Polyphenol enriched ethanolic extract of Cajanus scarabaeoides (L.) Thouars exerts potential antifilarial activity by inducing oxidative stress and programmed cell death

An ethnopharmacological approach to evaluate antiparasitic and health-promoting abilities of Pueraria tuberosa (Willd.) DC. in livestock

In eastern India, the tubers of Pueraria tuberosa (Willd.) DC. are used by the ethnic communities for its wide range of medicinal and nutritional value, especially to rejuvenate livestock health and to treat helminthiasis. The study is aimed to evaluate the ethnoveterinary medicinal importance of P. tuberosa as anthelmintic, to verify its nontoxic nature and identify the most potent phytoconstituents aided by in silico molecular docking technique. Ethnomedicinal data collected from 185 informants were quantitatively analyzed employing eight quantitative indices to highlight the use diversity and most frequently used part of the plant. High scores of certain indices employed, such as Use Value (UV = 0.52), Fidelity Level (FL = 68.42%) and Tissue Importance Value (TIV = 1) clearly illustrate an ethnomedicinal lead regarding medico-nutritional benefits of the tuber part used against intestinal helminthic diseases of veterinary animals. Based on this ethno-guided lead, root tuber has been investigated for its chemical profiling by the estimation of total phenolics, flavonoids, tannins and alkaloids, along with HPLC and GC-MS analyses. Anthelmintic property was evaluated with the tuber extracts by in vitro studies on some helminths of livestock and poultry birds, and it showed promising results against the tested parasites namely Cotylophoron cotylophorum, Raillietina tetragona and Setaria cervi. Toxicity assessments of tuber extract through in vitro and in vivo methods were performed using Vero cells and BALB/c mice. Nontoxic nature of the studied tuber extract was observed even in higher experimental doses. Out of 12 phytocompounds identified by GC-MS analysis, one compound [Morphinan-4,5-epoxy-3,6-di-ol,6- (7-nitrobenzofurazan-4-yl) amino-] exhibited the best binding conformations in cost of the lowest binding energy values with six target proteins that include one anti-inflammatory, one antioxidant, and four anthelmintic proteins. The findings of our study are found very encouraging to evaluate this tuber drug furthermore intensively towards the development of anthelmintic veterinary medicine.

Immune targeting of filarial glutaredoxin through a multi-epitope peptide-based vaccine: A reverse vaccinology approach

Despite the efforts of global programme to eliminate lymphatic filariasis (GPELF), the threat of lymphatic filariasis (LF) still looms over humanity in terms of long-term disabilities, and morbidities across the globe. In light of this situation, investigators have chosen to focus on the development of immunotherapeutics targeting the physiologically important filarial-specific proteins. Glutaredoxin (16.43 kDa) plays a pivotal role in filarial redox biology, serving as a vital contributor. In the context of the intra-host survival of filarial parasites, this antioxidant helps in mitigating the oxidative stress imposed by the host immune system. Given its significant contribution, the development of a vaccine targeting glutaredoxin holds promise as a new avenue for achieving a filaria-free world. Herein, multi-epitope-based vaccine was designed using advanced immunoinformatics approach. Initially, 4B-cell epitopes and 6 T-cell epitopes (4 MHC I and 2 MHC II) were identified from the 146 amino acid long sequence of glutaredoxin of the human filarid, Wuchereria bancrofti. Subsequent clustering of these epitopes with linker peptides finalized the vaccine structure. To boost TLR-mediated innate immunity, TLR-specific adjuvants were incorporated into the designed vaccine. After that, experimental analyses confirm the designed vaccine, Vac4 as anefficient ligand of human TLR5 to elicit protective innate immunity against filarial glutaredoxin. Immune simulation further demonstrated abundant levels of IgG and IgM as crucial contributors in triggering vaccine-induced adaptive responses in the recipients. Hence, to facilitate the validation of immunogenicity of the designed vaccine, Vac4 was cloned in silico in pET28a(+) expression vector for recombinant production. Taken together, our findings suggest that vaccine-mediated targeting of filarial glutaredoxin could be a future option for intervening LF on a global scale.

Programmed cell death pathways as targets for developing antifilarial drugs: Lessons from the recent findings

More than half a century has passed since the introduction of the National Filariasis Control Program; however, as of 2023, lymphatic filariasis (LF) still prevails globally, particularly in the tropical and subtropical regions, posing a substantial challenge to the objective of worldwide elimination. LF is affecting human beings and its economically important livestock leading to a crucial contributor to morbidities and disabilities. The current scenario has been blowing up alarms of attention to develop potent therapeutics and strategies having efficiency against the adult stage of filarial nematodes. In this context, the exploration of a suitable drug target that ensures lethality to macro and microfilariae is now our first goal to achieve. Apoptosis has been the potential target across all three stages of filarial nematodes viz. oocytes, microfilariae (mf) and adults resulting in filarial death after receiving the signal from the reactive oxygen species (ROS) and executed through intrinsic and extrinsic pathways. Hence, it is considered a leading target for developing antifilarial drugs. Herein, we have shown the efficacy of several natural and synthetic compounds/nanoformulations in triggering the apoptotic death of filarial parasites with little or no toxicity to the host body system.

The characterization and quantification of structures of Cajanus scarabaeoides phytochemicals and their seasonal variation analysis using ultra-performance liquid chromatography-tandem mass spectrometry

RATIONALE

Cajanus scarabaeoides, belonging to the Fabaceae family, is an underutilized herb and traditionally used to treat several ailments. However, it is not well explored phytochemically. Therefore, mass spectrometry (MS)-based phytochemical analysis was carried out to investigate the bioactive ingredients of the herb.

METHODS

A ultra-performance liquid chromatography (UPLC) coupled to photodiode array detection (PDA) and electrospray ionization (ESI) tandem mass spectrometry (UPLC-PDA-ESI-MS/MS) system was used for the qualitative and quantitative analysis of phytochemicals. The chromatographic separation was achieved on the Acquity BEH C18 column (150 × 2.1 mm, 1.7 μm) using a gradient system consisting of three solvents, acetonitrile, methanol, and 0.1% formic acid, used at a flow rate of 0.300 ml/min.

RESULTS

Sixteen bioactive ingredients (gallic acid, gallocatechin, epigallocatechin, catechin, procyanidin dimer, epicatechin, procyanidin trimer, isoorientin, orientin, vitexin, isovitexin, quercetin-mono-O-glycoside, isoquercitrin, luteolin-7-O-glucoside, quercetin, and luteolin) were identified and structurally characterized. Consequently, 12 compounds were reported for the first time from C. scarabaeoides, and 13 were quantitatively determined in different seasons. Isoorientin (10.2-7.1% w/w) and orientin (5.78-5.17% w/w) were the most abundant constituents in the dry weight of plant material, followed by vitexin and isovitexin in the rainy season.

CONCLUSIONS

The phytochemical investigation has revealed that C. scarabaeoides could be a potential alternate source of bioactive ingredients, namely, isoorientin, orientin, vitexin, and isovitexin, contributing to further exploration of its biological activity. In addition, analytical methods can be used for the rapid identification and quantification of bioactive ingredients in C. scarabaeoides.

Reverse vaccinology assisted design of a novel multi-epitope vaccine to target Wuchereria bancrofti cystatin: An immunoinformatics approach

Proteases are the critical mediators of immunomodulation exerted by the filarial parasites to bypass and divert host immunity. Cystatin is a small (∼15 kDa) immunomodulatory filarial protein and known to contribute in the immunomodulation strategy by inducing anti-inflammatory response through alternative activation of macrophages. Recently, Wuchereria bancrofti cystatin has been discovered as a ligand of human toll-like receptor 4 which is key behind the cystatin-induced anti-inflammatory response in major human antigen-presenting cells. Considering the pivotal role of cystatin in the immunobiology of filariasis, cystatin could be an efficacious target for developing vaccine. Herein, we present the design and in-silico analyses of a multi-epitope-based peptide vaccine to target W. bancrofti cystatin through immune-informatics approaches. The 262 amino acid long antigen construct comprises 9 MHC-I epitopes and MHC-II epitopes linked together by GPGPG peptide alongside an adjuvant (50S ribosomal protein L7/L12) at N terminus and 6 His tags at C terminus. Molecular docking study reveals that the peptide could trigger TLR4-MD2 to induce protective innate immune responses while the induced adaptive responses were found to be mediated by IgG, IgM and Th1 mediated responses. Notably, the designed vaccine exhibits high stability and no allergenicity in-silico. Furthermore, the muti epitope-vaccine was also predicted for its RNA structure and cloned in pET30ax for further experimental validation. Taken together, this study presents a novel multi-epitope peptide vaccine for triggering efficient innate and adaptive immune responses against W. bancrofti to intervene LF through immunotherapy.

Disruption of redox homeostasis with synchronized activation of apoptosis highlights the antifilarial efficacy of novel piperine derivatives: An in vitro mechanistic approach

A series of novel piperine derivatives were synthesized with high yield and were evaluated for its antifilarial potential against the bovine filarial parasite Setaria cervi. Among 21 (3a-3u) compounds screened, three of them (3k, 3l, 3s) showed significant potential against all the developmental stages (oocytes, microfilariae and adult) of the filarial worm in time and dose dependent manner. 3l showed the highest efficacy among the selected three compounds. These three compounds were further evaluated for both in vitro and in vivo toxicity analyses which further fortified the benign nature of the selected compounds. The antifilarial activities they exhibited were clearly fuelled through disparity of the internal redox homeostasis as evidenced from the alterations in the enzymatic and non-enzymatic antioxidants level which ultimately shifted towards activation of pro-apoptotic signaling cascade eventually leading to the death of the parasites. The ability of the compound 3l to bind thioredoxin reductase and CED-3 protein are the key findings of this study. The present study supported with several biological experiments is therefore a maiden report on the antifilarial effectiveness of these novel piperine derivatives.

Inhibition of thioredoxin reductase (TrxR) triggers oxidative stress-induced apoptosis in filarial nematode Setaria cervi channelized through ASK-1-p38 mediated caspase activation

Inhibition of an imperative antioxidant enzyme with subsequent death is a victorious and widely accepted strategy to combat various infectious diseases. Among different antioxidant enzymes, thioredoxin reductase (TrxR) is an exclusive one. Studies have revealed that direct inhibition of TrxR by different classes of chemical moieties promptly results in the death of an organism. Especially the structural as well as biochemical modifications of the enzyme upon inhibition project serious threat towards the subject organism. Herein, an attempt was made to inhibit TrxR of filarial species by administering Auranofin, 1 chloro 2,4 dinitrobenzene (CDNB), Curcumin, and a novel carbamo dithioperoxo(thioate) derivative (4a). Our study has revealed that inhibition of TrxR resulted in the induction of the classical CED pathway of apoptosis along with the intrinsic and extrinsic pathways of apoptosis (Caspase mediated) routed through the ASK-1/p38 axis. Druggability analysis of filarial TrxR for the selected compounds was performed in silico through molecular docking studies. Therefore, this study attempts to decipher the mechanism of apoptosis induction following TrxR inhibition. The safety of those four compounds in terms of dose and toxicity was taken under consideration. Thitherto, the mechanism of TrxR mediated initiation of cell death in filarial parasite has remained undercover, and therefore, it is a maiden report on the characterization of apoptosis induction upon TrxR inhibition which will eventually help in generating effective antifilarial drugs in the future.

Protective effects of extracts from Ephedra foeminea Forssk fruits against oxidative injury in human endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ephedra foeminea is a member of the Ephedraceae family which is widespread in the eastern Mediterranean area. In Lebanon, Ephedra is a popular remedy in traditional medicine to prevent and/or counteract many stress oxidative-related diseases like inflammation and bacterial infections.

AIM OF THE STUDY

Oxidative stress leads to endothelial cell dysfunction, and is a major factor contributing to etiology of atherosclerosis and related diseases. This study aims to investigate the antioxidant and cytoprotective potential of extracts from E. foeminea fruits on human endothelial cells exposed to hydrogen peroxide (H₂O₂) to mimic in vitro vascular endothelium dysfunction.

MATERIALS AND METHODS

Different extracts of E. foeminea fruits were prepared using pure ethanol (EE), methanol/water (EMW), pure hexane (Ehex) or ethyl acetate/water (Epoly) as extraction solvents. The phenolome profile of each extract was characterized using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). Total phenolic and flavonoid content, and radical scavenging properties of the extracts were assessed spectrophotometrically. Then, the effects on human endothelial cells HECV were evaluated.

RESULTS

Epoly extract showed the highest phenol and flavonoid content, and the highest radical scavenging capacity. On H₂O₂-insulted HECV cells Epoly was able: (i) to counteract the ROS/RNS production and lipid peroxidation; (ii) to rescue the ROS-dependent decrease in the mitochondrial membrane potential; (iii) to counteract the apoptosis induction; (iv) to restore endothelial cell viability and migration.

CONCLUSIONS

The findings indicated that the polyphenol-enriched extract Epoly from E. foeminea fruits is endowed with in vitro anti-oxidant and anti-apoptotic effects and might be used as nutraceutical for treating ROS-related endothelium dysfunction and inflammation.

Influence of autophagy, apoptosis and their interplay in filaricidal activity of C-cinnamoyl glycosides

The present work aims to explore the mechanism of action of C-cinnamoyl glycoside as an antifilarial agent against the bovine filarial nematode Setaria cervi. Both apoptosis and autophagy programmed cell death pathways play a significant role in parasitic death. The generation of reactive oxygen species, alteration of the level of antioxidant components and disruption of mitochondrial membrane potential may be the causative factors that drive the parasitic death. Monitoring of autophagic flux via the formation of autophagosome and autophagolysosome was detected via CYTO ID dye. The expression profiling of both apoptotic and autophagic marker proteins strongly support the initial findings of these two cell death processes. The increased interaction of pro-autophagic protein Beclin1 with BCL-2 may promote apoptotic pathway by suppressing anti-apoptotic protein BCL-2 from its function. This in turn partially restrains the autophagic pathway by engaging Beclin1 in the complex. But overall positive increment in autophagic flux was observed. Dynamic interaction and regulative balance of these two critical cellular pathways play a decisive role in controlling disease pathogenesis. Therefore, the present experimental work may prosper the chance for C-cinnamoyl glycosides to become a potential antifilarial therapeutic in the upcoming day after detail in vivo study and proper clinical trial.

Effect of bovine serum albumin on tartrate-modified manganese ferrite nano hollow spheres: spectroscopic and toxicity study

The emerging category of magneto-fluorescent tartrate-modified MnFe₂O₄ nano hollow spheres (T-MnFe₂O₄ NHSs) can be considered as promising candidates for biomedical applications. The interaction of bovine serum albumin (BSA) with T-MnFe₂O₄ NHSs has been studied using several spectroscopic techniques, which suggest that the interaction occurs by an electrostatic mechanism. Furthermore, BSA enhances the charge transfer transition from the tartrate ligand to the metal ions along with the d-d transition of Fe³⁺ ions on NHSs surfaces at different pH. Very strong salt bridge formation occurs between the lysine of the BSA surface and the tartrate in basic medium (pH 10), followed by the acidic (pH 3) and neutral medium (pH 7), respectively. Systematic fluorescence microscopic analysis reveals that BSA significantly enhances the contrast of T-MnFe₂O₄ NHSs in UV and blue light excitation because of the extended charge transfer from BSA to T-MnFe₂O₄ NHSs. Our report demonstrates great potential in the field of nanotechnology and biomedical applications. In vitro toxicity analysis using RAW 264.7 celline and in vivo studies on Wister rats revealed that the T-MnFe₂O₄ NHSs are benign. Furthermore, T-MnFe₂O₄ NHSs also appear to be an antimicrobial agent. Therefore, T-MnFe₂O₄ NHSs can be explored for future therapeutic applications.