Current Pharmaceutical Biotechnology - Volume 21, Issue 8, 2020

The term “vitamin P” is an old but interesting concept. Most substances in this category belong to the family of flavonoids. “Vitamin P” has also been used to define the activity of some flavonoids, including quercetin, myricetin, and rutin. According to experimental studies, the “quercetin-like natural plant flavonoids” are beneficial to the body due to their various physiological and pharmacological activities in large doses (5 μM in vitro, 50 mg/kg in mice and 100 mg/kg in rats). The physiologically achievable concentration is 10 to 100 nM, which is quite high and hard to achieve from a normal diet. Thus, the physiologic activity and mechanism of "vitamin P" are still not clear. It should be noted that the quercetin-like natural plant flavonoids are physiological co-factors of cyclooxygenases (COXs), which are the rate-limiting key enzymes of prostaglandins. These quercetin-like natural plant flavonoids can strongly stimulate prostaglandin levels at lower doses (10 nM in vitro and in 0.1 mg/kg in vivo in rats). Although these "vitamin P" substances are not original substances in the body, their physiological functions affect the body. This review is focused on the most compelling evidence regarding the physiologic role and mechanism of quercetin-like natural plant flavonoids, which may be useful in understanding the physiological functions of "vitamin P", with the goal of focusing on the role of flavonoids in human physiological health.

Background: Sorafenib is the first oral therapeutic agent to show the activity against human hepatocellular carcinoma. Sorafenib leads to severe toxicity due to the multiple-dose regimen. Reducing the overall dose of sorafenib through injectable dosage form to release sustainably is of therapeutically more important to combat drug-induced toxicity. Objective: The purpose of this study was to formulate and evaluate the physical parameters of sorafenib- loaded Sodium Selenite Nanoparticles (SSSNP). Methods: Two different methods: chemical crosslinking and solvent evaporation were applied for the formulation of nanoparticles using various crosslinkers such as formaldehyde, magnesium sulfate, tripolyphosphate, dextran sulfate, and aluminum hydroxide. Physical characterization was performed with zeta potential analysis, polydispersity index, particle size and scanning electron microscopic studies for morphological analysis for all the formulated nanoparticles developed using the chemical crosslinking technique based ionic interaction. Results: Tripolyphosphate was selected as an ideal crosslinker and used for nanoparticle formulation with the solvent evaporation technique. Based on the physical characterization, SSSNP was formulated successfully with the solvent evaporation technique using tripolyphosphate as a cross-linker. The zeta potential of SSSNP was -37.5 mV, PDI was approximately 0.3 to 0.4, and the observed size (diameter) was in the range of 208 nm to 0.2 μm. Furthermore, the particles were smooth in morphology and appeared as crystals. Conclusion: The novel injectable sorafenib loaded sodium selenite nanoparticle dosage form will serve better than conventional oral dosage form to elicit a safe therapeutic effect.

Background: Oxidative stress and mitochondrial dysfunction play a vital role in the pathogenesis of brain aging. Saponins from Panax japonicus (SPJ) have attracted much attention for their potential to attenuate age-related oxidative stress as the main ingredient in rhizomes of Panax japonicus. Objective: This study aimed to investigate the neuroprotective effects of SPJ on natural aging rats as well as the underlying mechanisms regarding oxidative stress and mitochondrial pathway. Methods: Sprague-Dawley rats were divided into control groups (3-, 9-, 15- and 24-month old groups) and SPJ-treated groups. For SPJ-treated groups, SPJ were orally administrated to 18-month old rats at doses of 10 mg/kg, 30 mg/kg and 60 mg/kg once daily. Control groups were given the same volume of saline. After the treatment with SPJ or saline for six months, the cortex and hippocampus were rapidly harvested and deposited at -80°C after the rats were decapitated under anesthesia. The neuroprotective effects of SPJ were estimated by histopathological observation, TUNEL detection, biochemical determination and western blotting. Results: SPJ improved pathomorphological changes in neuronal cells and decreased apoptosis in the cortex and hippocampus of aging rats, increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), Na+/K+-ATPase, Ca2+-ATPase and Ca2+/Mg2+-ATPase whereas, decreased malondialdehyde (MDA) contents in the cortex of aging rats. Furthermore, the SPJ increased silent mating type information regulation 2 homolog-1 (SIRT1) protein expression, decreased acetylated level of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) in the cortex and hippocampus of aging rats, and reversed the aging-induced decline of Forkhead box O3 (Foxo3a), Superoxide Dismutase 2 (SOD2), microtubule-associated protein light chain 3 (LC3II) and Beclin1 levels in the cortex and hippocampus. Conclusion: Our data showed that SPJ conferred neuroprotection partly through the regulation of oxidative stress and mitochondria-related pathways in aging rats.

Background: The role of Fe+2, Cu+2 and Zn+2 in facilitating aggregation of Amyloid β (Aβ) and consequently, the progression of Alzheimer's disease (AD) is well established. Objective: Development of non-toxic metal chelators is an emerging era in the treatment of AD, in which complete success has not been fully achieved. The purpose of this study was to determine plant extracts with high metal chelator and to encapsulate them in nano-micellar systems with the ability to pass through the Blood Brain Barrier (BBB). Methods: Extracts of 36 different Anatolian plants were prepared, total phenolic and flavonoid contents were determined, and the extracts with high content were examined for their Fe+2, Cu+2 and Zn+2 chelating activities. Apolipoprotein E4 (Apo E) decorated nano-formulations of active extracts were prepared using Poly (Lactide-co-Glycolide) (PLGA) (final product ApoEPLGA) to provide BBB penetrating property. Results: Verbascum flavidum aqueous extract was found as the most active sample, incubation of which, with Aβ before and after metal-induced aggregation, resulted in successful inhibition of aggregate formation, while re-solubilization of pre-formed aggregates was not effectively achieved. The same results were obtained using ApoEPLGA. Conclusion: An optimized metal chelator nano-formulation with BBB penetrating ability was prepared and presented for further in-vivo studies.

Objective: The purpose of this paper was to study the protective effect of paeoniflorin on acute cerebral ischemia. The animal model of cerebral infarction induced by Middle Cerebral Artery Occlusion (MCAO) was blocked by the suture method. Sixty SD rats were randomly divided into the shame group, MCAO group, paeoniflorin (60, 120, 240 mg/kg, respectively) and Nimodipine (NMDP) group (n = 10 per group). Methods: The rats were intragastrically administered immediately after the operation. After 7 days of gavage, the brains were decapitated at 24 h. Hematoxylin and Eosin (HE) staining was used to observe the degree of cell damage in the cerebral cortex of rats. Immunohistochemistry was used to detect silver plating and to observe changes in nerve cells. Rats in the model group showed obvious symptoms of neurological deficits, such as the ischemic morphological changed, the Malondialdehyde (MDA), Lactate Dehydrogenase (LD) content and lactate dehydrogenase (LDH) activity were significantly increased in the ischemic brain tissue, while the Superoxide Dismutase (SOD) activity was decreased. Results: The decrease in Na+-K+-ATPase activity was significantly lower than that in the sham group. The neurological symptoms and signs of MCAO in the different doses of paeoniflorin group were improved, and the neuronal edema in the cortical area was alleviated. The activities of SOD, LDH and Na+-K+-ATPase were significantly increased, and the contents of MDA and LD were decreased. Conclusion: Therefore, paeoniflorin could alleviate the degree of tissue damage in rats with acute cerebral infarction, inhabit the formation of free radicals in the brain tissue after ischemia, and reduce the degree of lipid peroxidation. Thus, the degree of cell damage was reduced greatly and a protective effect was showed on cerebral ischemia.

Background and Objective: Coronary bypass operations are commonly performed for the treatment of ischemic heart diseases. Coronary artery bypass surgery with autologous human saphenous vein maintains its importance as a commonly used therapy for advanced atherosclerosis. Vascular inflammation-related intimal hyperplasia and atherosclerotic progress have major roles in the pathogenesis of saphenous vein graft disease. Methods: In our study, we investigated the effect of anacardic acid (AA), which is a bioactive phytochemical in the shell of Anacardium occidentale, on atherosclerosis considering its inhibitory effect on NF-ΚB. We observed relative ICAM-1 and NF-ΚB mRNA levels by qRT-PCR method in a TNF-α- induced inflammation model of saphenous vein endothelial cell culture after 0.1, 0.5, 1 and 5 μM of AA were applied to the cells. In addition, protein levels of ICAM-1 and NF-ΚB were evaluated by immunofluorescent staining. The results were compared between different concentrations of AA, and also with the control group. Results: It was found that 5 μM, 1 μM and 0.5 μM of AA had toxic effects, while cytotoxicity decreased when 0.1 μM of AA was applied both alone and with TNF-α. When AA was applied with TNF-α, there was a decrease and suppression in NF-ΚB expression compared with the TNF-α group. TNF-α-induced ICAM-1 expression was significantly reduced more in the AA-applied group than in the TNF-α group. Conclusion: In accordance with our results, it can be said that AA has a protective role in the pathogenesis of atherosclerosis and hence in saphenous vein graft disease.

Objective: To investigate the role of miR-205 and GATA3 in Pulmonary Fibrosis (PF). Methods: Bleomycin (BLM) was used to induce PF in SD rats and in vitro PF model was established by using TGFβ1-induced RLE-6TN cells. miR-205 mimics were used for the overexpression of miR- 205. The expression of miR-205, GATA3, α-SMA, Collagen I, CHOP and GRP78 were measured using RT-qPCR or western blotting. Dual-luciferase reporter assay was used to confirm binding between GATA3 3’-UTR and miR-205. Results: The expression of miR-205 was significantly down-regulated, while the expression of GATA3 was remarkably up-regulated in the model rats. GATA3 levels were remarkably decreased when miR-205 was overexpressed. When miR-205 was overexpressed, the lung injury by BLM-induced fibrosis was improved. The expression of α-SMA, Collagen I, as well as GRP78 and CHOP, was significantly up-regulated in both in vivo and in vitro PF models, and overexpression of miR-205 remarkably reversed the effects. Dual-luciferase reporter assay showed that miR-205 directly targeted and negatively regulated GATA3. Conclusion: miR-205 improved pulmonary fibrosis through inhibiting ER-stress by targeting GATA3.

Background: Placental blood vessels play important roles in maternal-fetal circulation. Although pathologic mechanisms of preeclampsia are unclear, it is known that placental vascular dysfunction could contribute to pregnant hypertension. However, placental micro-vessel function or dysfunction at preterm has not been investigated. Methods: Human placentas from normal and preeclamptic pregnancies at preterm and term were obtained. Placental micro-vessels were used for determining vascular tension and responses to various vasoconstrictors as well as intracellular calcium store capability. It was the first time to show vascular responses in placental arteries to angiotensin II, endothelin-1, and other vascular drugs at preterm. Results: Compared to the control, placental vascular contractile responses to angiotensin II and caffeine were significantly decreased, while placental vascular responses to KCl, endothelin-1, and bradykinin were not significantly altered in the later term group in preeclampsia. In comparison of placental micro-vessel tension between the preterm and later term, caffeine- and serotonin-induced vascular contractions were significantly weaker in the preterm than that in the later term. On the contrary, vascular response to angiotensin II was increased in the preterm preeclampsia, while KCl-, endothelin-1, and bradykinin-mediated placental vessel responses in the preterm preeclampsia were similar to that in later term preeclampsia. Conclusion: New data showed that micro-vessel responses to angiotensin II and serotonin, not endothelin- 1 or bradykinin, were significantly reduced in the human placentas at preterm, and intracellular Ca2+ store capacity was damaged too, providing important information on possible contributions of placental vascular dysfunction to pregnant hypertension.

Background: Melittin, the major medicinal component of honeybee venom, exerts antiinflammatory, analgesic, and anti-arthritic effects in patients with Rheumatoid Arthritis (RA). RA is an inflammatory autoimmune joint disease that leads to irreversible joint destruction and functional loss. Fibroblast-Like Synoviocytes (FLS) are dominant, special mesenchymal cells characterized by the structure of the synovial intima, playing a crucial role in both the initiation and progression of RA. Objective: In this study, we evaluated the effects of melittin on the viability and apoptosis of FLS isolated from patients with RA. Methods: Cell viability was determined using CCK-8 assays; apoptosis was evaluated by flow cytometry, and the expression levels of apoptosis-related proteins (caspase-3, caspase-9, BAX, and Bcl-2) were also determined. To explore whether melittin alters inflammatory processes in RA-FLS, IL-1β levels were determined using an enzyme-linked immunosorbent assay (ELISA). Furthermore, we performed GFP-LC3 punctate fluorescence dot assays and western blotting (for LC3, ATG5, p62, and Beclin 1) to assess autophagy in RA-FLS. Results: Our results show that melittin can significantly impair viability, promote apoptosis and autophagy, and inhibit IL-1β secretion in RA-FLS. Conclusion: Melittin may be useful in preventing damage to the joints during accidental local stimulation.

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Methods: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Results: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.