Low molecular weight extraction process

A process for isolating native, low molecular weight (“LMW”) peptides, which have a molecular weight, wherein said molecular weight is less than or equivalent to 10 kDa from tissue in situ comprising:

• a) homogenizing the tissue;
• b) mixing the homogenized tissue with an organic solvent to form a fully-wetted slurry;
• c) standing or agitating the slurry to denature high molecular weight proteins proteins in situ within the homogenized tissue;
• d) removing and discarding the organic solvent from the homogenized tissue prior to undertaking step (e);
• e) mixing the organic solvent-treated homogenized tissue of step d) that comprises the in situ-denatured high molecular weight proteins and the low molecular weight (“LMW”) peptides, which have a molecular weight, wherein said molecular weight is less than or equivalent to 10 kDa with water or an aqueous, non-organic solution that consists essentially of water and aqueous salts and/or buffer solutions, and does not contain ethanol, to extract the low molecular weight (“LMW”) peptides, which have a molecular weight, wherein said molecular weight is less than or equivalent to 10 kDa;
• and
• f) separating a liquid extract from the homogenized tissue residue of step e) to obtain an aqueous solution containing the low molecular weight peptide fraction removed from the tissue.