ABSTRACT
Objective: To decipher the responsible compound present in the aqueous root extract of Vetiveria zizanioides which has tremendous immunomodulatory activity. Methods: Different fractions of the water extract were collected and analyzed for immunomodulatory activity by analyzing in vitro phagocytic activity and nitric oxide production. One fraction VF3 was selected and further analyzed for possible compounds by high performance liquid chromatography and gas chromatography coupled with a mass spectrometer. The in vitro immunomodulatory parameters such as phagocytic index, nitrite content, and tumor necrosis factor-α production in murine macrophages were analyzed. In vivo studies, sheep red blood cell induced haemagglutination titer, the number of antibody-producing cells, and sheep red blood cell induced delayed-type hypersensitivity were analyzed. Cytotoxic studies in L929 normal fibroblasts were also performed. Results: One of the fractions, VF3, was selected and confirmed the presence of an active compound valencene. The in vitro immunomodulatory parameters were significantly (P<0.05) increased by valencene treatment. In vivo studies in Swiss albino mice showed that valencene could significantly (P<0.05) increase haemagglutination titer, the number of antibody-producing cells, and delayed-type hypersensitivity. Cytotoxic studies also showed that valencene did not cause any morphological changes and DNA damage in normal fibroblasts. Conclusions: Valencene possesses immunomodulatory activities and can be commercially exploited for its immunostimulatory potentials.
ABSTRACT
Experiments were conducted to evaluate lead tolerance and accumulation in vetiver grass Vetiveria zizanioides (L.), grown in hydroponics and a pot study and to examine the effect of lead on vetiver oil production. Elevated concentrations of lead decreased the length of shoots and roots of plants. However, vetiver grown in highly contaminated soils showed no apparent phytotoxicity symptoms. Lead concentrations in the shoots and roots of vetiver plants grown in hydroponics were up to 144 and 19530 mg kg-1 and those grown in soil were 38 and 629 mg kg-1, respectively. Lead had an effect on vetiver oil production and composition by stimulating oil yield and the number of its constituents. Oil yield ranged from 0.4-1.3%; the highest yields were found in plants grown in nutrient solution with 100 mg Pb l-1 for 5 weeks (1.29%) and 7 weeks (1.22%). The number of total constituents of vetiver oil also varied between 47-143 compounds when lead was present in the growth medium. The highest number (143) was found in plants grown in soil spiked with 1000 mg Pb kg-1. The predominant compound was khusimol (10.7-18.1%) followed by (E)-isovalencenol (10.3-15.6%). Our results indicated that lead could increase the oil production of vetiver.