Background:The leaves of Hibiscus rosa-sinensis L. (Malvaceae) are used for the treatment of dysentery and diarrhea, to promote draining of abscesses and as analgesic agent in the traditional medicine of Cook Islands, Haiti, Japan and Mexico.Aim:The present study investigated the oral acute and subacute toxicity of methanol leaf extract of H. rosa-sinensis in mice.Materials and Methods:In the acute toxicity study, a single oral dose of 2000 mg/kg of extract was given to five mice at 48 h intervals. Animals were observed individually for any clinical signs of toxicity or mortality for 14 days. In the sub-acute toxicity study, mice were treated with 400 mg/kg and 800 mg/kg doses of the extract for 14 days. The hematological and biochemical parameters and histopathology of liver and kidneys of animals were studied at the end of the experiment.Results:For acute treatment, the extract did not reveal any signs of toxicity or mortality in any animal, during the 14 days observation period. The LD50 of extract was estimated to be greater than 2000 mg/kg. In the sub-acute toxicity study, administration of 400 mg/kg and 800 mg/kg doses of extract to mice for two weeks did not reveal any marked adverse effects on hematological, biochemical parameters and histopathology of liver and kidney in the 400 mg/kg group. However, hepato-renal toxicity as evidenced by elevated levels of alanine aminotransferase, aspartate aminotransferase, total and indirect bilirubin, urea and creatinine was seen in the animals that received 800 mg/kg dose of extract for 14 days. In addition, in the same group of animals, the histological assessments of liver and kidney also showed various adverse effects viz. dilated sinusoids, apoptotic nuclei and inflammatory infiltrate inside sinusoidal capillaries in the liver, and marked the disorganization of tubules and glomeruli, and enlarged interstitial spaces in the kidney.Conclusion:The results of this study suggest that for traditional medicinal purpose, only a low dose of H. rosa-sinensis leaf extract (i.e., 400 mg/kg) should be considered as safe.

Objective: Cynodon dactylon, Hibiscus rosa-sinensis, Elaeocarpus floribundus and Acorus calamus are anthelmintic medicinal plants of north-east India. Due to its pharmacological properties, the present study was aimed to investigate the phytochemical, antioxidant and heavy metal content of the plants.Methods: Preliminary phytochemical screening was carried out for the presence of phenolics, flavonoids, proteins, and carbohydrates following standard protocols. The antioxidant potential of plants was studied by phosphomolybdate, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay. The heavy metal content was estimated using atomic absorption spectrophotometer (Perkin Elmer 3110). Results:The result showed that the alcoholic extracts of the plant sample contain high quantity of proteins, carbohydrates, phenolics, and flavonoids. Antioxidant assays revealed appreciable free radical scavenging potential. The total antioxidant activity was highest in E. floribundus (62.48±1.53 µg/mg extract) while C. dactylon showed lowest (34.00±0.32 µg/mg extract). Similarly, DPPH and FRAP study also showed high in E. floribundus and lowest in H. rosa-sinensis and A. calamus. Elemental analysis of the plant extracts showed a high content of Mn in all the plants while Co was found to be lowest. The tested plants showed low levels of toxic elements. Conclusion:The high quantity of nutritional content and antioxidant property suggest that plants may be a good source of phytomedicine. Less quantity of toxic elements offers an opportunity to explore the medicinal application of the plants. However, further study needs to be carried out to know its mode of action.

The aim of this study was to investigate the in vitro and in vivo anticestodal effects of methanol extract of Hibiscus rosa-sinensis L. (Malvaceae) leaf against Hymenolepis diminuta (Rudolphi, 1819), a zoonotic tapeworm. Under the in vitro study, H. diminuta worms were exposed to 10, 20 and 40 mg/ml concentrations of methanol leaf extract and the effects were judged on the basis of physical motility/mortality of worms. On the other hand, in the case of in vivo study, H. diminuta infected rats were treated individually with 200, 400 and 800 mg/kg doses of leaf extract for 5 days. The effects were judged on the basis of reduction in eggs per gram (EPG) of faeces and worm counts. In case of in vitro test, the treatment with 40 mg/ml concentration of extract revealed prominent anticestodal effect and caused paralysis of worms in 3.00 ± 0.53 h and mortality in 4.08 ± 0.21 h. However, under in vivo study, the 800 mg/kg dose of extract revealed the highest anticestodal effect and caused 66.55 % reduction in EPG count and 75.00 % reduction in worm count in the treated animals. The results of this study indicated that H. rosa-sinesis leaf extract possesses concentration-dependent anticestodal effect against H. diminuta, indicating that the plant possesses promising active principle for the control of intestinal helminthic infections.

Background:The rhizomes of a herb Acorus calamus Linn. (Acoraceae) have been widely used as a traditional medicine to cure intestinal-helminthic infections in India and South Africa.Aim:This study was undertaken to investigate the in vivo anthelmintic activity of a standardized methanolic extract obtained from the rhizomes A. calamus in a rodent model.Materials and Methods:A methanolic extract obtained from rhizomes of A. calamus was characterized for active principle using nuclear magnetic resonance 1H NMR, 13C NMR, mass and infrared spectroscopy. The amount of active principle in rhizome isolated active fraction of plant was assayed using high-performance liquid chromatography (HPLC). Later, the standardized rhizome extract of plant and its active principle were tested for in vivo anthelmintic efficacy against experimentally induced Hymenolepis diminuta, a zoonotic cestode, infections in rats.Results:The study revealed that b-asarone is the active principle of plant. The HPLC analysis of local variety of A. calamus revealed that active fraction contains 83.54% (w/w) of b-asarone. The in vivo study revealed that treatment of H. diminuta infected rats by a single 800 mg/kg dose of rhizome extract for 5 days results into 62.30% reduction in eggs per gram of feces counts and 83.25% reduction in worm counts of animals. These findings compared well with the efficacy of a reference drug, praziquantel. The active principle b-asarone showed slightly better anthelmintic effects than crude extract. In acute toxicity assay, a single oral 2000 mg/kg dose of extract did not reveal any signs of toxicity or mortality in mice, and the LD50 of the extract was noted to be >2000 mg/kg.Conclusion:Taken together, the results of this study indicate that rhizomes of A. calamus bear significant dose-dependent effects against intestinal helminths. Further, the Indian variety of A. calamus contains high b-asarone content. Therefore, there exists a great potential to develop some suitable anthelmintic herbal products from this plant.

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