Rosa roxburghii, also known as "Burr Rose" or "Chestnut Rose", originated in
southwest China and was introduced to the botanic garden in Calcutta around
1824. It was named after William Roxburgh who was the superintendent. The
extract of fruit of the Rosa roxburghii plant is the base ingredient of a range of
products that is commercially sold under the Cili Bao label. The extract is
composed of a wide range of substances of nutritional value, in particular a
relatively high amount of antioxidants such as ascorbate and plant phenols. It
has been reported before that supplementation with the fruit extract
resulted in increased red blood cell superoxide dismutase, catalase and the
reduced form of glutathione. An enhancement of the antioxidant status could
contribute to the protection against several diseases where oxidative stress is a
major factor in the pathology, such as atherosclerosis, cancer and immunity
stress. Several anecdotal reports with little (published) scientific support claim
that human supplementation of the Rosa roxburghii extract to the diet has a
protective effect against several diseases, including the above mentioned.
Medicinal and herbal plants are used in large sections in developing countries for
primary care and there is now also an increase in the use of natural therapies in
developed countries. However, plant extracts can also consist of anti-nutritional
and possible toxic components, such as oxalic acid and nitrates, which could
express cytotoxic and genotoxic activities. Therefore, understanding the health
benefits but also the potential toxicity of these plants is important. The objective
of this study was to investigate the beneficial properties of Rosa roxburghii
extract from an antioxidant potential perspective and in particular to investigate
the safety of the product for human consumption. For this purpose in vitro
evaluation of the cellular toxicity, mutagenicity and genotoxicity was performed.
In addition, specific biochemical parameters relating to the antioxidant status of
the product, i.e. antioxidant capacity, oxidative stress prevention and glutathione
redox state profiles were investigated in vitro as well as in vivo.
The results indicated that Rosa Roxburghii fruit extract was not mutagenic when
tested with Salmonella typhimurium strains TA 98, TA 100 and TA 102 in the
Ames test. The results, however, pointed towards an antimutagenic effect of the
extract in these strains against metabolic activated mutagens 2-
acetylaminoflurorene (2-AAF) and aflatoxin B1, and the direct-acting mutagen,
methanesulfonate (MMS). In primary rat hepatocyte, Rosa roxbughii extract did
not elicit double or single strand DNA damage and cell viability loss using the
single cell gel electrophoresis (Comet assay), lactate dehydrogenase leakage
test or the mitochondria1 conversion test of MTT to formazan (MTT test). Again
the opposite effect was observed: pre-treatment of hepatocytes with Rosa
roxbughii extract significantly reduced the effect of oxidative stress-induced
cellular- and genotoxicity. These results point to a protective effect against
oxidative stress which is reflected in an increase of the antioxidant capacity and
glutathione redox state (GSH/GSSG) in vitro (lymphoblasts) and in vivo (humans)
reported in this study. This study underlines the previously suggested potential of
this plant extract as a natural and safe antioxidant supplement. / Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2004.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nwu/oai:dspace.nwu.ac.za:10394/191 |
| Date | January 2003 |
| Creators | Janse van Rensburg, Catharina Scholtz |
| Publisher | North-West University |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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