13 Practical Thesis Works in Biology

Dr Abe V Rotor
Living with Nature - School on Blog

Lesson: Looking for a researchable topic for your thesis or simply school project? What you have in mind is something you can perform with least time, expense and tools, and yet the result is directly beneficial.

Here are 13 researches conducted by pharmacy students at the University of Santo Tomas. They explored common plants as food and source of products for medicine and industry. The results provide home remedies using natural antibiotics, elixir substances, pesticides, and the like, with simple tools and methods.

Weeping willow is a natural pest repellant. It drives mosquitoes and flies around. You save on expensive and dangerous pesticides by having a tree in the yard. Its leaves exude fresh and pleasant smell in the surroundings. The leaves when crushed is best for aromatherapy. Its fresh menthol. Burn some dried leaves to drive out vermin. Try some crushed leaves as deodorant in the bathroom and bedroom.

1. Alginate from Sargassum can increase the shelf life of fruits

Tumambing K, Santok G, Seares A and V Verzola

If you happen to be walking along the beach those dry brown seaweeds washed ashore could bring in a lot of profit, not only as source of algin and alginic acid which are extracted for food conditioner and for industrial use. The researchers found out that by extracting the alginate substance by ordinary means, the extract is effective in delaying the spoilage of fruits such as mango, papaya and banana. The extract is diluted 5 to 10 percent with water before the ripe or ripening fruits are immersed, then allowed to dry.

The alginate compound leaves a coating on the fruit that delays ripening from two to four days, at the same time protects it from microorganisms that cause rotting and spoilage.

2. Common moss as a practical source of antibiotics

Nabong W, Aquino M, Orlino C Ramos J and H Sumabit

The common moss often used in its dried form as substrate for orchids has a puzzling characteristic. It resists rotting and does not arbor the breeding of microorganisms that are pathogenic to the orchid. From this observation coupled by the fact that indigenous people use dried moss to cover wounds and skin diseases, led the researches to conduct an experiment on the antibiotic properties of mosses. The results are positive to bacteria causing skin infection, but the range of antibiosis has yet to be determined.

The researchers recommend that further studies be conducted on methods of extraction, other than the use of ethanol, in isolating the active principle which is the key to the antibiotic property of mosses.

3. Make your own Marker Ink from Mayana

Galang E, Cu MV, Constantino A and C Flores

Marker inks or colorants come in bright green, pink, blue and in different hues and shades. They are used to highlight keywords and sentences, terms or simply for arts and graphics. Commercial highlighters as these markers are commonly called, are imported from Japan, US, Germany and China. Local brands make use of imported colorants.

Mayana (Coleus blumei) is a colorful annual plant, dominantly red, maroon, green pink, yellow in various patterns and combinations. The researchers extracted the pigment using volatile solvents. Comparing the different cultivars of mayana, they came up with two dominant colors. Flesh to brown color appeared to be the best among the colors tested. Drying time compared to the commercial brands is the same.

The researchers recommend other possible plant colorants such as Carissa, duhat (Syzygium cumini) and bright petalled plants like Hibiscus.

4. Reasons Caulerpa seaweed eaters live healthier and longer lives.
Chua AG, Fancubit AL, Flores F and MR Liwag

Ilocanos in particular, who love to eat lato or ar-arusip are known to enjoy healthy and long lives. Is it a myth? The researchers found out that this green seaweed sold commercially in two species, C. lentelifera and C. racemosa, possess antibiotic properties. Raw extract has been found effective in destroying bacteria, such as Pseudococcus and Escherischia coli, common pathogens causing human ailments. Aside from this property,

Caulerpa contains caulerpine that to many people has relaxing effect, but excessive intake of the vegetable may cause dizziness. It is the only known edible seaweed that causes this symptom. This active principle may be tapped for its tranquilizing effect.

5. We can grow pechay and tilapia in a home aquarium.

Del Rosario L, De La Calzada GR, Javillonar C, and V Roquero

This research is based on palay-isdaan, an indigenous practice in low lying ricelands where rice and fish naturally grow together during the monsoon months. Thus, the researchers experimented on growing pechay (Brassica chinensis) in an aquarium medium, which can at the same time sustain the normal growth of tilapia (Tilapia nilotica).

The result promises another aspect of urban green revolution where hobbyists can combine the growing of fish in home aquarium with the production of vegetables. The idea may be the answer to having fresh and safe food supply for the home and neighborhood, and in maintaining a balance aquarium with lesser cost.

6. Makabuhay and Neem tree extracts are effective in control cockroach (Periplaneta Americana)

Tenorio RW, Nudo L, Roxas R and AC Uichanco

Makabuhay (Tinospora rhumphii) is a liana that grows in the wild. Previous experiments proved that its extract is effective in controlling common rice insect pest and the golden kuhol. Could it be effective in controlling the tough and elusive cockroach? The same question was raised on Neem (Aziderachta asiatica), known as insecticide tree that was introduced into the country from India in the sixties. According to the researchers, extracts of both plants proved effective as direct spray on cockroach.

Comparative effectiveness showed that the diluted extract of makabuhay gave a higher mortality that the pure extract, indicating the synergistic effect of water solvent, but only for makabuhay. Neem extract at low level dilution is more effective than that of makabuhay at the same level. While synthetic chemical sprays are more effective than these herbal extracts, the advantage of the latter is its being safe to humans and the environment and does not leave toxic residues.

7. Rat Poison from the Seed of Botong (Barringtona asiatica)
Perez R, Dela Cruz K, Rivera M and J Santos

If botong (Barringtona asiatica) is effective as fish poison, could it be effective as rat poison just as well? The researchers found it to be effective, but the problem to lure the rodents to eating the bait is a problem. This is because of the shy nature of rats and their oliphagous characteristic that is they eat a wide range of food under natural field condition. When starved rats may consume any available food and this may include poison baits.

The advantage of using plant poison is its safe nature to humans and the environment. Presently used compounds include arsenicals, anticoagulants under the brand names Dethmor, Racumin, Dora, and the deadly “1081” a zinc phosphide compound which is now banned in the market.

8. Botong (Barringtonia asiatica) is safer poison against fish pest
Dequina MJ, Castro JC, Limtin R and J Patawaran

This is the rational of the experiment: Is there a safer compound than synthetic pesticides to clean up fishponds in order to eliminate fish predators at seeding time?

It is a known practice among fishpond owners to use Malathion, Endrin, and other chlorinated hydrocarbon, as well as phosphate compounds to eliminate fish such as tilapia, dalag, and Poecillia after harvesting a fishpond. These remaining fish pose danger as predator of bangus fries raised in the next season.

The researchers found out that the extract of botong seeds (B asiatica) is an effective substitute. Like other plant extract, it is environment friendly and leaves non-toxic residue to the incoming fries and fingerlings.

9. Antibiotics from papaya seeds
Casas JM, Cadiz RI, Calvelo AM and MC Cremen

With the increasing resistance of bacteria to the group of Penncilium antibiotics, scientists are looking into more potent antibiotics. Modern antibiotics however, are expensive and are not readily available particularly in the countryside. But natural antibiotics abound in nature. One such source is the ordinary papaya, specifically the native or solo variety.

The researchers claim that the papain in papaya has an antibiotic property and the most likely part where the active compound is concentrated is the seeds, which are thrown away for no use except as propagation material. The seed oil is potent against both gram negative and gram positive bacteria, such as Staphylococcus. This explains why papaya is a health food.

Although the oil has also shown anti-fungal effects, the researchers recommend further studies in this aspect. They also recommend further studies in the preparation of the seed oil as antibiotic drop or ointment.

10. Mosquito repellant from bottle brush (Salix sp)
Clemente R, Landan RP Luquinario MI and P Padua

If there is a way to rid mosquitoes from attacking us without net or special paraphernalia, it is that advertised “Off” mosquito repellant. But the commercial products are synthetic compounds and reports claim that they are carcinogenic affecting not only the skin but internal organs as well since poison can be absorbed by the skin and into the blood stream and other tissue of the body.

The researchers collected the volatile oil of the weeping willow which is also known as bottle brush for the formation and shape of the leaves. With ethyl alcohol as solvent, the preparation was tested against house mosquitoes (Culex pipens) in the same manner as the advertised commercial product is used. The results are positive.

11. How good are commercial organic fertilizers as claimed by their manufacturers?
Olivenza CR, King A, Reyes CJ and A Young

There are a number of organic fertilizers in the market manufactured from various raw materials. As such there is no standard set particularly for their nutrient content. They are advertised with various advantages which the researchers in this study say only by experimentation on at least one plant indicator can resolve – pechay (Brassica chinensis).

The results of the experiment are varied and therefore support the theory that organic fertilizers in the market do not have standard effects on the growth and development patterns on the test plant. The researchers believe that fortification of organic fertilizers with chemical fertilizers improves the formula and helps solve nutrient deficiency.

12. Bunga de Jolo has bactericidal propperties.
Villaluz MC, Enebrad K, Garcia R and V Guzman
Vetchia merillii, a palm relative of the bunga (Areca catechu) was found to have a unique potency against the bacterium, Bacillus proteus as well as others pathogens causing infection. Direct extract from the seed showed potent inhibition against the test organisms, a feat the control (Penncilium type) failed to show.

This explains the usefulness of Bunga de Jolo as a substitute of Areca in the absence of the latter. Both produce nuts, which are used by older people for mastication with or without the betel leaf and the occasional lime that goes with the preparation.

13. Beware of Ganoderma food supplement

Africa MA, Abulencia HM, Bautista A and AM Bebanco

This shelf fungus comes as food supplement, mainly as pre-packed coffee and tea, and advertised in several names. White mice fed freely with the raw fungus died after a few days. Even those given with limited amounts showed adverse physiologic effects like loss in weight, thinning of hair, and progressive weakness. Many died after two or three weeks. The results indicate that the fungus has toxic effect.

It will be recalled that among the most poisonous materials occurring in nature come from fungi, the classical example is the Amanita mushroom which when mistakenly eaten by humans can cause instant death. There is no known antidote of mushroom poisoning. At minimal dosage however, not exceeding 10 mg per 1 kg body weight, the test animals gained weight faster than those not given with Ganoderma.

Thus the researchers recommend judicious use of the food supplement, as it may be deleterious to health contrary to the claims of its manufacturers and distributors.

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Students find leisure in outdoor study. At the background is the historic building of the 400-year old university. (1611-2011)

These researches are dedicated to the memory of late Prof. Eduardo de Leon, Department Chairman in Botany of the Faculty of Pharmacy, University of Santo Tomas, who initiated and supervised these researches. Professor Ed and I worked together for many years as professors. These researches earned for the concerned students the thesis requirement of Bachelor of Science in Pharmacy.