valencene and humulene

The present study is designed to find out if sesquiterpenes, α-humulene (HUM), valencene (VAL), β-caryphyllene-oxide (CAO) and trans-nerolidol (NER), are able to improve the antiproliferative effect of classical cytostatic drugs, 5-fluorouracil (FU) and oxaliplatin (1,2-diaminocyclohexaneoxalato-platinum, OxPt), in colon cancer cell lines Caco-2 and SW-620. In addition, the possible mechanisms of sesquiterpene action are studied. The results show significant ability of HUM and especially of CAO to enhance the anti-proliferative effects of FU and OxPt in cancer cell lines Caco-2 and SW-620. On the other hand, VAL and NER are ineffective. The action of CAO could be partly based on its ability to disrupt the mitochondrial membrane potential and to activate initiator caspases, but other mechanisms are probably also involved. Based on these results, CAO seems to have the potential for combination therapy of colon cancers and deserves further study.

Topics: Caco-2 Cells; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Fluorouracil; Humans; Membrane Potential, Mitochondrial; Monocyclic Sesquiterpenes; Oxaliplatin; Polycyclic Sesquiterpenes; Sesquiterpenes

Topics: Cell Line, Tumor; Cell Proliferation; Cell Survival; Doxorubicin; Drug Resistance, Multiple; Drug Synergism; Drug Therapy, Combination; Humans; Monocyclic Sesquiterpenes; Myrica; Oils, Volatile; Polycyclic Sesquiterpenes; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Sesquiterpenes

Oviposition site-selection in insects is mediated through innate recognition templates (IRTs) tuned to specific chemical cues. These cues aid gravid insects in choosing suitable oviposition sites and may even enhance the fitness of their offspring by warding off predators and parasitoids. However, studies on the evolution of oviposition site-selection and cues instigating oviposition in domesticated insects remain elusive. Using the interaction between the silkmoth, Bombyx mori, and its host plant mulberry, Morus alba, as a model system, we demonstrate that centuries of domestication of silkmoth has not impaired its oviposition site-selection function. Silkmoths significantly preferred mulberry leaves to filter paper as oviposition sites. Oviposition assays with filter paper, filter paper treated with leaf volatiles and leaf alone proved that surface texture was not a significant criterion for oviposition site-selection, but volatile cues were. Oviposition assays with electrophysiologically active compounds from mulberry revealed that two of the volatiles, valencene and α-humulene, aided moths in choosing suitable oviposition sites and enhanced egg-laying significantly. Moreover, we show that generalist egg-parasitoids are strongly repelled by valencene and α-humulene. Our results demonstrate that IRTs tuned to cues that aid crucial functions like oviposition site-selection are less likely to be impaired even after centuries of domestication.

Topics: Animals; Animals, Domestic; Behavior, Animal; Bombyx; Chemotactic Factors; Chemotaxis; Cues; Eggs; Larva; Models, Biological; Monocyclic Sesquiterpenes; Morus; Oviposition; Pest Control, Biological; Plant Leaves; Sesquiterpenes; Wasps