Cytotoxicity of ethanol extracts from glanded and glandless cottonseed in cultured mouse RAW macrophages

Abstract

Cotton plant provides two economically important products, fiber as the major product and cotton seed as the minor product. However, cotton plant produces more seed in terms of quantity than fiber with a seed/fiber ratio of 1.5 – 1.7. Cottonseed typically accounts for 15 – 25% of the crop value. Due to presence of toxic gossypol in the commonly cultivated cotton (glanded cotton), the uses of cottonseed is limited to feeding cows and not for human and other animal consumption. To explore the potential use of glandless cottonseed which has only trace amount of gossypol, we investigated the cytotoxicity of extracts from glandless cottonseed along with those from glanded cottonseed and compared directly with gossypol and lipopolysaccharide (LPS) using cultured mouse macrophages. Cottonseeds were separated into coat and kernel fractions. Both fractions were homogenized in 0.1 N acetic acid, defatted with chloroform and hexane and extracted with ethanol. The ethanol extracts were rotoevaporated to remove ethanol and the dried extracts were reconstituted in DMSO before being added to cultured mouse RAW264.7 macrophages using gossypol and LPS as controls. Cell cytotoxicity was determined with MTT method. Dosage study showed that no cytotoxicity effect was observed in cells treated for 2–24 h with extracts (up to 1 mg/ml) from glandless cottonseed coat or kernels, nor with glanded cottonseed coat. However, mitochondrial activity measured by the MTT method was decreased by 40% with glanded cottonseed kernel extract after cells were treated with 0.1–1 mg/ml for 24 h. LPS (up to 1 ug/ml) did not show toxic activity but gossypol (≥5 ug/ml, 24h) almost completely inhibited cell viability. These results suggest that glandless cottonseed extractis harmless towards the cultured macrophages but glanded cottonseed extract from its kernel, like gossypol, is harmful to the immunological cells.Support or Funding InformationSupported by USDA‐ARS Quality and Utilization of Agricultural Products Research Program 306 through CRIS 6054‐41000‐103‐00D.