Andrographolide: A Novel Antimalarial Diterpene Lactone Compound from Andrographis paniculata and Its Interaction with Curcumin and Artesunate

Andrographolide (AND), the diterpene lactone compound, was purified by HPLC from the methanolic fraction of the plant Andrographis paniculata. The compound was found to have potent antiplasmodial activity when tested in isolation and in combination with curcumin and artesunate against the erythrocytic stages of Plasmodium falciparum in vitro and Plasmodium berghei ANKA in vivo. IC50s for artesunate (AS), andrographolide (AND), and curcumin (CUR) were found to be 0.05, 9.1 and 17.4 μM, respectively. The compound (AND) was found synergistic with curcumin (CUR) and addictively interactive with artesunate (AS). In vivo, andrographolide-curcumin exhibited better antimalarial activity, not only by reducing parasitemia (29%), compared to the control (81%), but also by extending the life span by 2-3 folds. Being nontoxic to the in vivo system this agent can be used as template molecule for designing new derivatives with improved antimalarial properties

PRELIMINARY PHYTOCHEMICAL SCREENING AND IN VITRO ANTI-MICROBIAL ACTIVITY OF ETHANOLIC EXTRACT OF DELONIX REGIA (HOOK) RAF. BARK (FAMILY-LEGUMINOSAE)

Objective: To estimate the anti-microbial activity of ethanolic extract of Delonix regia (Hook.) Raf (family-Leguminosae) in association with phytochemical analysis.Methods: The ethanolic extract of the bark of Delonix regia (Hook.) Raf was prepared and investigate for phytochemical constituents using standard methods. Antimicrobial activity of ethanolic extract of were carried out against one Gram positive bacteria= Staphylococcus aureus and one Gram negative bacteria= Escherichia coli. The anti-fungal activity of the plant extract was evaluated on Candida albicans. The testing was done by the disc diffusion method. A zone of inhibition of ethanolic extract was compared with that of standard Amikacin for anti-bacterial activities and Fluconazole for anti-fungal activity.Results: The present investigation shows the phytochemical analysis, antimicrobial activity of the ethanolic extract of the bark of Delonix regia (Hook.) Raf. Various phytochemical analyses revealed the presence of alkaloids, anthraquinone, phenol, terpenes, cardenolides, phlobatannins, tannin, chalcones, steroids. The anti-microbial activity of the ethanolic extract of the plant showed significant results against all three of the test organisms.Conclusion: The present study concluded that ethanolic extract of the bark of Delonix regia (Hook.) Raf contains the high existence of phytochemicals. The ethanolic extract of the plant was found to possess promising antimicrobial activity when compared with the standards

PRELIMINARY PHYTOCHEMICAL SCREENING AND IN VITRO ANTI-MICROBIAL ACTIVITY OF ETHANOLIC EXTRACTS OF FRUITS OF ANNONA RETICULATA AGAINST STANDARD PATHOGENIC STRAINS

Objective: To evaluate the anti-microbial activity of ethanolic extract of fruits of Annona reticulata (family-Annonaceae) in conjugation with phytochemical analysis.Methods: The ethanolic extract of fruits of Annona reticulata (family-Annonaceae) was prepared by Soxhlet extraction and analysed for phytochemical constituents using standard methods. The anti-microbial activity of the plant extract was examined against bacterial strains and fungal strains using disc diffusion method.Results: The present investigation shows the phytochemical analysis, anti-microbial activity of the ethanolic extract of the plant Annona reticulata. Various phytochemical analyses revealed the presence of alkaloids, saponin, flavonoids, carbohydrates, glycosides, steroids, proteins and amino acids and tannins. The anti-microbial activity of the ethanolic extract of the plant showed significant result against all the of the test organisms.Conclusion: The present study concluded that ethanolic extract of fruits of the Annona reticulata contain high presence of phytochemicals. The ethanolic extract of the plant was found to possess promising anti-microbial activity when compared with the standards

PRELIMINARY PHYTOCHEMICAL SCREENING AND IN VITRO ANTI-MICROBIAL ACTIVITY OF ETHANOLIC EXTRACTS OF SEEDS OF PUNICA GRANATUM AGAINST STANDARD PATHOGENIC STRAINS

Objective: To estimate the anti-microbial activity of ethanolic extract of Punica granatum seeds (family-Punicaceae) in association with phytochemical analysis.Methods: The ethanolic extract of the seeds of Punica granatum was prepared and investigate for phytochemical constituents using standard methods. Antimicrobial activities of ethanolic extract were carried out against one Gram positive bacteria (Staphylococcus aureus) and one Gram negative bacteria (Escherichia coli). The anti-fungal activity of the plant extract was evaluated on Candida albicans. The testing was done by the disc diffusion method. A zone of inhibition of ethanolic extract was compared with that of standard Tetracycline for anti-bacterial activities and Fluconazole for anti-fungal activity.Results: The result of this study showed a good antibacterial effect of pomegranate juice against both Gram negative and Gram positive bacteria. The antimicrobial activity of the fruit may be due to its high content of polyphenols which causes phenolic toxicity by interfering with the sulfhydryl group of the bacterial proteins and high content of tannins which interferes with bacterial membrane stability.Conclusion: The present study concluded that ethanolic extract of the seeds of Punica granatum contains the high existence of phytochemicals. The ethanolic extract of the plant was found to possess promising antimicrobial activity when compared with the standards

Anti-malarial activities of Andrographis paniculata and Hedyotis corymbosa extracts and their combination with curcumin

<p>Abstract</p> <p>Background</p> <p>Herbal extracts of <it>Andrographis paniculata </it>(AP) and <it>Hedyotis corymbosa </it>(HC) are known as hepato-protective and fever-reducing drugs since ancient time and they have been used regularly by the people in the south Asian sub-continent. Methanolic extracts of these two plants were tested in vitro on choloroquine sensitive (MRC-pf-20) and resistant (MRC-pf-303) strains of <it>Plasmodium falciparum </it>for their anti-malarial activity.</p> <p>Methods</p> <p>Growth inhibition was determined using different concentrations of these plant extracts on synchronized <it>P. falciparum </it>cultures at the ring stage. The interactions between these two plant extracts and individually with curcumin were studied in vitro. The performance of these two herbal extracts in isolation and combination were further evaluated in vivo on Balb/c mice infected with <it>Plasmodium berghei </it>ANKA and their efficacy was compared with that of curcumin. The in vivo toxicity of the plant derived compounds as well as their parasite stage-specificity was studied.</p> <p>Results</p> <p>The 50% inhibitory concentration (IC₅₀) of AP (7.2 μg/ml) was found better than HC (10.8 μg/ml). Combination of these two herbal drugs showed substantial enhancement in their anti-malarial activity. Combinatorial effect of each of these with curcumin also revealed anti-malarial effect. Additive interaction between the plant extracts (AP + HC) and their individual synergism with curcumin (AP+CUR, HC+CUR) were evident from this study. Increased in vivo potency was also observed with the combination of plant extracts over the individual extracts and curcumin. Both the plant extracts were found to inhibit the ring stage of the parasite and did not show any in vivo toxicity, whether used in isolation or in combination.</p> <p>Conclusion</p> <p>Both these two plant extracts in combination with curcumin could be an effective, alternative source of herbal anti-malarial drugs.</p

Knowledge-based Analogical Reasoning in Neuro-symbolic Latent Spaces

Analogical Reasoning problems challenge both connectionist and symbolic AI systems as these entail a combination of background knowledge, reasoning and pattern recognition. While symbolic systems ingest explicit domain knowledge and perform deductive reasoning, they are sensitive to noise and require inputs be mapped to preset symbolic features. Connectionist systems on the other hand can directly ingest rich input spaces such as images, text or speech and recognize pattern even with noisy inputs. However, connectionist models struggle to include explicit domain knowledge for deductive reasoning. In this paper, we propose a framework that combines the pattern recognition abilities of neural networks with symbolic reasoning and background knowledge for solving a class of Analogical Reasoning problems where the set of attributes and possible relations across them are known apriori. We take inspiration from the 'neural algorithmic reasoning' approach [DeepMind 2020] and use problem-specific background knowledge by (i) learning a distributed representation based on a symbolic model of the problem (ii) training neural-network transformations reflective of the relations involved in the problem and finally (iii) training a neural network encoder from images to the distributed representation in (i). These three elements enable us to perform search-based reasoning using neural networks as elementary functions manipulating distributed representations. We test this on visual analogy problems in RAVENs Progressive Matrices, and achieve accuracy competitive with human performance and, in certain cases, superior to initial end-to-end neural-network based approaches. While recent neural models trained at scale yield SOTA, our novel neuro-symbolic reasoning approach is a promising direction for this problem, and is arguably more general, especially for problems where domain knowledge is available.Comment: 13 pages, 4 figures, Accepted at 16th International Workshop on Neural-Symbolic Learning and Reasoning as part of the 2nd International Joint Conference on Learning & Reasoning (IJCLR 2022

Thermal and photochemical reactions ofbis(diamine)(sulfito)cobalt(III) complexes: effect ofchelate-ring size

The kinetics of formation of cis-[Co(tn)2(OH2)(OSO2-O )]+ (tn = 1,3-diaminopropane), its acid-catalysed aquation to the parent diaqua complex, anation of trans-[Co(tn)2(OH2)(SO3&#8722;S)]+ by N&#8722;, NCS&#8722;, SO32&#8722;&#8211;HSO3&#8722; , anation of trans-[Co(tn)2(OH)(SO3-S )] by SO32&#8722; and acid-catalysed aquation of trans-[Co(tn)2(SO3-S)2]- to the corresponding (aqua)(sulfito-S) complex were investigated and the results compared with analogous data for the corresponding 1,2-diaminoethane (en) complexes. Expanding the chelate-ring size from five to six had virtually no effect on the rate of formation of the sulfito-O complex, but retarded its acid-catalysed aquation. The latter effect was attributed to a pK perturbation; intramolecular hydrogen bonding between the co-ordinated H2O and sulfite in cis-[Co(tn)2(OH2)(OSO2-O )]+ hindered the protonation pre-equilibrium of the sulfito-O complex involved in the acid-catalysed aquation. This is further supported by the fact that there was no ring-size effect on the acid-catalysed aquation of trans-[Co(L&#8211;L)2(OH2)(OSO2) ]+ (L&#8211;L = tn or en). The strong labilising action due to chelate-ring expansion is remarkably attenuated by the trans effect of S-bonded sulfite as observed in the anation of trans-[Co(L&#8211;L)2(OH2/OH)(SO3 -S)]+/0. However, trans-[Co(tn)2(OH2)(SO3- S)]+ was found to be prone to intramolecular electron transfer between CoIIIand SIV under thermal conditions unlike its en analogue, further reflecting the ring-size effect. Flash photolysis of trans-[Co(L&#8211;L)2(OH2)(SO3 -S)]+ (L&#8211;L = en or tn) generated the transient trans-[Co(L&#8211;L)2(OH2)(OSO2 )]+. The photochemical ligand isomerisation of both complexes (CoIII&#8211;SO3+ &#8594; CoIII&#8211;OSO2+) also occurred at comparable rates [kiso = (4.1 &#177;0.8) &#215; 104 and (3.2 &#177;1.3) &#215; 104 s&#8722;1 at 25 &#176;C for the en and tn complexes respectively]. Steady-state photolysis at 254 nm indicated that trans&#8211;[Co(en)2(OH2)(SO3-S )]+ underwent photoaquation and photoreduction. Strikingly photoreduction could not be detected for this complex at pH &gt; 8