Tryptophan metabolites found in cannabis

Another discovery comes from the Italian scientists who first found THCp and CDBh in cannabis plants. Researchers discovered tryptophan and its active metabolites, including L-kynurenic acid and kynurenic acid, in cannabis. (1) Anyone who remembers that sleepy feeling after Thanksgiving turkey will at least understand the sedative effects of tryptophan.

Cannabinoids and terpenes are two broad classes of active compounds in cannabis. And cannabinoids are a special type of terpenoid. Beyond the terps there are several other groups of important molecules, including flavonoids and esters. The composition of the amino acids in cannabis plants is less discussed.

Parmesan cheese and turkey are good sources of the amino acid tryptophan. As it turns out, cannabis appears to be a richer source of this amino acid and its metabolites L-kynurenine (KYN) and kynurenic acid (KYNa). Importantly, the latter of the two facilitates therapeutic properties. Thus, the initial discovery of tryptophan and its metabolites in cannabis plants delves into the mysteries of the entourage (or ensemble) theory for edibles.

In addition, serotonin and melatonin are products of tryptophan. Melatonin production causes foods rich in tryptophan, including hemp and cannabis leaves, to promote better sleep.

In the leaves – cannabis growing conditions and tryptophan

Leaves were consistently more potent with amino acids compared to roots and stems, (1) which is not the case for triterpenes. (2) Research funded by the Italian Ministry revealed further deep differences in the potency of tryptophan depending on the growing conditions. Nonetheless, both soil grown and hydroponic cannabis crops exhibited notable levels of tryptophan’s two metabolites – KYN and KYNa. (1)

Tryptophan is a precursor to several important neurotransmitters.

Animals cannot synthesize tryptophan and need plants to ingest it. At the same time, plants poorly break down the amino acid into KYN or KYNa. Instead, plants tend to take up the metabolites via their roots from soil microbes. For this reason, the amount of KYN and KYNa in cannabis was considered unprecedented in the study funded by the Italian Ministry of Education, Universities and Research.

In plants, KNY and KYNa may have protective properties against certain toxins. However, in humans, the metabolites have been shown to have protective properties for the brain and heart. Antioxidant and anti-inflammatory effects may be involved in its protective functions. Additionally, tryptophan metabolites have great potential for regulating lipids and alleviating obesity.

Let us know in the comments if you think Italian researchers should be allowed to analyze tryptophan in cannabis flowers next. And stay tuned for more on the anti-inflammatory properties of cannabis root extract next week.

Show off your work

• Researchers cultivated early and late vegetative-stage plants from certified hemp seeds using strict growing practices for the hydroponics experiment.
• For the soil cultivation test, hemp samples were collected from field crops.
• Tryptophan and its metabolites are polar compounds that the researchers used standard techniques to extract.
• Extracts from hemp samples were analyzed using Ultra High Performance Liquid Chromatography coupled with an Ultra High Resolution Mass Spectrometer.

Sources

1. Russo F, Tolomeo F, Vandelli MA, et al. Kynurenine and Kynurenic Acid: Two Human Neuromodulators Found in Cannabis sativa L. J Pharm Biomed Anal. 2022;211:114636. doi:10.1016/j.jpba.2022.114636
2. Kim YN, Sim KS, Park S, Son HY, Kim T, Kim JH. In vitro and in vivo anti-inflammatory effects of cannabis sativa strain extract. J Med Food. 2022;25(4):408-417. doi:10.1089/jmf.2021.K.0200