Variability and Correlation Studies in Basil Scent Leaf (Ocimum Gratissimum)
AIM OF THE STUDY
The aim of this study is to cary out variability and correlation studies in basil scent leaf and to alsdetermine the effect of aqueous extract of Ocimum gratissimum leaves on pregnancy and its outcome in pregnant rats.
The objectives of the design of this research are to;
- Determine the effect of the aqueous extract of gratissimum leaves on pregnancy and weight gain in diabetic pregnant rats.
- Determine the effect of the aqueous extract of gratissimum leaves on fasting blood glucose in diabetic and non-diabetic pregnant rats.
- Determine the effect of aqueous extract of Ocimum gratissimum leaves on pregnancy outcome in diabetic and non-diabetic.
DESCRIPTION OF OCIMUM GRATISSIMUM
The use of plant materials as spices, condiments and for medicinal purposes dates back to the history of mankind (Garland, 1972, Ogunyemi, 1979 and Nweze et al, 2004,). Recently, the exploitation of wild plants for medicinal purposes has gained more acceptances in many countries of the world. To further underscore the importance of herbal medicine, most national
governments have established the traditional medicine regulatory council under the supervision of their various health ministries to tap the numerous potentials of herbs. This may be because traditional medicine has long been practiced even before the orthodox medical practice appeared (Okafor et al, 2001). Ocimum gratissimum belongs to the group of plants known as spices. The plant is an erect small plumb with many barnacles usually not more than 1 m high (Vierra and Simon, 2000). It is of the family Labiatea, genus Ocimum and species gratissimum (Iwu, 1993) In South East Asia, it is cultivated as a home garden crop but it is grown on a commercial scale in Vietnam. In Nigeria, it is Efinrin in Yoruba, Diadoyal in Hausa and Nchuanwu in Igbo (Owulade, 2004). It is used for a variety of reasons. In culinary, it is used in salads, soups, pastas, vinegars and jellies in many parts of the world. The Thai people are popularly known to use it in food flavoring. In traditional medicine, the leaves have been used as a general tonic and anti- diarrhea agent and for the treatment of conjunctivitis by instilling directly into the eyes; the leaf oil when mixed with alcohol is applied as a lotion for skin infections, and taken internally for bronchitis. The dried leaves are snuffed to alleviate headaches and fever among other uses (Iwu, 1993). Although, conventional antibiotics have been very useful in orthodox medicine, it has been argued by many that its concomitant use with herbal extracts is not desirable as one normally antagonizes the activity of the other. Considering the fact that Ocimum gratissimum is used in most local dishes/foods to achieve a variety of purposes, there is need to ascertain if its extract antagonizes or acts as a synergy when used together with conventional antibiotics. In addition, despite the fact that the various extracts of O. gratissimum have been tested in vitro and shown to be active against some bacterial and fungal isolates (Nakamura et al, 1999, Nakamura et al, 2004 and Silva et al, 2005).
NOMENCLATURE AND TAXONOMY OF OCIMUM GRATISSIMUM
Kingdom Plantae –Plants
Subkingdom Tracheobionta – Vascular plants
Superdivision Spermatophyta– Seed plants Division
Class Magnoliopsida– Dicotyledons
Family Lamiaceae – Mint family
Genus Ocimum L. – basil
Species gratissimum L. African basil
Ocimum gratissimum is found throughout the tropics and subtropics and its greatest variability occurs in tropical Africa and India. It is widely distributed throughout Central America, West African Coast and has been used in Trinidad and Tobago and in Nigeria for the treatment of various ailments including diabetes mellitus (Bailey and Day, 1989; Aguiyi et al, 2000).
MATERIALS AND METHODOLOGY
Some of the materials used in the course of this study (Research work) include; Animal Cages
Ocimum gratissimum leaves Stainless plates for feed and water Normal Saline
Scale Meter e.t.c.
COLLECTION AND IDENTIFICATION
The leaves of Ocimum gratissimum was harvested (collected) from Ubiaja, Edo State in Nigeria. The plant was subsequently identified and authenticated by Botanist of the Botany department of University of Nigeria, Nsukka and a sample was kept for reference in the University herbarium.
In the experiment, a total of 40 female rats with body weight ranging from 120g to 150g were used. The effect of aqueous extract of O. gratissimum leaves on fasting blood glucose, body weight gain and pregnancy outcome in alloxan-induced diabetic pregnant rats was investigated and the results are shown in the tables below.
CHAPTER FIVE DISCUSSION
Ocimum gratissimum is widely distributed throughout Central America, West African Coast and has been used in Trinidad and Tobago and in Nigeria for the treatment of various ailments including diabetes mellitus (Bailey and Day, 1989; Aguiyi et al, 2000). This work reports the results of an investigation into the effect of aqueous extract of Ocimum gratissimum leaves on fasting blood glucose, weight gain and pregnancy outcome in diabetic and non-diabetic pregnant rats. The aqueous extract of O. gratissimum leaves; produce significant reduction in fasting blood glucose in a dosage dependent manner in diabetic pregnant rats. This shows that the aqueous extract of the leaves of O. gratissimum plant is an effective antidiabetic agent in diabetic pregnant rats. On weight gain, the extract produces significant weight gain in diabetic pregnant rats in a dosage dependent manner compared to the control group. On pregnancy outcome, the extract increased litter size in a dosage dependent manner in diabetic and non-diabetic pregnant rats
EFFECT OF EXTRACT ON FASTING BLOOD GLUCOSE
The high fasting blood glucose observed at induction in diabetic pregnant rats, indicate establishment of diabetic state. However, from Table 4.1, three weeks administration of graded doses (100mg/kg, 200mg/kg and 300mg/kg of body weight) of aqueous extract of O. gratissimum leaves to diabetic pregnant rats produce significant gradual reduction or decrease (p<0.05) in the fasting blood glucose of the extract treated diabetic groups. Though not statistically significant, the blood glucose lowering effect of extract at dose 100mg/kg was seen at the third week (Third trimester) of extract administration. The administration of 200mg/kg and 300mg/kg of body weight of rats doses compared to the diabetic pregnant control group that was not extract treated, produce statistically significant reduction in fasting blood glucose. The blood glucose lowering effect of aqueous extract of O. gratissinum at 100mg/kg, 200mg/kg and 300mg/kg show that the aqueous extract of O. gratissimum is an effective antidiabetic agent in diabetic pregnant rats and that the effect produced by the extract is dose and time dependent.(Egesie et al, 2006, Mohammed et al., 2007)The administration of the same graded doses to non-diabetic pregnant rats did not produce any statistically significant difference in blood glucose of extract treated groups compared with the control group that was not extract treated (p<0.05).This could be due to glucose threshold that triggered the action of aqueous extract of O. gratissimum in diabetic pregnant rats. The mechanism of the blood glucose lowering effect of the aqueous extract of this plant leaves is not known. It is however important to note that the plant extract contain flavonoid and other phytochemical constituents believed to be responsible for its blood glucose lowering property (Oladele et al, 1995).The plant is also said to contain major mineral elements e.g. calcium, chloride, manganese, magnesium, zinc and potassium which suggest it could play a contributory role in enhancing blood glucose lowering property (Chen et al, 1995).However, it had been shown that antidiabetic plants may affect circulating insulin level (Lamela et al, 1985).It is also possible that treatment with O. gratissimum could be facilitating utilization of glucose by peripheral tissues. This mechanism have been observed in the use of infusion of African mistletoe (Obatomi et al 1994) and aqueous bark extract of ceiba pentandra (Ladeji et al, 2003) in the treatment of diabetes mellitus.
EFFECT OF EXTRACT ON WEIGHT GAININ DIABETIC PREGNANT RATS.
Table 4.3 shows that at first week (first trimester) of extract administration, extract-treated diabetic pregnant rats and diabetic pregnant control that was not extract-treated lose weight significantly (P< 0.05) compared with weight values at induction (i.e. initial reading of weight). This could be due to stress of pregnancy at first trimester. In third week (third trimester), there was weight gain in diabetic group treated with 100mg/kg compared to first week after induction, (p<0.05).But there was significant (p< 0.05) weight gain in diabetic pregnant rats treated with 200mg/kg and 300mg/kg doses in second and third weeks (second and third trimester) of extract administration compared to diabetic pregnant control that was not extract-treated. So, at 200mg/kg and 300mg/kg doses of aqueous extract of O. gratissimum leaves, there were gradual weight gains in diabetic pregnant rats in a time and dose dependent manner. Maybe aqueous extract of O. gratissimum leaves at higher doses (200mg/kg and 300mg/kg) caused significant
utilization of glucose by peripheral tissues in a duration dependent manner thereby leading to weight gain in diabetic pregnant rats. It could have also been that the extract increased the weight of the fetus or number of littersleading to weight gain in the expectant mother. Ithas been reported that one of the photochemical constituents of O. gratissimum is fat and oil (Emeka and Elizabeth, 2009). Therefore, weight gain in diabetic pregnant rats could have been due to the effect of fat metabolism resulting from the plant extract. However, the mechanism of weight gain effect of aqueous extract of O. gratissimum is not known as it was not investigated in this present study.
EFFECT OF EXTRACT ON WEIGHT GAIN IN NON-DIABETIC PREGNANT RATS
In table 4.4, it was observed that both the extract-treated and control groups without extract treatment of the non-diabetic pregnant rats lost weight at first week (first trimester) of extract administration. This may be due to stress of pregnancy at first trimester. At second week (second trimester) of extract administration, there was significant (p< 0.5) weight gain in groups treated with 100mg/kg, 200mg/kg and 300mg/kg doses of extract respectively compared with control group that was not extract treated. At the third week (third trimester) of extract administration, extract at 100mg/kg and 200mg/kg doses produce significant (p< 0.05) weight gain in their various groups compared with control group. Though, there was weight gain in the group treated with 300mg/kg, it was not statistically significant compared with control group (p<0.05). The weight gain effect of this extract in non-diabetic pregnant rats could be due to the suggestions mentioned earlier.
EFFECT OF EXTRACT ON PREGNANCY OUTCOME IN DIABETIC PREGNANT RATS
Also, the effects of the aqueous extract of O. gratissimum on pregnancy outcome in diabetic pregnant rats and non-diabetic pregnant rats were investigated in this study (as shown in Table
4.5 and 4.6). Table 4.5 shows that the diabetic control and 100mg/kg dose extract-treated groups could not give birth to life litters. Most interesting is that at higher doses (200mg/kg and 300mg/kg doses), the diabetic pregnant rats gave birth to litters. The litter size of diabetic pregnant rats treated with 300mg/kg dose of aqueous extract of O. gratissimum leaves was significantly (p< 0.05) greater than the litter size of diabetic pregnant rats treated with 200mg/kg dose of the extract. Which means the litter size of the various extract treated diabetic groups is dosage dependent. Also, the birth weight of extract-treated group litters (200mg/kg and 300mg/kg) was examined and it was discovered that the litters of the group treated with 200mg/kg dose of extract, significantly had more weight than group treated with 300mg/kg dose of extract. This means at greater litter size, in group treated with 300mg/kg, there was decrease birth weight and at lesser litter size, in group treated with 200mg/kg, there was greater birth weight. The reduced litter birth weight in group treated with 300mg/kg dose may be due to increased number of fetuses. There was however no significant difference in litter birth length. (p<0.05)
EFFECT OF EXTRACT ON PREGNANCY OUTCOME IN NON-DIABETIC RATS
Table 4.6 shows the effect of aqueous extract of Ocimum gratissimum on pregnancy outcome in non-diabetic pregnant rats. The effect of the extract on litter size and litter weight was significantly different compared to that of control in a dose dependent manner. (p<0.05) The mechanism of action for this effect is unknown as it was not investigated in this study. It could be stated that aqueous extract of O. gratissimum increases implantation of fetuses in a dosage
dependent manner. Progesterone has an antiestrogenic effect on the myometrial cell, decreasing their excitability, their sensitivity to oxytocin and their membrane potential (Ganong, 2003). It is possible that O. gratissimum elaborate the function of progesterone or maybe it contains progesterone like substances. So, the increased litter size could be due to the ability of progesterone to reduce myometrial cells excitability, thereby increasing the number of implantation and subsequent number of life fetuses. The reduced litter weight could be due to increased number of fetuses.
The findings from this study are summarized as follows:
- The aqueous extract of Ocimum gratissimum leaves, produces weight gain in diabetic pregnant
- The aqueous extract of Ocimumn gratissimum leaves, possesses blood glucose lowering properties in diabetic pregnant rats in dose and duration dependent manner. Which means the plant is an effective antidiabetic agent in alloxan induced diabetic pregnant
- There was weight gain in non-diabetic pregnant rats that was extract
- There was increased litter size in litters of diabetic pregnant rats that was extract treated in a dosage dependent
- There was increased litter size in litters of non-diabetic pregnant rats that was extract treated in dosage dependent
CONTRIBUTIONS TO KNOWLEDGE
- The weight gain observed in this present study, showed that the extract have metabolic effect or increases glucose absorption by tissues of diabetic and non-diabetic pregnant rats.
- In the present study, the decreased fasting blood glucose in diabetic pregnant rats treated with aqueous extract of gratissimum leaves, showed that the plant is an effective antidiabetic agent.
- The extract sustained pregnancies and made it possible for diabetic pregnant rats to give birth to life litters. The increased litter size observed in the present study showed that the extract interfered with the implantation processes since the extract treatment commenced on day one of pregnancy in both diabetic and non-diabetic pregnant
- Further work should be done on isolating the active ingredients in Ocimum gratissimum that gives its blood glucose lowering, weight gain and pregnancy outcome effect in diabetic correlational studies.
- The effect of the extract on reproductive hormones (progesterone, estrogen and oxytocine) should also be
- Also, comparative study should be done on the effect of aqueous extract of Ocimum gratissimum leaves between graded dose and quantity (as used by traditional practitioners).
- The mechanism for the blood glucose lowering and weight gain effect of aqueous extract of Ocimum gratissimum in diabetic pregnant rats observed in this study should also be investigated.
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