Quebrachitol from Putranjiva roxburghii Wall. (Putranjivaceae) a potent antimalarial: Pre-clinical efficacy and its interaction with PfLDH.

Researchers are exploring natural resources in search of a new and effective anti-malarial compound to address the challenges in malarial treatment due to emerging incidences of drug-resistant strains. Following background knowledge of traditional medicine, we evaluated the in-vitro and in-vivo anti-malarial efficacy of Putranjiva P. roxburghii (Putranjivaceae) twigs ethanol extracts and fraction (PRT). In-vitro parasite-specific lactate dehydrogenase (pLDH) assay was performed using a chloroquine-sensitive Plasmodium falciparum strain. The results of the in-vitro study were further validated by in-vivo anti-malarial studies on P. berghei Keyberg 173 (K173) infected mice. The crude ethanol extract of the PRT showed the most moderate antiparasitic activity (IC50 = 15.51 µg/mL). In contrast, its butanol fraction extract showed potent activity (IC50 = 5.14 µg/mL) with a selectivity index (SI) of 28.87. Two phytochemicals, viz. 2, 4 dihydroxy-5-(hydroxymethyl) benzoic acid (DHMBA), and quebrachitol (QBC), were identified with anti-parasitic activity (IC50 = 5.01 µg/mL and 0.87 µg/mL) and selectivity index (SI) of 45 and 158. The in-vivo studies confirmed the significant anti-malarial activity of QBC at the dose of 30 and 60 mg/kg body weight with chemo-suppression values of 73.26% and 61.88%, respectively. The present study demonstrates the bioactive marker-based standardization of P. roxburghii twig, the antiplasmodial potential of PRT, and the role of QBC in suppressing parasitemia. The findings of the study support QBC as a prospective lead for a natural product-based adjunct remedy to conventional antiparasitic agents for malarial infectious.

Standardization of Kaempferia galanga L. rhizome and vasorelaxation effect of its key metabolite ethyl p-methoxycinnamate.

ETHNOPHARMACOLOGICAL RELEVANCE: Kaempferia galanga L. rhizome (KGR) is part of more than sixty-one Ayurvedic formulations and commonly known as 'Chandramula'. KGR is widely used in traditional Indian medicines to treat fever (jwar), rheumatism (Amavata), respiratory (Shwasa), hypertension (Vyanabala vaishamya) and cardiovascular disorders (Vyanavayu Dushtijanya Hrudrog). Although ethnomedicinal properties have extensively been demonstrated in traditional medicines of south-east countries i.e. China, India, Indonesia, and Malaysia, the chemico-biological validation are still lacking. AIM OF THE STUDY: Chemico-biological standardization with respect to its vasorelaxation potential is the main objective of the present study. To investigate the vasorelaxation potential of key phytochemical of KGR, i.e., ethyl-p-methoxycinnamate (EPMC) and to study it's the mechanism of action. MATERIALS AND METHODS: A HPLC method was developed and validated for the quality assessment of KGR using its two major phytochemicals i.e. ethyl-p-methoxycinnamate (EPMC) and ethyl cinnamate (EC) in KGR. The vasorelaxation effect of major phytochemicals of KGR was evaluated on the main mesenteric arteries isolated from male Wistar rats. Specific BKca channel blocker tetraethylammonium (TEA), receptor antagonist, nitric oxide scavenging capacity, and antioxidant potential were also evaluated for its plausible mechanism. RESULTS: Present validated HPLC method facilitates simultaneous quantitation of EPMC and EC faster than classical GC techniques. EPMC has shown a dose-dependent relaxation in rat main mesenteric arteries (MMA) contracted by U46619 with an Emax of 58.68 ± 3.31%. Similarly, in endothelium-denuded MMA rings, relaxation was also observed (Emax of 61.83 ± 3.38%). Moreover, relaxation response to EPMC has strongly inhibited (Emax 14.76 ± 2.29%) when the tissue exposed to depolarizing high K+ containing buffer for the contraction. The point correlation dimension (pD2) values were also significantly decreased in high K+ treated arterial rings compared to control. Interestingly, when MMA rings incubated with a specific BKca channel blocker (TEA, 1 mM), the relaxation response to EPMC was also significantly blocked. CONCLUSIONS: The first time this study demonstrated the chemical standardization of K. galanga rhizome and EPMC is responsible for its vasorelaxation potential as demonstrated by the endothelium-independent response mediated by Ca2+ dependent potassium channels.

Novel bioactive compound from the bark of Putranjiva roxburghii Wall.

Putranjivah (Putranjiva roxburghii Wall, family - Putranjivaceae) is an Indian native medicinal plant used to treat many diseases such as treatment of mouth and stomach ulcers, hot swellings, smallpox, burning sensation and ophthalmopathy. The study of chemical constituents in the bark of P. roxburghii resulted in a new triterpene (6) along with five known triterpenoids (1-5). The chemical characterisation was based on 1H, 13C, 2D-NMR experimentation, and ESI-MS data. The anti-plasmodial activity was investigated by measuring parasite-specific lactate dehydrogenase (pLDH) based in vitro assay. The IC50 value results showed that friedlein (2.40 ± 0.70) and roxburghonol (4.10 ± 1.7 µg/ml) possess better anti-plasmodial activity than other isolated triterpenes (2-5) but not as potent as chloroquine (0.023 ± 0.002 µg/ml) against chloroquine-sensitive Plasmodium falciparum (3D7) strain.

Amruthapala (Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter): A Comprehensive Review on Diversity, Therapeutic Uses, and Valorization of Bioactive Constituents.

BACKGROUND: Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter is used primarily for nutrition besides its therapeutic values. Traditional preparations/formulations from its tuber are used as a vitalizer and blood purifier drink. The folklore medicinal uses cover inflammation, cough, wound healing, antipyretic, and digestive system management. A comprehensive review of the current understanding of the plant is required due to emerging concerns over its safety and efficacy. OBJECTIVE: The systematic collection of the authentic information from different sources with the critical discussion is summarised in order to address various issues related to botanical identity, therapeutic medicine, nutritional usage, phytochemical, and pharmacological potentials of the D. arayalpathra. Current use of traditional systems of medicine can be used to expand future research opportunities. MATERIALS AND METHODS: Available scripted information was collected manually, from peered review research papers and international databases viz. Science Direct, Google Scholar, SciFinder, Scopus, etc. The unpublished resources which were not available in database were collected through the classical books of 'Ayurveda' and 'Siddha' published in regional languages. The information from books, Ph.D. and MSc dissertations, conference papers and government reports were also collected. We thoroughly screened the scripted information of classical books, titles, abstracts, reports, and full-texts of the journals to establish the reliability of the content. RESULTS: Tuber bearing vanilla like signature flavor is due to the presence of 2-hydroxy-4-methoxybenzaldehyde (HMB). Among five other species, Decalepis arayalpathra (DA) has come under the 'critically endangered' category, due to over-exploitation for traditional, therapeutic and cool drink use. The experimental studies proved that it possesses gastro-protective, anti-tumor, and antiinflammatory activities. Some efforts were also made to develop better therapeutics by logical modifications in 2-Hydroxy-4-methoxy-benzaldehyde, which is a major secondary metabolite of D. arayalpathra. 'Amruthapala' offers the enormous opportunity to develop herbal drink with health benefits like gastro-protective, anti-oxidant and anti-inflammatory actions. CONCLUSION: The plant has the potential to generate the investigational new lead (IND) based on its major secondary metabolite i.e. 2-Hydroxy-4-methoxy-benzaldehyde. The present mini-review summarizes the current knowledge on Decalepis arayalpathra, covering its phytochemical diversity, biological potentials, strategies for its conservation, and intellectual property rights (IPR) status. Chemical Compounds: 2-hydroxy-4-methoxybenzaldehyde (Pubchem CID: 69600), α-amyrin acetate (Pubchem CID: 293754), Magnificol (Pubchem CID: 44575983), ß-sitosterol (Pubchem CID: 222284), 3-hydroxy-p-anisaldehyde (Pubchem CID: 12127), Naringenin (Pubchem CID: 932), Kaempferol (Pubchem CID: 5280863), Aromadendrin (Pubchem CID: 122850), 3-methoxy-1,2-cyclopentanedione (Pubchem CID: 61209), p-anisaldehyde (Pubchem CID: 31244), Menthyl acetate (Pubchem CID: 27867), Benzaldehyde (Pubchem CID: 240), p-cymene (Pubchem CID: 7463), Salicylaldehyde (Pubchem CID: 6998), 10-epi-γ-eudesmol (Pubchem CID: 6430754), α -amyrin (Pubchem CID: 225688), 3-hydroxy-4-methoxy benzaldehyde (Pubchem CID: 12127).

Ultra performance liquid chromatography coupled with principal component and cluster analysis of Swertia chirayita for adulteration check.

This article describes the study to standardize phytochemically and distinguish Swertia chirayita from that of possible substitution/adulteration using ultra performance liquid chromatography (UPLC) with photodiode array detector (PDA) and chemometric tools viz. principal component analysis (PCA) and hierarchical clustering analysis (HCA). Five ecotypes of Swertia chirayita and five possible substitutions, e.g.,Swertia bimaculata (SB), Swertia chordata (SCH), Swertia ciliata (SCL), Swertia paniculata (SP), and Halenia elliptica (HE) collected from different Indian Himalayan region. Samples evaluated for 04 marker compounds- swertiamarin (SM), mangiferin (MF), gentiopicroside (GP), and sweroside (SW). Reverse phase column (Waters Acquity BEH C18, 50 mm × 2.1 mm , 1.7 µm) provided high resolution for all target analytes with binary gradient elution. The detector response was linear (concentration 2.5-125 µg/mL, R2 > 0.999). The limit of detection (LOD) and quantification (LOQ) of targeted compounds was in the range of 1.40-2.06 and 4.57-6.27 µg/mL respectively. The combined relative standard deviation (%RSD) for intra-day and inter-day precision values were less than 2%. The recoveries study comply the method suitability. Chromatogram similarity analysis based on congruence coefficient was higher than 0.925 for the chirayita ecotypes while much lower than 0.629 for possible substitutes. HCA showed that the samples could be clustered (all 5 clusters in two-level) reasonably into different ecotypes and substitutes. HCA together with loading plots has indicated different chemical properties of all five groups. PCA results showed that the discrimination of chirayita ecotypes is because of the presence of SW while SM may have more influence on the targeted substitutes to discriminate from chirayita ecotypes. Therefore, UPLC fingerprint in association with chemometric tools provides a reliable and accurate quality assessment and detection of possible adulteration.

Structure-Based Drug Designing and Simulation Studies for Finding Novel Inhibitors of Heat Shock Protein (HSP70) as Suppressors for Psoriasis.

Psoriasis is a chronic immune-mediated inflammatory skin disorder. Heat shock proteins (HSPs) have been witnessed as a potential drug target for inhibition of psoriatic cell differentiation. The expression level of HSP is increased when the cells get exposed to elevated temperature, oxidative stress and nutritional deficiencies and thus plays major role in psoriatic progression pathway. Immunoreactivity intensity distribution index scores for HSP70 expression is significantly higher in psoriatic patients compared to normal. In the present work, the 3D structure of human Hsp70 has been taken. Inhibition of HSP70 can control the severity of psoriasis up to many folds; thus, virtual screening was performed against lead-like, drug-like and some natural product of ZINC database. The screened ligands were further introduced to ADMET prediction and simulations to see the drug proficiency and likeness property. The molecular dynamic of system was found stable during simulation trajectory and not much of significant changes occurred in the conformation of the protein-ligand complex. Thus, present study in all probability might prove useful for future design of new derivatives with higher potency and specificity.

Prevention of IcaA regulated poly N-acetyl glucosamine formation in Staphylococcus aureus biofilm through new-drug like inhibitors: In silico approach and MD simulation study.

OBJECTIVES: The effectiveness of various ligands against the protein structure of IcaA of the IcaABCD gene locus of Staphylococcus aureus were examined using the approach of structure based drug designing in reference with the protein's efficiency to form biofilms. RESULTS: Four compounds CID42738592, CID90468752, CID24277882, and CID6435208 were secluded from a database of 31,242 inhibitory ligands on the justification of the evaluated values falling under the four - tier structure based virtual screening. Under this principle value of least binding energy, human oral absorption and ADME properties were taken into consideration. Using the Glide module of Schrödinger, the above mentioned ligands showed an effective action against the protein IcaA which showed reduced activity as a glucosaminyl transferase. The complex of protein and ligand with best docking score was chosen for simulation studies. CONCLUSIONS: Structure based drug designing for the protein IcaA has given us potential leads as anti - biofilm agents. These screened out ligands might enable the development of new therapeutic strategies aimed at disrupting Staphylococcus aureus biofilms. The complex was showing stability towards the end of time for which it has been put for simulation. Thus molecule could be considered for making of biofilms.

A phenolic glycoside from Flacourtia indica induces heme mediated oxidative stress in Plasmodium falciparum and attenuates malaria pathogenesis in mice.

BACKGROUND: Flacourtia indica is especially popular among the various communities of many African countries where it is being used traditionally for the treatment of malaria. In our previous report, we have identified some phenolic glycosides from the aerial parts of F. indica as promising antiplasmodial agents under in vitro conditions. PURPOSE: Antimalarial bioprospection of F. indica derived phenolic glycoside in Swiss mice (in vivo) with special emphasis on its mode of action. METHODS: Chloroquine sensitive strain of Plasmodium falciparum was routinely cultured and used for the in vitro studies. The in vivo antimalarial potential of phenolic glycoside was evaluated against P. berghei in Swiss mice through an array of parameters viz., hematological, biochemical, chemo-suppression and mean survival time. RESULTS: 2-(6-benzoyl-ß-d-glucopyranosyloxy)-7-(1α, 2α, 6α-trihydroxy-3-oxocyclohex-4-enoyl)-5-hydroxybenzyl alcohol (CPG), a phenolic glycoside isolated from the aerial parts of F. indica was found to exhibit promising antiplasmodial activity by arresting the P. falciparum growth at the trophozoite stage. Spectroscopic investigations reveal that CPG possesses a strong binding affinity with free heme moieties. In addition, these interactions lead to the inhibition of heme polymerization in malaria parasite, augmenting oxidative stress, and delaying the rapid growth of parasite. Under in-vivo condition, CPG exhibited significant antimalarial activity against P. berghei at 50 and 75mg/kg body weight through chemo-suppression of parasitemia and ameliorating the parasite induced inflammatory and oxidative (hepatic) imbalance in the experimental mice. CONCLUSION: CPG was found to be a potential antimalarial constituent of F. indica with an explored mechanism of action, which also offers the editing choices for developing CPG based antimalarial chemotypes.

Antimalarial activity and safety assessment of Flueggea virosa leaves and its major constituent with special emphasis on their mode of action.

A clinical emergency stands due to the appearance of drug resistant Plasmodium strains necessitate novel and effective antimalarial chemotypes, where plants seem as the prime option, especially after the discovery of quinine and artemisinin. The present study was aimed towards bioprospecting leaves of Flueggea virosa for its antimalarial efficacy and active principles. Crude hydro-ethanolic extract along with solvent derived fractions were tested in vitro against Plasmodium falciparum CQ sensitive (3D7) and resistant (K1) strains, where all the fractions exhibited potential activity (IC50 values <10µg/mL) against both the strains. Interestingly, under in vivo conditions against P. berghei in Swiss mice, preferential chemo-suppression was recorded for crude hydro-ethanolic extract (77.38%) and ethyl acetate fraction (86.09%) at the dose of 500mg/kg body weight. Additionally, ethyl acetate fraction was found to be capable of normalizing the host altered pharmacological parameters and enhanced oxidative stress augmented during the infection. The bioactivity guided fractionation lead to the isolation of bergenin as a major and active constituent (IC50, 8.07±2.05µM) of ethyl acetate fraction with the inhibition of heme polymerization pathway of malaria parasite being one of the possible chemotherapeutic target. Furthermore, bergenin exhibited a moderate antimalarial activity against P. berghei and also ameliorated parasite induced systemic inflammation in host (mice). Safe toxicity profile elucidated through in vitro cytotoxicity and in silico ADME/T predications evidently suggest that bergenin possess drug like properties. Hence, the present study validates the traditional usage of F. indica as an antimalarial remedy and also insists for further chemical modifications of bergenin to obtain more effective antimalarial chemotypes.