Recent advances on the use of biochemical extracts as filaricidal agents

Larvicidal Activities of Allium sativum L. and Zingiber officinale Rosc. Extracts against Filariasis Vectors in Hadiya Zone, Ethiopia

Mosquitoes present an immense threat to millions of people worldwide and act as vectors for filariasis disease. The objective of the study was to determine the effect of Allium sativum and Zingiber officinale extracts against filariasis vectors. The larvae were collected from the breeding site by using standard procedures for identification and larvicidal activities. Twenty grams (20 g) from each (Allium sativum and Zingiber officinale) were extracted separately by aqueous, ethanol, and methanol solvents. The phytochemical analysis was determined in the crude sample by using standard methods. Then, larvicidal effects were determined by introducing 10 larvae of the vectors to the concentrations of 250 ppm, 500 ppm, and 750 ppm of the crude sample, and data were subjected to probit analysis to determine the LC50 and Chi-squared test to check the significance of the mortality by R software. Anopheles funestus, Anopheles gambiae s.l., Anopheles pharoensis, Culex antennatus, and Culex quinquefasciatus were the filariasis vectors identified during the study period. The presence of phytochemical tests such as anthraquinones, flavonoids, glycosides, phenol, saponin, steroids, tannin, and terpenes was obtained. The larvicidal effects of the selected plant extracts ranged from 0%-100%. The lowest LC50 (53 ppm) was observed for A. sativum methanol test extract against Cx. quinquefasciatus. Ethanol extracts of A. sativum have a significant effect on An. funestus (X2 = 7.5, p = 0.02352) and Cx. quinquefasciatus (X2 = 10.833, p = 0.0.0044), whereas aqueous extracts have a significant effect only on An. gambiae s.l. (X2 = 7.0807, p = 0.029. Ethanol extracts of Z. officinale have a significant effect only on the mortality of An. pharoensis (X2 = 7.0807, p = 0.029), but methanol and aqueous extracts have no significant effect against filariasis vectors. In conclusion, A. sativum have a high toxic effect than Z. officinale extract against filariasis vectors in all type of solvents. So using those plant extracts is the best to reduce the risk of the synthetic chemical on nontarget organisms and the environment, in addition to the control of mosquito-borne diseases, but further studies will be conducted to evaluate the toxicity at different stages of the vectors.

Comparative metabolomics analysis reveals alkaloid repertoires in young and mature Mitragyna speciosa (Korth.) Havil. Leaves

The fresh leaves of Mitragyna speciosa (Korth.) Havil. have been traditionally consumed for centuries in Southeast Asia for its healing properties. Although the alkaloids of M. speciosa have been studied since the 1920s, comparative and systematic studies of metabolite composition based on different leaf maturity levels are still lacking. This study assessed the secondary metabolite composition in two different leaf stages (young and mature) of M. speciosa, using an untargeted liquid chromatography-electrospray ionisation-time-of-flight-mass spectrometry (LC-ESI-TOF-MS) metabolite profiling. The results revealed 86 putatively annotated metabolite features (RT:m/z value) comprising 63 alkaloids, 10 flavonoids, 6 terpenoids, 3 phenylpropanoids, and 1 of each carboxylic acid, glucoside, phenol, and phenolic aldehyde. The alkaloid features were further categorised into 14 subclasses, i.e., the most abundant class of secondary metabolites identified. As per previous reports, indole alkaloids are the most abundant alkaloid subclass in M. speciosa. The result of multivariate analysis (MVA) using principal component analysis (PCA) showed a clear separation of 92.8% between the young and mature leaf samples, indicating a high variance in metabolite levels between them. Akuammidine, alstonine, tryptamine, and yohimbine were tentatively identified among the many new alkaloids reported in this study, depicting the diverse biological activities of M. speciosa. Besides delving into the knowledge of metabolite distribution in different leaf stages, these findings have extended the current alkaloid repository of M. speciosa for a better understanding of its pharmaceutical potential.

The Epitome of Novel Techniques and Targeting Approaches in Drug Delivery for Treating Lymphatic Filariasis

BACKGROUND

Lymphatic filariasis is a pervasive and life-threatening disease for human beings. Currently, 893 million people in 49 countries worldwide affected by lymphatic filariasis as per WHO statistics. The concealed aspects of lymphatic diseases such as delayed disease detection, inappropriate disease imaging, the geographical outbreak of infection, and lack of preventive chemotherapy have brought this epidemic to the edge of Neglected Tropical Diseases. Many medications and natural bioactive substances have seen to promote filaricidal activity against the target parasitic species. However, the majority of failures have occurred in pharmaceutical and pharmacokinetic issues.

OBJECTIVE

The purpose of the study is to focus on the challenges and therapeutic issues in the treatment of filariasis. The review brings novel techniques and therapeutic approaches for combating lymphatic filariasis. It also offers significant developments and opportunities for such therapeutic interventions.

CONCLUSION

Through this review, an attempt has made to critically evaluate the avenues of innovative pharmaceuticals and molecular targeting approaches to bring an integrated solution to combat lymphatic filariasis.

Antifilarial activity of caffeic acid phenethyl ester on Brugia pahangi in vitro and in vivo

Lymphatic filariasis (LF) is a vector borne disease caused by parasitic worms such as Wuchereria bancrofti, Brugia malayi and B. timori, which are transmitted by mosquitoes. Current therapeutics to treat LF are mainly microfilarcidal, and lack activity against adult worms. This set back, poses a challenge for the control and elimination of filariasis. Thus, in this study the activities of caffeic acid phenethyl ester (CAPE) against the filarial worm B. pahangi and its bacterial endosymbiont, Wolbachia were evaluated. Different concentrations (2, 5, 10, 15, 20 μg/ml) of CAPE were used to assess its effects on motility, viability and microfilarial (mf) production of B. pahangi in vitro. Anti-Wolbachial activity of CAPE was measured in worms by quantification of Wolbachial wsp gene copy number using real-time polymerase chain reaction. Our findings show that CAPE was found to significantly reduce adult worm motility, viability, and mf release both in vitro and in vivo. 20 μg/ml of CAPE halts the release of mf in vitro by day 6 of post treatment. Also, the number of adult worms recovered in vivo were reduced significantly during and after treatment with 50 mg/kg of CAPE relative to control drugs, diethylcarbamazine and doxycycline. Real time PCR based on the Wolbachia ftsZ gene revealed a significant reduction in Wolbachia copy number upon treatment. Anti-Wolbachia and antifilarial properties of CAPE require further investigation as an alternative strategy to treat LF.

Mining Filarial Genomes for Diagnostic and Therapeutic Targets

Filarial infections of humans cause some of the most important neglected tropical diseases. The global efforts for eliminating filarial infections by mass drug administration programs may require additional tools (safe macrofilaricidal drugs, vaccines, and diagnostic biomarkers). The accurate and sensitive detection of viable parasites is essential for diagnosis and for surveillance programs. Current community-wide treatment modalities do not kill the adult filarial worms effectively; hence, there is a need to identify and develop safe macrofilaricidal drugs. High-throughput sequencing, mass spectroscopy methods and advances in computational biology have greatly accelerated the discovery process. Here, we describe post-genomic developments toward the identification of diagnostic biomarkers and drug targets for the filarial infection of humans.

Antifilarial and Antibiotic Activities of Methanolic Extracts of Melaleuca cajuputi Flowers

We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis.