Whole transcriptome analysis identifies full-length genes for neoandrographolide biosynthesis from Andrographis alata, an alternate source for antiviral compounds.

Andrographolide and related compounds are effective against several viral diseases, including dengue, COVID-19, influenza, and chikungunya. Andrographis paniculata is the primary source for these compounds, but its availability is limited. A. alata is a potential alternative source, and neoandrographolide (NAG) is the major antiviral compound in this species. Since molecular studies in A. alata are scarce, we sequenced its leaf transcriptome to identify the full-length genes involved in neoandrographolide biosynthesis. We assembled 13.6 Gb RNA-Seq data and generated 81,361 transcripts with 1007 bp average length and 1,810 bp N50. The transcripts were categorized under biological processes (2,707), cellular components (678), and molecular functions (2,036). KEGG analysis mapped 975 transcripts to the secondary metabolite pathways. Among the 420 transcripts mapped to terpenoids and polyketides pathways, 142 transcripts were related to the biosynthesis of andrographolide and its derivatives. After a detailed analysis of these transcripts, we identified 32 full-length genes coding for all the 22 enzymes needed for andrographolide biosynthesis. Among them, 15 full-length genes were identified for the first time from Andrographis species. These full-length genes and the transcripts shall serve as an invaluable resource for the metabolic engineering of andrographolides and neoandrographolide in Andrographis and other species.

Ayurvedic antiviral agents: Overview of medicinal plants perspective

In recent years, it has been reported that many herbal plants contain antiviral agents which combat a human disease that is caused by pathogenic viruses. The natural products which are obtained from plants as antiviral agents against viruses have gone through researches to check the efficacy and potentials of the herbal products in the prevention of viral disorders. On the basis of randomized controlled studies and in-vivo studies, and in-vitro studies, some agents are utilized all across the globe. Progressively numerous studies on therapy of antivirals have been increased. Though, efficacy remains disputable for antiviral drugs that are employed for viral disorders. The viral diseases are challenging for the health of people around the world cause significant increase in mortality and enhance crises. There are many synthetic antiviral drugs that have a large number of side effects and have narrow therapeutic window range, while in the other hand herbal formulations have minimized side effects. The advantages of herbal formulation over synthetic drugs encourage us to devise and expand new herbal moieties against the emerging viral infections. The medicinal plants contain phytochemicals that have antiviral properties. In this paper, the activity of antiviral agents from medicinal plants which have importance in Ayurveda, are discussed along with their source.

Computational investigation on Andrographis paniculata phytochemicals to evaluate their potency against SARS-CoV-2 in comparison to known antiviral compounds in drug trials.

The outbreak due to SARS-CoV-2 (or Covid-19) is spreading alarmingly and number of deaths due to infection is aggressively increasing every day. Due to the rapid human to human transmission of Covid-19, we are in need to find a potent drug at the earliest by ruling-out the traditional time-consuming approach of drug development. This is only possible if we use reliable computational approaches for screening compounds from chemical space or by drug repurposing or by finding the phytochemicals and nutraceuticals from plants as they can be immediately used without the need for carrying out drug-trials to test safety and efficacy. A number of plant products were routinely suggested as drugs in traditional Indian and Chinese medicine. Here using molecular docking approach, and combined molecular dynamics and MM-GBSA based free energy calculations approach, we study the potency of the four selected phytochemicals namely andrographolide (AGP1), 14-deoxy 11,12-didehydro andrographolide (AGP2), neoandrographolide (AGP3) and 14-deoxy andrographolide (AGP4) from A. paniculata plant against the four key targets including three non-structural proteins (3 L main protease (3CLpro), Papain-like proteinase (PLpro) and RNA-directed RNA polymerase (RdRp)) and a structural protein (spike protein (S)) of the virus which are responsible for replication, transcription and host cell recognition. The therapeutic potential of the selected phytochemicals against Covid-19 were also evaluated in comparison with a few commercially available drugs. The binding free energy data suggest that AGP3 could be used as a cost-effective drug-analog for treating covid-19 infection in developing countries.Communicated by Ramaswamy H. Sarma.