Clinacanthus nutans (family Acanthaceae) has been used for the treatment of inflammation and herpes viral infection. Currently, there has not been any report on the qualitative and quantitative determination of the chemical markers in the leaves of C. nutans. The C-glycosidic flavones such as shaftoside, isoorientin, orientin, isovitexin, and vitexin have been found to be major flavonoids in the leaves of this plant. Therefore, we had developed a two-step method using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC) for the rapid identification and quantification of the flavones C-glycosides in C. nutans leaves. The TLC separation of the chemical markers was achieved on silica gel 60 plate using ethyl acetate : formic acid : acetic acid : water (100 : 11 : 11 : 27 v/v/v/v) as the mobile phase. HPLC method was optimized and validated for the quantification of shaftoside, orientin, isovitexin, and vitexin and was shown to be linear in concentration range tested (0.4–200 μg/mL, r 2 ≥ 0.996), precise (RSD ≤ 4.54%), and accurate (95–105%). The concentration of shaftoside, orientin, vitexin, and isovitexin in C. nutans leave samples was 2.55–17.43, 0.00–0.86, 0.00–2.01, and 0.00–0.91 mmol/g, respectively.

BackgroundThe development of resistant to current antimalarial drugs is a major challenge in achieving malaria elimination status in many countries. Therefore there is a need for new antimalarial drugs. Medicinal plants have always been the major source for the search of new antimalarial drugs. The aim of this study was to screen selected Malaysian medicinal plants for their antiplasmodial properties.MethodsEach part of the plants were processed, defatted by hexane and sequentially extracted with dichloromethane, methanol and water. The antiplasmodial activities of 54 plant extracts from 14 species were determined by Plasmodium falciparum Histidine Rich Protein II ELISA technique. In order to determine the selectivity index (SI), all plant extracts demonstrating a good antiplasmodial activity were tested for their cytotoxicity activity against normal Madin-Darby Bovine Kidney (MDBK) cell lines by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay.ResultsTwenty three extracts derived from Curcuma zedoaria (rhizome), Curcuma aeruginosa (rhizome), Alpinia galanga (rhizome), Morinda elliptica (leaf), Curcuma mangga (rhizome), Elephantopus scaber (leaf), Vitex negundo (leaf), Brucea javanica (leaf, root and seed), Annona muricata (leaf), Cinnamomun iners (leaf) and Vernonia amygdalina (leaf) showed promising antiplasmodial activities against the blood stage chloroquine resistant P. falciparum (EC50 < 10 μg/ml) with negligible toxicity effect to MDBK cells in vitro (SI ≥10).ConclusionThe extracts belonging to eleven plant species were able to perturb the growth of chloroquine resistant P. falciparum effectively. The findings justified the bioassay guided fractionation on these plants for the search of potent antimalarial compounds or formulation of standardized extracts which may enhance the antimalarial effect in vitro and in vivo.

BackgroundCarica papaya leaf juice (CPLJ) was well known for its thrombocytosis activity in rodents and dengue patients. However, the effect of CPLJ treatment on other parameters that could contribute to dengue pathogenesis such as nonstructural protein 1 (NS1) production and viremia level have never been highlighted in any clinical and in vivo studies. The aim of this study is to investigate the effect of freeze-dried CPLJ treatment on NS1 and viremia levels of dengue fever mouse model.MethodsThe dengue infection in mouse model was established by inoculation of non-mouse adapted New Guinea C strain dengue virus (DEN-2) in AG129 mice. The freeze-dried CPLJ compounds were identified by Ultra-High Performance Liquid Chromatography High Resolution Accurate Mass Spectrometry analysis. The infected AG129 mice were orally treated with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ, starting on day 1 post infection for 3 consecutive days. The blood samples were collected from submandibular vein for plasma NS1 assay and quantitation of viral RNA level by quantitative reverse transcription PCR.ResultsThe AG129 mice infected with dengue virus showed marked increase in the production of plasma NS1, which was detectable on day 1 post infection, peaked on day 3 post-infection and started to decline from day 5 post infection. The infection also caused splenomegaly. Twenty-four compounds were identified in the freeze-dried CPLJ. Oral treatment with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ did not affect the plasma NS1 and dengue viral RNA levels. However, the morbidity level of infected AG129 mice were slightly decreased when treated with freeze-dried CPLJ.ConclusionOral treatment of 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ at the onset of viremia did not affect the plasma NS1 and viral RNA levels in AG129 mice infected with non-mouse adapted New Guinea C strain dengue virus.Electronic supplementary materialThe online version of this article (10.1186/s12906-018-2390-7) contains supplementary material, which is available to authorized users.

Background: Hibiscus sabdariffa L. (Hs; Malvaceae) is commonly known as roselle or red sorrel in English or karkadè in Arabic. It is a tropical plant native to India and Malaysia. Roselle extracts have been widely reported to have beneficial health effects. The aim of this study was to determine the effective dose of Hs aqueous extract, which is a possible reducing agent in diet-induced obese rats, and monitoring any toxicological effect.Methods: Male Sprague Dawley rats (n= 24) aged 6-7 weeks and weighing 210 ± 3.5 g (mean ± S.E.M) were used.  The rats were fed a high fat diet (HFD) for 8 consecutive weeks to induce obesity. The animals were then randomly assigned to one of five groups based on the concentration of Hs aqueous extract. The normal group (NG) received a normal diet (commercial chow) throughout the study. The obese group (ObG) included obese rats administered with tap water ad libitum. Groups 1 (150 mg/kg), 2 (200 mg/kg), 3 (250 mg/kg), and 4 (300 mg/kg) were obese rats continuously fed with HFD in combination with the Hs extract for 10 weeks. The effect of Hs on some haematological and blood biochemical parameters were also evaluated.Results:  Hs aqueous extract is a rich source of anthocyanins. The main compounds detected are delphinidin-3-O-sambubioside and delphinidin-3-O-sambubioside. The extract also possesses high antioxidant properties which may be caused by these anthocyanins. The anti-obesity effect of Hs aqueous extract was demonstrated by the significant reduction in the weight gain and abdominal weight (p < 0.05) between treated and non-treated groups, which was dose-dependent. Overall, our study demonstrated that oral administration of Hs at doses of 150, 200, 250, and 300 mg/kg for ten weeks did not cause any toxicity effect within the obese rats.Conclusions: The results of the study implied Hs aqueous extract at 300 mg/kg is the dose which can the most weight reduction effect with no severe haematological and biochemical changes in all experimental animals.Keywords: Hibiscus sabdariffa, obese rats, roselle, aqueous extract, and body weight

Mitragyna speciosa Korth (MS) leaves are popularly used in Thailand and Malaysia. The leaves are used as a medicinal agent for treating diarrhea, worm infestations and acts as an analgesic and antipyretic agents. The present study investigated the acute toxicity of standardized MS leaf aqueous extract on Sprague Dawley rats at 175, 500 and 2000 mg/kg body weight. Dose selection was based on the Up-and-down procedure (OECD 425). No death was observed. The single oral dose of the extract also had no significant changes in the body weight, food and water consumption. The relative weights of the internal organs were also normal. However, the mean corpuscular hemoglobin concentration, albumin, calcium and cholesterol were significantly decreased. Histological examination showed steatosis and centrilobular necrosis only on several parts of the liver for the treated group. In short, the standardized MS aqueous extract did not cause any lethality and only caused slight toxic effects.