Background: Herbal practitioners in the Eastern Cape of South Africa use valerian root (Valeriana capensis, Valerianaceae) to manage pains, arthritis and inflammation. The herb prepared from this plant was studied to determine the chemical composition of its essential oil, carried out phytochemical screening and biological activities on its infusion extract as used by the herbal practitioner. Materials and Methods: Essential oil of Valerian root was obtained by hydrodistillation and subjected to chemical analyses. Infusion extract of the Valerian root was screened to determine its secondary metabolites and the relative abundance of some major metabolites. The infusion extract was further evaluated for acute toxicity (LD50), anti-inflammatory and analgesic activities in rodents. Results: The yield of the essential oil was 0.18% w/w. The GC/MS analysis indicated the presence of 42 compounds with major ones being caryophyllene oxide (18.11%), viridiflorol (9.37%) and bornyl acetate (8.84%). Phytochemicals found in the infusion extract were alkaloids, saponins, tannins and flavonoids while quantitative screenings showed saponins and flavonoids accounted for 6.39% and 7.40% respectively. The LD50 of the extract was found to be 3808 mg/kg per oral. The infusion extract of the root (250-500 mg/kg, p.o.) caused significant (p<0.01) activity in the carrageenan-induced rat paw oedema model comparable to aspirin, indicating anti-inflammatory activity; but lacked analgesic activity on the acetic acid-induced writhing test.
Conclusion:The infusion extract possessed significant anti-inflammatory but lacked analgesic activity; the present data justify the use of this herbal agent by the herbal practitioners from the Eastern Cape region of South Africa.
Key words:Valeriana capensis, essential oil, caryophyllene oxide, infusion extract, anti-inflammatory, analgesic
IntroductionMedicinal plants have been in use for centuries in South Africa, especially in the rural communities throughout the Eastern Cape Province where many people consult traditional healers who use medicinal plants as major sources of their medication (Cocks and Moller, 2002). Valerian root (Family: Valerianaceae) is a perennial flowering plant with over 350 species and several more subspecies (Bardakci et al., 2012). Valerian is native to Europe and Asia, although it has been naturalized in Eastern North America and other parts of the world including South Africa (Van Wyk et al., 1997). The part of the plant used medicinally is the root or rhizome which is light grayish brown, about the size of a finger joint, bearing many rootlets. The mature plant is about 50-150 cm tall with pinnate leaves and the stem is upright and without branches (Fleming, 1998). Valerian fresh root has no odour, while the dried root possesses distinctly unpleasant smell similar to old dirty socks (Schulz et al., 1998).Valerian is a popular herbal product often used to treat insomnia, anxiety and related ailments (Murti et al., 2011). Valerian root extracts contain essential oils...
