416
C (ratio of 100:1, vitamin C: vitamin K3) achieved cytotoxic dosages 10–50 times
lower than when singly administered. Vitamin K3 at 13.8 μg/mL produced a 50%
inhibition of breast cancer (MCF-7) cell growth. When combined with vitamin C
(99.01 μg/mL), K3 (1.38 μg/mL) increased inhibition by 74%. Increasing the concentrations of vitamins C and K (10
4
μmol/L and 10
5
nmol/L, respectively) produced a 93% inhibition. Using KB cells, a 50% inhibition of growth was seen with
K3 (13.8 μg/mL). When KB cells were subjected to vitamin C at 10
3
mmol/L or K3
at 10
4
nmol/L separately, no in vitro cytotoxic effect resulted. When combined at the
same concentrations, a synergistic inhibition of 100% was achieved. Similarly,
Vitamin K2 also exhibited anticancer effects with an ID50 value from 0.8–2 mM,
which, is higher than inhibitory levels of K3 (18–45 μM) (Wu et al. 1993). Similarly,
Nishikawa et al. (1999) have reported that lower concentrations of vitamin K2 are
effective anticancer agents for a number of cancer cell types through in vitro studies.
The HOS TE85 human osteosarcoma cell line and the MC3T3-E1 mouse osteoblastic cell line were cultured for three days in a medium containing various concentrations of MK-4. The proliferation of HOS cells was suppressed by vitamin K2 in a
dose-dependent manner up to 56% of control by 10
−7
M of K2, and that of
MC3T3-E1 cells was suppressed to 84% of control by 10
−6
M of vitamin K2. MK-3
had an ID50 of 112 μM for the human hepatoma cell line Hep3B.
The phytosterols are also effective against various cancers like colon, prostate,
and breast cancer. Awad et al. (2002) evaluated the dietary effect of phytosterols
versus cholesterol on the growth and metastasis of the PC-3 human prostate cancer
cells in mice. Also, their direct effect on the growth and migration of these cells
in vitro was analyzed. Animals fed with the phytosterol diet had tumors 40–43%
smaller than those fed with the cholesterol diet. Furthermore, the number of mice
with lymph node and lung metastasis was almost one-half that of the cholesterol-fed
group. In the in vitro studies, both β-sitosterol and campesterol inhibited the growth
of PC-3 cells by 70% and 14%, respectively, while cholesterol supplementation
increased the growth by 18% when compared with controls. It was concluded that
phytosterols indirectly (in vivo as a dietary supplement) and directly (in tissue culture media) inhibited the growth and metastasis of PC-3 cells. β-Sitosterol was more
effective than campesterol in offering this protection in most of the parameters
studied.
There are few lipophilic flavonoids and polyphenols, that are more effective
against various cancer. Curcumin is a polyphenol extracted from turmeric, with
anti-oxidation, anti-inflammation, and anti-cancer properties. However, the effects
of curcumin on human cancer cells remain largely unknown. Wang et al. (2017)
investigated the anticancer effects and the mechanisms by which curcumin affects
breast cancer cells. The anticancer effect of curcumin on cell viability and cytotoxicity on human breast cancer MCF-7 cells was analyzed. The results demonstrated that curcumin inhibited cell viability and induced cytotoxicity of MCF-7
cells in a concentration- and time-dependent manner, by inducing apoptosis and
increasing caspase-3/9 activities. Yu and Huang (2010) encapsulated curcumin in
G. J. Swamy et al.
C (ratio of 100:1, vitamin C: vitamin K3) achieved cytotoxic dosages 10–50 times
lower than when singly administered. Vitamin K3 at 13.8 μg/mL produced a 50%
inhibition of breast cancer (MCF-7) cell growth. When combined with vitamin C
(99.01 μg/mL), K3 (1.38 μg/mL) increased inhibition by 74%. Increasing the concentrations of vitamins C and K (10
4
μmol/L and 10
5
nmol/L, respectively) produced a 93% inhibition. Using KB cells, a 50% inhibition of growth was seen with
K3 (13.8 μg/mL). When KB cells were subjected to vitamin C at 10
3
mmol/L or K3
at 10
4
nmol/L separately, no in vitro cytotoxic effect resulted. When combined at the
same concentrations, a synergistic inhibition of 100% was achieved. Similarly,
Vitamin K2 also exhibited anticancer effects with an ID50 value from 0.8–2 mM,
which, is higher than inhibitory levels of K3 (18–45 μM) (Wu et al. 1993). Similarly,
Nishikawa et al. (1999) have reported that lower concentrations of vitamin K2 are
effective anticancer agents for a number of cancer cell types through in vitro studies.
The HOS TE85 human osteosarcoma cell line and the MC3T3-E1 mouse osteoblastic cell line were cultured for three days in a medium containing various concentrations of MK-4. The proliferation of HOS cells was suppressed by vitamin K2 in a
dose-dependent manner up to 56% of control by 10
−7
M of K2, and that of
MC3T3-E1 cells was suppressed to 84% of control by 10
−6
M of vitamin K2. MK-3
had an ID50 of 112 μM for the human hepatoma cell line Hep3B.
The phytosterols are also effective against various cancers like colon, prostate,
and breast cancer. Awad et al. (2002) evaluated the dietary effect of phytosterols
versus cholesterol on the growth and metastasis of the PC-3 human prostate cancer
cells in mice. Also, their direct effect on the growth and migration of these cells
in vitro was analyzed. Animals fed with the phytosterol diet had tumors 40–43%
smaller than those fed with the cholesterol diet. Furthermore, the number of mice
with lymph node and lung metastasis was almost one-half that of the cholesterol-fed
group. In the in vitro studies, both β-sitosterol and campesterol inhibited the growth
of PC-3 cells by 70% and 14%, respectively, while cholesterol supplementation
increased the growth by 18% when compared with controls. It was concluded that
phytosterols indirectly (in vivo as a dietary supplement) and directly (in tissue culture media) inhibited the growth and metastasis of PC-3 cells. β-Sitosterol was more
effective than campesterol in offering this protection in most of the parameters
studied.
There are few lipophilic flavonoids and polyphenols, that are more effective
against various cancer. Curcumin is a polyphenol extracted from turmeric, with
anti-oxidation, anti-inflammation, and anti-cancer properties. However, the effects
of curcumin on human cancer cells remain largely unknown. Wang et al. (2017)
investigated the anticancer effects and the mechanisms by which curcumin affects
breast cancer cells. The anticancer effect of curcumin on cell viability and cytotoxicity on human breast cancer MCF-7 cells was analyzed. The results demonstrated that curcumin inhibited cell viability and induced cytotoxicity of MCF-7
cells in a concentration- and time-dependent manner, by inducing apoptosis and
increasing caspase-3/9 activities. Yu and Huang (2010) encapsulated curcumin in
G. J. Swamy et al.