HPLC-based activity profiling for antiplasmodial compounds in the traditional Indonesian medicinal plant Carica papaya L

Ethnopharmacological relevance

Leaf decoctions of Carica papaya have been traditionally used in some parts of Indonesia to treat and prevent malaria. Leaf extracts and fraction have been previously shown to possess antiplasmodial activity in vitro and in vivo.

Materials and methods

Antiplasmodial activity of extracts was confirmed and the active fractions in the extract were identified by HPLC-based activity profiling, a gradient HPLC fractionation of a single injection of the extract, followed by offline bioassay of the obtained microfractions. For preparative isolation of compounds, an alkaloidal fraction was obtained via adsorption on cationic ion exchange resin. Active compounds were purified by HPLC–MS and MPLC–ELSD. Structures were established by HR-ESI-MS and NMR spectroscopy. For compounds 5 and 7 absolute configuration was confirmed by comparison of experimental and calculated electronic circular dichroism (ECD) spectroscopy data, and by X-ray crystallography. Compounds were tested for bioactivity in vitro against four parasites (Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum), and in the Plasmodium berghei mouse model.

Results

Profiling indicated flavonoids and alkaloids in the active time windows. A total of nine compounds were isolated. Four were known flavonols – manghaslin, clitorin, rutin, and nicotiflorin. Five compounds isolated from the alkaloidal fraction were piperidine alkaloids. Compounds 5 and 6 were inactive carpamic acid and methyl carpamate, while three alkaloids 7–9 showed high antiplasmodial activity and low cytotoxicity. When tested in the Plasmodium berghei mouse model, carpaine (7) did not increase the survival time of animals.

Conclusions

The antiplasmodial activity of papaya leaves could be linked to alkaloids. Among these, carpaine was highly active and selective in vitro. The high in vitro activity could not be substantiated with the in vivo murine model. Further investigations are needed to clarify the divergence between our negative in vivo results for carpaine, and previous reports of in vivo activity with papaya leaf extracts.     

东帝汶传统医学发展概况

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In vitro screening of traditional South African malaria remedies against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum

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The pattern of micro-organisms and the efficacy of new macrolide in acute lower respiratory tract infections

Abstract Lower respiratory tract infection (LRTI) is one of the major health problems in developing countries such as Indonesia. According to the National Household Health Survey conducted by the Ministry of Health in 1992, LRTIs still rank fourth as the main cause of death in Indonesia. The problem of LRTIs could be simply managed as long as the causative organism can be identified and the proper antibiotic known. In some occasions, it is not quite so easy to identify the causative micro-organism, especially in lower tract infections. There are several methods of obtaining specimens from LRTIs for cultures. The easiest, most simple way is to collect expectorated sputum. Unfortunately, because of the high rate of contamination by upper respiratory tract flora, this method is not reliable. Recognizing the difficulties with routine expectorated sputum cultures, two alternative approaches have been suggested. One approach is to bypass potential expectorated sputum ‘contaminants’ in the oropharynx by transtracheal aspiration or transthoracic aspiration. The second approach is to modify the usual technique of processing expectorated sputum by either washing techniques or by quantitative cultures. Azithromycin and clarithromycin are chemically related to macrolide erithromycin. Both antibiotics retain the traditional macrolide spectrum of activity against Gram-positive and atypical pneumonia pathogens, while demonstrating improved activity against Gram-negative bacteria. The American Thoracic Society (ATS) recommended the use of macrolide for outpatients with community-acquired pneumonia, without comorbidity and 60 years of age or younger. A total of 34 outpatients with acute LRTIs were open-comparative, randomly allocated to treatment with the new macrolide in Persahabatan Hospital, Jakarta, 1996. The purposes of this study were: (i) to identify the causative micro-organisms; and (ii) to evaluate the clinical efficacy of the new macrolide in these infections. Azithromycin 500 mg was given orally once a day for 3 days and was administered 1 h before or 2 h after every meal. Clarithromycin 500 mg was given orally every 12 h for 10 days. The diagnosis of the patients were: 16 with pneumonia, 10 with acute bronchitis and 8 with acute exacerbation of chronic bronchitis. In this study of 34 patients, the sputum specimens were washed with N acetylcysteine before culture and we could only detect micro-organisms in one patient. Before treatment, we found 47 strains in 33 (97.05%) patients and after treatment we found five strains. From serological examination, only four (11.76%) atypical bacterial were detected. The most frequently found micro-organisms were 23 strains of Klebsiella pneumoniae (40.42%), 10 of Streptococcus alpha haemolyticus (21.26%), five of Streptococcus pneumoniae (10.63%) and five of Staphylococcus aureus (10.63%). The atypical bacterial were: two Legionella pneumophila, one Mycoplasma pneumoniae and one Chlamydia pneumoniae. The clinical efficacy of new macrolides were 100% and the bacteriological responses with eradication of 94.12% vs 70.59% of isolates in the azithromycin and clarithromycin groups are shown in Table 1. There were no adverse reactions detected in the two treatment groups until the end of the study.