In the last two classes, we've introduced two types of Chinese herbs: one is rare and expensive; and the other is very common in our daily life known as food and herbs. No matter rare and expensive ones or those used as both food and medicine, they are related to two issues: efficacy and safety. For efficacy, we've mentioned in functions of specific herbs. I'd like to introduce another very important issue that now attracts more and more attention safety. So the last unit of this course is about safety of Chinese herbs and influencing factors. First, let's talk about basic concepts of safety. There are two entirely different misunderstandings regarding safety of Chinese herbs. Some people think Chinese herbs are almost atoxic, because they are natural plants and you can take them randomly in any doses, believing they can take Chinese herbs as they want. This is the first misunderstanding. What about the second misunderstanding? Over the recent years, people tend to be concerned about the safety of Chinese herbs. Some people think Chinese herbs are toxic. Some herbs are toxic, i.e., toxic herbs. In addition, many herbs are artificially cultivated, so there are issues like pesticide residues or heavy metals. Based on this, some think Chinese herbs are toxic. What's more, instrucdtions on Chinese herbs or patent Chinese medicine are not transparent enough but too general, saying that you cannot use these products blindly. Over the recent years, events related to safety of Chinese herbs made people suspect whether Chinese herbs are safe. That's why we say there are two entirely different misunderstandings: one is fearless, believing that Chinese herbs are atoxic; the other is scared, assuming Chinese herbs are poisonous. Before answering these questions, let's take a look at a couple of events related to safety of Chinese herbs. Over the last couple of years, people are crazy about Vitamin C Yin Qiao tablet [Yin Hua (honeysuckle flower) and Lian Qiao (Fructus Forsythiae)], Ban Lan Gen (Radix Isatidis) granules, and Zhen Ju blood-pressure lowering tablet [Zhen Zhe Fen (Pearl Powder) and Ju Hua (Flos Chrysanthemi)]. Let's take a look at a recent event about Yunnan Bai Yao. Last year, Yunnan Bai Yao was detected in Hong Kong as containing toxic ingredients. In mainland China, we've also found a highly toxic ingredient called Duan Chang Cao (literally means intestine-rotten grass) This is one aspect. Another aspect: one year ago, there was much criticism concerning safety of Chinese herbs. Some pediatric medicine have been detected to contain more mercury than it should. Before that, Long Dan Xie Gan Wan (Gentian Liver-Draining Pill) attracted much attention. These adverse events are related to herbs. Furthermore, we do not have supplementary support to these products. For example, the instructions are not transparent and therefore cause misunderstandings. In addition, attention or criticism is a good thing. However, the media reports are a little bit sensationalized. Why? As a matter of fact, all medicine including Chinese herbs are toxic, which is quite natural and objective; side effects or adverse reactions are also objective. The key point is related to people who use them. This is associated with doctors and with patients. Now let's take a look at two typical cases. The first one is about Long Dan Xie Gan Wan. We know that this is a very very effective and famous formula for excessive liver/gallbladder fire. What's the problem? After sensationalized report, such a good formula is now out of shelf. You cannot buy either in the pharamcy or hospital. Why? Because reports mentioned an ingredient in Long Dan Xie Gan Wan can damage the liver and kidney functions, causing kidney failure or even death. Such sensationalized reports stopped people from using this patent formula. However, maybe you do not know that Long Dan Xie Gan Wan itself is not that toxic as media reports; on the contrary, it is a very good formula for excessive liver/gallbladder fire. We know that it won't take long to treat excessive liver/gallbladder fire, symptoms such as a bitter mouth, pain in the hypochondriac region, restlessness and dark-yellow urine due to excessive liver/gallbladder fire can be treated with Long Dan Xie Gan Wan. This is an excessive syndrome. Long Dan Xie Gan Wan can clear excessive fire in the liver/gallbladder and alleviate above symptoms. Afterwards, you stop using it. Long Dan Xie Gan Wan cannot be used for an extended period of time. Those with damaged liver and kidney functions or death cases often used Long Dan Xie Gan Wan months or years rather than 1 or 2 weeks. In addition, Long Dan Xie Gan Wan was first used to treat chronic kidney problems by integrative Chinese and Western medicine and has been proven effective. Now ironically, it's believed to damage the liver and kidney functions. Then whose fault is it? We can say that Long Dan Xie Gan Wan is a very good formula; however, it is now discarded just because of side effects due to inappropriate use. We think this is 'overding in righting a wrong'. Modern medicine have proven that an ingredient in Long Dan Xie Gan Wan Guan Bu Tong (Caulis Aristolochiae Manshuriensis) contains aristolochic acid, which can damage the kidney function. However, there is a precondition. What? Dosage, course of treatment and indication. In Chinese medicine, Long Dan Xie Gan Wan cannot be used in a large dose. Why? This formula mainly consists of herbs that are bitter in flavor and cold in property. For example, Guan Mu Tong is very bitter. We have a saying goes, 'our life is more bitter than Huang Lian (Rhizoma Coptidis)'. Of Chinese herbs, Guan Mu Tong has a nickname 'bitter like Huang Lian' or 'bitter than Huang Lian'. This indicates that Guan Mu Tong is very bitter. Major ingredient of Long Dan Xie Gan Wan is Long Dan Cao (Radix et Rhizoma Gentianae). Long Dan Cao, literally meaning grass like the dragon gallbladder, as bitter as gallbladder. So just like Guan Mu Tong, Long Dan Cao is also very bitter. This formula also contains other similar bitter cold herbs. Combination of so many bitter cold herbs can be effective in a short period. However, if used for an extended period of time, this formula can affect your stomach and damage your liver and kidney. Not just Guan Mu Tong, other bitter herbs can damage the liver and kidney as well. So we say this issue is not about the formula itself but about inapproriate use. So personally I don't think it's right to give up this formula. We've have a better example. We all know that Xiong Huang (Realgar) can be used to treat leukemia. This is based on mechanism study on therapeutic efficacy of Xiong Huang on leukemia by a research team in Shanghai Ruijin Hospital. This internationally recognized study has obtained many prizes and published many papers. Why can Xiong Huang be used to treat leukemia? I've mentioned in the first class that Xiong Huang is strictly regulated by our government. Why? It contains poisonous ingredients, most toxic one is arsenicals, especially, the arsenic trioxide. What is it? It is arsenic. Who'd like to use arsenic? It is a highly toxic and fatal drug. But now we've found that it's effective for leukemia and its active ingredient is related to arsenic trioxide. Consequently, it's objective that a herb is toxic or atoxic. The point is to transform toxic herb into an active component. We cannot correcdt one extreme with another extreme. Although Chinese herbs do not fit all, they are surely not as dangerous as ferocious beasts. This is the first issue I'd like to address. The second issue, I'd like to say, is that safety of Chinese herbs is not just a toxic issue but also side effects. Side effects are sometimes inevitable. For example, I've mentioned Niu Bang Zi (Fructus Arctii) before. If we want to use Niu Bang Zi to resolve phlegm, stop coughing and at the same time, not to cause diarrhea. However, if you use Niu Bang Zi to resolve phlegm and relieve coughing for cough with profuse phlegm, it's very possible that patients may have loose stools, which is a side effect for the patient. This side effect is related to treatment dose but not to the treatment itself. This adverse reaction can actually be avoided, but sometimes cannot. However, we need to know it won't do great harm to the body; once you stop using it, the side effect will disappear. This is about the side effect. Now let's move on to toxic effect, which can really harm the body. This harm can be severe, either damaging the bodily functions or tissues, organs, even endangering life. This damage can be irreversible. These are concepts about side effects and toxic effects. Here, toxic effect is mainly related to its toxic ingredients. To explain this, we need to be clear about the concept of toxic herbs. About toxic herbs, in Chinese medicine, we first talk about the concept of medicine... all medicine that can treat diseases are toxic medicine (Du Yao in Chinese). By this we mean they are used to correct one deviation with another deviation. This is about its broad sense. In a narrow sense, actually it's easier for us to accept the narrow sense. Toxic medicine refers to medicine that contain toxic ingredients. These types of medicine can be classified according to their toxicity as highly toxic, very toxic, toxic and mildly toxic and atoxic. Of these medicine, highly and very toxic ones are inaccessible in the market and are strictly regulated by the government. You need legal procedure to apply for these medicine. Generally you do not have access. This is the concept of toxic medicine. It can be seen that you need to be cautious about the toxicity of Chinese herbs before you understand Chinese herbs and their safety. Only by this can you use them appropriately and then guarantee the safety. Secondly, you cannot focus on safety only and neglect their efficacy. For Chinese medicine, we need to ensure their efficacy. We use them only because we are sick and we need them, otherwise we don't use any medicine even if they are perfectly safe. When you know some herbs are toxic, we need to ensure safety first and appropriately make use of their toxicity to achieve the goal of attacking poison using poisonous herbs when necessay. Because very often this method can remove pathogenic factors cure diseases and also damage the body. We need to weigh risk and benefits. Our favorite method is inhibiting poison using poisonous herbs, i.e., inhibiting toxins using the toxicity ingredients in some herbs to produce therapeutic efficacies. So The correct way is to be cautious and use them appropriately. With that we conclude the basic concepts of Chinese medicine. In next class, I'm going to introduce several Chinese medicine that are related to recent safety events. So much for this class.