Antibacterial activity of chemical constituents isolated from Asparagus racemosus

Potential of Desert Medicinal Plants for Combating Resistant Biofilms in Urinary Tract Infections

Urinary tract infections (UTIs) are among the most prevalent bacterial infections worldwide, with 11% of the global population getting infected every year. These infections are largely attributed to quorum sensing (QS)-dependent ability of pathogens to form biofilms in the urinary tract. Antimicrobial resistance is increasing, and the use of antimicrobial medicines in the future is yet uncertain. The desert medicinal plants have great potential to treat several diseases as per the available ethnobotanical database. Some of these plants have been used in folklore medicines to treat urinary tract infections also. There are many bioactive compounds derived from these desert medicinal plants that have been documented to possess antimicrobial as well as antibiofilm activity against uropathogens. The minimum biofilm inhibitory concentration (MBIC) of these plant extracts have been reported in the range of 31.5-250 μg/mL. The rising prevalence of drug-resistant diseases necessitates standardised modern analytical technologies to detect and isolate novel bioactive compounds from medicinal plants. This review seeks to combine the studies of desert plants with antimicrobial and anti-quorum sensing properties, supporting their sustainable use in treatment of urinary tract infections.

Sustainable valorization of co-products from asparagus cultivation by obtaining bioactive compounds

Asparagus cultivation generates every year a significant amount of by-products that consist of root and frond. Leaving these residues on the fields after harvesting negatively affects the following asparagus crops, since they release autotoxic (allelopathic) substances into the soil, whose accumulation causes that asparagus yields gradually decrease over the years, becoming an unprofitable crop in a period of about 10 to 15 years. This phenomenon is known as decay and forces the entire asparagus plantation to be lifted (abandoned). On the other hand, once a certain plantation has been lifted, it is not profitable to immediately re-plant new asparagus plants, since the yields that are achieved are never more than half of normal ones. It is necessary to wait an average of 4 or 5 years before replanting asparagus in these lands. This phenomenon is known as the replanting problem, and causes the need to continually search for new land for growing asparagus. Another added problem for farmers is that the elimination of those plant residues from asparagus cultivation entails significant economic costs. For all these reasons, it is essential to seek alternatives for the management of that waste that improve the sustainability of the crop within the scope of the circular economy. In this context, this work proposes the valorization of asparagus by-products by obtaining bioactive compounds. Main objectives of the present work include: i) phytochemical analyses of asparagus fronds and roots; ii) obtaining bioactive extracts, with distinct technological and nutritional functionalities, by using an environmentally sustainable extraction process, easy to implement in the practice of a food industry and with methods compatible with food use. Characterization of asparagus by-products shown that fronds had an average flavonoid content of 2.637 ± 0.014 g/Kg fresh weight, which is up to 5-6 times higher than that of the spears; and roots contained up to 10 times more saponins (2.25 g/Kg fresh weight), which were accompanied by lower quantities of phenolic acids (368 mg/Kg fresh weight). Statistical analysis revealed that those phytochemical contents were mainly determined by location and phase of the vegetative cycle, whereas genetic factors did not significantly influence them. Based on the results of the present work, the proposal for the recovery and valorization of asparagus by-products is based on obtaining two bioactive extracts, the first being an antioxidant extract enriched in flavonoids, with an average yield of 10.7 g/Kg fresh frond and a flavonoid richness of 17%; and the second, a saponins extract with an average yield of 10.3 g/Kg fresh root and a richness of 51%. These natural extracts have great techno-functional potential in the agri-food industry and some of them are already being tested as additives in the preparation of soups, breads and meat products.

In-silico investigation of phytochemicals from Asparagus racemosus as plausible antiviral agent in COVID-19

COVID-19 has ravaged the world and is the greatest of pandemics in human history, in the absence of treatment or vaccine the mortality and morbidity rates are very high. The present investigation was undertaken to screen and identify the potent leads from the Indian Ayurvedic herb, Asparagus racemosus (Willd.) against SARS-CoV-2 using molecular docking and dynamics studies. The docking analysis was performed on the Glide module of Schrödinger suite on two different proteins from SARS-CoV-2 viz. NSP15 Endoribonuclease and spike receptor-binding domain. Asparoside-C, Asparoside-D and Asparoside -F were found to be most effective against both the proteins as confirmed through their docking score and affinity. Further, the 100 ns molecular dynamics study also confirmed the potential of these compounds from reasonably lower root mean square deviations and better stabilization of Asparoside-C and Asparoside-F in spike receptor-binding domain and NSP15 Endoribonuclease respectively. MM-GBSA based binding free energy calculations also suggest the most favourable binding affinities of Asparoside-C and Asparoside-F with binding energies of -62.61 and -55.19 Kcal/mol respectively with spike receptor-binding domain and NSP15 Endoribonuclease. HighlightsAsparagus racemosus have antiviral potentialPhytochemicals of Shatavari showed promising in-silico docking and MD resultsAsparaoside-C and Asparoside-F has good binding with target proteinsAsparagus racemosus holds promise as SARS-COV-2 (S) and (N) proteins inhibitor Communicated by Ramaswamy H. Sarma.

Nor-Lignans: Occurrence in Plants and Biological Activities-A Review

In this review article, the occurrence of nor-lignans and their biological activities are explored and described. Nor-lignans have proven to be present in several different families also belonging to chemosystematically distant orders as well as to have many different beneficial pharmacological activities. This review article represents the first one on this argument and is thought to give a first overview on these compounds with the hope that their study may continue and increase, after this.

Anti-nociceptive and Anti-inflammatory Activities of Asparacosin A Involve Selective Cyclooxygenase 2 and Inflammatory Cytokines Inhibition: An in-vitro, in-vivo, and in-silico Approach

Triterpenes possess anti-inflammatory and anti-nociceptive effects. In this study anti-inflammatory activities of Asparacosin A were evaluated' using in-vitro cyclooxygenases 1 and 2 (COX-1/2) inhibition assays. Moreover, anti-nociceptive activities were assessed in-vivo by carrageenan-induced paw edema test, xylene-induced ear edema tests, and acetic acid-induced writhing and formalin tests. Additionally molecular docking was conducted to elucidate the binding mechanism of the compound and to correlate the in-vitro findings with the in-silico data. Oral administration of Asparacosin A at the doses of 10, 20, and 40 mg/kg induced significant anti-inflammatory effects (^*p < 0.05, ^**p < 0.01, and ^***p < 0.001) in a dose-dependent manner in both models. Asparacosin A also inhibited the human recombinant COX-2 enzyme and caused a dose-dependent decrease in the levels of TNF-α, IL-1β, and PGE2 in the carrageenan-induced paws. Moreover, Asparacosin A displayed significant anti-nociceptive effects (^*p < 0.05, ^**p < 0.01, ^***p < 0.001) at the doses of 10, 20, and 40 mg/kg in acetic-acid induced writhing test. However, in formalin test, Asparacosin A (10–40 mg/kg, p.o) produced anti-nociceptive effects only in the late phase, similar to the effect observed with the reference drug celecoxib (50 mg/kg, p.o). Molecular docking was carried out on both COX-1 and COX-2 structures which revealed that Asparacosin A targets allosteric binding site similar to the binding mode of the selective COX inhibitor. In conclusion, Asparacosin A exhibits anti-inflammatory and peripheral anti-nociceptive activities which are likely mediated via inhibition of COX-2 enzyme and inflammatory cytokines. Furthermore, Asparacosin A can serve as a model to obtain new and more selective potent anti-inflammatory and anti-nociceptive drugs.