This study investigated the effects of vitamin C on oxidative stress induced by volatile anesthetics in pigs. One group of pigs was used as an anesthesia control group (group 1), and they were anesthetized with isoflurane in oxygen and saline (0.9% NaCl) was injected intravenously. The other group (group 2) was anesthetized with isoflurane and injected intravenously with vitamin C. Total oxidant status, total antioxidant status, and the oxidative stress index in group 2 were significantly different compared with those in group 1. The results showed that intravenous administration of vitamin C decreased oxidative stress during isoflurane anesthesia in pigs.
Administration, Intravenous ; Anesthesia ; Anesthetics ; Ascorbic Acid ; Isoflurane ; Oxidative Stress ; Oxygen ; Swine ; Vitamins

Changes in the intraoular pressure and serum osmolarity were investigated in albino rabbits after intravenous and topical administrations of ascorbic acid. Twenty percent solution of ascorbic acid administered intravenously produced reduction in intraocular pressure from 24.3 mmHg. to 14.0 mmHg. in 10 minutes. The lowering was maintained for 30 minutes followed by low recovery. The serum osmolarity rose from 285.1 mOsm. to 302.0 mOsm. in 10 minutes, and returned gradually thereafter. Intravenous injection of 10 % ascorbic acid brought about milder drop in intraocular pressure, from 21.7 mmHg. to 16. 9 mmHg and more rapid recovery. The serum osmolarity rose from 282.0 mOsm. to 290 mOsm and returned to the original level. No significant changes in the intraocular pressure were observed after the instillation of 10 % ascorbic acid solution.
Administration, Topical ; Ascorbic Acid* ; Injections, Intravenous ; Intraocular Pressure* ; Osmolar Concentration* ; Rabbits*

BACKGROUND: Intravenous administration of high doses of ascorbic acid (AA) for certain clinical conditions can cause high levels of blood AA to interfere with the measurement of blood glucose. In this study, we evaluated the potential interference by high concentrations of blood AA with glucose measurement in different instruments. METHODS: Using Hitachi 7600 chemistry autoanalyzer (Hitachi 7600) and Accu-Chek Active monitor glucometer (Accu-Check), glucose was measured in serum specimens in which AA had been added in vitro at concentrations ranging from 0 to 28, 388 micromol/L. To assess the effect of pharmacokinetics of AA on glucose concentrations, blood AA and glucose were measured serially in healthy subjects after 10 g of IV Vitamin C supplement was administered. RESULTS: Beginning at the concentration of 227 micromol/L, the blood AA interfered with glucose measurement negatively in Hitachi 7600, but positively in Accu-Chek. The extent of interference was proportional to AA concentrations in both directions. The in vivo study showed that, although both instruments were affected by high blood AA at 1 hour of IV administration, blood glucose levels were normalized at 5 hours in Hitachi 7600 and at 3 hours in Accu-Chek. CONCLUSIONS: When considering that IV high dose AA supplement is becoming more popular and the extent of its interference with blood glucose measurement is significantly high in commercial systems, it would be important for the clinical laboratory to be informed of the prescription informations of patients and the time of blood collection, and to choose a correct system for an accurate blood glucose measurement.
Administration, Intravenous ; Ascorbic Acid* ; Blood Glucose* ; Chemistry ; Glucose ; Humans ; Pharmacokinetics ; Prescriptions

The effects of topical dexamethasone on the endothelial healing and the change of aqueous composition were examined in the repair process of experimental corneal alkali wounds. Corneal alkali wounds were induced, then the eyes were treated topically with either 0.1%dexamethasone or abalanced salt solution[BSS]4 times per day for 8 weeks. Endothelial wound morphometry was performed after alizarin red and trypan blue staining. The concentrations of ascorbic acid, glucose, and the ions, Na, K , Ca2 and Mg2 , were measured in the aqueous humor. Endothelial healing in control corneas showed a biphasic pattern of healing:an initial short-term healing for the first week and then a late long-term healing following a secondary endothelial breakdown. Topical administration of 0.1%dexamethasone deterred endothelial healing during the early period and prevented secondary endothelial breakdown. Total repair process of endothelium was accelerated by the dexamethasone treatment. Among the various components of the aqueous humor examined, ascorbic acid seemed most sensitive to change caused by the alkali injury and dexametha-sone treatment. The present data indicate that dexamethasone may have a therapeutic potential in the management of endothelial healing after corneal alkali injury.
Administration, Topical ; Alkalies* ; Aqueous Humor ; Ascorbic Acid ; Cornea ; Dexamethasone ; Endothelium ; Glucose ; Ions ; Trypan Blue ; Wounds and Injuries*

BACKGROUND: Although there are several available management strategies for treatment of both acute pain of herpes zoster (HZ) and postherpetic neuralgia (PHN), it is difficult to treat them adequately. OBJECTIVE: The aim of this study was to evaluate the efficacy of intravenously administrated vitamin C on acute pain and its preventive effects on PHN in patients with HZ. METHODS: Between September 2011 and May 2013 eighty-seven patients who were admitted for HZ were assessed according to age, sex, underlying diseases, duration of pain and skin lesion, dermatomal distribution, and PHN. It was a randomized controlled study, in which 87 patients were randomly allocated into the ascorbic acid group and control group. Each patient received normal saline infusion with or without 5 g of ascorbic acid on days 1, 3, and 5 then answered questionnaires that included side effects and pain severity using visual analogue scale on days 1, 2, 3, 4, and 5. After discharge, the severity of pain was obtained at out-patient clinic or by telephone on weeks 2, 4, 8, and 16. RESULTS: There was no differences in severity of pain on patients' age, sex, underlying diseases, duration of pain and skin lesion and dermatomal distribution between two groups (p>0.05). Since 8th week, pain score in ascorbic acid treatment group was significantly lower than control group (p <0.05). The incidence of PHN was significantly lower in the treatment group compared to control group (p=0.014). The changes of overall pain score was significantly different between the two groups (p<0.05). CONCLUSION: Intravenously administered ascorbic acid did not relieve acute HZ pain; but is effective for reducing the incidence of PHN.
Acute Pain ; Administration, Intravenous* ; Ascorbic Acid* ; Herpes Zoster ; Humans ; Incidence ; Neuralgia, Postherpetic* ; Outpatients ; Skin ; Telephone ; Vitamins*

Administration, Intravenous ; Ascorbic Acid/therapeutic use* ; COVID-19 ; Humans ; Pneumonia ; SARS-CoV-2

A high performance liquid chromatography (HPLC) paired with UV-vis detection method to determine ascorbic acid and its oxidation product, dehydroascorbic acid, in human plasma was developed. Ascorbic acid in human plasma was extracted and stabilized using 10% metaphosphoric acid, and was analyzed by a Symmetry C18 column with 5 mM Hexadecyltrimethylammonium bromide and 50 mM KH2PO4 solution as the mobile phase (1.0 mL/min flow rate). Isoascorbic acid served as the internal standard and ultraviolet detector wavelength was 254 nm and 265 nm. Dehydroascorbic acid concentration was calculated from the differences in ascorbic acid concentration before and after reduction by dithiothreitol reagent. Quantification for ascorbic acid in human plasma was linear from 1–100 µg/mL. The inter- and intra-day precisions and accuracy were determined and the results were found to be within ±15%. This method was successfully applied to a human pharmacokinetic study of ascorbic acid as well as dehydroascorbic acid after oral administration of 4,000 mg vitamin C tablets to healthy Korean volunteers.
Administration, Oral ; Ascorbic Acid* ; Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Dehydroascorbic Acid* ; Dithiothreitol ; Humans* ; Plasma* ; Tablets ; Volunteers

Adult ; Ascorbic Acid ; administration & dosage ; analysis ; Humans ; Male ; Nutrition Surveys ; Occupational Health ; Riboflavin ; administration & dosage ; analysis ; Thiamine ; administration & dosage ; analysis ; Vitamins ; administration & dosage ; analysis

Administration, Oral ; Adult ; Antioxidants ; administration & dosage ; pharmacology ; Ascorbic Acid ; administration & dosage ; pharmacology ; Humans ; Lipid Peroxidation ; drug effects ; Male ; Middle Aged ; Occupational Health ; Vitamin E ; administration & dosage ; pharmacology

OBJECTIVETo explore the anesthetic effects of repeated administration of propofol combined with vitamin C in mice.

METHODSForty mice were subjected to daily intraperitoneal injections of 80 mg/kg propofol (P80 group), 70 mg/kg propofol and 50 mg/kg vitamin C (P70+Vc50 group), 55 mg/kg propofol and 100 mg/kg vitamin C (P55+Vc100 group), or 50 mg/kg propofol and 200 mg/kg vitamin C (P50+Vc200 group) for 6 consecutive days, and the anesthesia induction time and anesthesia duration were recorded.

RESULTSCompared with the P80 group, the mice in P55 + Vc100 group and P50 + Vc200 group showed significantly shorter anesthesia duration on the first 3 days (P<0.05). In all the groups, anesthesia duration was significantly shortened in the following days compared with that on day 1 (P<0.01); anesthesia duration was shorter on day 3 than on day 2 in P50 + Vc200 group (P<0.01), and was shorter on days 4, 5, and 6 than on day 2 in all the groups (P<0.01). In all the groups, the rate of loss of righting reflex (LORR) decreased gradually with time in a similar pattern.

CONCLUSIONVitamin C can reduce the dose of propofol without obviously affecting the anesthetic effect to reduce the incidence of drug tolerance and potential dose-related side effects of propofol.

Anesthesia ; Anesthesia Recovery Period ; Anesthetics, Intravenous ; administration & dosage ; pharmacology ; Animals ; Ascorbic Acid ; administration & dosage ; pharmacology ; Drug Tolerance ; Mice ; Propofol ; administration & dosage ; pharmacology