Physiological and biochemical analysis to reveal the molecular basis for black widow spiderling toxicity.

The early research found that the spiderlings of black widow spider (Latrodectus tredecimguttatus) exhibited obvious toxicity to animals. The present work performed a systematical analysis of the aqueous extract of newborn black widow spiderlings. The extract was shown to contain 69.42% of proteins varying in molecular weights and isoelectric points. Abdominal injection of the extract into mice and cockroaches caused obvious poisoning symptoms as well as death, with LD50 being 5.30 mg/kg in mice and 16.74 µg/g in Periplaneta americana. Electrophysiological experiments indicated that the extract at a concentration of 10 µg/mL could completely block the neuromuscular transmission in isolated mouse nerve-hemidiaphragm preparations within 21 ± 1.5 min, and 100 µg/mL extract could inhibit a certain percentage of voltage-activated Na⁺, K⁺, and Ca²⁺ channel currents in rat dorsal root ganglion neurons. These results demonstrate that the spiderlings are rich in neurotoxic components, which play important roles in the spiderling toxicity.