Phytochemical investigation of different extracts from guava (Psidium
guajava L.) leaves revealed the presence of carbohydrates and/or glycosides, tannins,
saponinis, f1avonoids, sterols and/or triterpenes and phenolic compounds while
alkaloids and coumarins were absent. Also quantitative analysis of different extracts
showed that crude ethanolic extract Et.1 contained more tannins, saponons,
flavonoids and phenolic compounds (9.60%, 1.12%, 0.88% and 3.03%) than other
extracts, also ethylacetate extract contained flavonoids and phenolic compounds
(0.74% and 0.82%), respectively but aqueous extract contained moderate contents
from these constituents (4.02%,1.32%,0.13% and 1.04%), respectively. Essential oil of dried P. guajava L. leaves was extracted by steam distillation
and analysed by Gas chromatography Mass Spectroscopy (GC-MS). Essential oil
yield was 0.67 g/100g from dried leaves. Thirty two components were identified by
GC-MS and the major constituents were limonene (15.22%), Junipene (9.58%),
glaucine (9.03%), beta terpinyl acetate (8.70%) and D-nerolidol (8.58%). The inhibitory effects of successive extraction of guava leaves with
petroleum ether (PE), chloroform (Ch1), ethyl acetate (EA), ethanol 96% (Et.2), v-ater
(W), complete ethanol 70% (Et.1) separately and three concentrations of essential oil
on lipid peroxidation induced by Fe++/ascorbate in rat liver mitochondria and
microsomes were determined. Also free radical scavenging activity of different
extracts and essential oil were determined using 2,2 - diphenyl - 1 - picrylhydryzyl
(DPPH·). The obtained results revealed that crude ethanolic extract Et.1 has high
effect in protected rat liver mitochondria and microsomes from lipid peroxidation and
was substantially more powerful antioxidant where the percentage of inhibition of lipid
peroxidation in mitochondria and microsomes were (95.80% and 97.88% compared
with rutin as standars (97.23% and 98.90%) and free radical scavenging using DPPH·
was (94.38% and rutin 95.69%). Et.1 and essential oil were evaluated for the
protective effect against liver damage induced by carbon tetrachloride (CCI4) in male
albino rats. Rats were orally administered with 50 and 100 mg/kg body weight from
ethanolic extract (Et.1) and essential oil for 14 days before CCl4 challenge and 100
mg from Et.1 and essential oil for toxicity analysis without CCl4 administration
significantly damaged the liver as evident from very high activity of serum marker
enzymes and glutathione - S - transferase. Also decrease total protein, albumin but
increa-ed bilirubin contents in the serum. Et.1 administration significantly restored the
elevated activities of Ii'ler marker enzymes, increased total protein and albumin,
content enhanced the antioxidant enzyme activity also decrease bilirubin content than
essential oil which gave slight effect at the same time Et.1 and essential oil at 100
mg/kg body weight had no any toxic effect. The results of antitumor activity of Et.1 and
essential oil on Erhlisch ascites carcinoma (EACC) cells indicated that essential oil
had higher antitumor activity than Et.1 which the dead cells percentage were ranged
from 87 - 100% but in Et.1 ranged from 76 - 95%.