Sympathomimetic effects of Scoparia dulcis L. and catecholamines isolated from plant extracts

A review on the phytochemistry and pharmacology of the herb Scoparia dulcis L. for the potential treatment of metabolic syndrome

This review discusses the chemical constituents and pharmacological effects of Scoparia dulcis L. (S. dulcis) plants. So far, approximately 160 compounds have been identified from S. dulcis, among which 115 compounds may be related to the treatment of metabolic syndrome. Extracts of S. dulcis have effects of reducing fasting blood glucose level, increasing the plasma insulin level, and stimulating insulin secretion to treat diabetes. They also produce antihyperlipidemic effects by increasing serum high-density lipoprotein levels, the anti-atherogenic index of plasma, and HMG-CoA reductase activity. The chemical composition of glutinol and glutinone, isolated from S. dulcis, provide potential anti-inflammatory effects. These compounds can also reduce total cholesterol, triacylglycerol, and low-density lipoprotein (LDL)-cholesterol and increase high-density lipoprotein (HDL)-cholesterol to provide the anti-atherosclerotic effect. S. dulcis exerts anti-arthritic properties through its effect on cytokine levels, significantly reducing IFN-γ and IL-6 levels and elevating IL-10 levels. The extracts carry out hepatoprotective effect by preventing the descent of the antioxidative enzymes of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRd), and glutathione-S-transferase (GST). Therefore, S. dulcis provides new potential for medicine given its numerous therapeutic properties and can be promoted as a complementary or alternative therapy for patients with chronic conditions.

This review discusses the chemical constituents and pharmacological effects of S. dulcis plants. S. dulcis provides new potential for medicine and can be promoted as a complementary or alternative therapy for patients with chronic conditions.

Antibacterial activities of the methanol extracts of Albizia adianthifolia, Alchornea laxiflora, Laportea ovalifolia and three other Cameroonian plants against multi-drug resistant Gram-negative bacteria

In the last 10 years, resistance in Gram-negative bacteria has been increasing. The present study was designed to evaluate the in vitro antibacterial activities of the methanol extracts of six Cameroonian medicinal plants Albizia adianthifolia, Alchornea laxiflora, Boerhavia diffusa, Combretum hispidum, Laportea ovalifolia and Scoparia dulcis against a panel of 15 multidrug resistant Gram-negative bacterial strains. The broth microdilution was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts. The preliminary phytochemical screening of the extracts was conducted according to the reference qualitative phytochemical methods. Results showed that all extracts contained compounds belonging to the classes of polyphenols and triterpenes, other classes of chemicals being selectively distributed. The best antibacterial activities were recorded with bark and root extracts of A. adianthifolia as well as with L. ovalifolia extract, with MIC values ranging from 64 to 1024 μg/mL on 93.3% of the fifteen tested bacteria. The lowest MIC value of 64 μg/mL was recorded with A. laxiflora bark extract against Enterobacter aerogenes EA289.

Finally, the results of this study provide evidence of the antibacterial activity of the tested plants and suggest their possible use in the control of multidrug resistant phenotypes.

Antisickling and toxicological evaluation of the leaves of Scoparia dulcis Linn (Scrophulariaceae)

BACKGROUND

Scoparia dulcis Linn (Scrophulariaceae) together with other medicinal plants serve as antisickling remedies in Africa. This study was aimed at investigating the antisickling activity of the leaves of the plant as well as establishing the toxicological profile.

METHOD

Chemical tests were employed in phytochemical investigations. Evaluation of the antisickling activity involved the inhibition of sodium metabisulphite-induced sickling of the HbSS red blood cells obtained from confirmed sickle cell patients who were not in crises. Concentrations of the crude extract and its fractions were tested with normal saline and p-hydroxybenzoic acid serving as controls. Acute toxicological evaluation was carried out in mice while 30-day assessment was done in rats.

RESULTS

Phytochemical screening revealed the presence of alkaloids, tannins, flavonoids and saponins. Percentage sickling inhibitions of the aqueous methanol extracts of S. dulcis were significant all through the period of assay p < 0. 05 compared to normal saline, but not significant with PHBA. The fractions had less activity compared to the crude extracts. The LD 50 of the extract in mice was above 8000 mg/kg body weight when administered orally. Toxicological evaluations at 250 and 500 mg/kg showed mild congestion in virtually all the target organs.

CONCLUSION

The antisickling results confirmed traditional usage of Scoparia dulcis in the management of Sickle cell disorders and a candidate for further investigations.

The use of plants in the traditional management of diabetes in Nigeria: pharmacological and toxicological considerations

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system.

MATERIALS AND METHODS

Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. 'Diabetes' and 'Nigeria' were used as keywords for the primary searches; and then 'Plant name - accepted or synonyms', 'Constituents', 'Drug interaction' and/or 'Toxicity' for the secondary searches.

RESULTS

The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs.

CONCLUSION

This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb-drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided.

Benzoxazinoids from Scoparia dulcis (sweet broomweed) with antiproliferative activity against the DU-145 human prostate cancer cell line

Sweet broomweed (Scoparia dulcis) is an edible perennial medicinal herb widely distributed in tropical and subtropical regions of Asia, Africa, and the Americas. Four compounds, (2R)-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-O-β-galactopyranoside [(2R)-HMBOA-2-O-Gal], 3,6-dimethoxy-benzoxazolin-2(3H)-one (3,6-M2BOA), 3-hydroxy-6-methoxy-2-benzoxazolinone (3-OH-MBOA), and scutellarein 7-O-β-glucuronamide, along with eight known compounds, including two 7-methoxy-1,4-benzoxazin-3(2H)-one 3-O-hexopyranosides [(2R)-HMBOA-2-O-Glc and (2R)-HDMBOA-2-O-Glc], 6-methoxy-benzoxazolin-2(3H)-one (MBOA), acteoside, sodium scutellarin, p-coumaric acid, and two monosaccharides (fructose and glucose), were isolated from the aqueous extract of S. dulcis. Antiproliferative activities of the six benzoxazinoid compounds against the DU-145 human prostate cancer cell line were assayed, and one of these displayed an IC₅₀ of 65.8 μg/mL.

In vivo inhibition of gastric acid secretion by the aqueous extract of Scoparia dulcis L. in rodents

The freeze-dried aqueous extract (AE) from the aerial parts of Scoparia dulcis was tested for its effects on experimental gastric hypersecretion and ulcer in rodents. Administration of AE to animals with 4h pylorus ligature potently reduced the gastric secretion with ED(50)s of 195 mg/kg (rats) and 306 mg/kg (mice). The AE also inhibited the histamine- or bethanechol-stimulated gastric secretion in pylorus-ligated mice with similar potency suggesting inhibition of the proton pump. Bio-guided purification of the AE yielded a flavonoid-rich fraction (BuF), with a specific activity 4-8 times higher than the AE in the pylorus ligature model. BuF also inhibited the hydrolysis of ATP by H(+),K(+)-ATPase with an IC(50) of 500 microg/ml, indicating that the inhibition of gastric acid secretion of Scoparia dulcis is related to the inhibition of the proton pump. Furthermore, the AE inhibited the establishment of acute gastric lesions induced in rats by indomethacin (ED(50)=313 mg/kg, p.o.) and ethanol (ED(50)=490 mg/kg, p.o.). No influence of the AE on gastrointestinal transit allowed discarding a possible CNS or a cholinergic interaction in the inhibition of gastric secretion by the AE. Collectively, the present data pharmacologically validates the popular use of Scoparia dulcis in gastric disturbances.

Antihyperlipidemic Effect ofScoparia dulcis(Sweet Broomweed) in Streptozotocin Diabetic Rats

We have investigated Scoparia dulcis, an indigenous plant used in Ayurvedic medicine in India, for its possible antihyperlipidemic effect in rats with streptozotocin-induced experimental diabetes. Oral administration of an aqueous extract of S. dulcis plant (200 mg/kg of body weight) to streptozotocin diabetic rats for 6 weeks resulted in a significant reduction in blood glucose, serum and tissue cholesterol, triglycerides, free fatty acids, phospholipids, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activity, and very low-density lipoprotein and low-density lipoprotein cholesterol levels. The decreased serum high-density lipoprotein cholesterol, anti-atherogenic index, and HMG-CoA reductase activity in diabetic rats were also reversed towards normalization after the treatment. Similarly, the administration of S. dulcis plant extract (SPEt) to normal animals resulted in a hypolipidemic effect. The effect was compared with glibenclamide (600 microg/kg of body weight). The results showed that SPEt had antihyperlipidemic action in normal and experimental diabetic rats in addition to its antidiabetic effect.

Efficacy of scopadulcic acid A against Plasmodium falciparum in vitro

Scoparia dulcis is a perennial herb widely distributed in many tropical countries. It is used as an herbal remedy for gastrointestinal and many other ailments, and in Nicaragua extracts are used to treat malaria. Phytochemical screening has shown that scopadulcic acid A (SDA), scopadulcic acid B (SDB), and semisynthetic analogues are pharmacologically active compounds from S. dulcis. SDB has antiviral activity against Herpes simplex virus type 1, antitumor activity in various human cell lines, and direct inhibitory activity against porcine gastric H(+), K(+)-ATPase. A methyl ester of scopadulcic acid B showed the most potent inhibitory activity against gastric proton pumps of 30 compounds tested in one study. Compounds with antiviral, antifungal, and antitumor activity often show activity against Plasmodium falciparum. In P. falciparum, the plasma membrane and food vacuole have H(+)-ATPases and the acidocalcisome has an H(+)-Ppase. These proton pumps are potential targets for antimalarial therapy and may have their function disrupted by compounds known to inhibit gastric proton pumps. We tested pure SDA and found in vitro activity against P. falciparum with an IC(50) of 27 and 19 microM against the D6 and W2 clones, respectively. The IC(50) against the multidrug-resistant isolate, TM91C235, was 23 microM.