RT Journal Article
ID 72f3730f3183e28a
A1 Kumar, Sudhir C.
A1 Ng, Mah-Lee
T1 Antitumor Activity of Oral Administration of Mycovirus Extract from <i>Lentinus edodes</i> (Berk.) Sing. (Agaricomycetideae) on Murine Lymphoma
JF International Journal of Medicinal Mushrooms
JO IJM
YR 2000
FD 2000-06-01
VO 2
IS 2
OP 8
AB The present study evaluated the antitumor activity of polyethylene glycol (PEG)-concentrated double-stranded RNA mycovirus, present abundantly in fresh 2-day-old buds of <i>Lentinus edodes</i> (shiitake mushroom). K36 cell-line induced murine lymphoma in male AKR mice was the tumor-model used. The difference in antitumor activity by three types of intervention in relation to leukemia cell inoculation was assessed. The three interventions were: prefeeding with mycovirus extract before K36 cell inoculation, simultaneously feeding of extract with K36 cell inoculation and administering the extract after tumors were induced. Tumors obtained 14 d after leukemia cell inoculation were investigated in detail. Prefeeding with mycovirus extract conferred the best antitumor activity with a tumor inhibition rate of 80.7% (<i>p</i> < 0.001). Simultaneous feeding and administering extract after tumors were induced were also effective with tumor regression rates of 73.8% (<i>p</i> < 0.001) and 67.6% (<i>p</i> < 0.001), respectively. In addition, the effective dose of mycovirus extract caused only a negligible body-weight reduction of 0.63% (<i>p</i> = 0.866) without any toxic effects in mice. Electron microscopy revealed apoptotic cells in all three regimens. These findings were confirmed by confocal microscopy on TUNEL-stained lymphoma sections, a hallmark of apoptosis. Interestingly, electron microscopy also revealed abundant defective tumor retrovirus in the prefed regimen and lesser in the other two regimens. Cytokines interferon-&gamma; and tumor necrosis factor-&alpha; in serum from healthy mice was assayed after oral administration of the extract. These surrogate markers of immunomodulation were significantly elevated (<i>p</i> = 0.004 and <i>p</i> = 0.025, respectively). This proved the formulated hypothesis that immunomodulation by mycovirus extract contributed to the observed antitumor activity and production of defective tumor retrovirus.
PB Begell House
LK https://www.dl.begellhouse.com/journals/708ae68d64b17c52,452b39d115b42ef7,72f3730f3183e28a.html