RESUMO
Background & objectives: Albizia lebbeck Benth. (Leguminosae) has long been used in Indian traditional medicine. The current study was designed to test antimalarial activity of ethanolic bark extract of A. lebbeck (EBEAL). Methods: EBEAL was prepared by soxhlet extraction and subjected to phytochemical analysis. The extract was evaluated for its in vitro antimalarial activity against Plasmodium falciparum chloroquine (CQ) sensitive (MRC2) and CQ resistant (RKL9) strains. Cytotoxicity (CC50) of extract against HeLa cells was evaluated. Median lethal dose (LD50) was determined to assess safety of EBEAL in BALB/c mice. Schizonticidal (100-1000 mg/kg) and preventive (100-750 mg/kg) activities of EBEAL were evaluated against P. berghei. Curative activity (100-750 mg/kg) of extract was also evaluated. Results: Phytochemical screening revealed presence of alkaloids, flavonoids, phenols, saponins, terpenes and phytosterols. The extract exhibited IC50 of 8.2 μg/ml (MRC2) and 5.1 μg/ml (RKL9). CC50 of extract on HeLa cell line was calculated to be >1000 μg/ml. EBEAL showed selectivity indices (SI) of >121.9 and >196.07 against MRC2 and RKL9 strains of P. falciparum, respectively. LD50 of EBEAL was observed to be >5 g/kg. Dose-dependent chemosuppression was observed with significant (P<0.001) schizonticidal activity at 1000 mg/kg with ED50>100 mg/kg. Significant (P<0.001) curative and repository activities were exhibited by 750 mg/kg concentration of extract on D7. Interpretation & conclusions: The present investigation reports antiplasmodial efficacy of EBEAL in vitro against P. falciparum as evident by high SI values. ED50 of <100 mg/kg against P. berghei categorizes EBEAL as active antimalarial. Further studies need to be done to exploit its antiplasmodial activity further.
RESUMO
Aim: Antiplasmodial potential of traditional medicinal plant Thlaspi arvense against Plasmodium falciparum in vitro has been evaluated. Cytotoxicity of plant extract against HeLa cell lines and normal fibroblasts has also been observed. Place and Duration of the Study: Department of Zoology, Panjab University, Chandigarh, India, between May 2013 to April 2014. Materials and Methods: Ethanolic whole plant extract of Thlaspi arvense (EWETA) was analyzed for its phytochemical constituents. In vitro cytotoxicity was determined colorimetrically by MTT assay. WHO protocol, based on assessment of schizont maturation inhibition, was employed for the evaluation of in vitro antiplasmodial activity of plant extract. Results: Phytochemical screening of EWETA revealed the presence of diterpenes, triterpenes, steroids, anthraquinones and phytosterols. EWETA was observed to inhibit schizont maturation of both chloroquine-sensitive (MRC-2) and resistant (RKL-9) strains of P. falciparum with IC50<5μg/ml and =5μg/ml respectively. The extract was revealed to be safe against both HeLa cells and normal fibroblasts with CC50>1000μg/ml. Selectivity index for Thlaspi arvense was calculated to be >200 and =200 both for chloroquine sensitive and chloroquine-resistant strains of P. falciparum with both HeLa and normal fibroblasts. Conclusion: Plant extract possesses considerable in vitro antimalarial activity with high selectivity index (SI>10) pointing field pennycress to be an active antimalarial. Hence, present study provides scientific evidence for traditional usage of the plant as an antipyretic agent.