Scoparia dulcis L. (Scrophulariaceae)

Synonyms

Scoparia grandiflora, S. ternata, Capraria dulcis

Vernacular Names:

English Bitterbroom, broomweed, licorice weed
Brazil Vassourinha

General Information

Description

Scoparia dulcis is an erect annual herb that grows to a height of 0.5 metres. It is widely distributed in many tropical countries and is found in abundance in South America and the Amazon rainforest. In many areas, the herb is considered an invasive weed (1).

Plant Part Used

Leaves, bark, roots

Chemical Constutuents:

The main plant chemical constituents include: acacetin, amellin, a-amyrin, apigenin,benzoxazin, benzoxazolin, benzoxalinone, betulinic acid, cirsimarin, cirsitakaoside, coixal, coumaric acid, cynaroside, daucosterol, dulcidion, dulcinol, dulcioic acid, 4-epi-scopadulcic acid, friedelin, gentisic acid, glutinol, hymenoxin, ifflaionic acid, iso-dulcinol, linarin, luteolin, mannitol, scopadiol, scopadulcic acid A, B & C, scopadulciol, scopadulin, scopanolal, scoparic acids A-C, scoparinol, scutellarein, scutellarin, sitosterol, stigmasterol, taraxerol, vicenin, and vitexin (1), (2), (3).

A flavone glycoside 5,7,8,3’,4’,5’-hexahydroxyflavone 7-O-b-D-glucuronide and a diterpene 6-benzoyl-labda-8(17), 13-diene-15,18-diol have also been isolated from Scoparia dulcis while 6-methoxybenzoxazolinone was obtained from its roots (4), (5), (6).

Traditional Use:

Indigenous people in Ecuador consume tea of the entire plant to reduce swellings, aches and pains. The Tikuna Indian women drink the plant decoction for three days each month during menstruation as a contraceptive and/or to induce abortions (1). The indigenous tribes in Nicaragua use a hot water infusion and/or decoction of the leaves (or the whole plant) for stomach pain, for menstrual disorders, as an aid in childbirth, as a blood purifier, for insect bites, fevers, heart problems, liver and stomach disorders, malaria, sexually transmitted diseases, and as a general tonic (1).

Pre-Clinical Data

Pharmacology

Antacid and Antiulcer activity:

A study was carried out to assess the efficacy of aqueous extracts of the aerial parts of Scoparia dulcis as a gastroprotective agent using in vivo rodent models (7). Administration of AE to animals with 4h pylorus ligature potently reduced the gastric secretion. The AE also inhibited the histamine- or bethanechol-stimulated gastric secretion in pylorus-ligated mice with similar potency suggesting inhibition of the proton pump. The AE inhibited the establishment of acute gastric lesions induced in rats by indomethacin.  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.

The above result is in agreement with a similar study when oral treatment with the water extracts of the whole aerial parts of Scoparia dulcis, at doses of 50, 100 and 200 mg/kg, dose-dependently inhibited the indomethacin-induced gastric damages in rats (8). These results collectively validate pharmacologically the popular use of Scoparia dulcis in gastric disturbances as an antiacid and antiulcer agent in Traditional Medicine.

Cytotoxicity acitivity:

Four new diterpenes, iso-dulcinol, 4-epi-scopadulcic acid, dulcidion and scopanolal were isolated from the aerial parts of Scoparia dulcis and had their structures extensively determined by NMR studies. Study of the crude extracts and pure diterpenes against a panel of six human cancer cell lines showed indication of cytotoxicity (2).

In another study, a diterpenoid, scopadulcic acid B, isolated from Scoparia dulcis L showed greater cytotoxicity against cell lines derived from tumour tissues with a 50% inhibitory concentration (IC50) of 0.068-0.076 μg/mL, compared with cell lines from normal tissues with an IC50 of 0.097-0.245 μg/mL (9). Oral administration of scopadulcic acid B at doses of 25 or 100 mg/kg/day prolonged the median survival time of tumour-induced mice. On the other hand, intraperitoneal administration of the compound showed dose-dependent increase in the survival rate without weight change over the treatment period.

Four scopadulane-type diterpenoids which includes scopadulcic acid C were isolated from the aerial parts of Scoparia dulcic of Vietnamese origin (3). All were tested for their cytotoxic effects on human epidermoid carcinoma KB cells. The plant extracts showed potent IC50 of 2.5, 2, 4, and 50m g/ml, respectively, in the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) cytotoxic assay against KB cells.

Antidiabetic activity:

In India,Scoparia dulcis (commonly known as Sweet Broomweed) has been used as a traditional remedy for diabetes mellitus. In order to understand the mechanism by which Scoparia dulcis alleviate hyperglycaemia, the following studies were investigated: the effect of a Scoparia dulcis plant extract (SPEt) on insulin secretion from isolated pancreatic cells of male mice (10); the effect of SPEt on streptozotocin (STZ) treated rat insulinoma cell lines (RINm5F cells) and isolated islets in vitro and in vivo (11); and the effect of SPEt on hepatic key metabolic enzymes of carbohydrate metabolism in STZ-induced diabetic rats (12).

 The administration of SPEt at a dose of 200 mg/kg body weight significantly decreased the blood glucose with significant increase in plasma insulin level in streptozotocin diabetic rats at the end of 15 days treatment. SPEt induced stimulation of insulin secretion from isolated pancreatic islet cells indicating its insulin secretagogue activity. SPEt protected against STZ-mediated cytotoxicity (88%) and nitric oxide production in rat insulinoma cell line (RINm5F). Flow cytometric assessment demonstrated that SPEt suppressed (21%) the level of STZ-induced (46%) intracellular oxidative stress in RINm5F cells (10), (11).

In the study of hepatic key metabolic enzymes of carbohydrate metabolism in STZ-induced diabetic rats, SPEt (aqueous, ethanol and chloroform) were orally administered at doses of 50, 100 and 200mg/kg body weight respectively for 3 weeks, after which the metabolic enzymes were assayed. In diabetic rats, the levels of blood glucose, glucose 6-phosphatase and fructose 1,6-bisphosphatase were significantly increased and plasma insulin, hexokinase. glucose 6-phosphate dehydrogenase and glycogen were significantly decreased. Diabetic rats treated with SPEt significantly reversed all these changes to near normal. Aqueous extract of Scoparia dulcis demonstrated better results than ethanol and chloroform extracts. These results indicate that the aqueous extract of Scoparia dulcis showed antihyperglycaemic effect by moderating the above biochemical alterations in streptozotocin diabetes (12). The overall results revealed the possible therapeutic value of Scoparia dulcis for the better control, management and prevention of diabetes mellitus progression.

Antioxidant activity:

Antioxidant activity of aqueous extract of Scoparia dulcis was investigated in vitro using thiobarbituric acid reactive substances (TBARS) assay based on fowl egg yolk (13). The extract showed marked and dose-dependent antioxidative activity in vitro. The results support the therapeutic effects claimed by traditional practitioners.

The effect of aqueous extract of Scoparia dulcis (SPEt) on extent of oxidative damage as well as the status of the antioxidant defense system in the brain of STZ diabetic rats was investigated (14). The study was assessed after 6 weeks treatment and the effect produced by Scoparia dulcis was compared with glibenclamide. Oral administration of SPEt and glibenclamide to diabetic-induced rats significantly reduced the glucose blood level and increased the plasma insulin level to near normal levels. The levels of lipidperoxidation markers (TBARS and hydroperoxides) in the brain were significantly reduced suggesting that SPEt possesses antioxidant potential that may be used for therapeutic purposes.

Antiviral activity:

Five diterpenoids isolated from Scoparia dulcis were examined in vitro against herpes simplex virus type 1 in a hamster test model (15). Only scopadulcic acid B was found to inhibit the viral replication.by interfering with considerably early events of virus growth as indicated by single-cycle replication experiments. Scopadulcic acid B, when applied orally or intraperitoneally immediately following virus inoculation, effectively prolonged both the appearance of herpetic lesions and the survival time at the dose of 100 and 200 mg/kg per day.

Toxicities

No documentation

Clinical Data

Clinical Trials

No documentation

Adverse Effects in Human:

No documentation

Use in Certain Conditions:

Pregnancy / Breastfeeding

It is advisable to avoid taking Scoparia dulcis during pregnancy as traditionally it has been used as an abortive.

Age Limitations

Neonates / Adolescents

Geriatrics

No documentation

Chronic Disease Conditions

No documentation

Interactions

Interactions with Drugs

One human study documented that an ethanol extract of Scoparia dulcis inhibited radioligand binding to dopamine and seratonin. Another study reported that a water extract given intragastrically to rats potentiated the effects of barbiturates. As such, it is possible that Scoparia dulcis may enhance the effect of barbiturates and selective serotonin reuptake inhibitor antidepressants (1).

Interactions with Other Herbs / Herbal Constituents

No documentation

Contraindications

Contradications

None documented by clinical studies; however it is advisable to avoid taking Scoparia dulcis during pregnancy as traditionally it has been used as an abortive and /or childbirth aid (1).

The plant extract demonstrated hypoglycaemic activity in experimental rats, as such this plant is contraindicated in people with hypoglycaemia (1).

Case Reports

No documentation

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  1)  Botanical Info

References

  1. The Healing Power of Rainforest Herbs. . 2005, Square One Publishers. New York..
  2. View Abstract: Ahsan, M. Cytotoxic Diterpenes from Scoparia dulcis. . J. Nat. Prod. 2003; 66(7): 958-61
  3. View Abstract: Phan, M. G.. Chemical and Biological Evaluation on Scopadulane-Type Diterpenoids from Scoparia dulcis of Vietnamese Origin. . Chem. Pharm. Bull. 2006; 54(4): 546-9
  4. View Abstract: Kawasaki, M. 8-Hydroxytricetin 7-glucuronide, a β-glucuronidase inhibitor from Scoparia dulcis. . Phytochemistry.. 1988; 27(11): 3709-11
  5. View Abstract: Hayashi, T. . A new chemotype of Scoparia dulcis. . Phytochemistry. 1993; 32(2): 349-52
  6. Chen, C.M. and Chin, M.T.. 6-methoxybenzoxazolinone and triterpenoids from roots of Scoparia dulcis.. Phytochemistry.. 1976; 15(12): 1997-9
  7. View Abstract: Vela, S.M. . In vivo inhibition of gastric acid secretion by the aqueous extract of Scoparia dulcis L. in rodents. . J. Ethnopharmacol. 2007; 111: 403-8
  8. View Abstract: Babincová, M., Schronerová, K, Sourivong, P. . Antiulcer activity of water extract of Scoparia dulcis.. Fitoterapia. 2008; 79(7-8): 587-8
  9. View Abstract: Hayashi, K.. Cytotoxic and antitumour activity of scopadulcic acid from Scoparia dulcis L. . Phytotherapy Research. 1992; 6(1): 6-9
  10. View Abstract: Latha, M. Pari, L. Sitasawad, S. Bhonde, R.. Insulin-secretagogue activity and cytoprotective role of the traditional antidiabetic plant Scoparia dulcis (Sweet Broomweed). Life Sci. 2004 9 , 3; 75:16: 2003-14
  11. View Abstract: Latha M. Scoparia dulcis, a traditional antidiabetic plant, protects against streptozotocin induced oxidative stress and apoptosis in vitro and in vivo. . J. Biochem. Mol. Toxicol. 2004; 18(5): 261-72
  12. View Abstract: Pari L and Latha M. Antihyperglycaemic Effect of Scoparia dulcis: Effect on Key Metabolic Enzymes of Carbohydrate Metabolism in Streptozotocin-Induced Diabetes.. Pharmaceut. Biol. . 2004; 42(8): 570-6
  13. View Abstract: Ratnasooriya, W. D.,. Antioxidant activity of water extract of Scoparia dulcis. . Fitoterapia. 2005; 76: 220-2
  14. View Abstract: Pari, L. and Latha. Protective role of Scoparia dulcis plant extract on brain antioxidant status and lipidperoxidation in STZ diabetic male Wistar rats. . BMC Complement. Altern Med.. 2004; 4: 16
  15. View Abstract: Hayashi, K.. In vitro and in vivo antiviral activity of scopadulcic acid B from Scoparia dulcis, Scrophulariaceae, against herpes simplex virus type 1.. Antiviral Res.. 1988; 9(6): 345-54