Determination of melatonin in edible plants and medicinal herbs: Comparison of different methods, including UV spectroscopy an

The pineal hormone melatonin has been shown to have beneficial effects in many aspects of health. Melatonin has been shown to be an important hormone in the regulation of important biological cycles. It has been shown, in human beings, to induce restfulness, and appears to play an important role in reproduction, having an influence on the onset of puberty (Cavallo, 1993; Puig-Domingo, Webb et al., 1992; Waldhauser, Boepple et al., 1991). In addition to its hormone function melatonin is also a far more powerful antioxidant than Vitamins C, E, and K, able to protect biological tissue from the harmful effects of free radicals (Poeggeler, Thuermann et al., 2002). This is because melatonin can penetrate all cells, whereas the other vitamins are capable of only selective penetration. In the human body, melatonin is secreted in a distinctive daily cycle which peaks significantly during the hours of darkness. It is thought that inducing sleep is one of melatonin’s primary roles (Dawson, Encel et al., 1993). A sleep research project carried out at Massachusetts Institute of Technology reported that a very small amount (0.1mg) of melatonin enhanced sleep in healthy young volunteers (Dolins, Wurtman et al., 1994). For people who suffer from disrupted sleep or insomnia the prescribed sleeping remedies are usually medicines from the benzodiazapine group of drugs. Benzodiazapines have a tranquilizing effect on the body but with this positive effect comes a myriad of less desirable side-effects including next day drowsiness, memory loss and disruption of essential sleep ‘levels’. These drugs should only be a short term solution but in many cases are prescribed to patients for a number of years. Benzodiazapines, despite their tranquilizing effect, disrupt the ‘normal’ sleep pattern often leaving users with a deficiency of REM and deep sleep (Steinburg,1989). Sleep induced by melatonin shows the same sleep level patterns and behavior as natural sleep (Cramer, 1974). Melatonin shows none of the side effects observed with traditional sleep medication. Studies on elderly patients, who are generally very sensitive to drug side effects, showed that even high dose (50mg) melatonin did not interfere with memory, concentration or motor control (Singer, 1994). The requirement of only small doses of melatonin to promote sleep was highlighted in a study by Richard Wurtman. In his first study melatonin was administered at a very high dose (240mg), this amount caused fatigue and sleepiness in the human subjects (Wurtman, 1984). In a further study the amounts of melatonin were reduced to doses of 1 and 0.3mg, Wurtman found that even these minute quantities were able to decrease the amount of time taken for the subject to fall asleep (Wurtman, 1995). There seems to be a definite link between physiological melatonin levels and cancer incidence. Suppression of the normal light/dark melatonin cycle by light during darkness hours can lead to a increase in the progression of cancerous tissue (Blask, Dauchy, 2002; Reiter, 2002; Sanchez-Barcelo, 2003). It has also been shown that cancer patients tend to have a lower secretion of melatonin when compared to healthy subjects (Kos-Kudla, 2002). Melatonin has been shown to have an inhibitory effect on the growth of endometrial (Kobayashi Y 2003), breast (Dillon, 2002; Anisimov, 2003; Bizzarri, 2003) and prostate (Shiu, 2003) cancer tumors. Studies have shown that melatonin can be very effective in lessening the toxicity of chemotherapy drugs. A five year survival study of non-small cell lung cancer patients taking the chemotherapy drugs cisplatin and etoposide with or without the concomitant administration of melatonin has been carried out (Lissoni, 2003). Both the tumor regression and survival rates were considerably higher in the cases where melatonin had been used. No patient treated with chemotherapy alone was alive after two years, in contrast 6% of the patients treated with chemotherapy and melatonin achieved a five year survival. In a separate paper Lissoni also reports melatonin’s potential for disease control in the case of metastatic solid tumours (Lissoni, Malugani , 2003). A