Osage orange or hedge apple and pharmacognosy

Osage orange or hedge apple and pharmacognosy

Maclura pomifera is a tree that grows throughout the US and part of southeastern Canada. It’s related to the mulberry tree although the fruit would make you think it’s citrus. The Osage Indians used it’s wood to make bows and clubs due to it’s resistance to decay and durability.  It’s no surprise that modern use of the wood is for fence posts and tool handles. The tree was planted in rows in the Great Plains  states to help break the wind, hence the nickname “hedge apple”.  The fruit used to be placed under the bed to repel some insects.

Fruits grow to their full size (ca. 500 g) every fall, and each fruit can bear up to 300 seeds per fruit. Osage orange has traditionally been used as an insect repellent and as a home remedy for pest control. Fruit extracts and extracts of the bark, seeds, leaves, and roots, as well as the two major isoflavone constituents of the fruit, osajin and pomiferin, were reported to possess a number of biological activities. Some of the reported activities include insect repellant, antimicrobial, anti-inflammatory/antinociceptive, antitumor, cardioprotective, and cholinesterase inhibitory activities. Osage orange isoflavones, especially pomiferin, also have marked antioxidant activity and have been shown to inhibit lipid peroxidation and to reduce free radicals, reactive oxygen species, and other unstable molecules. At present, there are no osage orange-based dietary supplements available on the market, but its potential has been suggested. Biological evaluation of semisynthetic osajin and pomiferin analogues, iso-osajin and iso-pomiferin, has also been attempted by Orhan et al. Being edible by squirrels, horses, and other animals suggests that osage orange is safe. Nevertheless, the toxicities of the different extracts have not been fully established. References removed for readability

HPLC Determination of Isoflavone Levels in Osage Orange from the Midwest and Southern United States

Ketur Darji, Cristina Miglis, Ashley Wardlow, and Ehab A. Abourashed

J. Agric. Food Chem., 2013, 61 (28), pp 6806–6811

http://www.ncbi.nlm.nih.gov/pubmed/23772950

You often hear about herbal or Ayurvedic remedies for a whole host of ailments. I won’t talk about homeopathy because that’s too easy to dismiss. Pharmacognosy is the study of medicinal compounds derived from plants.  You might hear about ethnobotany and phytochemistry in descriptions of pharmacognosy. Ethnobotany is the study of plants as they relate to culture, predominantly indigenous cultures. Phytochemistry is the study of the chemistry of plants (cue elderberry joke). It’s pharmacognosy that’s used to determine if a “traditional” remedy has any scientific basis.  Typically ethnobotany is used to find some candidate plants. I have a friend in this field and if I recall correctly, there was a time when western scientists would go to the jungle (for example) and take plants without working with the local government. Relationships soured and some areas are off limits. I believe most of the studies now have agreements with the local governments and indigenous people so that it’s not the new version of pillaging their gold, i.e., if a derived compound leads to a blockbuster drug, they’ll get a slice of the pie.

After a candidate plant is chosen, Maclura pomifera in this case, compounds are isolated from the bark, fruit, flower, leaves, and roots. Since this is a tree, I’m guessing the roots were not tested. Typically the compounds will be separated based on water solubility. You might know that a lot of old remedies are made with ethanol, i.e., a tincture. Then each compound is analyzed for it’s chemically properties, e.g., structure and then against a host of in vitro assays to scan for potential medicinal uses, possibly beyond what was learned from ethnobotany.

The paper referenced above (which is behind a paywall) used high pressure liquid chromatography (HPLC). Chromatography comes from the Greek chroma “color” and graphein “to write”. There are different types of chromatography but each results in a chromatograph. Its name derives from its early use in separating pigments in plants. Probably using thin layer chromatography (TLC), where a plate or piece of paper is used in a solvent. The sample is placed on one end of the plate/paper and the individual compounds separate as it travels through the solvent. This can be due to size, charge, or polarity. In HPLC, there is a mobile phase and stationary phase. Typically the stationary phase is made of special porous micron-size silica beads and is packed into a steel column. The mobile phase is typically a solvents like  toluene or acetonitrile. When the mobile phase is less polar than the stationary phase it’s called normal phase liquid chromatography. When that’s reversed, i.e., the mobile phase is more polar than the stationary phase, it’s called reverse phase liquid chromatography. The reference above used reverse phase.

For a long time the effluent from HPLCs were connected to a UV-Vis (ultraviolet and visible range) spectrophotometer. Each compound has a preference for each phase (mobile or stationary). They travel through the column at different rates and they have different spectra. That’s how you get the chromatograph. In the old days, the spectrometer was tuned to a single wavelength, typically where your compound of interest has a peak. Later, with photodiode array technology, the whole spectrum for each compound was acquired, resulting in a 3D chromatograph. However, now, HPLC detectors are predominantly mass spectrometers (MS). So you get the mass of each compound as it elutes from the column.

Going back to pharmacognosy and Maclura pomifera. Two of the main compounds isolated are pomiferin and osajin . In another study pomiferin was isolated and had an inhibitory effect on the growth of 5 tumor cell types.

Pomiferin, histone deacetylase inhibitor isolated from the fruits of Maclura pomifera.

Son IH, Chung IM, Lee SI, Yang HD, Moon HI.

Bioorg Med Chem Lett. 2007 Sep 1;17(17):4753-5. Epub 2007 Jun 26.

http://www.ncbi.nlm.nih.gov/pubmed/17662606

Not quite pharmacognosy but another group confirmed that the extract does have the ability to repel cockroaches.

Identification of Components of Osage Orange Fruit (Maclura pomifera) and Their Repellency to German Cockroaches

Chris Petersona, Junwei Zhua & Joel R. Coatsa 

Journal of Essential Oil Research Vol 14, Issue 3, 2002, pages 233-236

http://en.wikipedia.org/wiki/Maclura_pomifera

When ScienceSunday first started, Robby Bowles and Allison Sekuler had an idea that photographers could share interesting pictures with real scientist (Robby and Allison) and the Science Sunday team could either answer a science question or add some science goodness. Sunday was chosen because we do this in our “spare” time and Sunday seemed like the best day for spare time. So the hashtag  #ScienceSunday  was born, followed by the page. As the popularity of the hashtag grew, more curators were added: Rajini Rao, me and then Buddhini Samarasinghe. The hashtag and page continued to grow. So we often have guest curators to help out. Unfortunately a lot of people see a trending hashtag and use it because they think that people won’t want to see their post/photo otherwise. The curators have to sift through a lot of junk to find the good stuff. So welcome Aubrey Francisco our new co-curator with some good stuff. The pictures below were from my trip to the Fox River, Silver Springs State park, yesterday. Enjoy the rest of your #ScienceSunday  and don’t forget to tag one of the curators when you have a science question or some science to share.