Antioxidant activity of Sophora exigua and liposome development of its powerful extract.

Sophora exigua (SE) was sequentially extracted using hexane, ethyl acetate, and ethanol. The obtained extracts were tested for antioxidant activity. Among them, the fractionated ethyl acetate extract (SE-EA) showed the highest potential in free radical scavenging and ferric-reducing properties. The chemical analysis identified sophoraflavanone G as one of the active ingredients in SE-EA. According to SE-EA solubility, SE-EA liposomes were developed using a sonication-assisted thin film method. Cholesterol and phospholipids were used as the main compositions of the liposomes. The obtained liposomes were spherical with different nano-size ranges, size distribution, and zeta potential depending on SE-EA and total lipid concentrations. SE-EA liposomes were slightly bigger than their empty liposomes. All liposomes exhibited a phospholipid crystalline structure. Cholesterol and SE-EA existed in the liposomes as an amorphous state. SE-EA liposomes with high total lipid content exhibited high entrapment efficiency and sustained release behavior. Whereas liposomes with low total lipid content showed low entrapment efficiency and fast-release behavior. All SE-EA liposomes showed stronger antioxidant activity than the non-entrapped SE-EA. In conclusion, SE-EA is a natural source of potent antioxidants. The developed SE-EA liposomes are a promising pharmaceutical formulation to efficiently deliver the active ingredients of SE-EA and are suitable for further study in vivo.

Antioxidant, antiglycation, and anti-inflammatory activities of Caesalpinia mimosoides.

Oxidative stress, glycation and inflammation are the main causes of many severe diseases. To date, no single extract has been shown to simultaneously inhibit these three reactions. In this study, the antioxidant, antiglycation and anti-inflammatory activities of ethanol extracts from four edible plants that are commonly used as Thai folk medicine were compared. Among these extracts, Caesalpinia mimosoides extract (CME) showed the highest antioxidant potential with Trolox equivalent antioxidant activity (TEAC) of 5.9 ± 0.1 mM/mg followed closely by Zingiber officinale extract (ZOE) with a TEAC value of 5.4 ± 0.2 mM/mg. However, CME showed no cytotoxicity, whereas ZOE greater than 60 µg/mL showed cytotoxicity to normal human cells. Antiglycation assay using bovine serum albumin-ribose showed comparable potency between CME and Spondias dulcis extract (SDE). However, CME exhibited a high anti-inflammatory activity, significantly higher than SDE and activity depending on the dose. At a concentration of 60 µg/mL, approximately 85% of the interleukin-6 pro-inflammatory cytokine produced from human monocytes, induced by lipopolysaccharides, was completely inhibited by CME whereas SDE showed no inhibition. In summary, CME is the most potential extract with simultaneously activity of these three reactions. CME has the highest total phenolic content expressed as gallic acid equivalent to 301 ± 8 mg/g. Identification using high-performance liquid chromatography revealed the presence of at least four phenolic compounds, gallic acid, syringic acid, p-coumaric acid, and ellagic acid are existed in CME. Our finding suggests that CME is a promising natural source for inhibition of oxidative stress, glycation, and inflammation.

Doxorubicin-Loaded Polymeric Micelles Conjugated with CKR- and EVQ-FLT3 Peptides for Cytotoxicity in Leukemic Stem Cells.

Doxorubicin (Dox) is the standard chemotherapeutic agent for acute myeloblastic leukemia (AML) treatment. However, 40% of Dox-treated AML cases relapsed due to the presence of leukemic stem cells (LSCs). Thus, poloxamer 407 and CKR- and EVQ-FLT3 peptides were used to formulate Dox-micelles (DMs) and DM conjugated with peptides (CKR and EVQ) for improving AML-LSC treatment. Results indicated that DMs with a weight ratio of Dox to P407 of 1:200 had a particle size of 23.3 ± 1.3 nm with a high percentage of Dox entrapment. They were able to prolong drug release and maintain physicochemical stability. Following effective DM preparation, P407 was modified and conjugated with FLT3 peptides, CKR and EVQ to formulate DM-CKR, DM-EVQ, and DM-CKR+DM-EVQ. Freshly synthesized DMs displaying FLT3 peptides showed particle sizes smaller than 50 nm and a high drug entrapment level, comparable with DMs. DM-CKR+DM-EVQ was considerably more toxic to KG-1a (AML LSC-like cell model) than Dox-HCl. These FLT3-targeted DMs could increase drug uptake and induce apoptosis induction. Due to an increase in micelle-LSC binding and uptake, DMs displaying both peptides tended to improve the potency of Dox compared to a single peptide-coupled micelle.