OBJECTIVES: To assess the impact of antimalarial MDA on population asexual parasitaemia prevalence, parasitaemia incidence, gametocytaemia prevalence, anaemia prevalence, mortality and MDA-associated adverse events.
SEARCH METHODS: We searched the Cochrane Infectious Disease Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE+, EMBASE, to February 2013. We also searched CABS Abstracts, LILACS, reference lists, and recent conference proceedings.
SELECTION CRITERIA: Cluster-randomized trials and non-randomized controlled studies comparing therapeutic MDA versus placebo or no MDA, and uncontrolled before-and-after studies comparing post-MDA to baseline data were selected. Studies administering intermittent preventive treatment (IPT) to sub-populations (for example, pregnant women, children or infants) were excluded.
DATA COLLECTION AND ANALYSIS: Two authors independently reviewed studies for inclusion, extracted data and assessed risk of bias. Studies were stratified by study design and then subgrouped by endemicity, by co-administration of 8-aminoquinoline plus schizonticide drugs and by plasmodium species. The quality of evidence was assessed using the GRADE approach.
MAIN RESULTS: Two cluster-randomized trials, eight non-randomized controlled studies and 22 uncontrolled before-and-after studies are included in this review. Twenty-two studies (29 comparisons) compared MDA to placebo or no intervention of which two comparisons were conducted in areas of low endemicity (≤5%), 12 in areas of moderate endemicity (6-39%) and 15 in areas of high endemicity (≥ 40%). Ten studies evaluated MDA plus other vector control measures. The studies used a wide variety of MDA regimens incorporating different drugs, dosages, timings and numbers of MDA rounds. Many of the studies are now more than 30 years old. Areas of low endemicity (≤5%)Within the first month post-MDA, a single uncontrolled before-and-after study conducted in 1955 on a small Taiwanese island reported a much lower prevalence of parasitaemia following a single course of chloroquine compared to baseline (1 study, very low quality evidence). This lower parasite prevalence was still present after more than 12 months (one study, very low quality evidence). In addition, one cluster-randomized trial evaluating MDA in a low endemic setting reported zero episodes of parasitaemia at baseline, and throughout five months of follow-up in both the control and intervention arms (one study, very low quality evidence). Areas of moderate endemicity (6-39%)Within the first month post-MDA, the prevalence of parasitaemia was much lower in three non-randomized controlled studies from Kenya and India in the 1950s (RR 0.03, 95% CI 0.01 to 0.08, three studies, moderate quality evidence), and in three uncontrolled before-and-after studies conducted between 1954 and 1961 (RR 0.29, 95% CI 0.17 to 0.48, three studies,low quality evidence).The longest follow-up in these settings was four to six months. At this time point, the prevalence of parasitaemia remained substantially lower than controls in the two non-randomized controlled studies (RR 0.18, 95% CI 0.10 to 0.33, two studies, low quality evidence). In contrast, the two uncontrolled before-and-after studies found mixed results: one found no difference and one found a substantially higher prevalence compared to baseline (not pooled, two studies, very low quality evidence). Areas of high endemicity (≥40%)Within the first month post-MDA, the single cluster-randomized trial from the Gambia in 1999 found no significant difference in parasite prevalence (one study, low quality evidence). However, prevalence was much lower during the MDA programmes in three non-randomized controlled studies conducted in the 1960s and 1970s (RR 0.17, 95% CI 0.11 to 0.27, three studies, moderate quality evidence), and within one month of MDA in four uncontrolled before-and-after studies (RR 0.37, 95% CI 0.28 to 0.49, four studies,low quality evidence).Four trials reported changes in prevalence beyond three months. In the Gambia, the single cluster-randomized trial found no difference at five months (one trial, moderate quality evidence). The three uncontrolled before-and-after studies had mixed findings with large studies from Palestine and Cambodia showing sustained reductions at four months and 12 months, respectively, and a small study from Malaysia showing no difference after four to six months of follow-up (three studies,low quality evidence). 8-aminoquinolines We found no studies directly comparing MDA regimens that included 8-aminoquinolines with regimens that did not. In a crude subgroup analysis with a limited number of studies, we were unable to detect any evidence of additional benefit of primaquine in moderate- and high-transmission settings. Plasmodium species In studies that reported species-specific outcomes, the same interventions resulted in a larger impact on Plasmodium falciparum compared to P. vivax.
AUTHORS' CONCLUSIONS: MDA appears to reduce substantially the initial risk of malaria parasitaemia. However, few studies showed sustained impact beyond six months post-MDA, and those that did were conducted on small islands or in highland settings.To assess whether there is an impact of MDA on malaria transmission in the longer term requires more quasi experimental studies with the intention of elimination, especially in low- and moderate-transmission settings. These studies need to address any long-term outcomes, any potential barriers for community uptake, and contribution to the development of drug resistance.
AIM OF THE STUDY: The aim of the current study is to evaluate the traditionally used medicinal plants for in vitro anti-malarial activity against human malaria parasite Plasmodium falciparum and profiling secondary metabolite using spectroscopic and chromatographic methods. Chemical profiling of active secondary metabolites in the extracts was undertaken using LC-MS.
MATERIALS AND METHODS: Based on the ethno-botanical data V. negundo L. was selected for in vitro anti-malarial activity against P. falciparum chloroquine-sensitive (3D7) and multidrug resistant (K1) strains using SYBR Green-I based fluorescence assay. Cytotoxicity of extracts was evaluated in VERO cell line using the MTT assay. Haemolysis assay was performed using human red blood cells. Secondary metabolites profiling was undertaken using chromatographic and spectroscopic analysis. Liquid chromatography analysis was performed using a C18, 150 X 2.1, 2.6 μm column with gradient mobile phase Solvent A: 95% (H2O: ACN), Solvent B: Acetonitrile, Solvent C: Methanol, Solvent D: 5 mM NH4 in 95:5 (H2O: ACN) at a constant flow rate of 0.250 ml/min. The LC-MS spectra were acquired in both positive and negative ion modes with electrospray ionization (ESI) source.
RESULTS: The anti-malarial active extract of V. negundo L. leaf exhibited potent anti-malarial activity with IC50 values of 7.21 μg/ml and 7.43 μg/ml against 3D7 and K1 strains, respectively with no evidence of significant cytotoxicity against mammalian cell line (VERO) and no toxicity as observed in haemolysis assay. The HPLC-LC-MS analysis of the extract led to identification of 73 compounds. We report for the first time the presence of Sabinene hydrate acetate, 5-Hydroxyoxindole, 2(3,4-dimethoxyphenyl)-6, 7-dimethoxychromen-4-one, Cyclotetracosa-1, 13-diene and 5, 7-Dimethoxyflavanone in the anti-malarial active extract of V. negundo L. leaf. Agnuside, Behenic acid and Globulol are some of the novel compounds with no reports of anti-malarial activity so far and require further evaluation in pure form for the development of potent anti-malarial compounds.
CONCLUSIONS: The result report and scientifically validate the traditional use of V. negundo L. for the treatment of malaria providing new avenues for anti-malarial drug development. Several novel and unknown compounds were identified that need to be further characterized for anti-malarial potential.