Papaya as Medicaments 177
the premature stage, which is present in the seed after fruit ripening (Li et al. 2012).
The benzyl glucosinolate is hydrolysed to benzyl isothiocyante (BITC). The seed
extract demonstrated a rich source of BITC (Nakamura et al. 2007). It shows that
papaya is an excellent source of vitamin A, vitamin C and dietary fibre and a good
source of vitamin E.
16.2.3 Anti-Diabetic Activity
The aqueous extract of leaves significantly reduced plasma blood glucose level
and serum lipid profile in diabetic rats (Juárez-Rojop et al. 2012; Maniyar and
Bhixavatimath 2012). The ethanolic extract of leaves demonstrated significant
reduction in the blood glucose level and regeneration of the beta cells of pancreas
in diabetic mice (Azarkan et al. 2003). The aqueous extract of unripe fruit signifi-
cantly inhibited the key enzymes α-amylase and α-glucosidase involved in diabetes
and also inhibited the lipid peroxidation in rat pancreatic cells studied in vitro
(Oboh et al. 2013).
16.2.4 Anti-Infertility Activity
The seeds were shown to have antifertility properties in male albino rats. Seed extract
treated in male albino rats reduced the cauda epidymal and testicular sperm counts
(Lohiya and Goyal 1992). Male wistar rats treated orally with seed extract (200 mg/
kg) demonstrated hypertrophy of pituitary gonadotrophs and gradual degeneration
of germ cells, sertoli cells and leydig cells of testis thereby, drastically affecting the
male reproductive functions (Udoh et al. 2005). The aqueous extract of papaya seed
administered to male Sprague–Dawley rats suppressed the steroidogenic enzymes
in the testis and reversible changes occurred when the extract was withdrawn after
30–45 days of treatment (Uche-Nwachi et al. 2011). The papaya seed extract can also
be used as an effective male contraceptive (Chinoy et al. 1994). Women in India,
Bangladesh, Pakistan, Sri Lanka and other countries have long used green papaya
as a herbal medicine for contraception and abortion. Enslaved women in the West
Indies were noted for consuming papaya to prevent pregnancies and, thus, preventing
their children from being born into slavery.
16.2.5 Anti-Inflammatory Activity
The papaya leaf extract was examined in rats using oedema, granuloma and arthritis
models. The extract showed significant reduction in paw oedema, granuloma
formation and reduced inflammation in rats (Owoyele et al. 2008). Intake of papaya
fruits in healthy individuals alleviated anti-inflammatory response mediated through
regulatory T-cells (Abdullah et al. 2011). However, the latex obtained from unripe
fruit has the property of inducing inflammation and it has been proved in rat as a
model for testing the anti-inflammatory activity of compounds (Gupta et al. 1992).
Protein enzymes including papain and chymopapain and antioxidant nutrients found
in papaya, including vitamin C, vitamin E and beta-carotene, reduce the severity of
the conditions such as asthma, osteoarthritis and rheumatoid arthritis.