Effects of aqueous leaf extract of Tridax procumbens on contractile activity of corpus cavernosum in N-nitro-l-arginine methyl ester-induced hypertensive male rats

J Integr Med. 2018 Jan;16(1):51-56. doi: 10.1016/j.joim.2017.11.001. Epub 2017 Nov 26.

Abstract

Objective: This study investigated the effects of aqueous leaf extract of Tridax procumbens (ALETP) on contractile activity of corpus cavernosum in N-nitro-l-arginine methyl ester (l-NAME)-induced hypertensive male rats.

Methods: Twenty normal, adult male rats (130-150 g) were divided into four groups of five rats each. Group I (control) was given normal saline (0.6 mL/kg) and group II was given l-NAME (40 mg/kg) for 6 weeks. Groups III and IV also received l-NAME (40 mg/kg) for 6 weeks but were further co-treated with 100 and 200 mg/kg of ALETP, respectively, from week 4 to week 6. All treatments were given orally. Strips of corpus cavernosum from each of the four groups were exposed to increasing concentrations of acetylcholine (ACh) and sodium nitroprusside (SNP) (10-9-10-5mol/L) after contraction with phenylephrine (10-7 mol/L) to test for a dose-response effect. Response to potassium and calcium was also measured after cumulatively adding potassium and calcium (10-50 mmol/L) to potassium- and calcium-free organ chamber. Isometric contractions were recorded through an Ugo Basile data capsule acquisition system.

Results: Mean arterial blood pressure was significantly reduced in the ALETP co-treated group compared to the control and l-NAME-only groups (P < 0.05). Cavernosa strips from ALETP co-treated rats exhibited significant inhibition of contraction in response to phenylephrine, potassium chloride, and calcium chloride (P < 0.05). Relaxation in response to Ach and SNP was also significantly impaired in cavernosa strips from the l-NAME-only treated group (P < 0.05), while ALETP co-treated groups showed enhanced percentage relaxation.

Conclusion: ALETP treatment of l-NAME-induced hypertensive rats promotes a relaxant effect on isolated cavernosa strips. ALETP shows potential in correcting erectile dysfunction in hypertension.

Keywords: Acetylcholine; Corpus cavernosum; Hypertensive; N-Nitro-l-arginine methyl ester; Relaxation; Sodium nitroprusside; Tridax procumbens.

MeSH terms

  • Animals
  • Asteraceae / chemistry*
  • Erectile Dysfunction / drug therapy*
  • Erectile Dysfunction / etiology
  • Erectile Dysfunction / physiopathology
  • Humans
  • Hypertension / chemically induced
  • Hypertension / complications*
  • Male
  • NG-Nitroarginine Methyl Ester / adverse effects
  • Penis / drug effects
  • Penis / physiopathology*
  • Plant Extracts / administration & dosage*
  • Plant Extracts / isolation & purification
  • Plant Leaves / chemistry
  • Rats
  • Rats, Wistar

Substances

  • Plant Extracts
  • NG-Nitroarginine Methyl Ester