TOXINS AND VENOMS

Envenomization

injection of venom by specialized morphological structures by stinging, biting, spraying, or directing them to their target

Toxins

• specific chemical compound or molecule that causes harm to an organism on contact or when ingested

• cause immediate, and intense pain with localized swelling or erythema at the bite site

• serves to deter predators and other perceived threats

Toxins (Fat Soluble / Hydrophobic)

aid in penetrating the integument on contact

Venoms

• serves to deter predators and other perceived threats

• consists of complex mixtures with other chemicals that facilitate the effect of the toxic components once they penetrate the integument to enter the more aqueous environment

• typically proteins in nature (e.g. phospholipases, hyaluronidases, phosphatases, esterases, and proteases) causing lethality and damage

• contains biogenic amines (e.g. histamine, serotonin, acetylcholine, and epinephrine) that cause swelling and other reactions, and pain at sting sites

• neurotoxic (paralysis), necrotizing (severe inflammation and necrosis), hemolytic/ hemorrhagic (depletion of clotting factors)

Water Soluble

Venoms are

Localized and Systemic Toxicity

Two types of Toxicity

Localized Toxicity

venom/toxin remains at the site of stinging

Mild Toxicity

produces local pain, irritation, and swelling

Systemic Toxicity

sufficient venom/toxin is absorbed into systemic circulation (stung multiple times)

Severe Toxicity

produces acute allergic response ( vasodilation, hypotension, bronchoconstriction, inflammation, and edema)  followed by delayed response (haemolysis, and renal failure

mast cells

First step to alergic response: Binding of venom with antibodies associated with

histamine

Second step to allergic response: This is released after the first step

Leakage of fluid out of the blood and into body tissues.

Third step to allergic response

Laryngospasm and bronchospasm

Fourth step to allergic response: Blood pressure drops, fluid build up in lungs, then this starts

Anaphylactic shock

If allergy is not treated it would lead to

Immediate Type Hypersensitivity

- rapid release of mediators, such as histamine, causing dilation of local blood vessels and increased vascular permeability

- within an hour of manifestation

Delayed Type Hypersensitivity

- activated macrophages respond to the antigen by phagocytizing particulate antigens, secreting mediators that promote local inflammation and secreting cytokines and growth factors that facilitate immune clearance of the antigen

- 24h relapse between the antigen and the immune response

Immediate Type Hypersensitivity (ITH) and Delayed Type Hypersensitivity (DTH)

Two types of Hypersensitivity Reactions

Type I

IgE antibodies

Type II and Type III

IgG/IgM antibodies

Type IV

T-cells mediated

Honey Bees

Melittin came from

Melittin

- inhibit bacteria, including the Lyme disease agent Borrelia burgdorferi

- kills yeast (e.g., Candida albicans) and suppresses Mycoplasma and Chlamydia infections

- potential for treating epilepsy and acquired immune deficiency syndrome caused by the Human immunodeficiency virus (HIV)

Blister Beetles

Cantharidin comes from

Cantharidin

- used as an aphrodisiac, remove warts

Rove Beetles

Pederin comes from

Pederin

inhibit protein and DNA synthesis and to slow the division of cancer cells

Fire ants

Solenopsin comes from

Solenopsin

exhibit insecticidal, antibacterial, antifungal, and antiviral activity

Scorpions and Spiders

Peptide venom comes from

Peptide Venom

used as  antibacterial, antiviral, analgesics or painkillers and anti-cancer