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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An investigation into the topical and systemic safety and efficacy of a new carbohydrate derived fulvic acid (CHD-FA) product

Sabi, Riaz Ahmed 16 February 2009 (has links)
Humic substances are a group of ubiquitous compounds formed during the decay of plant and animal residues in the environment. These substances can be divided into humic acid, fulvic acid and humin on the basis of its solubility in water as a function of pH. Fulvic acid is the fraction that is soluble in water under all pH conditions and is usually extracted from brown coal and is therefore associated with high levels of heavy metals. These heavy metal levels have become a point of concern and a unique method for synthesizing fulvic acid from a carbohydrate source has been subsequently developed and patented in an attempt to address this problem. The purpose of this study was therefore, to test the topical and systemic safety and efficacy of this new carbohydrate derived fulvic acid (CHD-FA) product. Initial in vitro screening using the Kirby-Bauer disk diffusion method indicated that the product was active against the Staphylococcus aureus test organisms used (ATCC 12600 and P3938). Results showed that not only was it as effective as the oxacillin control, but in the case of a more virulent strain of S. aureus, the CHD-FA (3.9% w/v) proved more active. Subsequently, the ability of the product to cross full-thickness skin was ascertained using Franz-type diffusion cells fitted with 100ìm skin disks obtained from rats. At the end of a 12-hr period, results indicated that up to 20% of the CHD-FA at a pH of 2.9 was able to cross the skin barrier. Divided into 6 phases, extensive animal safety studies were conducted on the product. In phase I, toxicity and sensitivity to topical application was examined by applying the product to the ears of mice over a period of 30 days. Phase II and III was undertaken to study the long term effects (6-weeks and 6-months) of CHD-FA ingestion (150 mg/kg body mass) whilst phase IV tested the effects of CHD-FA ingestion on pregnant rats and their off-spring. Phase V was an acute toxicity study in which rats received a single oral dose of CHD-FA (150mg/kg bw) and then observed for a period of 7 days. Phase VI was a 6-week chronic study in which the animals received 100mg/kg bw daily for the duration of the experiment. Results obtained in all studies showed that CHD-FA is safe for topical as well as, oral use at the doses tested. In addition, it is safe for use during pregnancy. Finally, the in vivo anti-microbial efficacy of the CHD-FA was examined using an infected wound healing model. A pilot study indicated that the animals used should be immunocompromised and the wounds inoculated with a Staphylococcus aureus (ATCC 12600) concentration of 1x1010 CFU/ml. Results from the main study showed that topical applications of the CHD-FA (pH 1.98) product at a concentration of 1.75% w/v over the 5-day period produced a wound healing pattern similar to that of the positive fuscidic acid control. In contrast, animals receiving an oral treatment of the product did not produce a pattern different from that of the water control group. In conclusion, CHD-FA has been shown to be safe and effective in treating S. aureus infections in vitro and in animal models. This study indicates that the next phase of human studies is certainly warranted. / Dissertation (MSc)--University of Pretoria, 2009. / Pharmacology / unrestricted
2

An investigation of the effects of fulvic and humic acids on the absorption of selected drugs, vitamins and minerals using the everted mouse gut model

Willis, Kirsten January 2015 (has links)
Humic substances, such as the closely related humic and fulvic acids are ubiquitous, naturally occurring organic macromolecules of complex but undefined structure. These compounds are known complexing agents due to their supramolecular like structures and are capable of binding a wide variety of compounds. Numerous studies have confirmed that humic and fulvic acids exhibit diverse medicinal and therapeutic properties. For this reason, alternative or “natural” medicinal preparations rich in these substances are being self-administered, often concomitantly with conventional drugs. The possibility exists that these humic substances, found in the alternative medicinal products, may result in drug-drug interactions and bind to simultaneously ingested drugs. Complex formation may affect absorption and alter overall bioavailability. Changes in these parameters may lead to reduced therapeutic effect or toxic side effects of prescribed drugs in patients. Similarly, these humic substances may bind to and alter the uptake of ingested nutrients, such as vitamins and minerals, obtained from food sources as well as dietary supplements. Changes in absorption may result in a loss of proper physiological functioning in the body or in unwanted effects of overdose. This study investigated the effect of fulvic and humic acids on the absorption of commonly administered classes of drugs, vitamins and minerals using the everted mouse gut model that was successfully used to assess the membrane transport of the test compounds. This model made use of everted segments of excised intestinal tissue placed in Krebs Ringer Buffer (pH7.4), where physiological functioning of the tissue is maintained for up to two hours after excision. The amount of test compound which crossed through the intestinal membrane without and in the presence of each humic substance was quantified using LC-MS/MS methods developed for each of the drugs and vitamins, and ICP-MS, in the case of the minerals. The amount of test compound absorbed alone was compared to the amount absorbed when in the presence of each humic substance. Changes in the uptake, for each test compound was noted, the extent of the absorption increase or decrease was compound specific. The changes in absorption observed could be attributed to changes in compound solubility and mechanism of transport across the intestinal membrane once in complex. Drugs and vitamins were seen to be more prone to decreases in absorption in the presence of the humic substances, whereas the majority of the minerals showed significantly increased absorption. Binding of the minerals to the humic substances through chelation, and not complex formation, could have a greater effect on compound solubility. Health care professionals, as well as individuals ingesting these and other substances concurrently, should be aware of the potential effects on absorption that may occur due to drug-drug interactions in order to avoid a loss of therapeutic/physiological activity or negative toxic symptoms. / Dissertation (MSc)--University of Pretoria, 2015. / tm2015 / Pharmacology / MSc / Unrestricted
3

The antimicrobial efficacy of a carbohydrate derived fulvic acid as a pre-periodontal procedure mouth rinse

Abrahams, Gadija January 2017 (has links)
Magister Chirurgiae Dentium - MChD (Oral Medicine and Periodontics) / The aim of this study was to assess whether a mouthwash containing carbohydrate derived fulvic acid, is effective in reducing the salivary microbial count pre-operatively. Endeavours have been made to reduce the risk of infection, bacteraemia and cross-contamination during dental procedures by the application of topical antimicrobial agents. To date chlorhexidine is the most widely evaluated and efficacious agent against oral biofilms but there have been reports of adverse effects ranging from contact dermatitis to severe anaphylactic shock. A new mouth rinse containing carbohydrate derived fulvic acid are reported to have broad spectrum antimicrobial activity against specific oral microbes and Candida albicans with no side effects.

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