Exploring the efficacy of ethnomedicinal plants of Himalayan region against the malaria parasite.

ETHNOPHARMACOLOGICAL RELEVANCE: Plasmodium falciparum multi-drug resistant (MDR) strains are a great challenge to global health care. This predicament implies the urgent need to discover novel antimalarial drugs candidate from alternative natural sources. The Himalaya constitute a rich repository of medicinal plants which have been used traditionally in the folklore medicine since ages and having no scientific evidence for their activity. Crambe kotschyana Boiss. and Eremurus himalaicus Baker are used for their antipyretic and hepatoprotective properties in Kinnaur district of Himachal Pradesh, India. AIM OF THE STUDY: This study would investigate the antiplasmodial efficacy of C. kotschyana and E. himalaicus extracts, their fractions and active components using in vitro, in vivo and in silico approaches to provide a scientific insight into their activity. METHODS: The methanol extracts of C. kotschyana (CKME) and E. himalaicus (EHME) were prepared by maceration followed by fractionation using ethyl acetate. The isolation of flavonoid glycosides isorhamnetin-3, 7-di-O-glucoside from C. kotschyana and luteolin-6-C-glucoside (isoorientin) from E. himalaicus was carried out by antiplasmodial activity-guided isolation. In vitro antimalarial activity was assessed by WHO method while in vitro cytotoxicity was ascertained employing the MTT assay. Molecular docking and molecular dynamics simulation were performed using the Glide module of Schrödinger Software and Gromacs-2022 software package respectively. In vivo curative activity was assessed by Ryley and Peters method. RESULTS: The methanol extracts of both the plants illustrated the best antiplasmodial activity followed by the ethyl acetate fractions. Iso-orientin (IC50 6.49 µg/ml) and Isorhamnetin-3,7-di-O-glucoside (IC50 9.22 µg/ml) illustrated considerable in vitro activity even against P. falciparum resistant strain. Extracts/fractions as well as the isolated compounds were found to be non-toxic with CC50 > 640 µg/ml. Molecular docking studies were performed with these 2 O-glucosides against four malaria targets to understand the binding pose of these molecules and the results suggested that these molecules have selectivity for lactate dehydrogenase enzyme. CKME and EHME exhibited curative activity in vivo along with increase in Mean Survival Time of mice. CONCLUSION: The research delineated the scientific evidence that both the therapeutic herbs possessed antimalarial activity and notably, bioactive compounds responsible to exhibit the antimalarial activity have been isolated, identified and characterized. Further studies are underway to assess the antiplasmodial efficacy of isolated compounds alone and in combination with standard antimalarials.

Exploration of anticancer potential of Lantadenes from weed Lantana camara: Synthesis, in silico, in vitro and in vivo studies.

Naturally occurring pentacyclic triterpenoids and their semisynthetic analogues have engrossed increasing attention for their anticancer potential and exhibiting promising role in discovery of new anticancer agents. Present study include the semi synthetic modifications of Lantadenes from the weed Lantana carama and their structures delineation by FT-IR, 1H-NMR, 13C-NMR & mass spectroscopy. All the compounds were scrutinized for in vitro cytotoxicity, ligand receptor interaction and in vivo anticancer studies. Most of the novel analogues displayed potent antiproliferative activity against A375 & A431 cancer cell lines and found superior to parent Lantadenes. In particular, 3ß-(4-Methoxybenzoyloxy)-22ß-senecioyloxy-olean-12-en-28-oic acid was found to be most suitable compound, with IC50 value of 3.027 µM aganist A375 cell line having least docking score (-69.40 kcal/mol). Promising anticancer potential of the lead was further indicated by significant reduction in tumor volume and burden in two stage carcinoma model. These findings suggests that the Lantadene derivatives may hold promising potential for the intervention of skin cancers.

Preparation, Standardization and Anti-plasmodial Efficacy of Novel Malaria Nosodes.

BACKGROUND: Resistance to artemisinin and its partner drugs has threatened the sustainability of continuing the global efforts to curb malaria, which urges the need to look for newer therapies to control the disease without any adverse side effects. In the present study, novel homeopathic nosodes were prepared from Plasmodium falciparum and also assessed for their in vitro and in vivo anti-plasmodial activity. METHODS: Three nosodes were prepared from P. falciparum (chloroquine [CQ]-sensitive [3D7] and CQ-resistant [RKL-9] strains) as per the Homeopathic Pharmacopoeia of India, viz. cell-free parasite nosode, infected RBCs nosode, mixture nosode. In vitro anti-malarial activity was assessed by schizont maturation inhibition assay. The in vitro cytotoxicity was evaluated by MTT assay. Knight and Peter's method was used to determine in vivo suppressive activity. Mice were inoculated with P. berghei-infected erythrocytes on day 1 and treatment was initiated on the same day. Biochemical, cytokine and histopathological analyses were carried out using standard methods. RESULTS: In vitro: the nosodes exhibited considerable activity against P. falciparum with maximum 71.42% (3D7) and 68.57% (RKL-9) inhibition by mixture nosode followed by cell-free parasite nosode (62.85% 3D7 and 60% RKL-9) and infected RBCs nosode (60.61% 3D7 and 57.14% RKL-9). The nosodes were non-toxic to RAW macrophage cell line with >70% cell viability. In vivo: Considerable suppressive efficacy was observed in mixture nosode-treated mice, with 0.005 ± 0.001% parasitemia on day 35. Levels of liver and kidney function biomarkers were within the normal range in the mixture nosode-treated groups. Cytokine analysis revealed increased levels of IL-4 and IL-10, whilst a decline in IL-17 and IFN-γ was evident in the mixture nosode-treated mice. CONCLUSION: The mixture nosode exhibited promising anti-malarial activity against P. falciparum and P. berghei. Biochemical and histopathological studies also highlighted the safety of the nosode for the rodent host. The study provides valuable insight into a novel medicament that has potential for use in the treatment of malaria.

Sinigrin in combination with artesunate provides protection against lethal murine malaria via falcipain-3 inhibition and immune modulation.

Plant-derived antimalarials are indispensable for malaria treatment and a platform for new drugs. The present study explores sinigrin, for malaria using in vitro, in silico and in vivo strategies and the immune response generated after administration. The compound exhibited promising activity against chloroquine (CQ)-resistant (RKL-9) IC50 5.14 µg/mL and CQ-sensitive (3D7) IC50 5.47 µg/mL strains of P. falciparum and was safe in both in vitro (CC50 > 640 µg/mL) and in vivo (LD50 > 2 g/kg) toxicity studies. In addition, virtual screening showed hydrogen bonding, hydrophobic and van der Waals interactions with amino acid residues of 3BPM (falcipain-3). In vivo studies revealed promising antimalarial activity of sinigrin (200 mg/kg) with 87.44% chemo-suppression on day 5 and significantly (p < 0.0001) enhanced the mean survival time (21 ± 4.74 days) in contrast to the infected control (5.4 ± 1.14 days). In combination therapy, sinigrin (100 mg/kg and 200 mg/kg) augmented the efficacy of artesunate (AS 50 mg/kg) with 100% survival and no recrudescence. These observations are further corresponded and supported by DLC, NO production, cytokine analysis, biochemical and histopathological studies. Treatment with the combination resulted in a regulated interplay of immune cells and cytokines aiding in parasite clearance in addition to its specific inhibitory activity. We report the antimalarial activity of sinigrin first time with best D-score against falcipain-3. These findings highlight sinigrin as a HIT molecule, which may potentially be used in drug and vaccine development approaches.

Ethanol extract of Bergenia ciliata (Haw.) Sternb. (rhizome) impedes the propagation of the malaria parasite.

ETHNOPHARMACOLOGICAL RELEVANCE: The increasing resistant cases even against artemisinin-based combination therapy have necessitated the need to develop new antimalarials. Phytomedicinal therapy is a benchmark for malaria in the Himalayan region. As the dialect and traditional variations have been seen along with this, usage of medicinal plant, its portion (shoot and root system) and mode of preparation also varies. There is no scientific evidence available for illustrating the antiplasmodial activity of the rhizomes of Bergenia ciliata (Saxifragaceae), which is known to be an antipyretic (fever akin to malaria), hepato-protective, and also for spleen enlargement. AIM OF THE STUDY: The present study evaluates the antimalarial activity of ethanol extract of B. ciliata rhizomes (EREBC). MATERIALS AND METHODS: HPTLC was performed to identify and quantify three marker compounds in EREBC. The in vitro antimalarial activity was evaluated by schizont maturation inhibition assay. MTT assay was employed to test the cytotoxicity of EREBC. Peter's 4-day test and Peters method was employed to discern the suppressive and preventive activity of the extract respectively. RESULTS: HPTLC analysis revealed the presence of bergenin, epicatechin and gallic acid in the extract. EREBC exhibited considerable inhibition (IC50 < 5 µg/mL) of schizont maturation of both RKL-9 and MRC-2 strains of P. falciparum. EREBC was non-toxic to both HeLa cells and normal dermal fibroblasts (CC50 > 1000 µg/mL). The selectivity index was > 200 for both strains. Acute toxicity of EREBC was > 4 g/kg. EREBC exhibited considerable in vivo suppressive activity with 96.48% inhibition at 500 mg/kg in comparison to chloroquine (96.08%). The ED50 of the extract was < 50 mg/kg. No mortality was evident in mice administered with different doses of EREBC (50-500 mg/kg) throughout the follow up period of 28 days. EREBC exhibited safety to liver and kidney function of mice as observed from biochemical analysis. CONCLUSION: Overall, the study illustrates the marked efficacy and potential of EREBC as an antimalarial agent with bergenin, epicatechin and gallic acid its major constituents, which played a pivotal role in the generation of the immune response.

Improved biopharmaceutical attributes of lumefantrine using choline mimicking drug delivery system: preclinical investigation on NK-65 P.berghei murine model.

BACKGROUND: Lumefantrine (LMF) is first-line antimalarial drug, possesses activity against almost all human malarial parasites, but the in vivo activity of this molecule gets thwarted due to its low and inconsistent oral bioavailability (i.e. 4-12%) owing to poor biopharmaceutical attributes. METHODS: Lumefantrine phospholipid complex (LMF-PC) was prepared by rota-evaporation method following job's plot technique for the selection of apt stoichiometric ratios. Docking studies were carried out to determine the possible interaction(s) of LMF with phosphatidylcholine analogue. Comparative in vitro physiochemical, solid-state characterization, MTT assay, dose-response on P. falciparum, in vivo efficacy studies including pharmacokinetic and chemosuppression on NK-65 P. berghei infected mice were carried out. RESULTS: Aqueous solubility was distinctly improved (i.e. 345 times) with phospholipid complex of LMF. Cytotoxicity studies on Hela and fibroblast cell lines demonstrated safety of LMF-PC with selectivity indices of 4395 and 5139, respectively. IC50 value was reduced almost 2.5 folds. Significant enhancement in Cmax (3.3-folds) and AUC (2.7-folds) of rat plasma levels indicated notable pharmacokinetic superiority of LMF-PC over LMF suspension. Differential leukocytic count and cytokine assay delineated plausible immunoregulatory role of LMF-PC with nearly 98% chemosuppression and over 30 days of post-survival. CONCLUSION: Superior antimalarial efficacy and survival time with full recovery of infected mice revealed through histopathological studies.

Nebulised surface-active hybrid nanoparticles of voriconazole for pulmonary Aspergillosis demonstrate clathrin-mediated cellular uptake, improved antifungal efficacy and lung retention.

BACKGROUND: Incidence of pulmonary aspergillosis is rising worldwide, owing to an increased population of immunocompromised patients. Notable potential of the pulmonary route has been witnessed in antifungal delivery due to distinct advantages of direct lung targeting and first-pass evasion. The current research reports biomimetic surface-active lipid-polymer hybrid (LPH) nanoparticles (NPs) of voriconazole, employing lung-specific lipid, i.e., dipalmitoylphosphatidylcholine and natural biodegradable polymer, i.e., chitosan, to augment its pulmonary deposition and retention, following nebulization. RESULTS: The developed nanosystem exhibited a particle size in the range of 228-255 nm and drug entrapment of 45-54.8%. Nebulized microdroplet characterization of NPs dispersion revealed a mean diameter of ≤ 5 µm, corroborating its deep lung deposition potential as determined by next-generation impactor studies. Biophysical interaction of LPH NPs with lipid-monolayers indicated their surface-active potential and ease of intercalation into the pulmonary surfactant membrane at the air-lung interface. Cellular viability and uptake studies demonstrated their cytocompatibility and time-and concentration-dependent uptake in lung-epithelial A549 and Calu-3 cells with clathrin-mediated internalization. Transepithelial electrical resistance experiments established their ability to penetrate tight airway Calu-3 monolayers. Antifungal studies on laboratory strains and clinical isolates depicted their superior efficacy against Aspergillus species. Pharmacokinetic studies revealed nearly 5-, 4- and threefolds enhancement in lung AUC, Tmax, and MRT values, construing significant drug access and retention in lungs. CONCLUSIONS: Nebulized LPH NPs were observed as a promising solution to provide effective and safe therapy for the management of pulmonary aspergillosis infection with improved patient compliance and avoidance of systemic side-effects.

ß-Carboline Derivatives Tackling Malaria: Biological Evaluation and Docking Analysis.

Increasing resistance to presently available antimalarial drugs urges the need to look for new promising compounds. The ß-carboline moiety, present in several biologically active natural products and drugs, is an important scaffold for antimalarial drug discovery. The present study explores the antimalarial activity of a ß-carboline derivative (1R,3S)-methyl 1-(benzo[d][1,3]dioxol-5-yl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylate (9a) alone in vitro against Plasmodium falciparum and in vivo in combination therapy with the standard drug artesunate against Plasmodium berghei. Compound 9a inhibited both 3D7 and RKL-9 strains of P. falciparum with half-maximal inhibitory concentration (IC50) < 1 µg/mL, respectively. The compound was nontoxic (50% cytotoxic concentration (CC50) > 640 µg/mL) to normal dermal fibroblasts. Selectivity index was >10 against both the strains. The compound exhibited considerable in vivo antimalarial activity (median effective dose (ED50) = 27.74 mg/kg) in monotherapy. The combination of 9a (100 mg/kg) and artesunate (50 mg/kg) resulted in 99.69% chemosuppression on day 5 along with a mean survival time of 25.8 ± 4.91 days with complete parasite clearance. Biochemical studies indicated the safety of the HIT compound to hepatic and renal functions of mice. Molecular docking also highlighted the suitability of 9a as a potential antimalarial candidate.

Antiplasmodial potential of Thalictrum foliolosum (Ranunculaceae) against lethal murine malaria.

BACKGROUND AND OBJECTIVES: The emergence of multi-drug resistant (MDR) strains of Plasmodium falciparum highlights the need to develop novel antimalarial drugs. Present study explores the in vivo antiplasmodial activity of ethanol leaf extract of Thalictrum foliolosum (ELETF) against lethal murine malaria. METHODS: The acute toxicity of the extract was assessed by Limit test of Lorke. The suppressive activity of the extract was evaluated by Peter's 4 day test. In vivo preventive and curative activity of ELETF was assessed by Peter's method and Ryley and Peter's method respectively. Biochemical assays were carried out using standard methods. RESULTS: ELETF (1000 mg/kg) exhibited considerable in vivo schizontocidal activity with 67.11% chemosuppression on Day 5. The ED50 of the extract was 579.56 mg/kg. ELETF also showed significant repository activity with 87.70% chemosuppression at 750 mg/kg, which was greater than pyrimethamine (78.78%). ELETF exhibited dose dependent chemosuppression in the curative test with maximum 70.06% chemosuppression (750 mg/kg). Maximum Mean Survival Time (MST) was 19.2±4.60 and 22.66±4.41 days respectively in the suppressive and curative test, which was extremely statistically significant (p<0.0005) in comparison to untreated control which died by Day 9 post inoculation. Biochemical analysis revealed the safety of ELETF to the hepatic and renal functions of the rodent host. INTERPRETATION & CONCLUSION: The study reports the antiplasmodial potential of Thalictrum foliolosum (ELETF) against Plasmodium berghei infection. The extract can be developed as a phytomedicine against malaria. Alternatively, the active components can be isolated as new lead compounds against the disease.

Synthesis and Evaluation of Antiplasmodial Efficacy of ß-Carboline Derivatives against Murine Malaria.

The difficulty of developing an efficient malaria vaccine along with increasing spread of multidrug resistant strain of Plasmodium falciparum to the available antimalarial drugs poses the need to discover safe and efficacious antimalarial drugs to control malaria. An alternative strategy is to synthesize compounds possessing structures similar to the active natural products or marketed drugs. Several biologically active natural products and drugs contain ß-carboline moiety. In the present study, few selected ß-carboline derivatives have been synthesized and tested for their in vitro and in vivo antiplasmodial activity against the rodent malaria parasite Plasmodium berghei (NK-65). The designed analogs exhibited considerable in vitro antimalarial activity. Two compounds (1R,3S)-methyl 1-(benzo[d][1,3]dioxol-5-yl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylate (9a) and (1R,3S)-methyl 1-(pyridin-3-yl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylate (9b) were further selected for in vivo studies. Both the lead compounds (9a and 9b) were observed to be safe for oral administration. The therapeutic effective dose (ED50) for 9a and 9b were determined and in the animal model, 9a (at 50 mg/kg dose) exhibited better activity in terms of parasite clearance and enhancement of host survival. Biochemical investigations also point toward the safety of the compound to the hepatic and renal functions of the rodent host. Further studies are underway to explore its activity alone as well as in combination therapy with artesunate against the human malaria parasite P. falciparum.