Herbal texts

DRUG DISCOVERY FROM HISTORIC HERBAL TEXTS... 

Historic herbal texts can be considered both works of art and troves of information. Many of the original copies of the texts still available were hand copied and corrected as deemed necessary by the transcriptionist [21]. Frequently, the images accompanying the text descriptions were ornately hand painted. Often, these images contain such intricate detail that it is possible to accurately identify the genus and species of the plant described. For example, Figure 4.2 shows the illustration of the common pineapple from the 400-year-old Ambonese Herbal. 

Figure 4.2 Nearly 400 years ago G. E. Rumphius was stationed on the island of Ambon in Indonesia. This fignre shows his rendition of the common pineapple in the Ambonese Herbal. Freqnently, the illnstrations in historic herbal texts are detailed enough to accurately identify the plant described in the text.

There are many historic herbal texts throughout the world, some dating back as far as 3000 b.c. However, the ancient Greeks were the first to create herbal texts with enough detail to accurately identify the plant and ailment treated. Thus texts from around 500 b.c. and later are the only texts able to... 

Although manual extraction of information from herbal texts is straightforward (Fig. 4.3A), the work is labor intense and requires many areas of expertise (Fig. 4.3B). Historians must provide context for the language. Botanists are necessary to update the names and correctly identify the plants discussed. Physicians and biomedical scientists are required to extrapolate the potential pharmacological function of the plant compounds used to treat a certain disorder in the text. Luckily, the use of bioinformatics to extract this information can be more efficient than manual extraction [7]. 

Foremost it is critical to move the historic herbal text into an electronic format. This process can be very time consuming [28] however, it is essential for two reasons. First, these historic texts are rare and having them in an electronic format facilitates increased access for the collaborating groups. Second, the volume of information is difficult to handle when the data are not in an electronic format. We have recently employed the Kirtas system (Fig. 4.5) to move a number of texts into electronic format. We have yet to formally address the precision of the scanned-in documents however. 

Figure 4.4 The general protocol for information extraction from an herbal text (A-E) is paired with case examples from our work with the Ambonese Herbal by Rumphius. (A) Text is digitized. (B) Through either manual reading or automated extraction the plant name(s), plant part(s), and symptoms or disorders are identified. (C) These extracted data are then updated (as necessary) to reflect current names of the plants, using the International Plant Names Index (IPNI), and the pharmacological function(s) of the described medicinal plants are extrapolated from the mentioned symptoms and disorders. (D) The current botanical names are queried against a natural products database such as the NAPRALERT database to determine whether the plant has been previously examined. (E) Differential tables are generated that separate the plants examined in the literature from plants that may warrant further examination for bioactivity. (Adapted from Trends in Pharmacological Sciences, with permission.) See color plate.

Figure 4.5 The Kirtas APT BookScan 1200 allows for the automated scanning of historic herbal texts into electronic format. (Image supplied by Lisa Stasevich, Kirtas...

We have developed a system based on SNOW-MED to extract medical information from herbal texts. SNOW-MED is a semantic index that recognizes relationships between groups of words [26], For example, the semantic map for thrush is related to yeast, infection, and microbe. Although this system may eventually allow a potential pharmacological function to be extrapolated, we are currently using the system to simply extract disorders from the text. We have used the Mayo Vocabulary Server to perform this data mining [34, 35]. 

Incorporating the Kirtas system with the International Plant Names Index and SNOW-MED allows movement of the historic text into an electronic format, identihcation of current plant names, and identihcation of the symptoms treated with the plants. To complete the mining of historic herbal texts for novel drug leads we use the Natural Products Alert (NAPRALERT ) database to compare the information extracted from the historic herbal text to the reports of plant use in the current literature. The NAPRALERT database provides a summary of plants ethnopharmacological use, biochemical activities, and isolated compounds [27]. By querying each plant (with the current plant name) it is possible to identify any reports in the current literature regarding the plant. As an example, Table 4.1 shows the NAPRALERT output for Cycas rumphii. 

It is possible to extract novel drug leads from historic herbal texts. However, manual extraction techniques are laborious. The automated extraction system we have developed makes it possible to identify potential novel drug leads in a high-throughput fashion. 

The prospect of using historic herbal texts as a tool to resurrect lost traditional medicine knowledge and to identify new drugs is exciting. However, there are six significant challenges that need to be addressed to increase the efficiency of this system ... 

Identification of historic herbal texts. There are thousands of herbal texts in the world. Many of them are rare and unknown to our modern repositories. Identifying the location of these texts and the language in which the texts are written would allow a clearer outlook for the future of this field. 

Quantified evaluation of drugs that could have been identified in herbal texts. It would be a valuable assessment to quantify the number of pharmaceuticals that have been described with the correct purported uses in an herbal text. A project of this nature would incorporate selecting a historic... 

Effective movement of herbal texts into electronic format. We have used a single system to move herbal texts into an electronic format. This system has worked well for texts printed after the era of mass printing. However, there are many texts that were written before 1600 a.d. It is likely that there are other mechanisms to complete the task of moving historic herbal texts into an electronic format. For example, the Missouri Botanical Gardens has manually scanned a number of historic herbal texts into electronic format [28]. 

Proof-of-concept through new pharmaceuticals. We have generated preliminary data suggesting that one of Rumphius s purported pharmaceuticals does have the medicinal properties described. However, it has not been shown that the active compound is novel. Examining other plants identified in historic herbal texts for their purported medicinal properties may ultimately show that novel pharmaceuticals can be developed by mining historic herbal texts. 

Because not all of the species in the world are known, it is difficult to determine the exact rate of species extinction. Unfortunately, there are plants with medicinal properties that have gone extinct. The first case of a medicinal plant extinction documented in an herbal text is silphium [37]. 

Buenz EJ, Schnepple DJ, Bauer BA, Elkin PL, Riddle JM, Motley TJ. Techniques Bioprospecting historical herbal texts by hunting for new leads in old tomes. Trends Pharmacol Sci 2004 25 494-8. 

Jackson S. Classic herbal texts brought into the digital age. HerbalGram 2003 60 30-7. 

Figure 4.4 The general protocol for information extraction from an herbal text (A-E) is paired with case examples from our work with the Ambonese Herbal by Rumphius. For full caption see page 112.

By the same token, not all Chinese botanical products are compatible with each other. Classic Chinese herbal texts have mentioned 18 Incompatibles (Shi Ba Fan) and 19 Counteractions (Shi Jiu Wei). The 18 Incompatibles refer to a classic list of 18 botanical product botanical product interactions,... 

An older herbal text indicated that internal use of "large doses" of arnica may cause "heat in the throat, nausea, vomiting, purging, spasmodic contractions of the limbs, difficulty of respiration, and sometimes inflammation of the alimentary canal, and coma" (Felter and Lloyd 1898). 

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