these preparations significantly decreased the MAP for up to 3h after the administration of the extract. Additionally, the intravenous administration of ISQ, but not KPF, decreased MAP in rats. Otherwise, neither the extracts nor ISQ affected the heart rate. The oral administration of the HETM, TMLR or ISQ reduced ACE activity in serum samples at 90 min after administration. Finally, the intravenous administration of ISQ caused a significant reduction in the hypertensive response to angiotensin I, but not angiotensin II in normotensive rats.

CONCLUSION

Our results show that the hypotensive effects caused by the HETM, as well as by its TMLR, may be associated with the high levels of the flavonoid ISQ found in this plant. In addition, ISQ-induced hypotension in rats is an event dependent on the inhibition of angiotensin II generation by ACE.