Practical Phytochemistry
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practical phytochemistry The study of herbal constituents has been part of the herbalist’s repertoire for a long time – as “chemistry” since 1661, and as alchemy for long before that. The world of modern phytochemistry may seem intimidating or unnecessarily abstract, but it can also be a rich source of information that can guide our work as practitioners and medicine-makers. We can look at constituents in a variety of ways: focusing on their sensory or organoleptic qualities, considering their contributions to the energetic natures of the herbs in which they’re found, and exploring questions of solubility & compatibility in remedies. By getting to know our herbs from this perspective – while always recognizing the variability, synergy, and individuality inherent in herbal medicines – we can become better herbalists. phytochemistry on the macro scale Year after year, study after study, the evidence mounts up: humans just plain need to be involved with lots of plants in lots of ways, and if you can't get your plant time by going out into the forest, you can get it by drinking a lot of tea. constituents from the plant’s point of view Plants make two broad classes of constituents. First are the primary metabolites, which are necessary to sustain the life of the plant. These include proteins (including enzymes), lipids (fats), carbohydrates of various types – all serving functions analogous to those they perform in the human body – as well as chlorophyll, which is necessary for photosynthesis. Then there are the secondary metabolites which, while not strictly necessary to sustain life, perform a variety of functions within the plant which increase its survivability and adaptability to changing situations. This is where the interesting phytochemical constituents of our herbs come into play. We might wonder, why is it these plant chemicals are so active in animals and humans? It comes down to common ancestry. On the small scale, all the various chemicals plants produce are derived from the original product of photosynthesis, glucose – which is known in mammals as blood sugar. The structure of chlorophyll itself is extremely similar to hemoglobin, only with a magnesium atom in place of the iron – one more indicator of the similarities between people and plants. On the large scale, there’s the common ancestry of humans and plants, as well as our long history of co-evolution. Basically, these compounds are active in both plants and people because, when you get right down to it, we’re not really that different. Indeed, the role these constituents play in plants is usually analogous to the role they play in the human body. It’s often instructive to ask, what does this constituent do from the plant’s point of view, and how does that compare to its effects in humans? Carotenoids, for example, protect the plant from oxidative damage due to excessive exposure to UV light, and can convey this protection to us if we eat a lot of them. Tannins fend off microbial infections in a plant’s leaves and roots, and we can use them in a first aid application to prevent infection in a wound. Alkaloids, including caffeine, both fight microbes and discourage herbivores from eating a plant; in humans, though, their effects can be much more varied. It’s not always a one-to-one correlation. CommonWealth Center for Holistic Herbalism commonwealthherbs.com 1 practical phytochemistry forest bathing Another part of “being involved with lots of plants in lots of ways” requires us to consider the effects of "forest bathing", the act of going out into natural environments and deriving health benefits therefrom. This practice has been found to reduce the physiological effects of stress, improve immune function, lower blood pressure, and much more. A variety of contibuting factors seem to be at play, including the mere sight of natural colors and shapes – the field of varied greens and browns, the absence of hard straight human- shaped edges – but in particular, the variety of aromatic compounds you're exposed to in a wild environment. Plants are communicating constantly through scents, and when we breathe them in, our bodies respond. (Richard Mandelbaum framed exposure to this panoply of wild aromatics as a "macrobiome" in this presentation.) There’s no replacement for real forest time. Still, if we acknowledge the presence of various potent aromatic constituents in our herbs, and then learn how to make a good cup of tea, we can derive many of the same benefits even while we’re city-bound. whoever eats the most vegetables wins We inherited this slogan from Paul Bergner. It’s both a simple reminder that cuts across all forms of dietary dogma, as well as a summation of a variety of insightful observations about the relationship between varied and rich phytochemical intake and healthy outcomes. This helps us to step back a bit, from a limited focus on some specific constituent that has its fifteen minutes of fame (here’s looking at you, curcumin), to see the more general effects plant intake has. A favorite paper on this subject: The Metabolic Plant Feedback Hypothesis: How Plant Secondary Metabolites Nonspecifically Impact Human Health Jurg Gertsch, Planta Med 2016; 82(11/12): 920-929. CommonWealth Center for Holistic Herbalism commonwealthherbs.com 2 practical phytochemistry There are a few interesting points in this article, starting with the main one that low- potency phytochemicals like chlorophyll are more important to human health (specifically when it comes to metabolic and inflammatory illnesses) than the high-potency ones which make herbs medicinal – whoever eats the most vegetables wins again, see? The author also argues that medicinal plant use was actually fairly infrequent among hunter-gatherer groups; that they had little call for it since they were ingesting high amounts of non-starchy plants: "It is tempting to postulate that the lack of bulk phytochemicals once ingested in pre-agriculturist times gradually had to be compensated by spices and herbal remedies in the carbohydrate farming societies to diminish the mismatch of ancient genes and new diets." We might then compare that insight with something like these studies on the health of English people in the Mid-Victorian era, where again, high intake of fresh and wild greens led to surprisingly robust health. This boon was rapidly compromised in the following decades, however, with greater influx of sugar and refined grains, tinned meats, and condensed milk. Processed food, even moreso than early agriculturalists’ starchy diets, is extremely deficient in phytochemistry. In addition, most of our domesticated vegetables have lost a great deal of their nutrient content, due to generations of selective breeding for larger, sweeter varieties. This led to the loss of phytochemicals with bitter or strong flavors, which may please the palate but deprives the body of an ancestral protection. Fortunately, herbs can provide part of the solution to this problem! Take a look at these values (from Pedersen's Nutritional Herbology) for basic mineral content for various herbs: per 100 g (3.5 oz) calcium iron magnesium chromium nettle (Urtica dioica) 2900 mg 4.2 mg 860 mg 390 mcg burdock (Arctium lappa) 733 mg 14.7 mg 537 mg 200 mcg peppermint (Mentha piperita) 1620 mg 6.0 mg 661 mg trace horsetail (Equisetum arvense) 1890 mg 12.3 mg 437 mg 220 mcg comfrey (Symphytum off.) 1800 mg 1.2 mg 70 mg 180 mcg kelp (Fucus vesiculosis) 3040 mg 1.6 mg 867 mg 70 mcg ODI (optimum daily intake) 800 – 1200 mg 10 – 20 mg 400 – 800 mg 200 – 600 mcg Three and a half ounces is a lot of herb, but remember, this is in the context of your entire diet. A quart of herbal tea a day, made with an ounce of these or other herbs blended together, can make up for a lot of deficiencies even in a processed-food-heavy diet. It’s especially good at filling in the gaps created by modern agricultural methods, which tend to reduce the amount of micronutrients available in vegetables – even organic ones. CommonWealth Center for Holistic Herbalism commonwealthherbs.com 3 practical phytochemistry constituent energetics Beyond basic nutrients, herbs carry rich and interesting phytochemistry. These constituents can make gross adjustments or fine adjustments – compare the effects of chlorophyll versus those of caffeine, canadine, or capsaicin. Fine adjustment phytochemistry is one of those things that's thoroughly unreliable until you get your senses directly involved in your decision-making. This drives us necessarily towards organoleptic assessment – the use of your senses as a portable chemistry lab, to make determinations about an herb’s actions, or the potency of an extract – as well as the broader category of what herbalists call "energetics". There's a big starburst of trails to follow there, one interesting tail of which you can catch with an article like this one, where syndrome differentials from Traditional Chinese Medicine are used to improve clinical efficacy. That’s a simple example of a trend we’ve observed – Chinese, Korean, Saudi, Iranian, Russian, and a multitude of other university nationalities have published studies including differentiation based on syndromes according to traditional medicine practices – whether from TCM, Unani, Ayurveda, or others – and in every case we've seen, they've found better results than those observed with conventional diagnostics. This is very clearly the most effective study design for assessing herbal therapeutic efficacies. It makes us wonder: when will we see these kinds of studies in the US? Or at least, acknowledged by the FDA and similar authorities? CommonWealth Center for Holistic Herbalism commonwealthherbs.com 4 practical phytochemistry visual organoleptics: color Some constituents of herbs are detectable by looking at the color of the plant (or of an extract you make from it), because they reflect or absorb certain wavelengths of light.