For those with no other citrus, this species, like my Poncirus, can provide many of the phyto-nutrients common to many citrus species; my Poncirus fruits hang on late into autumn. Verzera et al. (2005) analyzed the oil of cultivar "Diamante," reporting 55 components, with the important anticancer compound limonene constituting circa 52% of the oil, gamma-terpinene at 27.7%, circa 2% ocimene, circa 2% alpha-pinene, circa 2% beta-pinene, 1.7% neral, and 2.8% geranial and perillaldehyde. Most of the other compounds were well below 2%, many below 0.1% (X15941331). I think limonene is a significant contribution from citrus. Israeli scientists (Keinan et al., 2005) suggest that limonene (constitutes more than 50% of citron's essential oil) might help asthmatics, especially those aggravated by ozone pollution. Could poor children in our inner cities, where asthma is increasing dramatically, reduce asthma attacks and/or symptoms (especially around ozone pollution, as on school buses in inner cities) by squeezing citrus peels (apparently all contain limonene) and inhaling the pleasant aroma periodically. Because the sedative antiinflammatory limonene is also absorbed through the skin, rather rapidly I might add, I would also consider adding crushed citrus peels to bath water, which might help at the end of the day's commute. Keinan's group predicted that electron-rich olefins, known ozone scavengers, could be used to prevent asthmatic episodes. Volatile, unsaturated monoterpenes, like limonene, could saturate the pulmonary membranes, equipping airways with local chemical protection against ozone. In Keinan's experimental rats, limonene inhalation significantly prevented bronchial obstruction (eucalyptol, alias cineole, saturated and inert to ozone, did not) (X15598576). I doubt I can convince our government to compare citrus inhalation in clinical trials as a third arm against placebo and some expensive pharmaceuticals. (As a gray-haired botanist, I cannot and do not prescribe. But if I had a hundred asthmatic grandchildren, you could bet some of them would be trying citrus peel and others would not, followed by a vice versa crossover, recording the frequency and severity of their attacks for old grandpa.) Faith-based types might best be praying too, and using the peel of the citron, called ethrog or etrog in some versions of the Bible. Without praying to improve my odds, I will still bet the citrus peel would score well along side the pharmaceuticals. I know it would be cheaper and bet it would be safer. That asthmatic possibility is relatively new; it has been known for a decade that limonene can also prevent cancers. Mondello et al. (1995) found that limonene was the most frequent monoterpene component in the citrus oils they examined, (from 50% in lime oil to circa 97% in grapefruit; about 52% in the etrog (X10554196). d-Limonene works in preclinical models of breast cancer, causing more than 80% of carcinomas to regress with little host toxic-ity (Crowell et al., 1994). Tsuda et al. (2004) singled out promising chemopreventive anticancer phytochemicals: vitamin derivatives, phenolic and flavonoid agents, fatty acids, organic sulfur compounds, isothiocyanates, curcumins, and d-limonene (X15499193). Those last four suggest a biblical chutney: the garlic and onion for organic sulfur compounds, watercress and horseradish for isothiocyanates, turmeric for curcumin, and citrus peels for limonene. Lu et al. (2003) showed that d-limonene exerts a cytotoxic effect on gastric cancer by inducing apoptosis (X12921557). Parija and Das (2003) and Kaji et al. (2001) reiterate the well-known anticarcinogenic activity of d-limonene, mentioning also its chemopreventive nature in hepatocarcinogenesis (X12688534;
X11433412). And during the month that we focused on lung cancer, PubMed only had 11 citations regarding limonene and lung cancer. If I were diagnosed with lung cancer today, I would be ingesting more garlic and more citrus too. I might even be inhaling limonene-containing essential oils as I squeezed citrus peels. Raphael and Kuttan (2003) note that several naturally occurring monoterpenes, such as carvone, limonene, and perillic acid, inhibit experimental lung metastasis. (Limonene at 100 ^M/kg body weight, 10 doses ipr, remarkably reduced metastatic tumor nodule formation.) Limonene and perillic acid just might even inhibit the metastatic progression of melanoma cells (X14582701). I doubt that Witschi (2000) would join me in judiciously inhaling citrus essential oils. Under the catchy title, "Successful and Not So Successful Chemoprevention of Tobacco Smoke-Induced Lung Tumors," Witschi notes that none of the following "chemopre-ventive" agents — green tea, phenethyl isothiocyanate, acetylsalicylic acid, N-acetylcysteine, 1,4-phenylenebis[methylene]selenocyanate, and the d-limonene — reduced lung tumor multiplicity or incidence (X11195468). I would still be eating my garlic, eating my Brazil nuts, and inhaling my citrus, although no clinical trials have indicated their safety or efficacy. I suspect they will do as much good and will do less harm at a much lower cost — economically, mentally, and physically — than the chemotherapeutic cocktails being offered by the allopaths and their covert sponsors, the pharmaceutical firms. Many people believe more in the faith-based botanical herbs than they do in the ACS and NCI poisons. Me too! Such people have a better chance of being helped by these safer food farmacy items, also improving their odds against the other diseases of modern man, cardi-opathy and diabetes and iatrogenesis.
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