Radioprotecting ability of the natural polyphenol, gallic acid (3,4,5-trihydroxybenzoic acid, GA), was investigated in Swiss albino mice. Oral administration of GA (100 mg/kg body weight), one hour prior to whole body gamma radiation exposure (2–8 Gy; 6 animals/group), reduced the radiation-induced cellular DNA damage in mouse peripheral blood leukocytes, bone marrow cells, and spleenocytes as revealed by comet assay. The GA administration also prevented the radiation-induced decrease in the levels of the antioxidant enzyme, glutathione peroxidise (GPx), and nonprotein thiol glutathione (GSH) and inhibited the peroxidation of membrane lipids in these animals. Exposure of mice to whole body gamma radiation also caused the formation of micronuclei in blood reticulocytes and chromosomal aberrations in bone marrow cells, and the administration of GA resulted in the inhibition of micronucleus formation and chromosomal aberrations. In irradiated animals, administration of GA elicited an enhancement in the rate of DNA repair process and a significant increase in endogenous spleen colony formation. The administration of GA also prevented the radiation-induced weight loss and mortality in animals (10 animals/group) exposed to lethal dose (10 Gy) of gamma radiation. (For every experiment unirradiated animals without GA administration were taken as normal control; specific dose (Gy) irradiated animals without GA administration serve as radiation control; and unirradiated GA treated animals were taken as drug alone control).

Despite the various reports on the toxicity of clove oil and its major component eugenol, systematic evaluations on the safety of polyphenolic extracts of clove buds have not been reported. Considering the health beneficial pharmacological effects and recent use of clove polyphenols as dietary supplements, the present study investigated the safety of a standardized polyphenolic extract of clove buds (Clovinol), as assessed by oral acute (5 g/kg b.wt. for 14 days) and subchronic (0.25, 0.5 and 1 g/kg b.wt. for 90 days) toxicity studies on Wistar rats and mutagenicity studies employing Salmonella typhimurium strains. Administration of Clovinol did not result in any toxicologically significant changes in clinical/behavioural observations, ophthalmic examinations, body weights, organ weights, feed consumption, urinalysis, hematology and clinical biochemistry parameters when compared to the untreated control group of animals, indicating the no observed-adverse-effect level (NOAEL) as 1000 mg/kg b.wt./day; the highest dose tested. Terminal necropsy did not reveal any treatment-related histopathology changes. Clovinol did not show genotoxicity when tested on TA-98, TA-100 and TA-102 with or without metabolic activation; rather exhibited significant antimutagenic potential against the known mutagens, sodium azide, NPD and tobacco as well as against 2-acetamidoflourene, which needed metabolic activation for mutagenicity.

Drug delivery systems capable of delivering free (unconjugated) curcuminoids is of great therapeutic significance, since the absorption of bioactive and permeable form plays a key factor in mediating the efficacy of a substance which undergoes rapid biotransformation. Considering the recent understanding on the relatively high bioactivities and blood-brain-barrier permeability of free curcuminoids over their conjugated metabolites, the present human study investigated the safety, antioxidant efficacy, and bioavailability of CurQfen (curcumagalactomannoside [CGM]), a food-grade formulation of natural curcumin with fenugreek dietary fiber that has shown to possess improved blood-brain-barrier permeability and tissue distribution in rats. In this randomized double-blinded and placebo-controlled trial, 60 subjects experiencing occupational stress-related anxiety and fatigue were randomized to receive CGM, standard curcumin, and placebo for 30 days (500 mg twice daily). The study demonstrated the safety, tolerance, and enhanced efficacy of CGM in comparison with unformulated standard curcumin. A significant improvement in the quality of life (P < 0.05) with considerable reduction in stress (P < 0.001), anxiety (P < 0.001), and fatigue (P < 0.001) was observed among CGM-treated subjects as compared with the standard curcumin group, when monitored by SF-36, Perceived Stress Scale with 14 items, and Beck Anxiety Inventory scores. Improvement in the quality of life was further correlated with the significant enhancement in endogenous antioxidant markers (P < 0.01) and reduction in lipid peroxidation (P < 0.001). Further comparison of the free curcuminoids bioavailability after a single-dose (500 mg once per day) and repeated-dose (500 mg twice daily for 30 days) oral administration revealed enhanced absorption and improved pharmacokinetics of CGM upon both single- (30.7-fold) and repeated-dose (39.1-fold) administrations.

Despite the various reports on the pharmacology of Clove bud [Syzygium aromaticum]-derived essential oil and its major component eugenol, systematic information on the bioactivity of clove polyphenols is very limited. Clove buds being one of the richest sources of dietary polyphenols with many traditional medicinal uses, the present contribution attempted to derive their standardized polyphenol-rich extracts as a water soluble free flowing powder (Clovinol) suitable for functional food applications, without the issues of its characteristic pungency and aroma. The extract was characterized by electrospray ionization-time of flight mass spectrometry (ESI-TOF-MS), and investigated for in vivo antioxidant, anti-inflammatory and anti-ulcerogenic activities. Clovinol showed significant antioxidant and anti-inflammatory effects as measured by cellular antioxidant levels, and the ability to inhibit carrageenan-induced paw swelling in mice. Further investigations revealed its significant anti-ulcerogenic activity (>97% inhibition of ethanol-induced stomach ulcers in Wistar rats when orally administered at 100 mg per kg b.w.) and up regulation of in vivo antioxidants such as superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT). Clovinol also reduced the extent of lipid peroxidation among ulcer induced rats, indicating its usefulness in ameliorating oxidative stress and improving gastrointestinal health, especially upon chronic alcohol consumption. The extract was also shown to be safe and suitable for further investigations and development upon acute toxicity studies at 5 g per kg body weight and 28 days of repeated dose toxicity studies at 2.5 g per kg b.w.

Purpose: To assess the transretinal penetration of intravitreally injected retinal multicell-derived exosomes and to develop exosome-based active targeting of choroidal neovascularization (CNV) by bioengineering with ASL, which is composed of a membrane Anchor (BODIPY), Spacer (PEG), and targeting Ligands (cyclic RGD peptide). Methods: Retinal multicell-derived exosomes were recovered from a whole mouse retina using differential ultracentrifugation. Their size, number, and morphology were characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Exosome markers were confirmed using an exosome detection antibody array. Intravitreal injection of fluorescent (PKH-26)-labeled or engineered ASL exosomes (1 × 10⁶ exosomes/μL) were given to the wild-type mouse or laser-induced CNV mouse model. Retinal uptake of exosomes was assessed by in vivo retinal imaging microscopy and histological staining with DAPI, GSA, and anti-integrin α_v for retinal sections or choroid/RPE flat mounts. Active targeting of CNV was assessed by comparing retinal uptake between areas with and without CNV and by colocalization analysis of ASL exosomes with integrin α_v within CNV. Staining with anti-F4/80, anti-ICAM-1, and anti-GFAP antibodies on retinal sections were performed to identify intracellular uptake of exosomes and immediate reactive retinal gliosis after exosome treatment. Results: An average of 2.1 × 10⁹ particles/mL with a peak size of 140 nm exosomes were recovered. Rapid retinal penetration of intravitreally injected exosomes was confirmed by retinal imaging microscopy at 3 and 24 h post-injection. Intravitreally delivered PKH-26-labeled exosomes reached inner and outer retinal layers including IPL, INL, OPL, and ONL at 1 and 7 days post-injection. Intravitreally injected ASL exosomes were predominantly delivered to the area of CNV including ONL, RPE, and choroid in laser-induced CNV mouse models with 89.5% of colocalization with integrin α_v. Part of exosomes was also taken intracellularly to vascular endothelial cells and macrophages. After intravitreal injection, neither naive exosomes nor ASL exosomes induced immediate reactive gliosis. Conclusions: Intravitreally delivered retinal multicell-derived exosomes have good retinal penetration, and ASL modification of exosomes actively targets CNV with no immediate reactive gliosis. ASL exosomes have a great potential to serve as an intraocular drug delivery vehicle, allowing an active targeting strategy.