Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Soudan → Quality of medicinal plants traditionally used in Sudan as affected by ionizing radiation treatments

University of Khartoum (2009)

Quality of medicinal plants traditionally used in Sudan as affected by ionizing radiation treatments

Ahmed Abdalla Musa, Hala

Titre : Quality of medicinal plants traditionally used in Sudan as affected by ionizing radiation treatments

Auteur : Ahmed Abdalla Musa, Hala

Université de soutenance : University of Khartoum

Grade : Doctor of Philosophy (PhD) 2009

Résumé
This investigation was conducted to study the effect of gammaradiation doses of 5, 10 and 15 KGy on the microbial and chemical quality as well as antioxidant activity of nine medical plants from 8 plant species grown in Sudan. The plant materials were collected from the country-side of Khartoum State as well as from local markets. Plant parts were selected according to their traditional uses as medicinal plants. Irradiation treatment was carried out for dried ground samples using doses of 5, 10, 15 KGy from experimental cobalt-60 Gamma source. Plants extracts were prepared using 80% methanol. The control and irradiated samples were analyzed for total bacterial count (cfu/g), secondary compounds, tannin content, total phenol, and antioxidant activity. Tannins, flavonoids, glycosides, anthraqinones, saponin and phenols were evaluated through major compounds in extracts. The total bacterial count indicated that the non-irradiated samples of Trigonella foenum-graecum L., Cassia senna (pods), Cassia senna (leaves), Acacia nilotica L., Brassica nigra L. Koch, Lepidium sativum L., Cymbopogon citratus and Hibiscus sabdariffa L. were highly contaminated with bacteria. The sample of Cymbopogon schoenanthus L. showed a lower count of bacteria (9×103 CFU/g), which did not exceed the acceptable level. The samples irradiated with 5, 10 and 15 KGy of gamma radiation dose had significantly lower bacterial counts than the non-irradiated control. The highest sensitivity to gamma rays at 5 KGy dose was observed in Trigonella foenum-graecum L. and Acacia nilotica L. while the lowest sensitivity was in Cymbopogon schoenanthus L. At 15 KGy dose Hibiscus sabdariffa L. and Cymbopogon citratus showed complete absence of microorganisms. The highest reduction in tannin content (mg/L catechin) due to irradiation with 15 KGy dose was observed in Cymbopogon citratus, followed by Cymbopogon schoenanthus L., Cassia senna L. leaves, Acacia nilotica L. and Hibiscus sabdariffa L.. Irradiation with 15 KGy dose increased the tannin content in Brassica nigra L. Koch, Trigonella foenumgraecum L., Lepidium sativum L. and Cassia senna L. (pods). Irradiation with 15 KGy dose caused slight increase in phenol content in Brassica nigra L. Koch followed by Cassia senna L. (pods) with highest increase observed in Cassia senna L. (leaves) followed by Lepidium sativum L. and Cymbopogon schoenanthus L. Irradiation with 15 KGy dose reduced the phenol content of Trigonella foenum-graecum L., Hibiscus sabdariffa L., Acacia nilotica and Cymbopogon citratus. Irradiation with 15 KGy dose resulted in an insignificant increase in the DPPH radical-scavenging ability of the extracts of Lepidium sativum, Cymbopogon schoenanthus L. and Trigonella foenum-graecum L., compared to the non-irradiated samples. Cassia senna L. pods, Cassia senna leaves, Brassica nigra, Hibiscus sabdariffa and Cymbopogon citratus, showed insignificant decrease in the radical-scavenging ability, and also there was no effect on the antioxidant potential of Acacia nilotica L. xiii It appeared that the high dose 15 KGy of gamma irradiation was the most suitable dose for microbial decontamination of the tested plants. Only Cymbopogon citratus and Hibiscus sabdariffa L. achieved commercial sterility (i.e. a total aerobic plate counts of <10 cfu/g). However, gamma radiation at a dose greater than 15 KGy may be required to achieve commercial sterility.

Présentation

Version intégrale (0,89 Mb)

Page publiée le 9 avril 2018