Enhancement of diterpenoid steviol glycosides by co-overexpressing SrKO and SrUGT76G1 genes in Stevia rebaudiana Bertoni.

Stevia rebaudiana (stevia) contains commercially important steviol glycosides, stevioside and rebaudioside A, these compounds have insulinotropic and anti-hyperglycemic effect. Steviol, stevioside and rebaudioside-A have taste modulation and insulin potentiation activity. Stevia leaves are composed of steviol (2-5%), stevioside (4-13%) and rebaudioside-A (1-6%). Stevioside has after-taste bitterness, rebaudioside-A is sweetest in taste among all the glycosides present. Therefore, lower ratio of rebaudioside-A to stevioside has bitter after-taste, which makes stevia plants unpalatable. By over-expressing the genes, SrUGT76G1 and SrKO, we propose to increase the ratio of RebA to stevioside in stevia. Various lines were generated and amongst them, seven lines had both the transgenes present. Co-overxpresion of SrUGT76G1 and SrKO led to the increased concentration of RebA in all the seven transgenic lines (KU1-KU7) than control plant and RebA to stevioside ratio also increased significantly. Steviol, stevioside and RebA showed a differential concentration in all the seven lines, but the pattern was the same in all of them and the ratio of RebA to stevioside increased dramatically. In transgenic line 2 (KU2), RebA showed a steep increase in concentration 52% the rebaudioside-A to stevioside ratio increased from 0.74 (control) to 2.83. In overall all the lines, RebA showed a positive correlation with steviol and stevioside. Overexpression of SrKO led to an increase in steviol which increased the stevioside, overexpression of SrUGT76G1 ultimately increased RebA concentration. In conclusion, concentration of RebA increased significantly with co- overexpression of SrUGT6G1 and SrKO genes. Lines with increased RebA are more palatable and commercially viable

Enhancement of diterpenoid steviol glycosides by co-overexpressing SrKO and SrUGT76G1 genes in Stevia rebaudiana Bertoni.

Stevia rebaudiana (stevia) contains commercially important steviol glycosides, stevioside and rebaudioside A, these compounds have insulinotropic and anti-hyperglycemic effect. Steviol, stevioside and rebaudioside-A have taste modulation and insulin potentiation activity. Stevia leaves are composed of steviol (2-5%), stevioside (4-13%) and rebaudioside-A (1-6%). Stevioside has after-taste bitterness, rebaudioside-A is sweetest in taste among all the glycosides present. Therefore, lower ratio of rebaudioside-A to stevioside has bitter after-taste, which makes stevia plants unpalatable. By over-expressing the genes, SrUGT76G1 and SrKO, we propose to increase the ratio of RebA to stevioside in stevia. Various lines were generated and amongst them, seven lines had both the transgenes present. Co-overxpresion of SrUGT76G1 and SrKO led to the increased concentration of RebA in all the seven transgenic lines (KU1-KU7) than control plant and RebA to stevioside ratio also increased significantly. Steviol, stevioside and RebA showed a differential concentration in all the seven lines, but the pattern was the same in all of them and the ratio of RebA to stevioside increased dramatically. In transgenic line 2 (KU2), RebA showed a steep increase in concentration 52% the rebaudioside-A to stevioside ratio increased from 0.74 (control) to 2.83. In overall all the lines, RebA showed a positive correlation with steviol and stevioside. Overexpression of SrKO led to an increase in steviol which increased the stevioside, overexpression of SrUGT76G1 ultimately increased RebA concentration. In conclusion, concentration of RebA increased significantly with co- overexpression of SrUGT6G1 and SrKO genes. Lines with increased RebA are more palatable and commercially viable

Crafting ɣ-L-Glutamyl-l-Cysteine layered Human Serum Albumin-nanoconstructs for brain targeted delivery of ropinirole to attenuate cerebral ischemia/reperfusion injury via "3A approach"

Treatment of Ischemic Stroke is inordinately challenging due to its complex aetiology and constraints in shuttling therapeutics across blood-brain barrier. Ropinirole hydrochloride (Rp), a propitious neuroprotectant with anti-oxidant, anti-inflammatory, and anti-apoptotic properties (3A) is repurposed for remedying ischemic stroke and reperfusion (I/R) injury. The drug's low bioavailability in brain however, limits its therapeutic efficacy. The current research work has reported sub-100 nm gamma-L-Glutamyl-L-Cysteine coated Human Serum Albumin nanoparticles encapsulating Rp (C-Rp-NPs) for active targeting in ischemic brain to encourage in situ activity and reduce unwanted toxicities. Confocal microscopy and brain distribution studies confirmed the enhanced targeting potentiality of optimized C-Rp-NPs. The pharmacokinetics elucidated that C-Rp-NPs could extend Rp retention in systemic circulation and escalate bioavailability compared with free Rp solution (Rp-S). Additionally, therapeutic assessment in transient middle cerebral occlusion (tMCAO) model suggested that C-Rp-NPs attenuated the progression of I/R injury with boosted therapeutic index at 1000 times less concentration compared to Rp-S via reinstating neurological and behavioral deficits, while reducing ischemic neuronal damage. Moreover, C-Rp-NPs blocked mitochondrial permeability transition pore (mtPTP), disrupted apoptotic mechanisms, curbed oxidative stress and neuroinflammation, and elevated dopamine levels post tMCAO. Thus, our work throws light on fabrication of rationally designed C-Rp-NPs with enormous clinical potential. [Abstract copyright: Copyright © 2022 Elsevier Ltd. All rights reserved.