Warm Up: Natural Remedies

Think about a time you or someone you know used a natural remedy for a common ailment (like a cold, a cut, or an upset stomach).

What was the remedy, and what was it used for?

Share your thoughts with a partner, then we'll discuss as a class.

Aloe Vera: A Botanical Powerhouse

Introduction

Aloe vera (Aloe barbadensis miller) is a succulent plant species from the genus Aloe. It grows wild in tropical climates around the world and is cultivated for agricultural and medicinal uses. The species is used for decorative purposes and grows successfully indoors as a potted plant. It is found in many consumer products, including beverages, skin lotion, cosmetics, or ointments for minor burns and sunburns.

Botanical Characteristics

Aloe vera plants are stemless or very short-stemmed, growing to 60–100 cm (24–39 in) tall, spreading by offsets. The leaves are thick and fleshy, green to grey-green, with some varieties showing white flecks on the upper and lower stem surfaces. The margin of the leaf is serrated and has small white teeth. The plant produces a gel from the cells in the center of the leaf, and a yellow latex from the cells just beneath the leaf skin.

Historical Uses

The use of Aloe vera dates back thousands of years. Ancient Egyptians referred to Aloe vera as the "plant of immortality" and included it among the burial gifts for pharaohs. Queens like Nefertiti and Cleopatra used it as part of their daily beauty regimes. Ancient Greek scientists regarded Aloe vera as a panacea (a cure-all). Dioscorides, a Greek physician and botanist, described Aloe's use for wound healing, hair loss, and intestinal discomfort in his book "De Materia Medica" in 41 A.D.

Modern Applications and Active Compounds

Today, Aloe vera is widely recognized for its soothing and healing properties. The clear gel found inside the leaves contains over 75 potentially active constituents, including vitamins (A, C, E, B12, folic acid), enzymes, minerals (calcium, chromium, copper, selenium, magnesium, manganese, potassium, sodium, zinc), sugars (monosaccharides and polysaccharides like acemannan), lignin, saponins, salicylic acids, and amino acids. Many of these compounds contribute to its anti-inflammatory, antiseptic, and moisturizing effects.

Polysaccharides and Immune Support

One of the most significant active compounds in Aloe vera is acemannan, a complex carbohydrate (polysaccharide). Research suggests that acemannan may have immune-stimulating properties, helping the body fight off infections. It's thought to encourage white blood cells to produce substances that can destroy viruses and other pathogens.

Antimicrobial Properties

Beyond its soothing effects, Aloe vera also exhibits mild antimicrobial properties, meaning it can help inhibit the growth of certain bacteria, fungi, and viruses. This is partly due to compounds like anthraquinones and saponins. While not as potent as pharmaceutical antiseptics, these natural compounds contribute to Aloe's overall health benefits and make it a valuable addition to many personal care products.

Connection to Skin Health

In skin care, Aloe vera is prized for its ability to hydrate and heal. It's often used to treat minor cuts, burns, and skin irritations because it forms a protective layer, promotes collagen production, and reduces inflammation. Its moisturizing capabilities are also why it's a popular ingredient in lotions and, as we will explore, hand sanitizers, where it helps counteract the drying effects of alcohol.

DIY Hand Sanitizer Recipe Card

Be Your Own Chemist! Create a Germ-Fighting Hand Sanitizer

Goal: To make an effective hand sanitizer that cleanses your hands and keeps them moisturized.

Important Safety Note: This activity involves rubbing alcohol. Handle with care. Do not ingest. Keep away from open flames. Follow teacher instructions carefully.

Ingredients & Materials:

• Rubbing Alcohol (Isopropyl Alcohol or Ethanol, 70% or higher): The germ-killing agent!
• Pure Aloe Vera Gel (100% pure): To moisturize your hands and help the sanitizer spread.
• Optional Essential Oils (e.g., Tea Tree, Lavender, Peppermint): For a pleasant scent and some may offer additional antimicrobial properties.
• Small mixing bowl
• Spoon or whisk for mixing
• Measuring spoons or cups
• Small, clean spray bottle or pump bottle (for your finished sanitizer)

Instructions:

1. Measure the Alcohol: Carefully pour 2 parts rubbing alcohol into your mixing bowl.
   Example: If you want to make a small bottle, start with 2 tablespoons of alcohol.

2. Add the Aloe Vera Gel: Add 1 part pure aloe vera gel to the bowl with the alcohol.
   Example: If you used 2 tablespoons of alcohol, add 1 tablespoon of aloe vera gel.

3. Mix Thoroughly: Stir the mixture well with your spoon or whisk until both ingredients are fully combined and the mixture has a consistent gel-like texture.

4. Add Essential Oils (Optional): If you like, add 5-10 drops of your chosen essential oil(s). Stir again to distribute the scent.

5. Transfer to Bottle: Carefully pour your homemade hand sanitizer into your clean spray or pump bottle. A funnel can be helpful here!

6. Label Your Bottle: Don't forget to label your bottle with the contents (e.g., "DIY Hand Sanitizer") and today's date.

Quick Science Check:

• Why 2 parts alcohol to 1 part aloe? This ratio ensures your final product has at least 60% alcohol, which is the minimum concentration recommended by the CDC for effective germ killing. Too much aloe would dilute the alcohol and make it less effective.
• What does the alcohol do? It breaks down the outer protective layers of bacteria and viruses, effectively neutralizing them.
• What does the aloe do? It prevents your hands from drying out and cracking due to the alcohol, and helps the sanitizer spread evenly on your skin.

Why Handwashing Matters: An Everyday Superpower

Discussion & Reflection Activity

Objective: To understand the critical role of hand hygiene in preventing the spread of illness, especially during cold and flu season.

Part 1: Initial Thoughts (Individual Reflection - 2 minutes)

Take a moment to silently reflect on the following questions:

1. How often do you think about washing your hands throughout the day?
2. What are the common times you make sure to wash or sanitize your hands?
3. What do you think are the biggest challenges to practicing good hand hygiene?

Part 2: Small Group Discussion (5-7 minutes)

In your small groups (2-3 students), discuss the following:

1. Germ Hotspots: Where do you think germs are most commonly found in places like school, your home, or public spaces? Brainstorm a list.
   
   
   
   
2. Chain of Transmission: Describe how germs can spread from one person to another, or from surfaces to people. Give a real-world example.
   
   
   
   
3. The Cold & Flu Battle: Why is diligent hand hygiene especially important during cold and flu season? What makes these illnesses so easy to spread?
   
   
   
   
4. Beyond Your Hands: Besides washing/sanitizing hands, what other habits or actions can help prevent the spread of illness?
   
   
   
   

Part 3: Class Share & Discuss (3-5 minutes)

We will now share some of our group discussions with the whole class. Be ready to share one interesting point or insight from your group.

Reflection Journal: Botany, Hygiene, and You

Take some time to reflect on today's lesson. Your responses should be thoughtful and demonstrate your understanding of the concepts discussed.

Prompt 1: The Versatility of Aloe

Before today's lesson, what did you primarily associate with Aloe vera? How has your understanding of this plant expanded after learning about its botanical properties and its use in hand sanitizers? Be specific about new knowledge gained.

Prompt 2: Science in Everyday Life

Describe the scientific principles behind why Aloe vera is included in hand sanitizer, specifically how it complements the alcohol. How does understanding these principles change your perspective on everyday products?

Prompt 3: Your Role in Public Health

Connect what you learned about hand hygiene (and the role of hand sanitizer) to the prevention of cold and flu during peak seasons. How might you apply this knowledge in your own life, and how can you encourage others to practice good hygiene?

Cool Down: One Big Idea

What is ONE big idea or important takeaway you learned today about Aloe vera, hand sanitizers, or preventing the spread of illness during cold and flu season?