Is Guaiacum sanctum Effective Against Arthritis?
An Ethnobotany Case

by
Eric Ribbens, Barbra Burdett, and Angela Green
Department of Biological Science
Western Illinois University

Part II—Rat Study

Mabel Gailke designed a research project to test whether Guaiacum sanctum resin has an anti-inflammatory effect on rats, which was approved by the Biology Department. Mabel’s experiment tested the response of rat paws to swelling induced by carrageenan, a skin irritant.

All rats were weighed, sexed, and, if possible, aged. The experimental rats were divided into six groups, balanced with representatives of various weights and equal ratios of males and females.

After coating the left front paw of each rat with carrageenan to induce swelling, each of the six groups received a different oral treatment. One group was treated with a placebo, four groups were given Guaiacum resin in four different concentrations, and one group was treated with indomethacin, an anti-inflammatory drug used to treat arthritis. The Guaiacum resin was obtained by boiling leaves under reflux in 70% ethanol.

Inflamed joints were measured over an 8-hour period at hourly intervals after administration to compare swelling over time. Observations of behavior and side effects were logged at hourly intervals during the same 8-hour period. Results follow.

Table 1: Effect of Drug Treatments on Paw Swelling and Frequencies of Side Effects
Treatment % Swelling After 8 Hours, ± 95% C.I. Frequency of Lethargy Frequency of Skin Irritation Frequency of Hyperactivity
Placebo 98.2 ±9.6 0.4 1.2 0.6
Resin, 100 mg/kg 95.4 ±12.7 0.9 3.2 0.2
Resin, 200 mg/kg 84.5 ±5.2 1.7 5.7 0.8
Resin, 300 mg/kg 76.3 ±4.6 2.6 6.3 1.3
Resin, 400 mg/kg 68.7 ±1.2 4.3 6.9 2.7
Indomethacin, 2.5 mg/kg 79 ±5.7 3.1 7.2 1.5

Questions

  1. What did Mabel find out about inflammation in rats treated with Guaiacum resin? Did using different dosages make a difference?
  2. What strength of Guaiacum resin was most beneficial? Why?
  3. In your opinion, which medication is better, indomethacin or Guaiacum resin? Why?
  4. Including the behavior and side effects of taking Guaiacum resin, what is your overall opinion of the use of Guaiacum resin as an anti-arthritic medication?
  5. Do you think Guaiacum sanctum will be a good candidate for marketing and further research? In other words, can this plant compete with drugs already on the market?
  6. What do these results mean for human use of this plant for rheumatoid arthritis? Should studies be conducted in humans? If so, how?
  7. Because this experiment did indicate that Guaiacum resin can be quite effective against inflammations, Dr. Tonoany and Mabel Gailke decided to collaborate with the nearby medical research clinic to test the effectiveness of Guaiacum resin on humans with severe arthritis. Design an experiment for the clinic to implement. Remember that this study should test whether Guaiacum resin has effects specifically on people with very severe arthritis.
  8. (Ethics question:) What concerns about intellectual property rights are raised in regard to this experiment?

Go to Part III—“Human Study”


Originally published at http://www.sciencecases.org/ethnobotany/ethnobotany2.asp

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