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

Exogenous application of salicylic acid and putrescine triggers physiological and biochemical changes in plants to improve growth and bioactive constituents of Ammi majus L

Ammi majus L. is a rich source of coumarins in addition to various flavonoids, alkaloids, and terpenoids. Medicinal products of Ammi majus seed, with sunlight exposure, are worldwide used for the treatment of vitiligo (pale-white patches on the skin). To increase the content of seed-coumarins and to investigate the physiological reasons in this respect, two net-house experiments were conducted using foliar-spray treatments (0, 25, 50, 100 and 200 mg L-1) of salicylic acid (SA) (Experiment 1) and putrescine (PUT) (Experiment 2). All studied parameters were improved due to the foliar application of both growth elicitors (SA and PUT). The best outcomes for SA and PUT were obtained at 50 mg L-1 which maximally increased the growth characteristics, physiological and biochemical attributes, and seed quality parameters. In comparison to the control, 50 mg L-1 of SA and PUT increased the chlorophyll content by 26.3% and 25.5%, carotenoid content by 31.4% and 18.5%. In addition 50 mg L-1 of both SA and PUT gives the best results of FTIR (Fourier Transform Infrared Spectrophotometer) & XRD (X-ray Diffraction) analysis. In GC-MS analysis, 50 mg L-1 of SA and PUT increases the Methoxsalen content (17.44 and 16.81%) and 7H-Furo[3,2-g]. Bown (1995) [1] Benzopyran-7-one, 4,9-dimethoxy content(14.92 and 13.93%) and p-camphorene content (13.11 and 12.27%) in contrast to the control. Other important constituents were Pimpinellin (6.31 and 4.08%), Bergapten (8.72 and 6.220, Isospathulenol (7.80 and 2.47), Octadecenoic acid (5.78 and 3.59) and Vitamin E (1.48 and 0.16).

The Cardiorenal Effects of Piper amalago Are Mediated by the Nitric Oxide/Cyclic Guanosine Monophosphate Pathway and the Voltage-Dependent Potassium Channels

Piper amalago L. is used in Brazilian traditional medicine to treat inflammation, chest pain, and anxiety. This study aimed to investigate the safety and the renal and cardiovascular effects of the volatile oil (VO) and the aqueous (AE) and hydroalcoholic (HE) extracts from P. amalago. The gas chromatography-mass spectrometry analyses identified 47 compounds in the VO, with β-cyclogermacrene, spathulenol, β-phellandrene, and α-pinene standing out. Among the 47 compounds also found in AE and HE by liquid chromatography-mass spectrometry, glycosylated flavones, organic acids, amino acids, and amides were highlighted. Some examples of these compounds are methoxy-methylenedioxy cis-cinnamoyl pyrrolidine, methoxy-methylenedioxy trans-cinnamoyl pyrrolidine, and cyclobutene-2,4-bis-(1,3-benzodioxol-5-methoxy-6-yl)-1,3-dicarboxapyrrolidide. The acute toxicity experiments were conducted on female rats (n = 5). The cardiorenal assays (n = 8) and evaluations of vasodilatory effects on the mesenteric vascular bed (n = 5) were conducted on male rats. In either extract or VO, there were no mortality or changes in relative weights or histopathological analysis of the organs. Urinary volume and renal electrolyte excretion were elevated significantly during repeated dose 7-day treatment with different preparations from P. amalago. None of the preparations induced hypotension or changes in cardiac electrical activity. Only HE promoted significant vasodilatory effects in rats' isolated mesenteric vascular beds. These effects were completely abolished in the presence of L-NAME plus 4-aminopyridine. Therefore, P. amalago leaves are safe and present diuretic activity after acute and repeated dose administration over 7 days. Moreover, the HE induced significant vasodilator response in rats' mesenteric vascular beds by NO/cGMP pathway and voltage-dependent K+ channels activation.

Diuretic, Natriuretic, And Ca2+-Sparing Effect Of The Alkaloid Boldine In Rats

BACKGROUND

Previous studies indicate the renal vasodilating effects of boldine, an alkaloid found in Peumus boldus. However, its potential to induce diuresis still needs to be studied.

METHODS

Wistar rats were used and the urine volume was noted for 8 h and further studied.

RESULTS

The acute treatment at 0.1 and 0.3 mg/kg of boldine showed a diuretic, natriuretic, and Ca2+-sparing effect in rats without changing the urinary elimination of K+and Cl-. When boldine was given in combination with hydrochlorothiazide, there was an increase in urinary volume compared to the vehicle group. However, this was not different from the treatments in its isolated form. Urine Ca2+values ​​remained low but were not enhanced by this association. The excretion of Na+and Cl- was significantly increased compared to the group that received only vehicle or boldine. On the other hand, although the association of amiloride plus boldine did not result in a diuretic effect, the increase in Na+and the reduction in K+excretion were significantly potentiated. Furthermore, in the presence of the non-selective muscarinic receptor antagonist atropine, boldine showed reduced capacity to increase urinary volume, maintaining the natriuretic and Ca2+-sparing effect, besides a very evident K+-sparing action. Similar results were obtained in the presence of the non-selective cyclooxygenase inhibitor indomethacin. Furthermore, boldine showed an ex vivo antiurolithiasis activity, reducing calcium oxalate's precipitation and crystallization.

CONCLUSIONS

This study reveals the diuretic, natriuretic, Ca2+-sparing, and antiurolithiatic effects of boldine, an action possibly related to muscarinic receptor activation and prostanoid generation.

Flavonoid Composition and Antioxidant Activity of Tragia volubilis L. Methanolic Extract

Several species from the genus Tragia L. in the family Euphorbiaceae are part of the ethnomedicine of traditional cultures, and have a variety of uses. Tragia volubilis L. is a species spread through tropical America and Africa with several ethnomedical uses, particularly for wound healing and reproductive issues. In this study, we assess the phytochemical composition and antioxidant activity of the methanolic extract of the aerial parts of T. volubilis collected in southern Ecuador. The phytochemical screening of the extract shows the preliminary presence of carbohydrates, alkaloids, flavonoids, and tannins. The extract shows an Antioxidant Activity Index of 1.14, interpreted as strong antioxidant activity. Four flavonoid compounds were isolated through chromatographic procedures and identified through NMR spectroscopy: avicularin, quercitrin, afzelin, and amentoflavone. The biological activity of these compounds matches the ethnopharmacological uses of the species. This is the first phytochemical study of T. volubilis and supports its traditional medicinal uses.

Natural Products as Modulators of Mitochondrial Dysfunctions Associated with Cardiovascular Diseases: Advances and Opportunities

The mitochondria have an important role in modulating cell cycle progression, cell survival, and apoptosis. In the adult heart, the cardiac mitochondria have a unique spatial arrangement and occupy nearly one-third the volume of a cardiomyocyte, being highly efficient for converting the products of glucose or fatty acid metabolism into adenosine triphosphate (ATP). In cardiomyocytes, the decline of mitochondrial function reduces ATP generation and increases the production of reactive oxygen species, which generates impaired heart function. This is because mitochondria play a key role in maintaining cytosolic calcium concentration and modulation of muscle contraction, as ATP is required to dissociate actin from myosin. Beyond that, mitochondria have a significant role in cardiomyocyte apoptosis because it is evident that patients who have cardiovascular diseases (CVDs) have increased mitochondrial DNA damage to the heart and aorta. Many studies have shown that natural products have mitochondria-modulating effects in cardiac diseases, determining them as potential candidates for new medicines. This review outlines the leading plant secondary metabolites and natural compounds derived from microorganisms as modulators of mitochondrial dysfunctions associated with CVDs.

Contribution to the Preclinical Safety Assessment of Lannea velutina and Sorindeia juglandifolia Leaves

Dried leaves of Lannea velutina A. Rich. and Sorindeia juglandifolia (A. Rich.) Planch. ex Oliv. (family Anacardiaceae) are used in African traditional medicine. Although these medicinal plants have widespread use in the treatment of inflammatory diseases, there is no scientific data concerning their preclinical or clinical safety. This work aimed to investigate the phytochemical properties of the leaves of both species using HPLC-UV/DAD, as well as the in vivo oral repeated-dose toxicity of 70% hydroethanolic leaf extract of S. juglandifolia and the in vitro genotoxicity of 70% hydroethanolic leaf extracts of L. velutina and S. juglandifolia. Clinical signs of toxicity, body weight variations, and changes in food consumption, mortality, and blood biochemical parameters were monitored. Genotoxicity was assessed using the bacterial reverse mutation assay (Ames test) with and without metabolic activation, according to OECD guidelines. The obtained results showed the presence of gallic acid and anacardic acid as the main marker constituents in both species. No significant changes in general body weight or food intake were observed; small significant changes with no critical relevance were observed in the blood biochemistry of animals treated with S. juglandifolia hydroethanolic extract (50, 400, and 1000 mg/kg body weight) compared to those in the control group. No genotoxicity was observed in the bacterial reverse mutation assay with S. juglandifolia and L. velutina extracts (up to 5 mg/plate). The safety data obtained in vivo and lack of genotoxic potential in vitro points to the safe medicinal use of S. juglandifolia and L. velutina extracts.

Diuretic and Natriuretic Effects of Hesperidin, a Flavanone Glycoside, in Female and Male Hypertensive Rats

Hesperidin (HSP) is a major flavanone glycoside in citrus fruits, including sweet oranges and lemons. It demonstrates numerous pharmacological activities, such as antihypertensive effects and cardiac and kidney tissue protection. However, its effect on modulating renal function has yet to be properly explored. Female and male Wistar spontaneously hypertensive rats (SHR) were used to test the effect of HSP on renal function. The rats were divided into different groups, treated orally, and placed in metabolic cages for urine collection for 8 h. HSP, at doses of 0.3-3 mg/kg, led to an increase in urine volume in both female and male SHR. This effect was associated with increased Na⁺ elimination (3 mg/kg) without causing any change in K⁺ excretion or pH and conductivity values. When given HSP in combination with hydrochlorothiazide (HCTZ) or amiloride (AMLR), urine volume and Na⁺ elimination were significantly increased compared to the group that received only HSP. In relation to K⁺ excretion, the depleting effect of HCTZ and the sparing of AMLR prevailed in both groups. Pre-treatment with a non-selective cholinergic receptor antagonist, atropine, partially prevented HSP-induced diuresis and natriuresis in male SHR, but this effect was not demonstrated with the non-selective inhibitor of the enzyme cyclooxygenase, indomethacin. This study shows the diuretic action of HSP in hypertensive rats, an activity probably associated with the cholinergic pathway. Although various biological actions have already been defined for HSP, this pioneering research reveals its potential as a diuretic medicine.

Diuretic and antiurolithic effect of Garcinia humilis (Vahl) C.D.Adams leaves, a medicinal plant native to South American countries

This study evaluated the diuretic and antiurolithic effect of methanolic extract (MEGHL), dichloromethane (DCM), and ethyl acetate (EtA) fractions obtained from the leaves of Garcinia humilis , a medicinal plant known as achachairu and native to South American countries such as Bolivia, Peru, and Brazil. For the analysis of diuretic effect, the female rats received the treatment with MEGHL (3, 10, and 30 mg/kg), DCM (1, 3 and 10 mg/kg), EtA (1, 3, and 10 mg/kg), hydrochlorothiazide (HCTZ; 10 mg/kg), or vehicle (VEH) after an overload of saline solution. At the end 8-h of the experiment, the urinary parameters were measured . Additionally, the antiurolithic effect was analyzed, in which sodium oxalate was added in synthetic urine in the presence or absence of MEGHL, DCM, and EtA in different concentrations (0.1, 0.3, and 1 mg/mL). MEGHL, DCM, and EtA were able to promote 8-h diuresis in rats. MEGHL treatment at dose 30 mg/kg was accompanied by increased urinary Na + , K + and Cl - excretion. Moreover, the DCM and EtA fractions treatment increased K + and Cl - excretion in the urine, although it does not cause any change in Na + elimination. All the preparations were able to exert an antiurolithic effect in vitro , decreasing the number of calcium oxalate crystals of the monohydrate and dihydrate types. Taking together, the results presented herein showed that the preparations of G. humilis leaves are promising strategies to induce diuresis and antiurolithic effects.

Exotic Medicinal Plants Used in Brazil with Diuretic Properties: A Review

Several exotic plants (non-native) are used in Brazilian traditional medicine and are known worldwide for their possible diuretic actions. Among the wide variety of plants, standing out Achillea millefolium L., Camellia sinensis L. Kuntze, Crocus sativus L., Hibiscus sabdariffa Linn., Petroselinum crispum (Mill.) A.W. Hill, Taraxacum officinale (L.) Weber, and Urtica dioica L., whose effects have already been the subject of some scientific study. In addition, we also discussed other exotic species in Brazil used popularly, but that still lack scientific studies, like the species Arctium lappa L., Carica papaya L., Catharanthus roseus (L.) G. Don, Centella asiatica (L.) Urb, Citrus aurantium L., and Persea americana Mill. However, generally, clinical studies on these plants are scarce. In this context, different plant species can be designated for further comprehensive studies, therefore, promoting support for developing an effective medicine to induce diuresis.