Exploring the antidiabetic and anti-obesity properties of Samanea saman through in vitro and in vivo approaches

In recent years, diabetes and obesity have become a major problem in global health care because of changes in lifestyle, food habits, and age-related metabolic disorders. Diabetes mellitus is one of the most common diseases, affecting millions of people worldwide. Currently, herbal drugs are used to control obesity and diabetes. The present study investigates the anti-obesity, antidiabetic, and antioxidant activities of Samanea saman leaf extract. A methanolic extract of S. saman leaves was prepared by a maceration method. The S. saman leaf extract was studied for its inhibitory effect on glucose utilization using specific in vitro procedures to analyze its antioxidant, anti-obesity, and antidiabetic activities via different assays, such as α-amylase and α-glucosidase inhibition assay, glucose uptake by yeast cells, nonenzymatic glycosylation assay followed by glucose diffusion assay. The outcome of the study showed that the methanolic extract strongly inhibited the pancreatic lipase, α-amylase, and glucosidase activities, compared with the standard drug. The results showed that the extract possessed considerable antioxidant and antidiabetic activities, and further studies are needed to confirm the results using an in vivo model. Thus, it is proposed that S. saman can be used as a therapeutic agent.     

A locking mechanism regulates RNA synthesis and host protein interaction by the hepatitis C virus polymerase

Mutational analysis of the hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp) template channel identified two residues, Trp(397) and His(428), which are required for de novo initiation but not for extension from a primer. These two residues interact with the Delta1 loop on the surface of the RdRp. A deletion within the Delta1 loop also resulted in comparable activities. The mutant proteins exhibit increased double-stranded RNA binding compared with the wild type, suggesting that the Delta1 loop serves as a flexible locking mechanism to regulate the conformations needed for de novo initiation and for elongative RNA synthesis. A similar locking motif can be found in other viral RdRps. Products associated with the open conformation of the HCV RdRp were inhibited by interaction with the retinoblastoma protein but not cyclophilin A. Different conformations of the HCV RdRp can thus affect RNA synthesis and interaction with cellular proteins.     

In Vitro Regeneration of Mat Sedge (Cyperus pangorei Rottb)

An in vitro protocol was developed for regeneration of Cyperus pangorei that may supplement enough raw materials for the mat weaving community. Callus was initiated from inflorescence explants on Murashige and Skoog’s (MS) medium supplemented with 5 and 10 μM each of 2, 4-D, 2, 4, 5-T and CPA. Development of numerous de novo spikelets from immature inflorescence explants grown in (10 μM) 2, 4, 5-T was observed. MS with 5 μM Kn and 100 ml l^?1 Coconut milk (CM) promoted shoot regeneration from calli. Calli from 2,4-D and CPA medium sub-cultured on medium containing 5 μM BAP, 5 μM Kn, 1 μM IAA and 100 ml l^?1 CM produced extensive and rapid rhizogenesis with wiry and scaly roots. Micropropagation using rhizome buds on MS medium with BAP, Kn and Zeatin at 10 μM concentrations resulted in shoot release and multiplication by breaking the bud dormancy. An average of 10 shoots per explant was produced in 10 μM BAP, whereas (10 μM) Kn and (10 μM) Zeatin induced only single shoot formation. The shoots were transferred to rooting media comprising 10 μM IAA with 1 μM BAP or Kn and then acclimatized. The results accomplished were found to be useful in developing a complete in vitro regeneration protocol towards the mass production of Cyperus species, which may provide a basis for further genetic improvements that may prove its use as an alternative natural fibre resource in commercial applications.     

High synergistic antibacterial,antibiofilm, antidiabetic and antimetabolic activity of Withania somnifera leaf extract-assisted zinc oxide nanoparticle

Nanotechnology is currently gaining immense attention to combat food borne bacteria, and biofilm. Diabetes is a common metabolic disease affecting majority of people. A better therapy relies on phytomediated nanoparticle synthesis. In this study, W. somnifera leaf extract-assisted ZnO NPs (Ws-ZnO NPs) was synthesized and characterized. From HR-TEM analysis, it has been found that the hexagonal wurtzite particle is 15.6 nm in size and − 12.14 mV of zeta potential. A greater antibacterial effect of Ws-ZnO NPs was noticed against E. faecalis and S. aureus at 100 µg mL⁻¹. Also, the biofilm of E. faecalis and S. aureus was greatly inhibited at 100 µg mL⁻¹ compared to E. coli and P. aeruginosa. The activity of α-amylase and α-glucosidase enzyme was inhibited at 100 µg mL⁻¹ demonstrating its antidiabetic potential. The larval and pupal development was delayed at 25 µg mL⁻¹ of Ws-ZnO NPs. A complete mortality (100%) was recorded at 25 µg mL⁻¹. Ws-ZnO NPs showed least LC₅₀ value (9.65 µg mL⁻¹) compared to the uncoated ZnO NPs (38.8 µg mL⁻¹) and leaf extract (13.06 µg mL⁻¹). Therefore, it is concluded that Ws-ZnO NPs are promising to be used as effective antimicrobials, antidiabetic and insecticides to combat storage pests.